IRF2BP2 mutation with autoimmune enteropathy, immune deficiency, and respiratory failure

Case history: We present the case of a 31-year-old Hispanic male with history of recurrent bronchiectasis, invasive aspergillosis, and severe persistent asthma, who is now status post lung transplant for end-stage lung disease. He initially presented at 7 years of age with diarrhea, failure to thrive, and nearly absent immunoglobulin levels (IgG < 33 mg/dL, IgA < 7 mg/dL, IgM = 11 mg/dL, IgE = 4 IU/dL) necessitating IVIG treatment. Small intestinal biopsy showed villous atrophy consistent with autoimmune enteropathy. Sweat chloride was reported as indeterminate (44 me/dL). Initial WBC, platelet, and T- and NK-cell counts were within normal range, and B-cell count and percentage were borderline low. Most recently, he was found to have increased immature B-cell count (CD21low), decreased memory B-cells, and poor pneumococcal vaccine antibody response. Patient has been hospitalized numerous times with increasingly severe bronchiectasis, pneumonitis, and COVID-19 infections twice despite vaccination, leading to respiratory failure and lung transplantation. Family history is negative for immune deficiency and lung diseases. Discussion(s): Of these 3 VUSs (see the table), the one in IRF2BP2 has the most pathogenic potential due to its autosomal dominant inheritance, its location in a conserved domain (Ring), and previous case reports of pathogenic variants at the same or adjacent alleles 1-3. Baxter et al reported a de novo truncating mutation in IRF2BP2 at codon 536 (c.1606CinsTTT), which is similar to our patient's mutation. This patient was noted to have an IPEX-like presentation, with chronic diarrhea, hypogammaglobulinemia, and recurrent infections. Variant Functional Prediction Score for our variant predicts a potentially high damage effect. There are 2 other case reports of heterozygous mutations in loci adjacent to this allele;one (c.1652G>A)2 with a similar clinical phenotype to our patient and the other (C.625-665 del)3 with primarily inflammatory features and few infections. Impact: This case highlights a variant in IRF2BP2 associated with severe hypogammaglobulinemia, recurrent pulmonary infections, and autoimmune enteropathy. [Table presented]Copyright © 2023 Elsevier Inc.

A Case of a Relapsing Remitting Macrophage Activating Syndrome After Covid-19 Vaccine In a Teenager with UNC13D Heterozygous Variant of Uncertain Significance

Introduction: Macrophage activation syndrome (MAS) is a severe hyper inflammatory condition caused by the over-activation and proliferation of T cells, NK cells and macrophages. It is often associated with complications of rheumatic/immune diseases. We present a case of a 15-year-old female who experiences recurrent episodes of MAS without any known definitive underlying etiology. Case Presentation: A 15-year-old previously healthy female developed fatigue, fevers, myalgia, chest pain, splenomegaly and lymphadenopathy 10 days after receiving her first Pfizer COVID-19 vaccine. Her symptoms recurred 10 days after receiving the second dose. Her myocarditis, MIS-C, and infectious work up was negative except for positive EBV IgG. Laboratory studies revealed anemia, hypertriglyceridemia, hypofibrinogenemia, and hyperferritinemia. She initially responded to decadron;however, her symptoms recurred with steroid taper. Bone marrow biopsy revealed hemophagocytosis. Whole exome sequencing (WES) revealed a heterozygous variant of uncertain significance in UNC13D c.962C>A (p.Thr321Asn). She had multiple re-admissions with significantly elevated inflammatory markers, including extremely high IL2-R, IL-18 and CXCL9. Each episode was complicated by an acute viral infection. She responds to high dose steroids, anti-IL-1, and JAK inhibitors. Nonetheless, it has been difficult to wean decadron without triggering a flare. She continues to require increasing doses of baricitinib. Discussion(s): MAS may be seen as a complication of rheumatic diseases, as well as inborn errors of immunity. However, none of these conditions have been diagnosed in this patient despite extensive testing, including WES. The degree of her immune dysregulation has been very severe making her disease process unpredictable and extremely difficult to control. She has frequent flares precipitated by viral infections or attempts at adjusting her immunomodulators. Weaning her medications has been challenging as she continues to require increasing doses of baricitinib and corticosteroids. The UNC13D gene is associated with autosomal recessive familial hemophagocytic lymphohistiocytosis type 3 (FHL3). Our patient is heterozygous for an UNC13D variant of uncertain significance. Additional genetic inquiries with whole genome sequencing to help elucidate the underlying etiology of her severe condition is being conducted. We hypothesize she developed MAS due to a combination of genetic predisposition, prior EBV infection, and immune stress associated with the COVID-19 vaccine. [Formula presented] [Formula presented] [Formula presented]Copyright © 2023 Elsevier Inc.

Primary immunodeficiency associated with a SAMD9L mutation

Background: SAMD9L is a tumor suppressor involved in regulating the proliferation and maturation of cells, particularly those derived from the bone marrow, and appears to play an important role in cerebellar function. It can be activated in hematopoietic stem cells by type I and type II interferons. It has been hypothesized to act as a critical antiviral gatekeeper regulating interferon dependent demand driven hematopoiesis. Gain of function mutations can present with an immunodeficiency due to transient severe cytopenias during viral infection. Case presentation: We report a 3-year-old boy born full term with a history of severe thrombocytopenia requiring transfusions, developmental delay, ataxia, seizure disorder, and recurrent severe respiratory viral infections. His infectious history was significant for respiratory syncytial virus with shock requiring extracorporeal membrane oxygenation complicated by cerebral infarction and a group A streptococcus empyema, osteomyelitis requiring a left below the knee amputation, and infections with rhinovirus, COVID-19, and parainfluenza requiring hospitalizations for respiratory support. Initial immunologic evaluation was done during his hospitalization for parainfluenza. His full T cell subsets was significant for lymphopenia across all cell lines with CD3 934/microL, CD4 653/microL, CD8 227/microL, CD19 76/microL, and CD1656 61/microL. His mitogen stimulation assay to phytohemagglutinin and pokeweed was normal. Immunoglobulin panel showed a mildly decreased IgM of 25 mg/dL, but normal IgA and IgG. Vaccine titers demonstrated protective titers to 12/22 pneumococcus serotypes, varicella, diphtheria, mumps, rubella, and rubeola. Repeat full T cell subsets 6 weeks later revealed marked improvement in lymphocyte counts with CD3 3083/microL, CD4 2101/microL, CD8 839/microL, CD19 225/microL, and CD1656/microL. A primary immunodeficiency genetic panel was ordered and positive for a heterozygous SAMD9L c.1549T>C (p.Trp517Arg) mutation classified as a variant of unknown significance. Discussion(s): This patient's history of severe viral infections, ataxia, thrombocytopenia, and severe transient lymphopenia during infection is suggestive of a SAM9DL gain of function mutation. Protein modeling done by the laboratory suggests this missense mutation would affect protein structure. The mutation found has been observed in individuals with thrombocytopenia. This case highlights the importance of immunophenotyping both during acute illness and once recovered.Copyright © 2023 Elsevier Inc.

"Actionable" host genetic markers for repurposing "add-on therapy" in COVID-19

Background/Objectives: COVID-19 still represents a lifethreatening disease in individuals with a specific genetic background. We successfully applied a new Machine Learning method on WES data to extract a set of coding variants relevant for COVID- 19 severity. We aim to identify personalized add-on therapy. Method(s): A subset of identified variants, "actionable" by repurposed drugs, were functionally tested by in vitro and in vivo experiments. Result(s): Males with either rare loss of function variants in the TLR7 gene or L412F polymorphism in the TLR3 gene benefit from IFN-gamma, which is specifically defective in activated PBMCs, restoring innate immunity. Females heterozygous for rare variants in the ADAMTS13 gene and males with D603N homozygous polymorphism in the SELP gene benefit from Caplacizumab, which reduces vWF aggregation and thrombus formation. Males with either the low-frequency gain of function variant T201M in CYP19A1 gene or with poly-Q repeats >=23 in the AR gene benefit from Letrozole, an aromatase inhibitor, which restores normal testosterone levels, reducing inflammation and which rescues male golden hamsters from severe COVID-19. Conclusion(s): By adding these commonly used drugs to standard of care of selected patients, the rate of intubation is expected to decrease consistently, especially in patients with high penetrance rare genetic markers, mitigating the effect of the pandemic with a significant impact on the healthcare system.

Fatal COVID-19 in an infant prompted an early diagnosis of ZNFX1 deficiency in a sibling

Background: NFX1-type zinc finger-containing 1 (ZNFX1) is an interferon-stimulated double-stranded RNA sensor that restricts the replication of RNA viruses in mice. ZNFX1 deficiency in humans is very rare;to date, only fifteen cases have been reported by Vavassori S et al. (10.1016/j.jaci.2021.03.045). The disease presented in all cases as severe viral infections complicated by multisystem inflammation evolved to multiorgan failure with a high mortality rate. Pediatric Allergy and Immunology Section at Queen Rania Children's Hospital in Jordan had confirmed the diagnosis of ZNFX1 deficiency in an infant at his first presentation with severe viral illness based on the positive family history of one sibling death caused by complicated COVID-19 infection. Case presentation: A 12-month-old boy was born to consanguineous parents, full-term, with no NICU admission. He was doing well till the age of four months when he was admitted to the hospital with fever, hypoactivity, and maculopapular skin rash. On admission, he was ill, hypoactive, and febrile, and a physical exam showed hepatosplenomegaly and maculopapular skin rash. His lab showed thrombocytopenia, elevated transaminases, hyperferritinemia, and high CRP;he was treated with broad-spectrum antibiotics, but he continued to deteriorate, and his infectious workup was unrevealing, including COVID-19 PCR. His older sibling died at eight months in 2020 when she got a COVID-19 infection, deceased after rapid deterioration evolved to multiorgan failure. Unfortunately, she had no stored DNA, as she was treated at a peripheral hospital. Based on this presentation and the fatal COVID-19 infection, pediatric immunology service got consulted;we did an immunological workup, which showed normal lymphocyte subsets, Immunoglobulins, and bacterial antibodies. Whole exome sequencing showed a homozygous frameshift mutation in the ZNFX1 gene, protein change defect had detected;p.Tyr555MetfsTer6, and nucleotide change variant: c.1663_1665delTACinsAT. Family screening showed heterozygous for the same variant in both parents and a healthy sibling. The patient was diagnosed with the hemophagocytic lymphohistiocytosis-like disease and treated with steroids, intravenous immunoglobulin, and antimicrobials, he showed complete recovery, and we are going to do bone marrow transplantation as his brother is 8/8 HLA matched.Copyright © 2023 Elsevier Inc.

Effectiveness and safety of elexacaftor/tezacaftor/ivacaftor therapy: An Italian center experience

Background: Elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA), a triple CFTR modulator combination, has proved to be highly effective in Phe508del homozygous and Phe508del/minimal function compound heterozygous people with cystic fibrosis (PwCF).We report preliminary data on the realworld effectiveness and safety of ELX/TEZ/IVA after 6 months of treatment. Method(s):We collected prospective data on PwCF who started ELX/TEZ/IVA and evaluated changes in pulmonary function (spirometry and lung clearance index [LCI]), nutritional status (body mass index [BMI]), sweat chloride, and rate of hospitalization from baseline to 6 months of treatment. Result(s): Between August 2021 and October 2021, ELX/TEZ/IVAwas started in 24 PwCF (12 female,10 Phe508del-homozygous, median age 20.5 (range 13-37), all with pancreatic insufficiency). After 6 months of treatment, all respiratory function indicators improved (median change: +16% percentage predicted forced expiratory volume in 1 second, +12% percentage predicted forced vital capacity, +23% percentage predicted forced expiratory flow at 25/75%, -2 lung clearance index). Improvement was also observed in BMI (+0.41 z-score) and sweat chloride concentrations (-54 mMol/L, 6 PwCF had Cl concentrations within the limit of normality) (Table 1). Over a 6-month period, only one hospitalization due to pulmonary exacerbations was observed, compared with 22 hospitalizations observed in the 6 months before starting ELX/TEZ/IVA (rate per 100 patient-months 15.3 vs 0.7, rate ratio 0.05, 95% CI, 0.01-0.29). Treatment was well tolerated, with only mild and transient adverse events consisting of headache (n = 4), cutaneous rash (n = 2), and mild hemoptysis (n = 2). One PwCF had intestinal subocclusion and required hospitalization. One patient had liver function test elevation after 6 months of therapy during an Changes in clinical variables and sweat test results from baseline through 6 months in patients treated with elexacaftor, tezacaftor and ivacaftor. Data are medians (interquartile ranges). Baseline vs 6 months compared usingWilcoxon signed-rank test. ppFEV1, percentage predicted forced expiratory volume in 1 second;ppFVC, percentage predicted forced vital capacity;ppFEV25/75, percentage predicted forced expiratory flow at 25/75%;LCI, lung clearance index;BMI, body mass index;Cl, chloride. (Table Presented) episode of SARS-COV2 infection, which required adjustment of the dose administered. Conclusion(s): Our data confirm that ELX/TEZ/IVA treatment is safe, well tolerated, and effective in PwCF. ELX/TEZ/IVA improved pulmonary function and nutritional status and remarkably reduced hospitalization rate. Our data indicate that introduction of ELX/TEZ/IVA in CF care will radically change the natural history of and management approach to the disease.Copyright © 2022, European Cystic Fibrosis Society. All rights reserved

Essential fatty acid and lipoprotein status in pediatric cystic fibrosis: Impact of cystic fibrosis transmembrane conductance regulator modulators

Background: Dyslipidemias and essential fatty acid deficiencies (EFADs) are well established complications of cystic fibrosis (CF). In the general population, a diet high in saturated fat is associated with hyperlipidemia and greater risk of cardiovascular disease and type 2 diabetes. Increasing life expectancy in CF brings concern about the risks of the "legacy" high-fat CF diet. The impact of CFTR modulators on CF-related dyslipidemia and EFAD is not known. Previous studies reported dyslipidemia in people with CF (PwCF) using traditional lipid measures. This study aimed to evaluate the lipoprotein and fatty acid profiles in children and adolescents with CF and to correlate biochemical results with clinical and molecular findings. Plasma and red blood cell (RBC) samples were studied to compare the ability of each method to identify EFAD markers. Method(s): Blood samples (n = 171) were obtained from 142 (78 female) children with CF aged 9.8 +/- 4.7 (range 4 months to 18 years) during routine laboratory draws at pediatric CF center clinic visits. Pancreatic insufficiency was present in 92% and glucose intolerance or diabetes in 14%. Body mass index percentile (BMI%ile) for age z-scorewas 0.23 +/- 0.89 (range -2.4-2.6). F508del mutation was homozygous for 56% and heterozygous for 41%. CFTR modulator therapy had been initiated 3 or more months before for 62% of samples. Sample collection began in September 2019, paused during the COVID-19 pandemic, and resumed in July 2021. An accredited, regional laboratory with expertise in fatty acid analysis processed all samples. Serum was separated and refrigerated for lipoprotein analysis, plasmawas separated and frozen, and RBCs were washed and frozen for fatty acid analysis. Nuclear magnetic resonance lipoprotein assayswere conducted to determine particle number and size of lipoprotein classes. Triglyceride, total cholesterol, and high-density lipoprotein cholesterol (HDL-C) were measured directly (Roche). Low-density lipoprotein cholesterol (LDL-C) and very low-density lipoprotein cholesterol (VLDL-C) were calculated. To correlate laboratory results with clinical findings, medical records were reviewed, and a CF clinic dietitian conducted 24-hour dietary recalls concurrent with study labs. Result(s): Of PwCF homozygous F508del/F508del, 43% tested positive for EFAD biomarkers (RBC linoleic acid, RBC mead acid, RBC triene/tetraene ratio), compared with 13% of PwCF heterozygous F508del ( p <=0.01) (Figure 1). There was no significant difference in concentrations of fatty acid and EFAD biomarkers between those who had or had not initiated CFTR modulator therapy. Lipoprotein abnormalities were identified in 69% of samples with low HDL-C and 39% with large HDL-C, 87% with large VLDL-C particle size and 52% with large VLDL-C particle number, and 5% with high LDL-C or small LDL-C particle numbers. High total cholesterol was found in 15% and high triglycerides in 17%. HDL-C was low in 24%, and 3% had high LDL-C. (Figure Presented) Figure 1. Differences in concentrations of red blood cell (RBC) linoleic and mead acids and triene/tetraene (T/T) ratio between F508del homozygous and F508del heterozygous individuals Conclusion(s): Despite clinical advances and use of CFTR modulator therapy, EFAD remains prevalent and underrecognized in the pediatric CF population. Of PwCF, those homozygous for f508del may have a higher risk of EFAD. Limitations of this study (four different CFTR modulator therapies and small sample sizes in each group) may have precluded significant findings for EFAD and lipid profiles, but PwCF receiving modulator therapy appear to have healthier lipid profiles than those not receiving therapy. Lipids and fatty acid are not routinely evaluated in PwCF, but evaluation should be included in the standard of care for timely dietary interventionsCopyright © 2022, European Cystic Fibrosis Society. All rights reserved

Novel heterozygous PLCG2 variant presenting with very early-onset perianal abscess

Case report Background: Mutations in the PLCG2 gene can cause PLCG2-associated antibody deficiency and immune dysregulation (PLAID) or auto-inflammation with PLCG2-associated antibody deficiency and immune dysregulation (APLAID). PLAID is characterized by urticarial eruptions triggered by evaporative cooling along with cutaneous granulomas. APLAID may present with early-onset skin inflammation and non-infectious granulomas, uveitis, and colitis. Method(s): Case report and literature review. We performed in silico analysis for variants of uncertain significance (VUS). Result(s): A 29-day-old boy presented to emergency department for failure to thrive. He was found to be SARS-CoV2 positive, had an E. coli UTI in the setting of bilateral perinephric masses which subsequently resolved. He also had a perianal soft tissue abscess measuring 4cm in diameter. Mom reported a similar infection when she was age 2. She also reported intermittent diffuse urticaria triggered following perspiration evaporation.Abscess wall histology showed diffuse neutrophil and lymphocytic infiltration, with cultures growing polymicrobial enteric flora. His serum immunoglobulins G, A, M, and E were within reference range. Naive and memory CD4, CD8, CD19 lymphocyte subsets (including NK cells) were also within age-appropriate reference range. He had a normal neutrophil oxidative burst measured using dihydrorhodamine (DHR) flow cytometry following PMA stimulation, which ruled out a diagnosis of chronic granulomatous disease. On evaporative cooling, the patient had a 2mm wheal with surrounding erythema which resolved rapidly with warming. A targeted primary immunodeficiency panel showed a heterozygous VUS in PLCG2, c.688C > G (p.Leu230Val). The variant was absent from major databases and had a calculated CADD score of 17.77. He had symptomatic resolution after completing 3 weeks of ceftriaxone and metronidazole antimicrobials. Given the concern for PLCG2-associated very early-onset inflammatory bowel disease (VEO-IBD), a fecal calprotectin was obtained at 3 months and found to be elevated (157 mcg/g [ < = 49 mcg/g]). However, he had no symptomatic or macroscopic evidence for VEO-IBD. Conclusion(s): Presence of very early onset abscesses has not been previously described in patients with heterozygous PLCG2 deficiency. This case adds to the expanding variable phenotype of PLCG-2-associated immune dysregulation.

Dilated Cardiomyopathy: Unmasking Contributing Etiologies

Background: The role of genetic conditions in the development of cardiomyopathy is well established;however, recognition and referral for genetic testing remains underutilized. Systematic review of complex cases can increase general awareness in this area of practice. Here we describe the case of a patient with resolved severe stress induced cardiomyopathy (SIC), who was ultimately found to have heterozygous transthyretin-mediated amyloidosis (TTRA). Case: A 27-year-old man (family history positive for a brother status post heart transplant) presented with ataxia and cough due to legionella pneumonia. TTE showed left ventricular (LV) diastolic diameter of 6.2cm, LV ejection fraction 20-25%. He suffered rapid decompensation with mixed cardiogenic/septic shock requiring peripheral VA ECMO and Impella-CP placement. Course notable for brief cardiac arrest on hospital day (HD) 2, incidental diagnosis of COVID 19 on HD 14, conversion to VV ECMO on HD 15, and ECMO decannulation on HD 23. Repeat TTE prior to discharge showed normalization of biventricular function. Discussion(s): Despite resolution of refractory shock and normalization of biventricular function prior to discharge, the TTE finding of mild LV dilation and strong family history prompted outpatient pursuit of genetic testing which revealed a heterozygous TTRA mutation (val142ile). Work-up to assess cardiac involvement included: a 99m-technetium pyrophosphate scintigraphy found to be indeterminate, an aborted endomyocardial biopsy due to inability to smoothly advance a bioptome (presumably related to ECMO cannulation), and a cardiac MRI (pending at the time of this submission). If a cardiac phenotype is discovered, the patient will be started on targeted treatment of cardiac amyloid. Screening of first-degree family members has been initiated. Conclusion(s): Given the current state of under-diagnosis of genetic cardiomyopathies and its association with significant morbidity and mortality, it is prudent to consider genetic testing in young patients based on clinical history. Examples of clinical scenarios to prompt further testing include: anatomical findings (i.e. cardiac chamber enlargement, left ventricular hypertrophy), family history of cardiomyopathy, or clinical markers suggestive of alternative diagnoses (i.e. neuropathy, renal insufficiency, mediastinal lymphadenopathy). This thoughtful and algorithmic use of genetic testing may help improve long-term patient outcomes given improvements in both detection, family screening, and treatment for disease-specific cardiomyopathies.Copyright © 2022

Kidney Limited Complement-Mediated Thrombotic Microangiopathy- a Challenging Case

Introduction: Complement-mediated thrombotic microangiopathy (CM-TMA) is a rare disease characterized by microangiopathic hemolytic anemia (MAHA), thrombocytopenia and organ injury. The absence of hemolysis and thrombocytopenia is rare. We present a case of kidney limited CM-TMA successfully treated with eculizumab. Method(s): A 36 year-old man with poorly controlled hypertension, obesity, CKD (baseline creatinine (sCr) 2,6mg/dL, albuminuria 150mg/g), hyperlipidemia, obstructive sleep apnea, hyperuricemia, SARS-CoV-2 infection 3 months earlier, and family history of CKD of unknown etiology (father started kidney replacement therapy (KRT) at young age) presented to the ER with high blood pressure and right hemiplegy. Head CT scan showed left thalamo-capsular hemorrhage. Oftalmologic exam was normal. Laboratory findings were: hemoglobin (Hb) 12.5g/dL, elevated white cell count (17.900/uL), platelet count 214.000/uL, sCr 4.3mg/dL, lactate dehydrogenase (LDH) 303U/L. Urine dipstick revealed protein+ and Hb++. Chest X-ray showed signs of pneumonia. The patient was admitted in ICU and mechanically ventilated. After 3 weeks, renal function recovered to its baseline (sCr 1.5mg/dL, no proteinuria) without KRT, and the patient was transferred to the medical ward. Several infectious complications prolonged hospital stay. After 3 months, a new mild SARS-CoV-2 infection was detected. At this time: Hb 9.9g/dL, platelets 220.000/uL, sCr 2.2mg/dL. Six days later the patient showed Hb 9.5 g/dL, without reticulocytosis, platelets 195.000/uL, sCr 6.3mg/dL, LDH 348U/L, normal haptoglobin, no schizocytes on blood smear. After 3 days, the patient was anuric and sCr increased to 10mg/dL, prompting KRT. Kidney ultrasound showed no abnormalities. Autoimmunity study was negative, normal C3/C4, no monoclonal gammopathy, and negative viral serologies. Kidney biopsy (KB) was performed as the etiology of AKI remained unclear. Light microscopy revealed thickned glomerular capillary walls with subendothelial expansion forming double contouring, arteriolar intimal expansion and fibrin thrombi occluding the vascular lumina. Scarse C3 deposition was observed in capillary walls. Since the morphological features were consistent with TMA, secondary causes were excluded and primary causes also investigated: ADAMTS13 activity, complement factor B and I were within normal range, slight decrease of factor H with normal anti factor H antibody. The molecular studies of complement genes were performed by NGS-based gene panel revealing a rare heterozygous missense mutation on gene CFB, c.1189G>A (p.Asp397Asn), described as a genetic risk factor of CM-TMA in the presence of a trigger. Result(s): Treatment with eculizumab was started and the patient showed signs of kidney recovery allowing KRT suspension 1 month later (sCr 5.53mg/dL). Of note, the patient never presented MAHA or thrombocytopenia. After 5 months, renal function improved to sCr 3.9mg/dL. Conclusion(s): We report a case of CM-TMA with isolated kidney injury without laboratory hallmarks of TMA. Patients usually require a secondary trigger for the disease to manifest, and in this case SARS-CoV-2 infection may have been the causative agent. A mutation in gene CFB may have predisposed the patient to the outcome. KB was crucial for diagnosis and prompted the treatment with eculizumab with partial recovery without the need for chronic KRT. No conflict of interestCopyright © 2023

Family History of Alport Syndrome with Spectrum of Chronic Kidney Disease, Dialysis and Transplantation

Introduction: Alport syndrome should be considered in the differential diagnosis of patients with persistent microhematuria. Electron microscopic examination of renal tissue remains the most widely available and applied means for diagnosing AS. The presence of diffuse thickening and multilamellation of the GBM predicts a progressive nephropathy, regardless of family history. Unfortunately, ultrastructural information alone does not establish the mode of transmission in a particular family. Method(s): 18 years-old male patient was followed in the clinic due to persistent microscopic haematuria and proteinuria. Family history is significant for one brother in his early 20s, who started to have the presentation early in life and his initial biopsy showed thin basement membrane disease. The brother subsequently progressed to renal failure and a repeat biopsy confirmed the presence of Alport syndrome. Another brother had end-stage renal disease and underwent renal transplantation. The patient status was revised, and genetic studies confirmed the presence of an autosomal recessive type of Alport syndrome involving collagen for A3 chain COL4A3. His kidney function remained stable initially with an estimated GFR of approximately 90 mL/min/1.73 m2. The most recent eGFR is around 70 ml/min/1.73 m2. His proteinuria disappeared once Losartan 25 mg was added to Ramipril 5 mg. His blood pressure has been on target. Creatinine increased to 147 micromol/L and he was diagnosed as having acute kidney injury on chronic renal disease which was obvious post covid infection, then back to baseline. Current proteinuria 3 g/g Cr on Angiotensin receptor blockers. BP 110/70, all other systemic examination is unremarkable. No hearing or visual abnormalities. Result(s): The initial renal manifestations in early childhood include asymptomatic-persistent microscopic hematuria and rarely gross hematuria. At the onset, the serum creatinine and blood pressure are normal. Over time, proteinuria, hypertension, and progressive renal insufficiency develop. ESRD usually occurs between the ages of 16 and 35 years and rarely can occur between 45 and 60 years. Renal biopsy findings of thinning and multilaminar splitting of the glomerular capillary basement membrane seen on electron microscopic examination are pathognomonic. In 2013, an expert panel issued guidelines recommending genetic testing as the gold standard for the diagnosis of Alport syndrome. Currently, a skin biopsy using commercially available monoclonal antibody against the type IV collagen alpha-5 chain (COL4A5). If the protein is clearly absent in a suspected male, a diagnosis of Alport syndrome can be made without further testing. Conclusion(s): Males with X-linked AS due to a deletion mutation of the alpha 5 chain of type IV collagen usually progress to ESRD by the second or third decade of life. Likewise, patients with autosomal recessive AS due to mutations affecting alpha 3 or 4 chains of type IV collagen tend to progress to ESRD by age 30. Autosomal-dominant AS with heterozygous mutations of COL4A3 or COL4A4 usually has a slower progression of CKD. Treatment is blood pressure control with RAAS inhibitors where clinically appropriate. Cyclosporine may be helpful in some patients with stage I and II CKD with significant proteinuria. Caution using calcineurin inhibitors is indicated in all patients with more advanced CKD stages due to potential nephrotoxicity. No conflict of interestCopyright © 2023

GATA2 deficiency presenting as fever and rash

Case Report: Our patient is an 8-year-old Caucasian female with a history of choanal atresia, first degree heart block, recurrent urinary tract infections, and recent COVID-19 infection, who initially presented with an episode of syncope and vomiting. By history, she had two weeks of daily fever and an intermittent nonspecific rash. She was diagnosed with a UTI 5 days prior to presentation but had not defervesced despite treatment. Shewas initially found to be in shock with tachycardia and poor perfusion and was treated with fluid resuscitation, antipyretics, and empiric antibiotics. Labs were significant for leukopenia, elevated inflammatory markers, lactic acidosis, coagulopathy, and mildly elevated troponin. Chest x-ray showed abnormal but non-specific widespread infiltrates. She was initially treated with IVIG and pulse steroids for a working diagnosis of MIS-C, however she did not improve and a more extensive infectious, oncologic, and rheumatologic work-up was performed. Her workup revealed a disseminated Mycobacterium abscessus infection. Bone marrow biopsy revealed myelodysplasia with monosomy 7. Her buccal swab testing revealed a heterozygous germline mutation in the GATA2 gene, a variant that is predicted to cause loss of normal protein function. She is presently on multidrug regimen for her mycobacterial infection. Her myelodysplasia evolved into an acute leukemia, and she is undergoing chemotherapy for that at this time. Discussion(s): GATA2 deficiency, first identified in 2011, is a rare immune disorder resulting in a wide variety of clinical presentations. It is caused by a germline mutation of the GATA2 gene that disrupts blood cell differentiation, resulting in decreased or absent monocytes, B cells, NK cells, and dendritic cells1. This case presented multiple challenges due to the broad range of differential diagnoses. This patient was ultimately diagnosed with myelodysplastic syndrome associated with monosomy 7 and GATA2 deficiency, confirmed by FISH testing. Due to the presentation and lab derangements this patient had, there was a delay in targeted treatment while managing her cytopenias and presumed pulmonary infection. GATA2 deficiency carries a high risk of progression from myelodysplastic syndrome to acute myelogenous leukemia. The best long-term treatment for GATA2 deficiency is hematopoietic stem cell transplant, which is the ultimate goal for our patient. Copyright © 2023 Southern Society for Clinical Investigation.

Thrombin generation test in patients with Covid-19

Background: TGA is a sensitive and specific method for diagnosing thrombin formation and one of the best methods correlating with bleeding or thrombotic events. TGA provides information about the total clotting potential, because thrombin generation does not stop after the formation of fibrin clots. Aim(s): To evaluate the parameters of the thrombin generation test in patients with Covid-19. Method(s): A retrospective study on the basis of the regional center for antithrombotic therapy of SBHI CCH 1 City Hospital named after E.E.Volosevich . Patients with confirmed Covid-19 (n = 100). Blood sampling to determine the parameters of the thrombin generation (kinetics) test (TGA) was performed on the 1st day of the study. The automatic formulation of the TGA method is carried out on an open-type coagulometer Ceveron alpha TGA. Genetic methods -Real- time PCR, Litech Company (Russia): Hemostasis system genes: FII G20210A, FGB G455A, PAI-1675 5G/4G. Result(s): It was found that Tlag (min) and tPeak (min) significantly decreased in patients on the 1st day of hospitalization. Correlation analysis of Tlag (min) with the genotype of F I (fibrinogen) rS = - 0.3 (p = 0.02), confirming that heterozygous polymorphism of the FI gene is associated with a decrease in Tlag (min). The presence of polymorphism in the PAI-1 gene is associated with a decrease in tPeak (min), i.e. in patients with polymorphism in PAI-1, the peak of thrombin is achieved faster (rS = 0.5;p = 0.03). The presence of polymorphism in the F I gene is associated with an increase in Peak (nmol/l), which is significantly higher in contrast to patients without polymorphism. The presence of polymorphisms in the PAI-1 and F I genes is associated with an increase in EPT (nmol/min: RS = 0.3;p = 0.04 and rS = 0.6;p = 0.02). Conclusion(s): The results of TGA in our study reflect data on an increase in the procoagulant potential of blood in patients with COVID-19.

IL-2 (T330G) gene promoter polymorphism and its effect on lymphocyte-platelet adhesion in patients with coronavirus infection SARS-COV- 2 (COVID-19)

Background: Cytokines are signaling molecules and involve lymphocytes and macrophages in the immune response. Lymphocyte-platelet adhesion is one of the mechanisms that ensure the cooperation of various subpopulations of cells and allow them to migrate through the vascular wall into the tissue. Aim(s): To study the function of lymphocyte-platelet adhesion depending on SNP of IL-2 (T330G) gene in healthy subjects and patients with COVID-19. Method(s): The research involved 168 patients with COVID-19 and 100 healthy people of the same age and gender. The participants of the study were Caucasian race and lived in the Trans-Baikal Territory. The examine of LPA was carried out by the method of Yuri Vitkovsky et al. (1999). The SNP of IL-2 (T330G) gene was determined by PCR. Such methods as Equilibrium Hardy-Weinberg, chi2-test, odds ratio descriptive statistics and the mean values (M) and standard deviation (SD) were used. Statistical significance was measured at the value p < 0.05. Result(s): We found all the studied IL-2 mutations in accordance with the Hardy-Weinberg law (p>0.05). The heterozygous T/G of IL-2 gene was registered significantly more frequently in the group of patients in comparison with the control group. Based on the obtained data on frequency distribution, the chance of developing SARS-COV- 2 increased in carriers of the allele T and the T/T genotype of IL-2 gene (p < 0.001). It was found that patients with SARS-COV- 2 had an increase in the LPA index compared to the group of healthy individuals (15.2 +/- 1.1%). The maximum amount of LPA was detected among patients with T/T genotype -39.7 +/- 2.1%, the minimum amount -in the owners of G/G (31.4 +/- 1.9%) (p< \0.001). Conclusion(s): 1) SARS-COV- 2 is accompanied by an increase in LPA function indicators, which depend on SNP of IL-2 (T330G) gene. 2) Carriers of allele T and T/T genotype of IL-2 gene (T330G) predispose to the development of COVID-19.

Abstracts for the 29th Annual Conference of the German Society for Immunogenetics (Deutsche Gesellschaft fur Immungenetik - DGI)

The proceedings contain 15 papers. The topics discussed include: eplet analysis: a tool for risk assessment of de novo donor-specific HLA-DQ-antibodies in patients after lung transplantation;beta-2-microglobulin the neglected edge of HLA class I;temporal loss of HLA heterozygosity in an AML patient prior to stem cell transplantation: does it affect HLA typing strategies?;in-vivo monitoring of CAR-T cell expansion using TaqMan real time PCR;immunogenetic features with SARS-COV-2 breakthrough infections: analyzing 1st/2nd and omicron waves;uterus transplantation from the immunological point of view - experiences from the first center in Germany;follow-up of HLA class I antibodies in neonatal thrombocytopenia;monitoring the in-vivo persistence and expansion of CAR-T cells by TaqMan real-time PCR;and detection of complement-fixing anti-HLA antibodies by a C3D-detecting Luminex technique. is there any additional diagnostic value not available through the use of standard antibody specification at the single antigen level?.

MTHFR C677T GENOTYPE IN CORRELATION WITH THROMBOSIS AND ASSOCIATION WITH FVIII COAGULANT ACTIVITY IN GREEK PAEDIATRIC POPULATION

Background: The polymorphism C>T substitution in position 677 (C677T) of the encoding gene of methylenetetrahydrofolate reductase (MTHFR), creates a thermolabile enzyme with reduced activity that may predispose to hyperhomocysteinemia , an established risk factor for arterial thrombosis and premature atherosclerosis and a probable risk factor for venous thromboembolic disease and its recurrence in the general population. There are conflicting results as to the role of the MTHFR C677T polymorphism as a risk factor for thrombosis. Although the homozygous substitution is often associated with hyperhomocysteinemia, mainly in folate deficiency, a clear association between this genetic marker and thrombosis has not yet been established. Aims: Primary aim was to evaluate the prevalence of mutant C677T MTHFR and its association with thrombosis in the Greek paediatric population. Secondary aim was to evaluate whether different MTHFR genotype is associated with evidence of activation of coagulation cascade through increased factor VIII activity. Methods: Data were retrospectively collected from children referred to our Haemostasis and Thrombosis Centre for laboratory screening of thrombophilia between 2018 and 2020. Some of them were checked due to history of thrombosis. Children were categorized according to MTHFR C677T genotype. FVIII Coagulant activity (%) was measured by One Stage Assay, away from acute thrombosis. The identification of mutations was based on polymerase chain reaction (PCR) and reverse- hybridization. Statistical analysis was performed with t-test and ANOVA. Results: A total of 688 children (boys: 49 %) of mean age 8.9± 8 years (0-18) were investigated. Twelve percent (81/688) of them had history of thrombosis, mainly venous thromboembolic disease. Children were categorized as follows: homozygous MTHFR C677T (15%), heterozygous (47%) and normal (38%). There was thrombosis history in 12% of homozygous MTHFR C677T, 11% heterozygous and 12 % of normal, fact showing that there is no association between MTHFR C677T genotype with thrombosis. Children with homozygosity MTHFR C677T, compared to children with heterozygosity and normal MTHFR C677T showed increased factor VIII values (132.8 vs 126.4 and 131.6, %, respectively), but without statistically significant difference. However, independently of MTHFR C677T genotype, mean factor VIII values were significantly increased in all children, with thrombosis history when they were compared to children without thrombosis history (161.3 vs 125.1, %, p<0.001). Interestingly, in children with thrombosis, mean factor VIII level was statistically increased in heterozygous and normal MTHFR C677T in contrast to children with MTHFR C677T homozygosity, in whom no statistically significant increase was found (166.9 vs 121.4, %-p<0.05, 160.2 vs 127.6, %-p<0.05 and 148.3 vs 130.6, %-p>0.05, respectively). Finally, it should be noticed that during the year 2020 mean factor VIII values were much increased in all children in comparison to the years 2018, 2019 and 2021 (137 vs 129, 123 and 127, %, respectively), probably reflecting the effects of unknown pandemic COVID-19 which initiated in 2020, and showing that factor VIII could be an evidence of stress condition. Summary/Conclusion: There is no probably association between MTHFR C677T genotype and thrombosis in our paediatric population. Moreover, it was not proved that different MTHFR genotypes affect factor VIII activity.

A SINGLE CENTER COVID-19 VACCINE EXPERIENCE in FAMILIAL MEDITERRANEAN FEVER PATIENTS

Background: To prevent COVID-19 disease SARS-CoV 2 vaccines put into use worldwide with emergency use authorizations despite ongoing safety concerns. Since pyrin mediated infammasome response is dysregulated in FMF, exposure to SARS-CoV 2 proteins via vaccination may potentially trigger infammation, leading to attacks and/or increased rate of adverse events (AE). Objectives: Aim of this study to investigate frequency of adverse events and attacks related to vaccination in recipients of CoronaVac and BNT162b2 comparatively in our FMF patients. Methods: Data regarding, number of vaccine doses, types of vaccines (Coro-naVac or BNT162b2), presence of AEs and/or FMF attacks after any vaccine dose within a month, history of COVID-19 infection before or after vaccination, adherence to FMF treatment during vaccination were collected from hospital database or via telephone. Results: A total of 161 vaccinated FMF patients were included. Mean ± SD age was 40.5 ± 11.7 years. 57.1% was female. 10.6% of the patients had chronic kidney disease and 9.3% had amyloidosis. Most common MEFV mutations were M694V heterozygous (27%) and M694V homozygous (21.6%). 93.2% of the patients were under colchicine, 21.8% under anti-interleukin 1 agents, 2.5% under TNF-a inhibitors. 96.3% of the patients adhered to FMF treatment during vaccination. Vaccination properties and data regarding adverse events are presented in Table 1. 57.8% of patients reported to suffer from an AE/attack after a vaccine dose. Number of patients with AE after BNT162b2 was signifcantly higher (p<0.001). None of the patients had severe AEs. 39 patients had COVID-19 infection prior to primary vaccination. 61.5% of these suffered from an adverse reaction/attack after vaccination, in comparison to 56.6% of the patients without prior COVID-19 infection (p=0.584). When patients with and without AEs/attacks were compared, no signifcant differences were observed regarding age, gender, body mass index, comorbidities, FMF treatments and total vaccine doses. Conclusion: We observed considerable number of FMF patients suffered from vaccine related AEs/attacks, particularly with BNT162b2. However, no serious AE was detected. Demographics, clinical characteristics and prior history of vaccination did not signifcantly affect AE/attack occurrence.

An APOL1 genotype associated with adverse Covid- 19 outcomes: UK-Biobank data, September 2021

Introduction/ Background: The risk of hospitalisation/death from Covid-19 in the UK is disproportionately high in black populations. In people of African ancestry, variants of the APOL1 gene (G1 and G2) are associated with risk of noncommunicable diseases, and sleeping sickness. We hypothesise that adverse Covid-19 outcomes are also associated with these variants. Methods: The UK Biobank contains genetic, lifestyle, and health information from 7,643 individuals who self-report as being of black ethnicity. Within this cohort there had been 142 hospitalisations and 36 deaths attributed to Covid-19 as of September 2021. Taking risk factors previously associated with poor Covid-19 outcomes (age, sex, chronic kidney disease, atrial fibrillation, hypertension, depression, chronic obstructive pulmonary disease, dementia, type 2 diabetes, obesity, and Townsend deprivation index) as covariates, we used Firth's Bias Reduced Logistic Regression in R to identify APOL1 genotypes that were associated with hospitalisation and death. Results: Individuals who are heterozygous for variants at both the G1 and the G2 loci are termed G1/G2 compound heterozygotes. G1/G2 compound heterozygosity was associated with hospitalisation (odds ratio = 2.4, 95% confidence interval: 1.2-4.5, p = 0.010) and death (odds ratio = 5.4, 95% confidence interval: 1.8-15.4, p = 0.004). This association has not previously been detected in genome wide association studies, as they usually examine individual loci separately rather than considering combinations of loci. Impact: This has implications at the individual and population level by identifying those at higher risk of severe Covid-19 who would benefit from early vaccination and treatment. This is especially relevant to geographical regions where APOL1 G1 and G2 variants are common, such as West and Central Africa and their diaspora. Conclusion: This data supports hypotheses proposing APOL1 genotype (and specifically G1/G2 compound heterozygosity) as a significant contributory factor in the increased rates of poor Covid-19 outcomes observed in people of African ancestry.

HYPERCOAGULABLE AND GENETICALLY THROMBOPHILIC PATIENTS WITH CEREBRAL VENOUS THROMBOSIS

Introduction Cerebral venous thrombosis (CVT) may occur due to a number of common etiologies such as thromboembolism, atherosclerotic disease, or small vessel disease. When these are ruled out or considered unlikely, a hypercoagulability workup is performed. We describe a series of 30 patients with CVT and medical and/or genetic basis for the underlying hypercoagulable state and thrombophilia. Methods A retrospective review of all CVT cases treated with venous thrombectomy between June 2016 and August 2021 was performed within our institutional, neuroendovascular database. Results Of the 30 patients identified, 18 were associated with a hypercoagulable state and/or thrombophilia. Underlying illness was present in seven (36.8%) patients due to polycythemia vera, systemic lupus erythematosus, a combination of nephrotic syndrome and morbid obesity, a combination of rheumatoid arthritis and diabetes, chronic rejection of a small bowel transplant further complicated by acute renal failure and ARDS, a combination of diabetes, DVT, and a dyslipidemic state, and Covid-19. Hypercoagulable states were identified in seven (36.8%) patients due to elevated Factor VIII (1/ 7), antiphospholipid syndrome (3/7), and Protein S deficiency (3/7). Genetic thrombophilia was identified in four (16.4%) patients in the form of a heterozygous Factor V mutation in R506Q (2/4), a heterozygous Prothrombin Factor II mutation in G20210A (1/4), and a homozygous 4G/4G promoter Plasminogen Activator inhibitor I deletion mutation (1/4). Overall, no subset of hypercoagulability (I.e. mutation, disease, transient state) nor hypercoagulability overall was predictive of outcome as measured by recanalization, discharge disposition, or reocclusion likelihood. Conclusion The most common cause of hypercoagulability was underlying disease or transient antiphospholipid syndrome/elevated pro-coagulation factor. While we are unable to report hypercoagulability as a predictive variable of outcome in our cohort, we outline the presence of various coagulopathies within this medically refractory, CVT cohort. While CVT may occur due to many common pathologies, in cases where the cause is unknown a hypercoagulability workup my shed light on mitigating factors underlying the thrombosis.