Immune System Development Processes with Special Emphasis on Relationship to Potential Mechanisms of MIS-C

Development of the mammalian immune system requires the intersection of myriad internal and external signals, from the migration of pluripotent stem cells to interactions with the vaginal microbiome during partuition to environmental factors that shape immune processes throughout life. Because the sequence of immune developmental events is fairly transcripted across time, multiple windows of susceptibility exist that can lead to immune dysfunction when these developmental events are perturbed. Additionally, early-life immune dysfunction can persist, leading to increased disease risk across the lifespan. Immune dysfunction can present functionally as suppression, hyperresponsivity, or inappropriate inflammation and molecularly, may involve multiple cells and signaling pathways. Thus, scenarios that lead to multisystem inflammatory syndrome in children (MIS-C) can be complex and multifaceted. This presentation will consider windows of susceptibility as well as external factors that may increase the risk of MIS-C.

Lichen planus after COVID-19 infection and vaccination

Background: Lichen planus (LP) is an inflammatory disorder believed to result from CD8+ cytotoxic T-cell (CTL) mediated autoimmune reactions against basal keratinocytes. We present a review of LP following COVID-19 infection and vaccination. Method(s): Literature searches were conducted on PubMed and Google Scholar from 2019 to 7/2022. 35 articles were selected based on subject relevance, and references within articles were also screened. Result(s): 39 cases of post-vaccination LP and 6 cases of post-infection LP were found among case reports and case series. 150 cases of postvaccination LP and 12 cases of post-infection LP were found in retrospective and prospective studies. Conclusion(s): LP is a rare complication of COVID-19 infection and vaccination that may be mediated by overstimulation of T-cell responses and proinflammatory cytokine production. However, it does not represent a limitation against COVID-19 vaccination, and the benefits of vaccination considerably outweigh the risks.

A Case of X-Linked Moesin-Associated Immune Deficiency in a Pediatric Patient

Background: X-Linked Moesin-Associated Immune Deficiency (X-MAID) is a rare severe combined immunodeficiency (SCID) subtype that can present at any age due to its variability. Depending on severity, patients demonstrate failure to thrive, recurrent bacterial and viral infections, and increased susceptibility to varicella zoster. It has been characterized by marked lymphopenia with hypogammaglobulinemia and impaired T-cell migration and proliferation. Case Presentation: This is a report of a Cuban 7-year-old male with poor weight gain and facial dysmorphia. He had a history of recurrent bacterial gastrointestinal infections and pneumonia beginning at 4 months of age. He additionally had 4-6 upper respiratory tract and ear infections annually. While still living in Cuba, he was admitted for a profound EBV infection in the setting of significant leukopenia. A bone marrow biopsy confirmed no malignancy. After he moved to the United States, his laboratory work-up revealed marked leukopenia with low absolute neutrophil and lymphocyte count with low T and B cells, very low immunoglobulin levels IgG, IgA, and IgM, and poor vaccination responses to streptococcus pneumonia, varicella zoster, and SARS-CoV-2. Genetic testing revealed a missense pathogenic variant c.511C>T (p.Arg171Trp) in the moesin (MSN) gene associated with X-MAID. He was managed with Bactrim and acyclovir prophylaxis, and immunoglobulin replacement therapy, and considered for hematopoietic stem cell transplantation. Discussion(s): Diagnosis of X-MAID should be considered in patients with recurrent infections and profound lymphopenia. As with SCID, early diagnosis and intervention is of utmost importance to prevent morbidity and mortality. This case demonstrates the importance of genetic testing in identifying this disease as it may prompt an immunologist to consider HSCT if conservative management is suboptimal. In the current literature, HSCT appears promising, but the long-term outcomes have yet to be described.Copyright © 2023 Elsevier Inc.

Characterization of Adaptive Immune Responses to SARS-CoV-2 Updated Bivalent Booster

Bivalent COVID-19 vaccines that contain two mRNAs encoding Wuhan-1 and Omicron BA.4/5 spike proteins are successful in preventing infection from the original strain and Omicron variants, but the quality of adaptive immune responses is still not well documented. This study aims at characterizing adaptive immune responses to the bivalent booster vaccination in 46 healthy participants. Plasma and PBMC were collected prior and three weeks after bivalent booster. We measured anti-N, anti-S, and RBD IgM, IgA, IgG plasma titers against original, Omicron BA.1, and BA.5 variants (pending) as well as total anti-S IgG titers and surrogate Virus Neutralization capacity against the Alpha, Delta, and BA.1 variant. With spectral flow-cytometry we identified peripheral blood B-cells specific for the RBD of the S-protein of the original and BA.1 variants. T-cell-specific responses were assessed by cytokine release assay after stimulation with SARS-CoV-2 peptides from the original, BA.1, BA.4, and BA.5 variants (pending). Finally, we performed TRB and IGH repertoire studies on sorted CD4+, CD8+, CD19+ lymphocytes, to study breadth of SARS-CoV-2 specific clonotypes (pending). 27/46 participants were analyzed;9 had SARS-CoV-2 infection (COVID+), while 18 are infection naive (COVID-). In both groups, median time since last dose of SARS-CoV-2 vaccine (3rd or 4th) was 11 months. All subjects were positive for anti-S IgG prior to bivalent booster. The COVID + group displayed anti-S IgG pre-booster levels and neutralization against BA.1 higher than the COVID- group. Significant increase post-boost of total anti-S IgG and BA.1 neutralizing activity was detected in the COVID- but not in the COVID+ group;however, no difference in neutralization activity post-boost was detected between the two groups. Furthermore, the COVIDgroup showed significant increase in the frequency of CD19+ and CD27+ switched memory B-cells specific for BA.1 RBD in post-boost compared to pre-boost samples. However, post-boost frequencies of the same B-cells were higher in the COVID+ compared to the COVID- group. These preliminary findings confirm that among individual immunized with the original COVID-19 mRNAvaccine, prior COVID infection provides increased protection against SARS-CoV-2 variants. They also demonstrate that booster immunization with the bivalent vaccine induces robust adaptive immune responses against Omicron variant.[Formula presented][Formula presented]Copyright © 2023 Elsevier Inc.

Coronavirus disease (COVID-19) in patients with type 2 diabetes mellitus: clinical and laboratory peculiarities

This study aims to study the clinical-laboratory peculiarities of the coronavirus disease (COVID-19) course in patients with type 2 diabetes mellitus (DM). There were examined 60 patients with the coronavirus disease COVID-19. Patients were divided into two groups: group I - 30 patients with the coronavirus disease (COVID-19) with concomitant type 2 diabetes mellitus;group II - 30 patients with coronavirus disease (COVID-19) without diabetes mellitus;control group - 20 people. There were studied peculiarities of clinical-laboratory changes in patients with coronavirus disease with type 2 diabetes mellitus. General clinical laboratory tests, determination of biochemical parameters, coagulogram, ferritin, CRP, procalcitonin, D-dimer and endothelin-1 were performed. Blood saturation was measured. Out of the instrumental methods, an ultrasound examination of the lungs and RTG of thoracic organs was performed. Patients were admitted on the 5.46+/-0.87 day of the disease. The length of the hospital stay for patients of group I was 19.9+/-1.66 bed days and 14.7+/-0.91 bed days for the patients of group II. A severe course of the disease was observed in 83.3% of patients of group I and 33.3% of group II;a moderate severity course was observed in 16.7% of patients with concomitant DM and 66.7% of patients without concomitant DM. Respiratory failure (RF) of 1 degree was observed in 30% of patients of group 1, RF of the 2 degree - in 16.7% of patients, and RF of the 3 degree - in 10% of patients. In patients without DM, RF of 1 degree - was in 30% of patients, and RF of the 2 degree - was in 13.3% of patients. The laboratory diagnostic methods determined that the levels of leukocytes, D-dimer, endothelin-1, IL-6, procalcitonin, and ferritin were higher in patients with concomitant type 2 DM. In patients with type 2 DM, the course of the coronavirus disease is more severe and longer, with the development of pneumonia and respiratory failure. It is accompanied by leukocytosis, lymphopenia, increased ESR, prothrombin index, IL-6, CRP level, procalcitonin and endothelin-1. Copyright © 2023 The Authors.

The Effect of CRP/Albumin, Platelet/Lymphocyte, SOFA, and APACHE II in Predicting Mortality in Covid-19 Patients in Intensive Care Unit

Objectives: It is important to predict the prognosis during hospital admission of Covid-19 patients. The purpose of this study was to see how CRP/ Albumin (CAR) and Platelet/Lymphocyte (PLR) ratios, obtained from patients in the intensive care unit (ICU) within the first 24 hours of their hospitalization with a Covid-19 diagnosis, predictmortality and how they correlated with acute physiology and chronic health evaluation (APACHE II) and sequential organ failure assessment (SOFA). Method(s): Using hospital records, records of 83 patients hospitalized in the ICU with a diagnosis of Covid-19 between 11.03.2020 and 01.01.2021 were retrospectively analyzed . Patients were divided into two groups discharged (Group I) and exits (ex) group (Group II). CAR and PLR were recorded during the first 24 hours of ICU admission, and APACHE II and SOFA scores were computed. The calculated CAR and PLR were correlated with APACHE II and SOFA scores and their association with mortality was investigated. Result(s): SOFA, APACHE II, PLO, and age were higher, and albumin was lower in patients in the mortal course (p<0.05). ROC analysis revealed that APACHE II and SOFA scores could be employed to estimate mortality. Conclusion(s): We believe that APACHE II and SOFA scores can be used to predict mortality in patients admitted to the ICU due to Covid-19, whereas CRP/Albumin and Platelet/Lymphocyte ratios cannot. Copyright © 2023 by The Cardiovascular Thoracic Anaesthesia and Intensive Care.

Re-vaccination against SARS-COV2 in allogeneic HSCT patients: Repeated primary vaccines doses increases seroconversion rates

Patients undergoing treatment for haematological malignancies have been shown to have reduced antibody responses to vaccination against SARS-COV2. This is particularly important in patients who have undergone allogeneic haemopoietic stem cell transplantation (HSCT), in whom there is limited data about vaccine efficacy. In this retrospective single-centre analysis, we present data on serologic responses following one, two, three or four doses of either Pfizer-BioNTech (PB), AstraZeneca (AZ) or Moderna (MU) SARS-CoV- 2 vaccines from a series of 75 patients who have undergone allogeneic HSCT within 2 years from the time they were revaccinated. The seroconversion rates following post-HSCT vaccination were found to be 50.7%, 78%, 79% and 83% following the first, second, third and fourth primary post -HSCT vaccine doses, respectively. The median time from allograft to first revaccination was 145 days (range 79-700). Our findings suggest that failure to respond to the first SARS-CoV- 2 vaccine post-HSCT was associated with the presence of acute GVHD (p = 0.042) and treatment with rituximab within 12 months of vaccination (p = 0.019). A statistical trend was observed with the presence of chronic GVHD and failure to seroconvert following the second (p = 0.07) and third (p = 0.09) post-HSCT vaccine doses. Patients who had received one or more SARS-CoV- 2 vaccines prior to having an allogeneic stem cell transplant were more likely to demonstrate a positive antibody response following the first dose of revaccination against Sars-CoV- 2 (p = 0.019) and retained this seropositivity following subsequent doses. The incidence of confirmed COVID-19 diagnosis among this cohort at the time of analysis was 16%. 17% of these were hospitalised and there was one recorded death (8%) secondary to COVID-19 in a patient who was 15.7 months post allogeneic transplant. In summary, this study suggests that despite the initial low seroconversion rates observed postallogeneic transplant, increasing levels of antibody response are seen post the second primary vaccine dose. In addition, there seems to be lower risk of mortality secondary to COVID-19 in this vaccinated population, compared to what was reported in the earlier phases of the pandemic prior to use of SARS-COV2 vaccination. This adds support to the widely adopted policy of early full revaccination with repeat of primary vaccine doses and boosters post-HSCT to reduce mortality in this population. Finally, we have identified rituximab use and active GVHD as potential risk factors influencing serological responses to SARS-COV2 vaccination and further work should focus on further characterising this risk and optimum dosing schedule both pre-and post-transplant.

Increases in expression of carbohydrate sulfotransferases CHST11 and CHST15 and decline in N-acetylgalactosamine-4-sulfatase (Arylsulfatase B, ARSB) require phospho-p38-MAPK following exposure to SARS-CoV-2 spike protein receptor binding domain in human a

Objective: Immunohistochemistry of post-mortem lung tissue from Covid-19 patients with diffuse alveolar damage demonstrated marked increases in chondroitin sulfate and CHST15 and decline in N-acetylgalactosamine-4-sulfatase. Studies were undertaken to identify the mechanisms involved in these effects. Method(s): Human primary small airway epithelial cells (PCS 301-010;ATCC) were cultured and exposed to the SARSCoV- 2 spike protein receptor binding domain (SPRBD;AA: Lys310-Leu560;Amsbio). Expression of the spike protein receptor, angiotensin converting enzyme 2 (ACE2), was enhanced by treatment with Interferon-beta. Promoter activation, DNA-binding, RNA silencing, QPCR, Western blots, ELISAs, and specific enzyme inhibitors were used to elucidate the underlying molecular mechanisms. Result(s): Treatment of the cultured cells by the SPRBD led to increased CHST15 and CHST11 expression and decline in ARSB expression. Sulfotransferase activity, total chondroitin sulfate, and sulfated glycosaminoglycan (GAG) content were increased. Phospho-T180/T182-p38-MAPK and phospho- S423/S425-Smad3 were required for the activation of the CHST15 and CHST11 promoters. Inhibition by SB203580, a phospho-p38 MAPK inhibitor, and by SIS3, a Smad3 inhibitor, blocked the CHST15 and CHST11 promoter activation. SB203580 reversed the SPRBD-induced decline in ARSB expression, but SIS3 had no effect on ARSB expression or promoter activation. Phospho-p38 MAPK was shown to reduce retinoblastoma protein (RB) S807/S811 phosphorylation and increase RB S249/T252 phosphorylation. E2F-DNA binding declined following exposure to SPRBD, and SB203580 reversed this effect. This indicates a mechanism by which SPRBD, phospho-p38 MAPK, E2F, and RB can regulate ARSB expression and thereby impact on chondroitin 4-sulfate and dermatan sulfate and molecules that bind to these sulfated GAGs, including Interleukin-8, bone morphogenetic protein-4, galectin-3 and SHP-2 (Src homology region 2-containing protein tyrosine phosphatase 2). Conclusion(s): The enzyme ARSB is required for the degradation of chondroitin 4-sulfate and dermatan sulfate, and accumulation of these sulfated GAGs can contribute to lung pathophysiology, as evident in Covid-19. Some effects of the SPRBD may be attributable to unopposed Angiotensin II, when Ang1-7 counter effects are diminished due to binding of ACE2 with the SARS-CoV-2 spike protein and reduced production of Ang1-7. Aberrant cell signaling and activation of the phospho-p38 MAPK and Smad3 pathways increase CHST15 and CHST11 production, which can contribute to increased chondroitin sulfate in infected cells. Decline in ARSB may occur as a consequence of effects of phospho-p38 MAPK on RB phosphorylation and E2F1 availability. Decline in ARSB and the resulting impaired degradation of sulfated GAGs have profound consequences on cellular metabolic, signaling, and transcriptional events. Funding is VA Merit Award.Copyright © 2023 The American Society for Biochemistry and Molecular Biology, Inc.

Association of SARS-COV-2 viral RNAemia, IL- 6 gene polymorphism, serum IL-6 and peripheral blood lymphocytes and monocytes with disease severity in COVID-19 patients

Coronavirus disease 2019 (COVID-19) is a fatal pandemic viral disease caused by the severe acute respiratory syndrome corona virus type-2 (SARS-CoV-2). The aim of this study is to observe the associations of IL-6, SARS-COV-2 viral load (RNAemia), IL- 6 gene polymorphism and lymphocytes and monocytes in peripheral blood with disease severity in COVID-19 patients. This study was carried out from March 2021 to January 2022. RT-PCR positive 84 COVID-19 patients and 28 healthy subjects were enrolled. Blood was collected to detect SARS-COV-2 viral RNA (RNAemia) by rRT-PCR, serum IL-6 level by chemiluminescence method, SNPs of IL-6 by SSP-PCR, immunophenotyping of lymphocytes and monocyte by flow cytometry. Serum IL-6 level (pg/ml) was considerably high among critical patients (102.02 +/- 149.7) compared to severe (67.20 +/- 129.5) and moderate patients (47.04 +/- 106.5) and healthy controls (3.5 +/- 1.8). Serum SARS-CoV-2 nucleic acid positive cases detected mostly in critical patients (39.28%) and was correlated with extremely high IL-6 level and high mortality (R =.912, P < 0.001). Correlation between IL-6 and monocyte was statistically significant with disease severity (severe group, p < 0.001, and 0.867*** and critical group p < 0.001 and 0.887***). In healthy controls, moderate, severe and critically ill COVID-19 patients, IL-6 174G/C (rs 1800795) GG genotype was 82.14%, 89.20%, 67.85% and 53.57% respectively. CC and GC genotype had strong association with severity of COVID-19 when compared with GG genotype. Significant statistical difference found in genotypes between critical and moderate groups (p < 0.001, OR-10.316, CI-3.22-23.86), where CC genotype was associated with COVID-19 severity and mortality. The absolute count of T cell, B cell, NK cell, CD4+ T cells and CD8+ T cells were significantly decreased in critical group compared to healthy, moderate and severe group (P < 0.001). Exhaustion marker CD94/NKG2A was increased on NK cells and CD8+ cytotoxic T cell among critical and severe group. Absolute count of monocyte was significantly increased in critical group (P < 0.001). Serum IL-6, IL-6 174 G/C gene and SARS-CoV-2 RNAaemia can be used in clinical practice for risk assessment;T cell subsets and monocyte as biomarkers for monitoring COVID-19 severity. Monoclonal antibody targeting IL-6 receptor and NKG2A for therapeutics may prevent disease progression and decrease morbidity and mortality.Copyright © 2023 Elsevier Inc.

Examining the frequency of endoscopic findings in patients with covid-19 with upper gastrointestinal bleeding referred to al-Zahra Hospital of Isfahan.

Background: Gastrointestinal bleeding is one of the consequences of COVID-19, which is associated with increased hospitalization and patient mortality. This study was conducted to determine the prevalence of endoscopic findings and the outcome of gastrointestinal bleeding in patients with COVID-19 who were hospitalized from September to December 2019 in Al-Zahra Hospital, Isfahan. Method(s): In this cross-sectional study, out of 5800 patients who were admitted to Al-Zahra Hospital in Isfahan from September to December 2019 due to COVID-19 (according to the positive PCR test result), 87 patients who underwent endoscopy due to upper gastrointestinal bleeding by a skilled gastroenterologist, were selected and studied. Demographic characteristics, underlying diseases, use of anticoagulants, and laboratory findings were studied and evaluated and finally, the disease was evaluated and compared based on endoscopic findings. Result(s): Based on the results obtained from this research, the patients with endoscopic lesions had higher average age (P=0.041), lower blood oxygen saturation percentage (P=0.028), and higher bleeding intensity (P=0.018). The frequency of using anticoagulant drugs in the group whose endoscopy results were abnormal was higher but insignificant. Hemoglobin, platelet, lymphocyte, and CRP levels were higher in the group whose endoscopy was normal, and NLR, LDH, and D-dimer levels were higher in the group whose endoscopy was abnormal (P<0.050). Three people (11.55%) from the group with normal endoscopy and 18 people (29.5%) from the group with abnormal endoscopy died, but the frequency of death was not significantly different between the two groups (P=0.070). Conclusion(s): The findings of the present study showed that the COVID patients with upper gastrointestinal bleeding who had endoscopic lesions had significant differences in some characteristics such as age, bleeding intensity, and blood oxygen saturation percentage with patients with normal endoscopy. Also, the frequency of death in patients with endoscopic lesions was relatively higher. Therefore, COVID patients with gastrointestinal bleeding should undergo endoscopy as soon as possible and necessary measures should be taken to control and prevent gastrointestinal bleeding.Copyright © 2022 Tabesh et al. Tehran University of Medical Sciences. Published by Tehran University of Medical Sciences.

Mechanism of interferon induction by cannabidiol (CBD) and analogues in lung cancer cells

CBD, an FDA approved drug for epilepsy, may have therapeutic potential for other diseases and is currently being tested for efficacy in cancer-related clinical trials. As the literature about CBD, especially in vitro reports, is often contradictory, increasing our understanding of its specific action on a molecular level will allow to determine whether CBD can become a useful therapy or exacerbates specific cancers in a context-dependent manner. Due to its relative lipophilicity, CBD is challenging to dispense at therapeutic concentrations;therefore, one goal is to identify cannabinoid congeners with greater efficacy and reduced drug delivery challenges. We recently showed that CBD activates interferons as a mechanism of inhibiting SARS-CoV-2 replication in lung carcinoma cells. As factors produced by the innate immune system, interferons have been implicated in both pro-survival and growth arrest and apoptosis signaling in cancer. Here we show that CBD induces interferon production and interferon stimulated genes (ISGs) through a mechanism involving NRF2 and MAVS in lung carcinoma cells. We also show that CBDV, which differs from CBD by 2 fewer aliphatic tail carbons, has limited potency, suggesting that CBD specifically interacts with one or more cellular proteins rather than having a non-specific effect. We also identified other CBD-related cannabinoids that are more effective at inducing ISGs. Taken together, these results characterize a novel mechanism by which CBD activates the innate immune system in lung cancer cells and identify related cannabinoids that have possible therapeutic potential in cancer treatment.

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 New Registry for Genetic Diagnosis of Inborn Errors of Immunity within the Military Health System

Genotypic definition of monogenic inborn errors of immunity (IEIs) continues to accelerate with broader access to next generation sequencing, underscoring this aggregated group of disorders as a major health burden impacting both civilian and military populations. At an estimated prevalence of 1 in 1200 individuals, IEIs affect ~8,000 patients within the Military Health System (MHS). Despite access to targeted gene/exome panels at military treatment facilities, most affected patients never receive a definitive genetic diagnosis that would significantly improve clinical care. To address this gap, we established the first registry of IEI patients within the MHS with the goal of identifying known and novel pathogenic genetic defects to increase diagnosis rates and enhance clinical care. Using the registry, a research protocol was opened in July 2022. Since July we have enrolled 75 IEI patients encompassing a breadth of phenotypes including severe and recurrent infections, bone marrow failure, autoimmunity/autoinflammation, atopic disease, and malignancy. Enrolled patients provide blood and bone marrow samples for whole genome, ultra-deep targeted panel and comprehensive transcriptome sequencing, plus cryopreservation of peripheral blood mononuclear cells for future functional studies. We are also implementing and developing analytical methods for identifying and interrogating non-coding and structural variants. Suspected pathogenic variants are adjudicated by a clinical molecular geneticist using state-of-the-art analysis pipelines. These analyses subsequently inform in vitro experiments to validate causative mutations using cell reporter systems and primary patient cells. Clinical variant validation and return of genetic results are planned with genetic counseling provided. As a proof of principle, this integrated genetic evaluation pipeline revealed a novel, candidate TLR7 nonsense variant in two adolescent brothers who both endured critical COVID-19 pneumonia, requiring mechanical ventilation and extracorporeal membrane oxygenation. Our protocol is therefore poised to greatly enrich clinical genetics resources available in the MHS for IEI patients, contributing to better diagnosis rates, informed family counseling, and targeted treatments that collectively improve the health and readiness of the military community. Moreover, our efforts should yield new mechanistic insights on immune pathogenesis for a broad variety of known and novel IEIs.Copyright © 2023 Elsevier Inc.

Covid-19: Is the placenta a safe space

Problem: Several large studies have demonstrated that COVID-19 pregnant individuals are at a significant risk for severe disease and adverse pregnancy outcomes. The mechanisms underlying these phenomena remain to be elucidated and are the focus of our project. Although fetal and placental infection is rare, placental abnormalities and adverse pregnancy outcomes associated with placental dysfunction in COVID-19 cases have been widely reported. In particular, placental thrombosis and lesions consistent with maternal vascular malperfusion (MVM) of the placenta are common in individuals with COVID-19. Since thrombotic complications have been associated with COVID-19, it is not surprising that pregnant individuals with COVID- 19 are at risk for placental thrombosis. Method of Study: Placentas were evaluated histologically. Extracellular vesicles were isolated by serial centrifugation. Result(s): Adverse pregnancy outcomes associated with these placental lesions, including hypertensive disorders of pregnancy (gestational hypertension and preeclampsia), small for gestational age (SGA, birthweight < 10th percentile for gestational age), and preterm birth (PTB, < 37 weeks) are significantly increased among pregnant individuals with COVID-19. Placental infection with SARSCoV- 2 is uncommon, but multiple inflammatory and metabolic factors are likely to affect the placenta, including circulating extracellular vesicles (EVs) derived from various organs that have been associated with COVID-19 pathology and disease severity.We have analyzed over 500 placentas from COVID-19 pregnancies and found marked changes in placental morphology, characterized by abnormal maternal and fetal vessels, intervillous thrombi, and fibrin deposition, even in the face of mild or asymptomatic disease. We detected increased levels of small EVs in maternal serum from COVID-19 cases compared to controls and increased levels of mitochondrial DNA in EVs from COVID-19 cases. In in vitro experiments, we found increased oxidative stress in uterine endothelial cells and primary trophoblasts. Syncytialization of trophoblast cells following exposure to EVs from pregnant COVID-19 patients was markedly reduced. RNAseq of trophoblast cells exposed to EVs from pregnant COVID-19 patients revealed disruption of multiple pathways related to mitochondria function, oxidative stress, coagulation defects, and inflammation. Timing of infection during pregnancy (first, second, and third trimester) altered EV size distribution, cargo content, and functional consequences of trophoblast EV exposure. Conclusion(s): Our studies show that COVID-19 infection during pregnancy has profound effects on placenta morphology and function. It remains to be determined what the long-term consequences are on the offspring.

Mild COVID-19 clinical course among paediatric patients with primary immunodeficiency

Background: The clinical course of coronavirus disease-2019 (COVID-19) varies from those who are asymptomatic, experience mild symptoms such as fever, cough, and dyspnea, to more severe outcomes including acute respiratory distress, pneumonia, renal failure, and death. Early reports suggested severe outcomes in patients with primary immunodeficiency (PID), particularly those with type 1 interferon signalling defects. This prompted a rigid approach to social distancing to protect this patient population, particularly children. To date, real-world data describing the course and outcome of COVID-19 in paediatric PID patients remains scarce. Method(s): In this retrospective case series, we describe the clinical course of 36 paediatric patients with underlying primary immunodeficiency (PID) followed by SickKids Hospital (Toronto, Canada) who were symptomatic and tested positive for SARS-CoV-2 infection between October 2020 to November 2022. Result(s): Our cohort consisted of patients with combined immunodeficiency (66.7%), antibody deficiency (22.2%), neutrophil dysfunction (8.3%), and immune dysregulation (2.8%). The median age was 7.5 years (range: 8 months - 17 years), with 21 male and 15 female patients. Three (8.3%) patients were post-hematopoietic stem cell transplant (HSCT) and 12 (33%) patients were on immunoglobulin replacement. Nine (25%) patients had underlying lung problems including bronchiectasis (1), interstitial lung disease on home oxygen therapy (1), and underlying asthma (7). Most patients had mild clinical course and were managed at home. The most common symptoms were fever (80%), cough (75%) and other upper respiratory tract symptoms (72%). Nineteen (52.7%) patients experienced other symptoms which included headache, lethargy, or gastrointestinal upset. At the time of the infection, 13 patients (36.1%) had received 2 doses of a SARS-CoV-2 vaccine, 5 patients (13.9%) had received 1 dose, and 18 (50%) were not vaccinated. None of the patients received antiviral or monoclonal antibody as prophylaxis or treatment. Only 1 patient required hospital admission out of precaution given the close proximity to HSCT. All patients recovered without complications. Conclusion(s): The paediatric patients with PID followed by our centre experienced mild to moderate COVID-19 symptoms and recovered fully without complications. These findings support the return of much needed social interactions among children, which were impacted severely during the COVID-19 pandemic.Copyright © 2023 Elsevier Inc.

Teclistamab in combination with daratumumab and lenalidomide in multiple myeloma (MajesTEC-2 study)

Introduction: Combination of daratumumab (Dara) and lenalidomide (Len) may enhance the function of teclistamab (Tec), potentially resulting in improved antimyeloma activity in a broader population. We present initial safety and efficacy data of Tec-Dara- Len combination in patients with multiple myeloma (MM) in a phase 1b study (MajesTEC-2;NCT04722146). Method(s): Eligible patients who received 1-3 prior lines of therapy (LOT), including a proteasome inhibitor and immune-modulatory drug, were given weekly doses of Tec (0.72-or- 1.5 mg/kg with step-up dosing) + Dara 1800 mg + Len 25 mg. Responses per International Myeloma Working Group criteria, adverse events (Aes) per CTCAE v5.0, and for cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) per ASTCT guidelines, were assessed. Result(s): 32 patients received Tec-Dara- Len (0.72 mg/kg, n = 13;1.5 mg/kg, n = 19). At data cut-off (11 July 2022), median follow-up (range) was 5.78 months (1.0-10.4) and median treatment duration was 4.98 months (0.10-10.35). Median age was 62 years (38-75);87.5% were male. Median prior LOT was 2 (1-3), 18.8% were refractory to Dara and 28.1% refractory to Len. CRS was most frequent AE (81.3% [n = 26], all grade 1/2), 95% occurred during cycle1. Median time to onset was 2 days (1-8), median duration was 2 days (1-22). No ICANS were reported. Frequent Aes (>=25.0% across both dose levels) were neutropenia (75.0% [n = 24];grade 3/4: 68.8% [n = 22]), fatigue (43.8% [n = 14];grade 3/4: 6.3% [n = 2]), diarrhoea (37.5% [n = 12];all grade 1/2), insomnia (31.3% [n = 10];grade 3/4: 3.1% [n = 1]), cough (28.1% [n = 9];all grade 1/2), hypophosphatemia (25.0% [n = 8];all grade 1/2), and pyrexia (25% [n = 8];grade 3/4: 6.3% [n = 2]). Febrile neutropenia frequency was 12.5% (n = 4). Infections occurred in 24 patients (75.0%;grade 3/4: 28.1% [n = 9]). Most common were upper respiratory infection (21.9% [n = 7]), COVID-19 (21.9% [n = 7]), and pneumonia (21.9% [n = 7]). Three (9.4%) had COVID-19 pneumonia. One (3.1%) discontinued due to COVID-19 infection and this patient subsequently died of this infection. Overall response rate (ORR, median follow-up) was 13/13 (8.61 months) at 0.72 mg/kg and 13/16 evaluable patients (less mature at 4.17 months) at 1.5 mg/kg. 12 patients attained very good/better partial response at 0.72 mg/kg dose, and response was not mature for 1.5 mg/kg group. Median time to first response was 1.0 month (0.7-2.0). Preliminary pharmacokinetic concentrations of Tec-Dara- Len were similar as seen with Tec monotherapy. Tec-Dara- Len- treatment led to proinflammatory cytokine production and T-cell activation. Conclusion(s): The combination of Tec-Dara- Len has no new safety signals beyond those seen with Tec or Dara-Len individually. Promising ORR supports the potential for this combination to have enhanced early disease control through the addition of Tec. These data warrant further investigation.

Angiotensin-converting enzyme 2 (ACE2) in COVID-19 and other diseases.

The coronavirus SARS-CoV-2 was detected in isolates of pneumonia patients in January 2020. The virus cannot multiply extracellularly but requires access to the cells of a host organism. SARS-CoV-2 uses angiotensin-converting enzyme 2 (ACE2) as a receptor, to which it docks with its spikes. ACE2 belongs to the renin angiotensin system (RAS), whose inhibitors have been used for years against high blood pressure. Renin is an endopeptidase that is predominantly formed in the juxtaglomerular apparatus of the kidney and cleaves the decapeptide angiotensin I (Ang I) from angiotensinogen. Through the angiotensin-converting enzyme (ACE), another 2 C-terminal amino acids are removed from Ang I, so that finally the active octapeptide angiotensin II (Ang II) is formed. The biological effect of Ang II via the angiotensin II receptor subtype 1 (AT1-R) consists of vasoconstriction, fibrosis, proliferation, inflammation, and thrombosis formation. ACE2 is a peptidase that is a homolog of ACE. ACE2 is predominantly expressed by pulmonary alveolar epithelial cells in humans and has been detected in arterial and venous endothelial cells. In contrast to the dicarboxy-peptidase ACE, ACE2 is a monocarboxypeptidase that cleaves only one amino acid from the C-terminal end of the peptides. ACE2 can hydrolyze the nonapeptide Ang-(1-9) from the decapeptide Ang I and the heptapeptide Ang-(1-7) from the octapeptide Ang II. Ang-(1-7) acts predominantly antagonistically (vasodilatory, anti-fibrotic, anti-proliferative, anti-inflammatory, anti-thrombogenetically) via the G protein-coupled Mas receptor to the AT1-R-mediated effects of Ang II. In the pathogenesis of COVID-19 infection, it is therefore assumed that there is an imbalance due to overstimulation of the AT1 receptor in conjunction with a weakening of the biological effects of the Mas receptor.Copyright © 2022 Dustri-Verlag Dr. K. Feistle.

Mastocytosis and COVID19 infection and vaccination: A pediatric series

Introduction: Mastocytosis encompasses a heterogeneous group of diseases characterized by an accumulation of clonal mast cells (MC) in the skin and/or internal organs, and symptoms of MC activation. This MC activation can be elucidated by several factors, including infections or vaccination. Objective(s): We present our experience with COVID infection and vaccination in a series of 133 patients with pediatric mastocytosis. Method(s): Between January 1998 and December 2022, 133 pediatric patients have been referred to our hospital owing to clinically suspected MC disorder, mainly with mastocytosis in the skin. The final diagnoses of mastocytosis were established by the presence of typical skin lesions together with an increase of MC numbers in a biopsy from lesional skin or activating KIT mutations in lesional skin tissue. Serum baseline tryptase and total immunoglobulin E levels were measured, and patients underwent a comprehensive allergy workup to confirm atopic status and history of anaphylaxis. Regarding vaccination, REMA's (Spanish Network on Mastocytosis) protocol was followed. Result(s): 13 patients with COVID infection were identified, of which 25 (56,8%) were female and 0% had symptoms of MC activation. All of them had an asymptomatic or mild course of COVID infection. None of the patients experimented MC activation symptoms during viral illness. Regarding COVID vaccination, all patients received premedication with antihistamine 60 minutes prior vaccination. No one experimented immediate reactions and only one patient (0,75%) referred worsening of MC activation symptoms (baseline pruritus, urtication and brain fog) only after the first doses, recovering without changes in his treatment (oral cromoglycate and antihistamine) in two months. Discussion(s): Although MC have been implicated in the pathogenesis of cytokine storm in COVID19, there is no clinical evidence of SARSCoV- 2-induced MC activation, perhaps related to the fact that bone marrow MC lack angiotensin-converting enzyme 2 receptors.