Children With Type 1 Interferonopathy: Commonalities and Diversities in a Large Patient Cohort.

OBJECTIVE: This study aimed to provide a comprehensive overview of the clinical features, laboratory and screening results, treatment options, and outcomes of patients with type I interferonopathy. Our secondary goal was to identify the predictors of long-term morbidity or mortality. METHODS: We included children with genetically confirmed type I interferonopathies, with a follow-up duration of > 1 year. Data were obtained retrospectively from medical records. RESULTS: Of the 40 eligible patients for the study, 52.5% were female, with a median age of disease onset of 1.5 years (range 0.1-13.2 yrs). They were diagnosed at an average age of 6.8 (SD 4.6) years. Aicardi-Goutières syndrome was the most common diagnosis (n = 15, 37.5%). The central nervous system was the most frequently affected system (n = 27, 67.5%). Janus kinase inhibitors were administered to 17 (42.5%) patients. Twenty-five patients (62.5%) developed at least 1 permanent morbidity or died during follow-up; thus, they were included in the poor outcome group. Although younger age at disease onset, intracranial calcification (ICC), and lack of chilblains and elevated acute-phase reactants were significant in univariate logistic regression analysis, only ICC on magnetic resonance imaging at admission (adjusted odds ratio 19.69, 95% CI 1.08-359.05, P = 0.04) was found to be a significant predictor of poor outcomes in multivariate logistic regression analysis. CONCLUSION: For the first time, we evaluated the predictors of poor outcomes in patients with type I interferonopathy with a broad spectrum of subtypes. Further, our study's unique patient characteristics can provide valuable insights into these extremely rare conditions.

Artemis deficiency: A large cohort including a novel variant with increased radiosensitivity.

BACKGROUND: Artemis deficiency is an autosomal recessive disorder characterized by a combined immunodeficiency with increased cellular radiosensitivity. In this review, the clinical and genetic characteristics of 15 patients with DCLRE1C variants are presented. METHODS: The demographic, clinical, immunologic, and genetic characteristics of patients with confirmed DCLRE1C variants diagnosed between 2013 and 2023 were collected retrospectively. Three patients were evaluated for radiosensitivity by the Comet assay, compared with age- and sex-matched healthy control. RESULTS: Seven patients who had severe infections in the first 6 months of life were diagnosed with T-B-NK+ SCID (severe combined immunodeficiency). Among them, four individuals underwent transplantation, and one of those died due to post-transplant complications in early life. Eight patients had hypomorphic variants. Half of them were awaiting a suitable donor, while the other half had already undergone transplantation. The majority of patients were born into a consanguineous family (93.3%). Most patients had recurrent sinopulmonary infections (73.3%), and one patient had no other infection than an acute respiratory infection before diagnosis. Two patients (13.3%) had autoimmunity in the form of autoimmune hemolytic anemia. Growth retardation was observed in only one patient (6.6%), and no malignancy was detected in the surviving 11 patients during the median (IQR) of 21.5 (12-45) months of follow-up. Three patients who had novel variants exhibited increased radiosensitivity and compromised DNA repair, providing a potential vulnerability to malignant transformation. CONCLUSION: Early diagnosis, radiation avoidance, and careful preparation for transplantation contribute to minimizing complications, enhancing life expectancy, and improving the patient's quality of life.

Perioperative hypersensitivity in children: A prospective multidisciplinary study.

BACKGROUND: There are few studies of perioperative hypersensitivity reactions in children. The diagnosis of perioperative hypersensitivity reactions may be under estimated because it is difficult to recognize the reactions. Anaphylaxis may go unnoticed because of patient unconsciousness. Urticaria may be missed due to sterile drapes. The aim of this study was to prospectively evaluate perioperative hypersensitivity reactions. METHODS: In this prospective study, patients with suspected perioperative hypersensitivity reactions aged 0-18 years who underwent surgery at the Department of Pediatric Surgery, Cerrahpasa Faculty of Medicine, between 2019 and 2021 were investigated. Suspected reactions in the perioperative period were graded according to the Ring and Messmer scale. Patients with suspected reactions were examined 4-6 weeks after the reaction. If necessary, specific IgE and basophil activation tests were performed. Reactions of grades III-IV were considered anaphylaxis. If one test modality was strongly positive and there was a relevant time point or repeated allergic reactions, or at least two test modalities were positive, hypersensitivity was confirmed. In all patients, serum tryptase levels were analyzed at the time of the reaction, 2 h after the reaction, and 4-6 weeks after the reaction as part of the allergic evaluation. RESULTS: A total of 29 patients (8 female, 21 male) suspected of having an intraoperative reaction during the study were included in the analysis. Perioperative hypersensitivity reactions were noted in 1 patient. The incidence of perioperative hypersensitivity reactions was reported to be 0.03% (n = 1/2861). While anaphylaxis was confirmed in 1 patient, 5 patients were considered possible anaphylaxis cases. CONCLUSION: Perioperative hypersensitivity reactions can be life-threatening and may recur with further administration. Collaboration between pediatric surgeons, anesthesiologists, and allergists can prevent further reactions. All suspected cases should be evaluated by an experienced allergist soon after the initial reaction.

Neurologic Status of Patients with Purine Nucleoside Phosphorylase Deficiency Before and After Hematopoetic Stem Cell Transplantation.

BACKGROUND: Purine nucleoside phosphorylase (PNP) deficiency is a rare autosomal recessive combined immunodeficiency. The phenotype is profound T cell deficiency with variable B and NK cell functions and results in recurrent and persistent infections that typically begin in the first year of life. Neurologic findings occur in approximately two-thirds of patients. The mechanism of neurologic abnormalities is unclear. Hematopoietic stem cell transplantation (HSCT) is the only curative treatment for PNP deficiency. METHODS: We report here six patients from five unrelated families with PNP deficiency treated in two centers in Turkey. We evaluated the neurological status of patients and compared to post-transplantation period if available. Then, we performed PubMed, Google Scholar, and Researchgate searches using the terms "PNP" and "hematopoietic stem cell transplantation" to find all reported cases of PNP transplantation and compared to our cohort. RESULTS: Six patients were treated in two centers in Turkey. One patient died from post-transplant complications. The other four patients underwent successful HSCT with good immune reconstitution after transplantation (follow-up 21-48 months) and good neurological outcomes. The other patient with a new mutation is still waiting for a matching HLA donor. DISCUSSION: In PNP deficiency, clinical manifestations are variable, and this disease should be considered in the presence of many different clinical findings. Despite the comorbidities that occurred before transplantation, HSCT currently appears to be the only treatment option for this disease. HSCT not only cures immunologic disorders, but probably also improves or at least stabilizes the neurologic status of patients.

Therapeutic modalities and clinical outcomes in a large cohort with LRBA deficiency and CTLA4 insufficiency.

BACKGROUND: LPS-responsive beige-like anchor (LRBA) deficiency (LRBA-/-) and cytotoxic T-lymphocyte-associated antigen-4 (CTLA4) insufficiency (CTLA4+/-) are mechanistically overlapped diseases presenting with recurrent infections and autoimmunity. The effectiveness of different treatment regimens remains unknown. OBJECTIVE: Our aim was to determine the comparative efficacy and long-term outcome of therapy with immunosuppressants, CTLA4-immunoglobulin (abatacept), and hematopoietic stem cell transplantation (HSCT) in a single-country multicenter cohort of 98 patients with a 5-year median follow-up. METHODS: The 98 patients (63 LRBA-/- and 35 CTLA4+/-) were followed and evaluated at baseline and every 6 months for clinical manifestations and response to the respective therapies. RESULTS: The LRBA-/- patients exhibited a more severe disease course than did the CTLA4+/- patients, requiring more immunosuppressants, abatacept, and HSCT to control their symptoms. Among the 58 patients who received abatacept as either a primary or rescue therapy, sustained complete control was achieved in 46 (79.3%) without severe side effects. In contrast, most patients who received immunosuppressants as primary therapy (n = 61) showed either partial or no disease control (72.1%), necessitating additional immunosuppressants, abatacept, or transplantation. Patients with partial or no response to abatacept (n = 12) had longer disease activity before abatacept therapy, with higher organ involvement and poorer disease outcomes than those with a complete response. HSCT was performed in 14 LRBA-/- patients; 9 patients (64.2%) showed complete remission, and 3 (21.3%) continued to receive immunosuppressants after transplantation. HSCT and abatacept therapy gave rise to similar probabilities of survival. CONCLUSIONS: Abatacept is superior to immunosuppressants in controlling disease manifestations over the long term, especially when started early, and it may provide a safe and effective therapeutic alternative to transplantation.

Immune Reconstitution Inflammatory Syndrome After Hematopoietic Stem Cell Transplantation in a FOXN1 -deficient Patient.

The FOXN1 gene mutation is a unique disorder that causes the nude severe combined immunodeficiency phenotype. In patients with severe combined immunodeficiency, hematopoietic stem cell transplantation (HSCT) is life-saving if performed earlier. Thymic transplantation is the curative treatment for FOXN1 deficiency because the main pathology is thymic stromal changes. In this report, we describe the clinical features of a Turkish patient with a homozygous FOXN1 mutation treated with HSCT from his human leukocyte antigen-matched sibling. On follow-up, he showed Bacille Calmette Guerin adenitis and was evaluated as having immune reconstitution inflammatory syndrome. By presenting our patient, we aimed to draw attention to the development of HSCT and subsequent immune reconstitution inflammatory syndrome as a treatment option in patients with FOXN1 deficiency.

Chronic Rhinosinusitis in Patients with Primary Immunodeficiency.

INTRODUCTION: Primary immunodeficiencies are a heterogeneous group of diseases associated with an increased incidence of infections, autoimmunity, autoinflammatory diseases, allergies, and cancer. Rhinosinusitis is one of the most common infections in these patients. In our study, we aimed to determine the presence of chronic rhinosinusitis in our patients with primary immunodeficiency and to investigate the etiology of chronic rhinosinusitis. METHODS: Forty-four patients (age range: 4-26 years) diagnosed with primary immunodeficiency were enrolled in our study. Patients were interviewed about the symptoms of chronic rhinosinusitis, and nasal endoscopic examinations were performed prospectively. The results of laboratory tests, medications, skin allergy tests, and the patients' lung computed tomography were retrospectively recorded from patient files. RESULTS: The distribution of patients' diagnoses included 38.6% (n = 17) primary antibody deficiencies, 6.6% (n = 3) combined immunodeficiencies, 27.3% (n = 12) combined immunodeficiencies with syndromic features, 6.8% (n = 3) phagocytic disorders, and 20.5% (n = 9) immune dysregulation disorders. There was no significant difference in the frequency of chronic rhinosinusitis among the different immunodeficiency groups. There were no significant differences between chronic rhinosinusitis and conditions such as atopy, hypogammaglobulinemia, and treatments with immunoglobulin and/or azithromycin. The incidence of chronic rhinosinusitis was 77.8% (n = 7) in patients with a history of acute sinusitis and 20% (n = 7) in patients without a history of sinusitis, with a statistically significant difference between them (p = 0.002). CONCLUSION: Chronic rhinosinusitis is more common in patients with primary immunodeficiencies than in the normal population. For effective treatment, it is necessary to identify the factors that cause chronic rhinosinusitis. Further studies involving larger patient populations are needed to explain the mechanisms of chronic rhinosinusitis.

A case of severe DRESS syndrome treated with therapeutic plasma exchange and intravenous immunoglobulin therapy.

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome in children is a rare adverse drug reaction with skin rash, fever, hematologic abnormalities, and multiorgan involvement. The diagnosis is difficult because of its various clinical presentations, nonetheless is extremely important due to the mortality rate. We describe a 14-year-old boy who developed hypersensitivity to either teicoplanin or meropenem therapy. After failing to improve with corticosteroids, he was successfully treated with therapeutic plasma exchange (TPE). TPE should be considered in the treatment with corticosteroid-resistant DRESS syndrome.

Expanding the Clinical and Immunological Phenotypes and Natural History of MALT1 Deficiency.

PURPOSE: MALT1 deficiency is a combined immune deficiency characterized by recurrent infections, eczema, chronic diarrhea, and failure to thrive. Clinical and immunological characterizations of the disease have not been previously reported in large cohorts. We sought to determine the clinical, immunological, genetic features, and the natural history of MALT-1 deficiency. METHODS: The clinical findings and treatment outcomes were evaluated in nine new MALT1-deficient patients. Peripheral lymphocyte subset analyses, cytokine secretion, and proliferation assays were performed. We also analyzed ten previously reported patients to comprehensively evaluate genotype/phenotype correlation. RESULTS: The mean age of patients and disease onset were 33 ± 17 and 1.6 ± 0.7 months, respectively. The main clinical findings of the disease were recurrent infections (100%), skin involvement (100%), failure to thrive (100%), oral lesions (67%), chronic diarrhea (56%), and autoimmunity (44%). Eosinophilia and high IgE were observed in six (67%) and two (22%) patients, respectively. The majority of patients had normal T and NK cells, while eight (89%) exhibited reduced B cells. Immunoglobulin replacement and antibiotics prophylaxis were mostly ineffective in reducing the frequency of infections and other complications. One patient received hematopoietic stem cell transplantation (HSCT) and five patients died as a complication of life-threatening infections. Analyzing this cohort with reported patients revealed overall survival in 58% (11/19), which was higher in patients who underwent HSCT (P = 0.03). CONCLUSION: This cohort provides the largest analysis for clinical and immunological features of MALT1 deficiency. HSCT should be offered as a curative therapeutic option for all patients at the early stage of life.

Food-induced anaphylaxis in early childhood and factors associated with its severity.

Background: Several factors that increase the risk of severe food-induced anaphylaxis have been identified. Objective: We aimed to determine the demographic, etiologic, and clinical features of food-induced anaphylaxis in early childhood and also any other factors associated with severe anaphylaxis. Methods: We carried out a medical chart review of anaphylaxis cases from 16 pediatric allergy and immunology centers in Turkey. Results: The data of 227 patients with 266 food-induced anaphylaxis episodes were included in the study. The median (interquartile range) age of the first anaphylaxis episode was 9 months (6-18 months); 160 of these patients were boys (70.5%). The anaphylaxis episodes were mild in 75 cases (28.2%), moderate in 154 cases (57.9%), and severe in 37 cases (13.9%). The most frequent food allergens involved were cow's milk (47.4%), nuts (16.7%), and hen's egg (15.8%). Epinephrine was administered in only 98 (36.8%) of these anaphylaxis episodes. A logistic regression analysis revealed two statistically significant factors that were independently associated with severe anaphylaxis: the presence of angioedema and hoarseness during the anaphylactic episode. Urticaria was observed less frequently in patients who developed hypotension. In addition, confusion and syncope were associated with 25.9- and 44.6-fold increases, respectively, in the risk of concomitant hypotension. Conclusion: Cow's milk, nuts, and hen's egg caused the majority of mild and moderate-to-severe anaphylaxis episodes. The presence of angioedema and hoarseness in any patient who presents with a history of food-induced anaphylaxis should alert clinicians that the reaction may be severe. In addition, the presence of confusion, syncope, or stridor probably indicates concomitant hypotension.

Proven Food-Induced Acute Urticaria and Predictive Factors for Definitive Diagnosis in Childhood.

BACKGROUND: Urticaria can be the only sign of a food allergy or can be seen together with other signs and symptoms of a food allergy. OBJECTIVE: To determine the demographic, etiologic, and clinical features of food-induced acute urticaria in childhood. METHODS: Patients suspected of food-induced acute urticaria were included in this prospective cross-sectional multicenter study. RESULTS: Two hundred twenty-nine urticaria cases were included in this study. Seventeen patients who did not meet the inclusion criteria of the study were excluded. Of the 212 included cases, 179 (84.4%) were diagnosed with definitive food-induced acute urticaria. The most common foods causing acute urticaria were cow's milk, hen's eggs, and nuts in 56.4, 35.2, and 19% of cases, respectively. The positive predictive value of a history of milk-induced acute urticaria together with a milk-specific IgE >5 kU/L for cow's milk-induced acute urticaria was 92% (95% CI: 81-96%). A history of cow's milk-induced and/or hen's egg-induced acute urticaria was consistent with a definitive diagnosis of food-induced urticaria (Chen's kappa: 0.664 and 0.627 for milk and eggs, respectively). Urticaria activity scores were higher in patients with food-induced acute urticaria (p = 0.002). CONCLUSION: Cow's milk, hen's eggs, and nuts were the most common allergens in the etiology of childhood food-induced acute urticaria. Although the urticaria activity score provides guidance for diagnosis, an oral food challenge is often essential for the definitive diagnosis of a patient with a history of food-induced acute urticaria.

Two patients with chronic mucocutaneous candidiasis caused by TRAF3IP2 deficiency.

BACKGROUND: TRAF3 interacting protein 2 (TRAF3IP2) (Act1) is an adapter protein that interacts with IL-17R via its similar expression to fibroblast growth factor genes and IL-17R domain and coordinates 2 separate proinflammatory pathways following IL-17 cytokine stimulation. OBJECTIVE: We sought to elucidate the immunologic consequences of TRAF3IP2 homozygous mutations to improve treatments for immunodeficiency patients with chronic mucocutaneous candidiasis. METHODS: We describe 2 patients presenting with chronic mucocutaneous candidiasis who harbor biallelic nonsense mutations in TRAF3IP2. The cellular and molecular features of this genetic defect were assessed using in vitro cytokine assays and protein analysis. RESULTS: We show that the homozygous mutation causes complete loss of protein expression. We also show that the absence of TRAF3IP2 was associated with a defective response to combined IL-2/IL-25 (IL-17E) stimulation. CONCLUSIONS: Failure to initiate normal signaling downstream of IL-17R engagement likely contributes to the patients' recurrent fungal infections. These findings add to our molecular understanding of genetic defects affecting this critical pathway of antifungal immunity.

Telemedicine Applications in a Tertiary Pediatric Hospital in Turkey During COVID-19 Pandemic.

Background: A novel type of Coronavirus emerged at Wuhan in late 2019 involving preferentially the respiratory system. Owing to the rapid spread, almost 22 million people became infected and 700,000 died. Similar to other countries, the need for additional hospital beds and intensive care units required diversion of health care resources toward the care for those with COVID-19 in Turkey. Telemedicine appeared as a safe and low-cost alternative for the maintainability of pediatric health services during the pandemics. Within this context, we aimed to deliver the health services through telemedicine during the follow-up of chronic childhood diseases. Materials and Methods: This prospective study included five pediatric subspecialties, including allergy immunology, hematology and oncology, nephrology, rheumatology, and inborn metabolic disorders. After the interview, patients and involved physicians were requested to fill out a questionnaire designed to measure the level of satisfaction and the quality of the service we offered. Results: Of the 263 interviews, overall patient and physician satisfaction was 99% and 87%, respectively. As results of the interviews, 250 routine visits were performed, 181 acute complaints were assessed, drug changes were made in 118 patients, 9 patients were determined to be unable to get their drugs, and 12 who misused their drugs. The main advantage of the telemedicine declared by the patients was "not to waste time for transportation." The main concerns of the participants were inability to perform physical and laboratory examinations. Conclusion: Consequently, we considered telemedicine as a feasible alternative not only during pandemics but also in daily practice in Turkey.

Diagnostic Modalities Based on Flow Cytometry for Chronic Granulomatous Disease: A Multicenter Study in a Well-Defined Cohort.

BACKGROUND: Chronic granulomatous disease (CGD) is characterized by defective microbial killing due to mutations affecting subunits of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex. Definitive genetic identification of disease subtypes may be delayed or not readily available. OBJECTIVE: Sought to investigate the role of intracellular staining of NADPH oxidase enzyme subunits in predicting the respective genetic defects in patients with CGD and carriers. METHODS: Thirty-four patients with genetically inherited CGD, including 12 patients with X-linked CGD (gp91phagocyte oxidase (phox) deficiency due to cytochrome b-245, beta polypeptide [CYBB] mutations) and 22 patients with autosomal-recessive CGD (p22phox, p47phox, and p67phox deficiency due to cytochrome b-245, alpha polypeptide [CYBA], neutrophil cytosolic factor 1 [NCF1] and NCF2 mutations, respectively) were recruited from different immunology centers and followed up prospectively. Dihydrorhodamine testing and NADPH oxidase subunit expression in white blood cells were determined by flow cytometry. RESULTS: gp91phox and p22phox defects, which result in simultaneous loss of both proteins due to their complex formation, were differentiated only by comparative analysis of patients' and mothers' intracellular staining. p47phox and p67phox protein expression was almost undetectable in patients compared with carrier mothers and healthy controls. The expression values of the respective subunits were found to be significantly higher in all controls as compared with carrier mothers, which in turn were higher than those of patients. CONCLUSIONS: Analysis of NADPH oxidase enzyme subunits by flow cytometry in patients and carriers is useful in the rapid prediction of the genetic defect of patients with CGD, thus guiding targeted sequencing and aiding in their early diagnosis.