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.

Comparison of refugee patients with cystic fibrosis and their counterpart children from Turkey during the war.

Since the outbreak of the Syrian civil war in 2011, the population of Arab refugees in Turkey has rapidly increased. While cystic fibrosis (CF) is believed to be rare among Arabs, recent studies suggest it is underdiagnosed. This study aims to present the demographic, clinical, and genetic characteristics of CF patients among Arab refugees in Turkey. Additionally, a comparison is made between the findings in the National CF Registry 2021 in Turkey (NCFRT) and the refugee CF patient group. The study included refugee patients between the ages of 0 and 18 years who were diagnosed with CF and received ongoing care at pediatric pulmonology centers from March 2011 to March 2021. The study examined demographic information, age at diagnosis, age of diagnosis of patients through CF newborn screening (NBS), presenting symptoms, CF transmembrane conductance regulator (CFTR) mutation test results, sputum culture results, weight, height, and body mass index (BMI) z score. Their results were compared with the NCFRT results. The study included 14 pediatric pulmonology centers and 87 patients, consisting of 46 (52.9%) boys and 41 (47.1%) girls. All of the patients were Arab refugees, with 80 (92%) being Syrian. All the patients were diagnosed in Turkey. The median age at diagnosis of patients was 22.33 (interquartile range, 1-258) months. The median age of diagnosis of patients through NBS was 4.2 (interquartile range, 1-12) months. The median age of older patients, who were unable to be included in the NBS program, was 32.3 (interquartile range, 3-258) months. Parental consanguinity was observed in 52 (59.7%) patients. The mutation that was most frequently found was F508del, which accounted for 22.2% of the cases. It was present in 20 patients, constituting 32 out of the total 144 alleles. There was a large number of genetic variations. CFTR genotyping could not be conducted for 12 patients. These patients had high sweat tests, and their genetic mutations could not be determined due to a lack of data. Compared to NCFRT, refugee patients were diagnosed later, and long-term follow-up of refugee CF patients had significantly worse nutritional status and pseudomonas colonization.  Conclusion: Although refugee CF patients have equal access to NBS programs and CF medications as well as Turkish patients, the median age at diagnosis of patients, the median age of diagnosis of patients through NBS, their nutritional status, and Pseudomonas colonization were significantly worse than Turkish patients, which may be related to the difficulties of living in another country and poor living conditions. The high genetic heterogeneity and rare mutations detected in the refugee patient group compared to Turkish patients. Well-programmed NBS programs, thorough genetic studies, and the enhancement of living conditions for refugee patients in the countries they relocate to can have several advantages such as early detection and improved prognosis. What is Known: • Children who have chronic diseases are the group that is most affected by wars. • The outcome gets better with early diagnosis and treatment in patients with Cystic Fibrosis (CF). What is New: • Through the implementation of a newborn screening program, which has never been done in Syria previously, refugee patients, the majority of whom are Syrians were diagnosed with cystic fibrosis within a duration of 4 months. • Despite equal access to the newborn screening program and CF medications for both Turkish patients and refugee patients, the challenges of living in a foreign country have an impact on refugees.

Childhood interstitial lung disease in Turkey: first data from the national registry.

The childhood interstitial lung diseases (chILD) Turkey registry (chILD-TR) was established in November 2021 to increase awareness of disease, and in collaboration with the centers to improve the diagnostic and treatment standards. Here, the first results of the chILD registry system were presented. In this prospective cohort study, data were collected using a data-entry software system. The demographic characteristics, clinical, laboratory, radiologic findings, diagnoses, and treatment characteristics of the patients were evaluated. Clinical characteristics were compared between two main chILD groups ((A) diffuse parenchymal lung diseases (DPLD) disorders manifesting primarily in infancy [group1] and (B) DPLD disorders occurring at all ages [group 2]). There were 416 patients registered from 19 centers. Forty-six patients were excluded due to missing information. The median age of diagnosis of the patients was 6.05 (1.3-11.6) years. Across the study population (n = 370), 81 (21.8%) were in group 1, and 289 (78.1%) were in group 2. The median weight z-score was significantly lower in group 1 (- 2.0 [- 3.36 to - 0.81]) than in group 2 (- 0.80 [- 1.7 to 0.20]) (p < 0.001). When we compared the groups according to chest CT findings, ground-glass opacities were significantly more common in group 1, and nodular opacities, bronchiectasis, mosaic perfusion, and mediastinal lymphadenopathy were significantly more common in group 2. Out of the overall study population, 67.8% were undergoing some form of treatment. The use of oral steroids was significantly higher in group 2 than in group 1 (40.6% vs. 23.3%, respectively; p = 0.040).   Conclusion: This study showed that national registry allowed to obtain information about the frequency, types, and treatment methods of chILD in Turkey and helped to see the difficulties in the diagnosis and management of these patients. What is Known: • Childhood interstitial lung diseases comprise many diverse entities which are challenging to diagnose and manage. What is New: • This study showed that national registry allowed to obtain information about the frequency, types and treatment methods of chILD in Turkey and helped to see the difficulties in the diagnosis and management of these patients. Also, our findings reveal that nutrition should be considered in all patients with chILD, especially in A-DPLD disorders manifesting primarily in infancy.

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.

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.

Clinical and subclinical acute kidney injury in children with mild-to-moderate COVID-19.

BACKGROUND: Our aim was to identify acute kidney injury (AKI) and subacute kidney injury using both KDIGO criteria and urinary biomarkers in children with mild/moderate COVID-19. METHODS: This cross-sectional study included 71 children who were hospitalized with a diagnosis of COVID-19 from 3 centers in Istanbul and 75 healthy children. We used a combination of functional (serum creatinine) and damage (NGAL, KIM-1, and IL-18) markers for the definition of AKI and subclinical AKI. Clinical and laboratory features were evaluated as predictors of AKI and subclinical AKI. RESULTS: Patients had significantly higher levels of urinary biomarkers and urine albumin-creatinine ratio than healthy controls (p < 0.001). Twelve patients (16.9%) developed AKI based on KDIGO criteria, and 22 patients (31%) had subclinical AKI. AKI group had significantly higher values of neutrophil count on admission than both subclinical AKI and non-AKI groups (p < 0.05 for all). Neutrophil count was independently associated with the presence of AKI (p = 0.014). CONCLUSIONS: This study reveals that even children with a mild or moderate disease course are at risk for AKI. Association between neutrophil count and AKI may point out the role of inflammation in the development of AKI. IMPACT: The key message of our article is that not only children with severe disease but also children with mild or moderate disease have an increased risk for kidney injury due to COVID-19. Urinary biomarkers enable the diagnosis of a significant number of patients with subclinical AKI in patients without elevation in serum creatinine. Our findings reveal that patients with high neutrophil count may be more prone to develop AKI and should be followed up carefully. We conclude that even children with mild or moderate COVID-19 disease courses should be evaluated for AKI and subclinical AKI, which may improve patient outcomes.

Humoral and cellular immune response to SARS-CoV-2 mRNA BNT162b2 vaccine in pediatric kidney transplant recipients compared with dialysis patients and healthy children.

BACKGROUND: Compared with the general population, the immune response to COVID-19 mRNA vaccines is lower in adult kidney transplant recipients (KTRs). However, data is limited for pediatric KTRs. In this study, we aimed to assess humoral and cellular immune responses to the COVID-19 mRNA vaccine in pediatric KTRs. METHODS: This multicenter, prospective, case-control study included 63 KTRs (37 male, aged 12-21 years), 19 dialysis patients, and 19 controls. Humoral (anti-SARS-CoV2 IgG, neutralizing Ab (nAb)) and cellular (interferon-gamma release assay (IGRA)) immune responses were assessed at least one month after two doses of BNT162b2 mRNA vaccine. RESULTS: Among COVID-19 naïve KTRs (n = 46), 76.1% tested positive for anti-SARS-CoV-2 IgG, 54.3% for nAb, and 63% for IGRA. Serum levels of anti-SARS-CoV-2 IgG and nAb activity were significantly lower in KTRs compared to dialysis and control groups (p < 0.05 for all). Seropositivity in KTRs was independently associated with shorter transplant duration (p = 0.005), and higher eGFR (p = 0.007). IGRA titer was significantly lower than dialysis patients (p = 0.009). Twenty (43.4%) KTRs were positive for all immune parameters. Only four of 11 seronegative KTRs were IGRA-positive. COVID-19 recovered KTRs had significantly higher anti-SARS-CoV-2 IgG and nAb activity levels than COVID-19 naïve KTRs (p = 0.018 and p = 0.007, respectively). CONCLUSIONS: The humoral and cellular immune responses to SARS-CoV-2 mRNA BNT162b2 vaccine are lower in pediatric KTRs compared to dialysis patients. Further prospective studies are required to demonstrate the clinical efficacy of the mRNA vaccine in KTRs. This prospective study was registered in ClinicalTrials.gov (NCT05465863, registered retrospectively at 20.07.2022). A higher resolution version of the Graphical abstract is available as Supplementary information.

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.

Evaluation of pediatric patients with suspected polyethylene glycol and polysorbate allergy before mRNA SARS-CoV2 vaccination.

mRNA vaccines, particularly, have been associated with an increased risk of allergic reactions and rarely anaphylaxis. Although rare, vaccine reactions can cause significant anxiety and fear in the population, leading to indecision and vaccine refusal. This study aimed to retrospectively evaluate the role of polyethylene glycol (PEG) sensitivity in vaccination decision-making in pediatric patients at high risk of allergy or with suspected allergic reactions to the first dose of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) vaccine. Seventeen enrolled patients were found to have decreased readiness to receive the Coronavirus Disease 2019 (COVID-19) vaccine after developing hypersensitivity to multiple and/or injectable drugs. Skin testing was performed. A basophil activation test with PEG-2000 and 4000 was performed on three patients who were ineligible for skin prick tests. Nine patients with negative tests received the vaccine without complications. One patient had urticarial angioedema despite negative tests. Three patients with positive tests did not agree to desensitization with the mRNA vaccine, and one of them was vaccinated with the inactivated COVID-19 vaccine. Four patients recurred despite negative tests. The general recommendation for patients describing severe reactions to drugs, foods, and allergens, such as toxins that do not contain the adjuvants of the SARS-CoV-2 vaccines, is to be routinely vaccinated with safety precautions. Excipients such as PEG and polysorbate-80 used in COVID-19 vaccines could be potential allergens, but this hypothesis is unclear. The predictive values of these adjuvants for skin testing and in vitro testing are controversial. Further research is needed on the hypersensitivity reactions of adjuvants, the predictive values of skin tests, and etiopathogenesis.

[Analysis of IFN-γR1 (CD119) and IL-12Rß1 (CD212) Deficiency by Flow Cytometry]. / IFN-γR1 (CD119) ve IL-12Rß1 (CD212) Eksikliginin Akan Hücre Ölçer ile Analizi.

Mendelian susceptibility to mycobacterial diseases (MSMD) is a rare primary immune deficiency (PID). IL-12Rß1 deficiency is the most frequently observed of more than 16 genetic defects that have been identified for MSMD. Genetic and immunological tests are remarkable in the diagnosis of PID. In this study, it was aimed to determine the expression of IFN-γR1 and IL-12Rß1 in patients with MSMD, their relatives, and healthy individuals and to evaluate the importance of flow cytometry as a fast and reliable method in the diagnosis of MSMD. IFN-γR1 and IL-12Rß1 expression levels were analyzed in 32 volunteers including six patients, six relatives, and 20 healthy individuals. The normal range of IFN-γR1 and IL-12Rß1 levels among healthy individuals were determined. IL-12Rß1 expression level in lymphocytes was found to be low in one patient's relative, and less than 1% in three patients and in one patient's relative. It was observed that the IL-12Rß1 expression levels of the patient with STAT1 deficiency were increased compared to the healthy individuals. No difference was found in the expression levels of IFN-γR1 and IL-12Rß1 in one patient, but IFN-γR1 expression was decreased in one patient compared to healthy individuals. Our results show that the determination of IL-12Rß1 and IFN-γR1 deficiencies by flow cytometry can be used as a rapid and reliable method for the diagnosis of MSMD. The use of this method as a screening test will enable early diagnosis especially in patients whose genetic diagnosis has not been confirmed and clinically compatible with MSMD. In addition, it is thought that IL-12Rß1 and IFN-γR1 range data obtained from healthy individuals will be considered as a reference source in routine and research studies to be conducted with MSMD.

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.

Adverse COVID-19 outcomes in immune deficiencies: Inequality exists between subclasses.

BACKGROUND: Genetic deficiencies of immune system, referred to as inborn errors of immunity (IEI), serve as a valuable model to study human immune responses. In a multicenter prospective cohort, we evaluated the outcome of SARS-CoV-2 infection among IEI subjects and analyzed genetic and immune characteristics that determine adverse COVID-19 outcomes. METHODS: We studied 34 IEI patients (19M/15F, 12 [min: 0.6-max: 43] years) from six centers. We diagnosed COVID-19 infection by finding a positive SARS-CoV-2 PCR test (n = 25) and/or a lung tomography scoring (CORADS) ≥4 (n = 9). We recorded clinical and laboratory findings prospectively, fitted survival curves, and calculated fatality rates for the entire group and each IEI subclass. RESULTS: Nineteen patients had combined immune deficiency (CID), six with predominantly antibody deficiency (PAD), six immune dysregulation (ID), two innate immune defects, and one in the autoinflammatory class. Overall, 23.5% of cases died, with disproportionate fatality rates among different IEI categories. PAD group had a relatively favorable outcome at any age, but CIDs and IDs were particularly vulnerable. At admission, presence of dyspnea was an independent risk for COVID-related death (OR: 2.630, 95% CI; 1.198-5.776, p < .001). Concerning predictive roles of laboratory markers at admission, deceased subjects compared to survived had significantly higher CRP, procalcitonin, Troponin-T, ferritin, and total-lung-score (p = .020, p = .003, p = .014, p = .013, p = .020; respectively), and lower absolute lymphocyte count, albumin, and trough IgG (p = .012, p = .022, p = .011; respectively). CONCLUSION: Our data disclose a highly vulnerable IEI subgroup particularly disadvantaged for COVID-19 despite their youth. Future studies should address this vulnerability and consider giving priority to these subjects in SARS-Cov-2 therapy trials.

Comparing the levels of CTLA-4-dependent biological defects in patients with LRBA deficiency and CTLA-4 insufficiency.

BACKGROUND: Lipopolysaccharide-responsive beige-like anchor protein (LRBA) deficiency and cytotoxic T-lymphocyte protein-4 (CTLA-4) insufficiency are recently described disorders that present with susceptibility to infections, autoimmunity, and lymphoproliferation. Clinical and immunological comparisons of the diseases with long-term follow-up have not been previously reported. We sought to compare the clinical and laboratory manifestations of both diseases and investigate the role of flow cytometry in predicting the genetic defect in patients with LRBA deficiency and CTLA-4 insufficiency. METHODS: Patients were evaluated clinically with laboratory assessments for lymphocyte subsets, T follicular helper cells (TFH ), LRBA expression, and expression of CD25, FOXP3, and CTLA4 in regulatory T cells (Tregs) at baseline and 16 h post-stimulation. RESULTS: LRBA-deficient patients (n = 29) showed significantly early age of symptom onset, higher rates of pneumonia, autoimmunity, chronic diarrhea, and failure to thrive compared to CTLA-4 insufficiency (n = 12). In total, 29 patients received abatacept with favorable responses and the overall survival probability was not different between transplanted versus non-transplanted patients in LRBA deficiency. Meanwhile, higher probability of survival was observed in CTLA-4-insufficient patients (p = 0.04). The T-cell subsets showed more deviation to memory cells in CTLA-4-insufficiency, accompanied by low percentages of Treg and dysregulated cTFH cells response in both diseases. Cumulative numbers of autoimmunities positively correlated with cTFH frequencies. Baseline CTLA-4 expression was significantly diminished in LRBA deficiency and CTLA-4 insufficiency, but significant induction in CTLA-4 was observed after short-term T-cell stimulation in LRBA deficiency and controls, while this elevation was less in CTLA-4 insufficiency, allowing to differentiate this disease from LRBA deficiency with high sensitivity (87.5%) and specificity (90%). CONCLUSION: This cohort provided detailed clinical and laboratory comparisons for LRBA deficiency and CTLA-4 insufficiency. The flow cytometric approach is useful in predicting the defective gene; thus, targeted sequencing can be conducted to provide rapid diagnosis and treatment for these diseases impacting the CTLA-4 pathway.

Evolution and long-term outcomes of combined immunodeficiency due to CARMIL2 deficiency.

BACKGROUND: Biallelic loss-of-function mutations in CARMIL2 cause combined immunodeficiency associated with dermatitis, inflammatory bowel disease (IBD), and EBV-related smooth muscle tumors. Clinical and immunological characterizations of the disease with long-term follow-up and treatment options have not been previously reported in large cohorts. We sought to determine the clinical and immunological features of CARMIL2 deficiency and long-term efficacy of treatment in controlling different disease manifestations. METHODS: The presenting phenotypes, long-term outcomes, and treatment responses were evaluated prospectively in 15 CARMIL2-deficient patients, including 13 novel cases. Lymphocyte subpopulations, protein expression, regulatory T (Treg), and circulating T follicular helper (cTFH ) cells were analyzed. Three-dimensional (3D) migration assay was performed to determine T-cell shape. RESULTS: Mean age at disease onset was 38 ± 23 months. Main clinical features were skin manifestations (n = 14, 93%), failure to thrive (n = 10, 67%), recurrent infections (n = 10, 67%), allergic symptoms (n = 8, 53%), chronic diarrhea (n = 4, 27%), and EBV-related leiomyoma (n = 2, 13%). Skin manifestations ranged from atopic and seborrheic dermatitis to psoriasiform rash. Patients had reduced proportions of memory CD4+ T cells, Treg, and cTFH cells. Memory B and NK cells were also decreased. CARMIL2-deficient T cells exhibited reduced T-cell proliferation and cytokine production following CD28 co-stimulation and normal morphology when migrating in a high-density 3D collagen gel matrix. IBD was the most severe clinical manifestation, leading to growth retardation, requiring multiple interventional treatments. All patients were alive with a median follow-up of 10.8 years (range: 3-17 years). CONCLUSION: This cohort provides clinical and immunological features and long-term follow-up of different manifestations of CARMIL2 deficiency.

COVID-19 Disease in Presenting to the Pediatric Emergency Department: A Multicenter Study of 8886 Cases.

BACKGROUND: The aim was to evaluate the epidemiological, clinical, laboratory, and radiologic data of children with SARS-CoV-2 positivity by polymerase chain reaction (PCR) together with treatment strategies and clinical outcomes and to evaluate cases of multisystem inflammatory syndrome in children (MIS-C) in this population. METHODS: This was a multicenter retrospective observational cohort study performed in the pediatric emergency departments of 19 tertiary hospitals. From March 11, 2020, to May 31, 2021, children who were diagnosed with confirmed nasopharyngeal/tracheal specimen SARS-CoV-2 PCR positivity or positivity for serum-specific antibodies against SARS-CoV-2 were included. Demographics, presence of chronic illness, symptoms, history of contact with SARS-CoV-2 PCR-positive individuals, laboratory and radiologic investigations, clinical severity, hospital admissions, and prognosis were recorded. RESULTS: A total of 8886 cases were included. While 8799 (99.0%) cases resulted in a diagnosis of SARS-CoV-2 with PCR positivity, 87 (1.0%) patients were diagnosed with MIS-C. Among SARS-CoV-2 PCR-positive patients, 51.0% were male and 8.5% had chronic illnesses. The median age was 11.6 years (IQR: 5.0-15.4) and 737 (8.4%) patients were aged <1 year. Of the patients, 15.5% were asymptomatic. The most common symptoms were fever (48.5%) and cough (30.7%) for all age groups. There was a decrease in the rate of fever as age increased (p < 0.001); the most common age group for this symptom was <1 year with the rate of 69.6%. There was known contact with a SARS-CoV-2 PCR-positive individual in 67.3% of the cases, with household contacts in 71.3% of those cases. In terms of clinical severity, 83 (0.9%) patients were in the severe-critical group. There was hospital admission in 1269 (14.4%) cases, with 106 (1.2%) of those patients being admitted to the pediatric intensive care unit (PICU). Among patients with MIS-C, 60.9% were male and the median age was 6.4 years (IQR: 3.9-10.4). Twelve (13.7%) patients presented with shock. There was hospital admission in 89.7% of these cases, with 29.9% of the patients with MIS-C being admitted to the PICU. CONCLUSION: Most SARS-CoV-2 PCR-positive patients presented with a mild clinical course. Although rare, MIS-C emerges as a serious consequence with frequent PICU admission. Further understanding of the characteristics of COVID-19 disease could provide insights and guide the development of therapeutic strategies for target groups.

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.

Altered immune response in organic acidemia.

BACKGROUND: Most patients with organic acidemia suffer from recurrent infections. Although neutropenia has been reported in multiple studies, other components of the immune system have not been evaluated thoroughly. This study was conducted to assess the immune status of patients with organic acidemia (OA). METHODS: Thirty-three patients with OA who were followed up in Istanbul University-Cerrahpasa, Cerrahpasa School of Medicine, Nutrition and Metabolism Department and a total of 32 age- and sex-matched healthy controls were enrolled to the study. The demographic and clinical data were recorded retrospectively from patient files. Complete blood counts, immunoglobulins, and lymphocyte immunophenotyping were recorded prospectively in a symptom- (infection-) free period. RESULTS: Of the 33 patients enrolled to the study, 21 (88%) were diagnosed with methylmalonic acidemia, 10 (33%) with propionic acidemia, and two (6.6%) with isovaleric acidemia. The mean age of the patients with OA and healthy subjects were 5.89 ± 4.11 years and 5.34 ± 4.36, respectively (P = 0.602). Twenty-nine (88%) of the patients had experienced frequent hospital admission, 13 (39%) were admitted to pediatric intensive care unit, and 18 (55%) suffered from sepsis. Naïve helper T cells and recent thymic emigrants were significantly lower in OAs (P < 0.001). Various defects in humoral immunity have also been documented including memory B cells and immunoglobulins. CONCLUSIONS: Patients with OAs may show adaptive immune defects rendering them susceptible to infections. Metabolic reprogramming based on nutritional modifications may be a promising therapeutic option in the future.

The effects of nusinersen treatment on respiratory status of children with spinal muscular atrophy.

BACKGROUND: Respiratory involvement is the main factor predicting the prognosis of spinal muscular atrophy (SMA). Significant responses in motor functions have been demonstrated with nusinersen, but pulmonary outcomes are still varied. We aimed to explore the effects of nusinersen on the respiratory functions of patients with SMA. METHODS: Patients with SMA who were receiving regular nusinersen treatment in our tertiary care hospital were enrolled in this study. We evaluated the patients in terms of the necessity to ventilatory or nutritional support, presence of motor involvement and other comorbidities related with prognosis at three consecutive assessments. RESULTS: The study group consisted of 43 patients (18 type 1, 12 type 2, and 13 type 3) with SMA with a mean age of 27.8 months at diagnosis and 60.8 months at the beginning of nusinersen treatment. The respiratory function improvements were noted in six patients at third assessment. Early initiation of nusinersen was significantly correlated with reduced hospital admissions (P = 0.026). Nutritional support and weight gain were remarkable in the ventilatory-supported group. Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders scores were significantly higher in the non-tracheostomized group in patients with SMA type 1 (P < 0.005). CONCLUSIONS: We posit that nusinersen may change the natural prognosis of SMA and improve care of children with SMA. Following up children with SMA for longer periods under nusinersen may be beneficial for understanding the effects of treatment. Results of our study need to be supported by future long-term studies to reach a consensus on nusinersen, considering the overall genetic and environmental status as well as the cost-effectiveness of the treatment.

Diagnosis of primary immunodeficiency diseases in pediatric patients hospitalized for recurrent, severe, or unusual infections.

BACKGROUND: Primary immunodeficiency diseases (PID) usually presents itself with recurrent, severe, and unusual infections, along with autoimmunity and various other malignancies. But, the diversity of PID often makes the diagnosis of patients difficult for physicians other than clinical immunologists. This study aimed to describe the characteristics of patients diagnosed with PIDs during the inpatient treatment for infectious diseases, and to highlight the cases in which a PID diagnosis should be considered. METHODS: The clinical, immunological, and molecular features of 81 pediatric patients treated for infectious diseases, who were diagnosed with a PID during hospitalization was retrospectively analyzed. The diagnosis was based on the PID criteria of the International Union of Immunological Societies. RESULTS: The five main PID sub-types were identified. Predominantly, antibody deficiencies were the most common (61.7%) group. The average delay in diagnosis was 34.6 months, and the positive family history rate was 24.7%, while the consanguineous marriage rate was 45.7%. Around thirty-five (43%) patients were found to have mutated PID-related genes. While lower respiratory tract infections were the most common symptom, a fever of unknown origin was another remarkable diagnosis. Eight (9.9%) patients underwent allogeneic hematopoietic stem cell transplantation. CONCLUSIONS: Clinicians should consider a PID diagnosis, especially in the cases of recurrent, severe, or atypical infections. Increased knowledge of the alarm features of PID can promote early diagnosis.