Primary immune regulatory disorders (PIRD): expanding the mutation spectrum in Turkey and identification of sixteen novel variants.

Human Inborn Errors of Immunity (IEIs) encompass a clinically and genetically heterogeneous group of disorders, ranging from mild cases to severe, life-threatening types. Among these, Primary Immune Regulatory Disorders (PIRDs) constitute a subset of IEIs characterized by diverse clinical phenotypes, prominently featuring severe atopy, autoimmunity, lymphoproliferation, hyperinflammation, autoinflammation, and susceptibility to malignancies. According to the latest report from the International Union of Immunological Societies (IUIS), PIRDs arise from mutations in various genes including LYST, RAB27A, AP3B1, AP3D1, PRF1, UNC13D, STX11, STXBP2, FAAP24, SLC7A7, RASGRP1, CD70, CTPS1, RLTPR, ITK, MAGT1, PRKCD, TNFRSF9, SH2DIA, XIAP, CD27 (TNFRSF7), FAS (TNFRSF6), FASLG (TNFSF6), CASP10, CASP8, FADD, LRBA, STAT3, AIRE, ITCH, ZAP70, TPP2, JAK1, PEPD, FOXP3, IL2RA, CTLA4, BACH2, IL2RB, DEF6, FERMT1, IL10, IL10RA, IL10RB, NFAT5, TGFB1, and RIPK1 genes. We designed a targeted next-generation sequencing (TNGS) workflow using the Ion AmpliSeq™ Primary Immune Deficiency Research Panel to sequence 264 genes associated with IEIs on the Ion S5™ Sequencer. In this study, we report the identification of 38 disease-causing variants, including 16 novel ones, detected in 40 patients across 15 distinct PIRD genes. The application of next-generation sequencing enabled rapid and precise diagnosis of patients with PIRDs.

Successful management of delayed-onset adenosine deaminase deficiency with novel mutation.

A 4-year-old boy presented with acute-onset autoimmune cytopenia with severe, persistent lymphopenia, autoimmune thyroiditis, elevated IgE and glucose 6-phosphate dehydrogenase enzyme deficiency. In immunologic evaluation, lower T, B and natural killer cells and higher levels of adenosine deaminase (ADA) metabolites were observed. The compound heterozygous novel ADA gene mutations causing ADA deficiency were detected. Successful immunologic and metabolic cure was achieved with enzyme replacement therapy, followed by reduced intensity conditioning hematopoietic stem cell transplantation from a matched unrelated donor. An interesting aspect of this patient is the detection of novel compound heterozygous mutations without consanguinity and a secondary outcome is the recovery of glucose 6-phosphate dehydrogenase deficiency after hematopoietic stem cell transplantation.

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.

Atypical Localization of Eczema Discriminates DOCK8 or STAT3 Deficiencies from Atopic Dermatitis.

PURPOSE: Autosomal recessive dedicator of cytokinesis 8 (DOCK8-/-) and autosomal dominant signal transducer and activator of transcription 3 (STAT3-/+) deficiencies are inborn errors of immunity (IEI) disorders present with the classic features of eczema and create a dilemma during differentiation from atopic dermatitis (AD). Therefore, an appropriate approach is required for eczema to diagnose DOCK8-/- and STAT3-/+ early. Here, we described a set of clinical and immunological variables, including atypical AD localizations and lymphocyte subsets, to differentiate DOCK8-/- or STAT3-/+ from AD. METHODS: This multicenter study involved 100 patients with DOCK8-/- and STAT3-/+ and moderate/severe AD. We recruited disease manifestations, including detailed localizations of eczema, infections, and allergy. Principle component analysis (PCA) was used to discriminate DOCK8-/- or STAT3-/+ from AD. RESULTS: There were 43 patients with DOCK8-/-, 23 with STAT3-/+, and 34 with AD. Pneumonia, severe infections, mucocutaneous candidiasis, and skin abscesses were commonly observed in DOCK8 and STAT3 deficiencies. Atypical skin involvement with neonatal rash, retro auricular, axillary, sacral, and genital eczema discriminate DOCK8-/- and STAT3-/+ from AD with high specificity ranges between 73.5 and 94.1% and positive predictive index ranges between 55 and 93.1%. Together with using absolute numbers of CD3+, CD4+, and CD8+ T cells, the combined clinical and laboratory features showed perfect differentiation between DOCK8-/- or STAT3-/+ and AD via PCA. CONCLUSIONS: The described features can be easily implemented by physicians providing early diagnosis of DOCK8 and STAT3 deficiencies.

Defective Treg generation and increased type 3 immune response in leukocyte adhesion deficiency 1.

In 15 Turkish LAD-1 patients and controls, we assessed the impact of pathogenic ITGB2 mutations on Th17/Treg differentiation and functions, and innate lymphoid cell (ILC) subsets. The percentage of peripheral blood Treg cells, in vitro-generated induced Tregs differentiated from naive CD4+ T cells were decreased despite the elevated absolute counts of CD4+ cells in LAD-1 patients. Serum IL-23 levels were elevated in LAD-1 patients. Post-curdlan stimulation, LAD-1 patient-derived PBMCs produced more IL-17A. Additionally, the percentages of CD18-deficient Th17 cells expanded from total or naïve CD4+ T cells were higher. The blood ILC3 subset was significantly elevated in LAD-1. Finally, LAD-1 PBMCs showed defects in trans-well migration and proliferation and were more resistant to apoptosis. Defects in de novo generation of Tregs from CD18-deficient naïve T cells and elevated Th17s, and ILC3s in LAD-1 patients' peripheral blood suggest a type 3-skewed immunity and may contribute to LAD-1-associated autoimmune symptoms.

CD4+CD25+CD127loFOXP3+ cell in food allergy: Does it predict anaphylaxis?

BACKGROUND: Food allergy (FA), hence the incidence of food anaphylaxis, is a public health problem that has increased in recent years. There are still no biomarkers for patients with FA to predict severe allergic reactions such as anaphylaxis. OBJECTIVE: There is limited information on whether regulatory T (Treg) cell levels are a biomarker that predicts clinical severity in cases presenting with FA, and which patients are at a greater risk for anaphylaxis. METHODS: A total of 70 children were included in the study: 25 who had IgE-mediated cow's milk protein allergy (CMPA) and presented with non-anaphylactic symptoms (FA/A-), 16 who had IgE-mediated CMPA and presented with anaphylaxis (FA/A+) (a total of 41 FA cases), and a control group consisting of 29 children without FA. The study was conducted by performing CD4+CD25+CD127loFOXP3+ cell flow cytometric analysis during resting at least 2 weeks after the elimination diet to FA subjects. RESULTS: When the FA group was compared with healthy control subjects, CD4+CD25+CD127loFOXP3+ cell rates were found to be significantly lower in the FA group (p < 0.001). When the FA/A- and FA/A+ groups and the control group were compared in terms of CD4+CD25+CD127loFOXP3+ cell ratios, they were significantly lower in the FA/A- and FA/A+ groups compared to the control group (p < 0.001). CONCLUSIONS: Although there was no significant difference between the FA/A+ group and the FA/A- group in terms of CD4+CD25+CD127loFOXP3+ cells, our study is important, as it is the first pediatric study we know to investigate whether CD4+CD25+CD127loFOXP3+ cells in FA predict anaphylaxis.

CD4+CD25+CD127loFOXP3+ cell in food allergy: Does it predict anaphylaxis?

Background: Food allergy (FA), hence the incidence of food anaphylaxis, is a public health problem that has increased in recent years. There are still no biomarkers for patients with FA to predict severe allergic reactions such as anaphylaxis. Objective: There is limited information on whether regulatory T (Treg) cell levels are a biomarker that predicts clinical severity in cases presenting with FA, and which patients are at a greater risk for anaphylaxis. Methods: A total of 70 children were included in the study: 25 who had IgE-mediated cow’s milk protein allergy (CMPA) and presented with non-anaphylactic symptoms (FA/A−), 16 who had IgE-mediated CMPA and presented with anaphylaxis (FA/A+) (a total of 41 FA cases), and a control group consisting of 29 children without FA. The study was conducted by performing CD4+CD25+CD127loFOXP3+ cell flow cytometric analysis during resting at least 2 weeks after the elimination diet to FA subjects. Results: When the FA group was compared with healthy control subjects, CD4+CD25+CD127loFOXP3+ cell rates were found to be significantly lower in the FA group (p < 0.001). When the FA/A− and FA/A+ groups and the control group were compared in terms of CD4+CD25+CD127loFOXP3+ cell ratios, they were significantly lower in the FA/A− and FA/A+ groups compared to the control group (p < 0.001). Conclusions: Although there was no significant difference between the FA/A+ group and the FA/A− group in terms of CD4+CD25+CD127loFOXP3+ cells, our study is important, as it is the first pediatric study we know to investigate whether CD4+CD25+CD127loFOXP3+ cells in FA predict anaphylaxis (AU)

The Middle East and North Africa Diagnosis and Management Guidelines for Inborn Errors of Immunity.

Human inborn errors of immunity (IEI) are a group of 485 distinct genetic disorders affecting children and adults. Signs and symptoms of IEI are heterogeneous, and accurate diagnosis can be challenging and depends on the available human expertise and laboratory resources. The Middle East and North Africa (MENA) region has an increased prevalence of IEI because of the high rate of consanguinity with a predominance of autosomal recessive disorders. This area also exhibits more severe disease phenotypes compared with other regions, probably due to the delay in diagnosis. The MENA-IEI registry network has designed protocols and guidelines for the diagnosis and treatment of IEI, taking into consideration the variable regional expertise and resources. These guidelines are primarily meant to improve the care of patients within the region, but can also be followed in other regions with similar patient populations.

Eight years of follow-up experience in children with mendelian susceptibility to mycobacterial disease and review of the literature.

BACKGROUND: Mendelian susceptibility to mycobacterial disease (MSMD) is a rare primary immunodeficiency, caused by non-tuberculous mycobacteria or Bacillus Calmette-Guerin (BCG) vaccine and characterized by severe diseases in childhood. OBJECTIVE: In this study, we examined eight years followed-up 12 Turkish children with genetically proven MSMD and we tried to evaluate the survival rate with succesfull disease management, rate of consanguinity, molecular, cellular and clinical features of patients. In addition, we wanted to emphasize the importance of early diagnosis before administration of BCG vaccine in countries where this vaccine is routinely used. METHODS: Twelve patients diagnosed with molecular studies [IFNγR1 complete (n = 1), IFNγR2 partial (n = 3), IL12Rß1 (n = 6), NEMO (n = 1), STAT1 mutation (n = 1)] were included. RESULTS: Ten patients (83%) were born from consanguineous parents and frequency of family history for the primary immunodeficiency was 58% (n = 7). All the cases had been immunized with BCG vaccine (Mycobacterium bovis) due to lack of early diagnosis. Two patients had BCG-itis and four patients had "BCG-osis". Survival rate was 75% after successful disease management with antibiotics, anti-tuberculous agents and recombinant IFN-γ. CONCLUSIONS: It was concluded that MSMD must be differentiated from different forms of primary immunodeficiencies, so clinicians should be aware of MSMD especially in patients with BCG vaccine complications and non-tuberculous mycobacterial infection.

Evaluation of children diagnosed with a lower respiratory tract infection due to Human metapneumovirus.

BACKGROUND: Human metapneumovirus (hMPV) is one of the leading causes of acute respiratory infections and bronchiolitis in infants. A history of prematurity and chronic diseases such as congenital heart disease or asthma/reactive airway disease (RAD) increases the risk of severe lower respiratory tract infection (LRTI) due to hMPV. In this cross-sectional study, we aimed to analyze the clinical outcome and risk factors for severe disease in children with LRTI due to hMPV. METHODS: The current cross-sectional study included children between 28 days and 18 years of age with the diagnosis of hMPV-associated LRTI hospitalizations, over two years from January 2016 to September 2018 in Health Science University Dr. Behçet Uz Child Disease and Pediatric Surgery Training and Research Hospital. hMPV virus was detected by the multiplex polymerase chain test (PCR) (Commercial Multiplex Real-Time PCR: FTD Respiratory 21 plus, Fast Track Diagnostics, Luxembourg) from a nasopharyngeal swab. Patients who had positive results in multiplex PCR tests with other viral agents simultaneously were not included in the study. Data were retrospectively collected from the computerized hospital system. RESULTS: In this cross-sectional study, 62 patients who were hospitalized with the diagnosis of LRTI due to hMPV infection were included. Thirty-five (55.7%) of the patients were male. The median age was one year (2 months-15 years). Fifty-one (82.2%) patients were younger than two years. The median hospital length of stay was found to be 10 days (2-33 days) in patients with an underlying disease and 7,5 days (ranging from 2 to 20 days) in the patients without an underlying disease, this difference was significant (p=0.031). CONCLUSIONS: Clinicians should consider hMPV as an important pathogen of LRTI even in healthy children, although we expect a poor course of disease in children with an underlying disease.

Prevalence of Viruses in Acute Asthma Exacerbations in Childhood in a Hospital in West Part of Turkey.

Acute asthma exacerbations (AAE) are episodes characterized by potentially life-threatening and rapidly deteriorating asthma symptoms. Viral respiratory infections are one of the major triggers in the pathophysiology of childhood asthma exacerbations. In this study, we aimed to determine the distribution of viral agents among pediatric AAE patients. One hundred and three AAE patients, aged 5 or older, hospitalized between from February 2017 through February 2020 at Pediatric Immunology and Allergic Diseases Unit were included in this study. Fifty patients (48.5%) were female, and the mean age of the patients was 108.2 months. Viruses were detected in 58 (%56.3) of the patients, in 5 of whom more than one virus type was detected. The most commonly detected virus was human rhinovirus (n=43, 67.1%). Other types included respiratory syncytial virus (n=8; 12.5%), influenza (n=6; 9.3%), human metapneumovirus (n=4; 6.2%), adenovirus (n=1; 1.5%), enterovirus (n=1; 1.5%), and parainfluenza (n=1; 1.5%). Viral agents were detected in 29 out of the 47 patients with allergic asthma, with human rhinoviruses comprising the majority (18 patients). The mean length of hospital stay was 7.89 days. Human rhinovirus is the most common virus that triggers AAE, with similar distributions in allergic and non-allergic asthma. We found no correlation between virus type and the length of hospital stay.

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.

Severe combined immunodeficiencies: Expanding the mutation spectrum in Turkey and identification of 12 novel variants.

Human Inborn Errors of Immunity (IEIs) are clinically and genetically heterogeneous group of diseases, with relatively mild clinical course or severe types that can be life-threatening. Severe combined immunodeficiency (SCID) is the most severe form of IEIs, which is caused by monogenic defects that impair the proliferation and function of T, B, and NK cells. According to the most recent report by the International Union of Immunological Societies (IUIS), SCID is caused by mutations in IL2RG, JAK3, FOXN1, CORO1A, PTPRC, CD3D, CD3E, CD247, ADA, AK2, NHEJ1, LIG4, PRKDC, DCLRE1C, RAG1 and RAG2 genes. The targeted next-generation sequencing (TNGS) workflow based on Ion AmpliSeq™ Primary Immune Deficiency Research Panel was designed for sequencing 264 IEI-related genes on Ion S5™ Sequencer. Herein, we present 21 disease-causing variants (12 novel) which were identified in 22 patients in eight different SCID genes. Next-generation sequencing allowed a rapid and an accurate diagnosis SCID patients.

Consensus Middle East and North Africa Registry on Inborn Errors of Immunity.

BACKGROUND: Inborn errors of immunity (IEIs) are a heterogeneous group of genetic defects of immunity, which cause high rates of morbidity and mortality mainly among children due to infectious and non-infectious complications. The IEI burden has been critically underestimated in countries from middle- and low-income regions and the majority of patients with IEI in these regions lack a molecular diagnosis. METHODS: We analyzed the clinical, immunologic, and genetic data of IEI patients from 22 countries in the Middle East and North Africa (MENA) region. The data was collected from national registries and diverse databases such as the Asian Pacific Society for Immunodeficiencies (APSID) registry, African Society for Immunodeficiencies (ASID) registry, Jeffrey Modell Foundation (JMF) registry, J Project centers, and International Consortium on Immune Deficiency (ICID) centers. RESULTS: We identified 17,120 patients with IEI, among which females represented 39.4%. Parental consanguinity was present in 60.5% of cases and 27.3% of the patients were from families with a confirmed previous family history of IEI. The median age of patients at the onset of disease was 36 months and the median delay in diagnosis was 41 months. The rate of registered IEI patients ranges between 0.02 and 7.58 per 100,000 population, and the lowest rates were in countries with the highest rates of disability-adjusted life years (DALY) and death rates for children. Predominantly antibody deficiencies were the most frequent IEI entities diagnosed in 41.2% of the cohort. Among 5871 patients genetically evaluated, the diagnostic yield was 83% with the majority (65.2%) having autosomal recessive defects. The mortality rate was the highest in patients with non-syndromic combined immunodeficiency (51.7%, median age: 3.5 years) and particularly in patients with mutations in specific genes associated with this phenotype (RFXANK, RAG1, and IL2RG). CONCLUSIONS: This comprehensive registry highlights the importance of a detailed investigation of IEI patients in the MENA region. The high yield of genetic diagnosis of IEI in this region has important implications for prevention, prognosis, treatment, and resource allocation.

22q11.2 deletion syndrome: 20 years of experience from two pediatric immunology units and review of clues for diagnosis and disease management.

INTRODUCTION AND OBJECTIVES: The purpose of this study was to evaluate patients diagnosed with 22q11.2 deletion syndrome and determine the clues directing to diagnosis and evaluation of immunological findings for excellent management of the disease. MATERIAL AND METHODS: Thirty-three pediatric patients with 22q11.2 deletion syndrome diagnosed between 1998 and 2019 at Pediatric Immunology Division of Ege University Faculty of Medicine and SBU Izmir Dr Behcet Uz Children's Education and Research Hospital were evaluated. RESULTS: This study includes the largest case series reported from Turkey. Congenital cardiac anomalies were the most common pathology associated with the syndrome (90.9%). Hypocalcemic symptoms were observed in 13 patients (40%). Twenty-two of the 33 (66.6%) patients were diagnosed before two years of age. Autoimmune diseases, dysmorphic facial findings, recurrent infections, growth retardation, and speech impairment were other clues for diagnosis in older patients. Clinical spectrum and immunological abnormalities of this syndrome are quite variable. All T-cell subset counts were less than 5th percentile below median by age in one patient (3%) and 10 patients had normal all T-cell subset counts (30.3%). Overall, 69.6% of the patients had normal IgG, IgA, and IgM levels and two patients had panhypogammaglobulinemia. Recurrent infections were revealed in 75.7% of the patients during follow-up. CONCLUSIONS: Presence of cardiac anomaly is more helpful in the diagnosis, especially under two years of age. Patients with immunologically high or standard risk did not show any difference in terms of numbers and severity of infections and autoimmunity.

22q11.2 deletion syndrome: 20 years of experience from two pediatric immunology units and review of clues for diagnosis and disease management

INTRODUCTION AND OBJECTIVES: The purpose of this study was to evaluate patients diagnosed with 22q11.2 deletion syndrome and determine the clues directing to diagnosis and evaluation of immunological findings for excellent management of the disease. MATERIAL AND METHODS: Thirty-three pediatric patients with 22q11.2 deletion syndrome diag­nosed between 1998 and 2019 at Pediatric Immunology Division of Ege University Faculty of Medicine and SBU Izmir Dr Behcet Uz Children's Education and Research Hospital were evaluated. RESULTS: This study includes the largest case series reported from Turkey. Congenital car­diac anomalies were the most common pathology associated with the syndrome (90.9%). Hypocalcemic symptoms were observed in 13 patients (40%). Twenty-two of the 33 (66.6%) patients were diagnosed before two years of age. Autoimmune diseases, dysmorphic facial findings, recurrent infections, growth retardation, and speech impairment were other clues for diagnosis in older patients. Clinical spectrum and immunological abnormalities of this syn­drome are quite variable. All T-cell subset counts were less than 5th percentile below median by age in one patient (3%) and 10 patients had normal all T-cell subset counts (30.3%). Overall, 69.6% of the patients had normal IgG, IgA, and IgM levels and two patients had panhypogam­maglobulinemia. Recurrent infections were revealed in 75.7% of the patients during follow-up. CONCLUSIONS: Presence of cardiac anomaly is more helpful in the diagnosis, especially under two years of age. Patients with immunologically high or standard risk did not show any differ­ence in terms of numbers and severity of infections and autoimmunity

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Children with chronic-refractory autoimmune cytopenias: a single center experience.

BACKGROUND AND OBJECTIVES: Autoimmune cytopenias are a group of heterogeneous disorders characterized by immune-mediated destruction of one or more hematopoietic lineage cells. The differential diagnosis of children with autoimmune cytopenias requires much time and laboratory investigations. The aim of the present study was to evaluate the clinical course and significance of autoimmune cytopenias due to immunodeficiency or autoimmune diseases in children at a single children`s hospital. METHOD: Between February 1997 and September 2015, chronic/refractory autoimmune cytopenias patient data were evaluated retrospectively. Twenty-three patients were assessed in this study. RESULTS: The median duration of following was 2.6 years (4 months-18.5 years). The median age of diagnosis was 3.1 years (6 months-16 years). A total of 13 patients (56.5%) had single-lineage and 10 (46.5%) had multilineage cytopenias. The most frequent single-lineage cytopenia was thrombocytopenia, followed by anemia. In 22 of the patients, cytopenias was detected before the primary diseases. All of the patients were treated with corticosteroids or intravenous immune globulin as first-line treatment. Ten patients (43.5%) needed second or further-line immunosuppressive therapies that patients diagnosed as systemic lupus erythematosus, hypogammaglobulinemia, or common variable immunodeficiency. A total of 8 patients (34.7%) recovered from autoimmune cytopenias after the treatment of primer disease. Cytopenias were continued in 14 patients. CONCLUSION: Cytopenia may be the first finding of an immunodeficiency or autoimmune disease and primary disease may be diagnosed in the clinical course. Taking the new targeted treatment options into consideration; early diagnosis is likely to become more important in the near-future in order to begin the treatment for the underlying disease as early as possible.

Different clinical presentation in a patient with two novel pathogenic variants of the FBXL4 gene.

BACKGROUND: The recently described FBXL4-related encephalomyopathic mitochondrial DNA depletion syndrome 13 (MTDPS13) manifests with severe encephalopathy, early-onset lactic acidosis, hypotonia, developmental delay and feeding difficulty. Less than 100 cases with FBXL4-related MTDPS13 and 47 pathogenic mutations in the FBXL4 gene have been identified thus far. Here, we describe a patient diagnosed with MTDPS13 with two novel variants of the FBXL4 gene. CASE: A 51-day-old male was admitted with the complaint of bloody stool. His physical examination revealed facial dysmorphic features, developmental delay and truncal hypotonia with lack of head control. Laboratory investigations showed anemia, neutropenia, metabolic acidosis with hyperlactatemia, elevated fumaric acid, 2-ketoglutaric acid in urine and elevated alanine level in plasma which were consistent with mitochondrial dysfunction. Brain magnetic resonance imaging (MRI) showed large ventricles, thin corpus callosum and poor myelination. Drug-resistant epilepsy developed during the clinical follow-up. Ketogenic diet was initiated for intractable epilepsy; which was then interrupted due to severe metabolic acidosis. Compound heterozygous pathogenic variants were detected in the FBXL4 gene [p.Gly258* (c.772G > T, Exon 5)/p.Trp354Ser (c.1061G > C, Exon 6)] with whole-exome sequencing. CONCLUSION: We detected two novel variants of the FBXL4 gene. To the best of our knowledge, this is the first case in the literature that presented with gastrointestinal bleeding as an encephalomyopathic form of mitochondrial DNA depletion syndromes and for whom ketogenic diet was initiated due to intractable epilepsy, which was not reported in previous cases.

Influenza-related hospitalizations due to acute lower respiratory tract infections in a tertiary care children's hospital in Turkey.

BACKGROUND: The influenza virus is a significant cause of acute lower respiratory tract infections (LRTI) requiring hospitalization in childhood and leads to severe morbidity and mortality, especially in certain risk groups. OBJECTIVES: The study aims to evaluate acute LRTI due to influenza in a tertiary care hospital and the risk factors for hospitalization among Turkish children. STUDY DESIGN: Children between 1 month and 18 years of age who were hospitalized at Dr. Behçet Uz Children's Hospital between January 2016 and March 2018 with lower respiratory tract infection that tested positive for influenza by PCR were included. Children with viral coinfections were excluded. Patient files were retrospectively scanned from the hospital computerized system in terms of age, underlying diseases, whether antiviral therapy was used, and length of hospital stay. Statistical analysis was performed using SPSS statistical software. RESULTS: The study included 131 patients with a median age of 2 years (1 month-15 years). Sixty-seven (51,1%) patients were younger than two years. Influenza A was isolated in 129 patients and B in 2 patients. Fifty-two patients (39,7%) had underlying medical conditions, and the most common one was malignancies (12/52, 23%). This was followed by neurodevelopmental diseases (9/52, 17,3%), prematurity (9/52 patients, 17,3%), primary immunodeficiency (8/52, 15,4%), asthma (7/52, 13,4%), Down syndrome (4/52, 7,7%), chronic renal disease (2/52, 3,8%) and congenital heart diseases (1/52, 1,9%). The mean length of stay (LOS) was 12,3 ± 9,5 days (2-60 days). The LOS was found to be statistically longer (15,2 ± 12,1 days, 3-60 days) in patients with an underlying disease compared to previously healthy patients (10,4 ± 6,7 days, 2-35 days) (p = 0.01). CONCLUSIONS: Hospitalization due to influenza-related acute LRTI is not an issue only for patients with an underlying medical condition. Vaccination should be considered not only for those with underlying medical conditions but also for healthy children.