DOCK8 functions as an adaptor that links TLR-MyD88 signaling to B cell activation.

The adaptors DOCK8 and MyD88 have been linked to serological memory. Here we report that DOCK8-deficient patients had impaired antibody responses and considerably fewer CD27(+) memory B cells. B cell proliferation and immunoglobulin production driven by Toll-like receptor 9 (TLR9) were considerably lower in DOCK8-deficient B cells, but those driven by the costimulatory molecule CD40 were not. In contrast, TLR9-driven expression of AICDA (which encodes the cytidine deaminase AID), the immunoglobulin receptor CD23 and the costimulatory molecule CD86 and activation of the transcription factor NF-κB, the kinase p38 and the GTPase Rac1 were intact. DOCK8 associated constitutively with MyD88 and the tyrosine kinase Pyk2 in normal B cells. After ligation of TLR9, DOCK8 became tyrosine-phosphorylated by Pyk2, bound the Src-family kinase Lyn and linked TLR9 to a Src-kinase Syk-transcription factor STAT3 cascade essential for TLR9-driven B cell proliferation and differentiation. Thus, DOCK8 functions as an adaptor in a TLR9-MyD88 signaling pathway in B cells.

Transient hypogammaglobulinemia of infancy and unclassified syndromic immunodeficiencies are highly common in oesophageal atresia patients.

Due to the high rate of post-operative sepsis and other infectious complications, a routine immunological screening protocol has been initiated since 2015 in our paediatric surgery clinic for all patients admitted with oesophageal atresia (EA) and warrant a delayed definitive treatment. In our study, we aimed to evaluate the immunodeficiencies in EA patients, by comparing them to healthy age-matched controls. As a prospective cohort study, EA patients admitted between 2015 and 2022, who had their definitive operation after the newborn period (>28 days of age) were included. On admission, serum concentrations of IgG, IgA, IgM, lymphocyte subset levels, C3 and C4 levels, specific IgG antibody responses against hepatitis B, hepatitis A, measles, varicella zoster were evaluated. The patients were age-matched with healthy controls to compare the results and followed up until three years of age. If a humoral immunodeficiency was detected, intravenous immunoglobulin treatment was administered before major oesophageal surgery and during follow-up. 31 EA patients (18 M/13F) with a mean age of 13.3 ± 9.0 months were compared with 40 age-matched healthy controls. Mean serum IgG levels were found to be statistically lower than controls in all age groups (P < .05). Transient hypogammaglobulinemia of infancy (THI) and unclassified syndromic immunodeficiencies (USI) were found to be strikingly high, accounting for 29.0% and 22.5%, respectively, adding up to 51.5% of EA patients. This is the first study evaluating immunodeficiencies in EA patients found in the reviewed literature. More than half of EA patients that required delayed surgery had humoral immunodeficiency, so preoperative screening and immunology referral may improve patient outcomes.

Autoimmune Cytopenias Are Highly Associated with Inborn Errors of Immunity and They May Be the Initial Presentations in Cases without Severe Infections.

INTRODUCTION: Inborn errors of immunity (IEIs) are inherited disorders that present with increased susceptibility to infections as well as noninfectious complications. Due to the aberrant immune functions of patients with IEI, autoimmune cytopenia (AIC) may be the initial finding, which makes diagnosis a challenge. We aimed to evaluate the clinical course, laboratory findings, and treatment response of AIC in children with IEI. METHODS: Data of children with autoimmune hemolytic anemia (AIHA) and/or immune thrombocytopenic purpura (ITP) were obtained from a retrospective chart review of IEI patients diagnosed and followed in our center. Demographic and clinical features and therapeutic outcomes were evaluated. Immunologic findings were compared between patients with AIHA, ITP, and Evans syndrome (ES). The patients were also divided into two subgroups based on the presence or absence of immune dysregulation diseases (IDDs), and all data were compared between these two groups. RESULTS: Out of 562 patients with IEI, 6% (n: 34) had AIC which were ITP (23.5%), AIHA (35.5%), and ES (41.2%). AIC was the initial finding in 50% of these 34 patients. Patients with ES had a higher mean percentage of CD8+ T lymphocytes than ITP patients (40.77 ± 20.21% vs. 22.33 ± 12.48%, p = 0.011). Patients with IDDs were more likely to develop ES (p = 0.004), lymphoproliferation (p = 0.005), and resistance to first-line therapy (p = 0.021) than other IEI groups. CONCLUSION: This study shows that AIC may be the initial finding of IEI, particularly when lymphoproliferation and resistance to first-line therapy co-occur. Therefore, detailed investigation should be offered to all patients to avoid diagnostic delay.

Facilitated Subcutaneous Immunoglobulin Treatment Increases the Quality of Life and Decreases the Number of Infections and Hospitalizations in Children with Primary Immunodeficiencies.

INTRODUCTION: Immunoglobulin replacement therapy is an effective lifelong treatment modality used in patients with primary immunodeficiency to prevent and/or reduce the incidence of serious infections. Facilitated subcutaneous immunoglobulin (fSCIG) was developed to combine the advantages of intravenous immunoglobulin (IVIG) and subcutaneous immunoglobulin (SCIG) and is the latest method of immunoglobulin G (IgG) administration. In this study, switching to fSCIG administration in primary immunodeficiency patients receiving regular IVIG or SCIG therapy was evaluated, and serum IgG trough levels, frequency of infections, frequency and duration of hospitalizations, duration of absence from school/work, and quality of life were determined. METHODS: In this study, fifteen patients with primary immunodeficiency who were previously receiving IVIG or SCIG treatment, followed by fSCIG, were evaluated retrospectively. Age, diagnosis, current complications, mean IgG value, frequency of infection, frequency of hospitalization, and duration of absenteeism from school and work were recorded during and before fSCIG treatment. At the beginning of fSCIG treatment, at 6th and 12th months, "The Quality of Life Scale" was also evaluated in patients and parents. RESULTS: The most common indications for initiation of fSCIG treatment were the difficulty of access to the hospital and the long transfusion periods. No systemic adverse reactions were reported except for redness, swelling, and mild pain on the injection site. The median IgG values for the last 1 year were 529.6 mg/dL for IVIG (n = 9), 876.2 mg/dL for SCIG (n = 6) and 856.7 mg/dL for fSCIG (n = 15, all patients) treatment. The frequency of infections and the number of hospitalizations decreased significantly in the fSCIG group compared to both previous treatment modalities. There was a significant increase in the quality of life score of the patients and their families when compared with previous treatment modalities. CONCLUSION: fSCIG is an effective treatment method and is well tolerated in patients with immunodeficiency. It provides stable immunoglobulin levels and excellent protection against infections and offers the patients the possibility of home-based therapy.

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.

Analysis of IL-1ß, TGF-ß, IL-5, ACE, PTPN22 gene polymorphisms, and gene expression levels in Turkish children with IgA vasculitis.

OBJECTIVE: Immunoglobulin-A vasculitis (IgAV) is an inflammatory disease that affects small blood vessels. This study was performed to identify an association between protein tyrosine phosphatase non-receptor type 22 (PTPN22) + 788G > A (rs33996649), transforming growth factor-beta (TGF-ß) -509C > T (rs18004069), interleukin 1-beta (IL-1ß) -511C > T (rs16944), interleukin 5 (IL-5) -746C/T (rs2069812), and angiotensin-converting enzyme (ACE) I/D (rs4646994) gene polymorphisms, susceptibility to IgAV, as well as the mRNA levels of IL-1ß, IL-1ß, and TGF-ß. METHOD: A total of 53 patients with IgAV and 50 healthy controls were enrolled. PTPN22, TGF-ß, IL-1ß, ACE gene polymorphisms, ACE gene I/D polymorphisms, and mRNA expression levels were analyzed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, allele-specific PCR, and real-time PCR with TaqMan kits, respectively. RESULTS: PTPN22, TGF-ß, IL-1ß, IL-5, and ACE variants showed no genotype or allele differences between patients with IgAV and controls. Increased levels of IL-1ß and TGF-ß mRNA expressions were observed in patients with IgAV (p < 0.001). Patients with the IL-1ß AG genotype showed significantly increased amounts of arthritis than patients with non-AG (p = 0.004). Age at disease onset was found to be significantly different in patients with IgAV according to the presence of TGF-ß TT genotype (p = 0.047). CONCLUSION: Polymorphisms in PTPN22, TGF-ß, IL-5, IL-1ß, and ACE genes are unlikely to confer susceptibility to IgAV. However, the presence of the AG genotype of IL-1ß is associated with susceptibility to IgAV-related arthritis. This is the first study to report a significant increase in serum mRNA levels of IL-1ß and TGF-ß in IgAV patients, supporting a susceptibility to IgAV in childhood.

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.

Mid-Regional Proadrenomedullin Levels in Primary Immunodeficiencies Complicated with Pulmonary Manifestations.

The development of lower respiratory complications in children with primary immunodeficiencies characterized by recurrent infections significantly contributes to morbidity and mortality. This is clinically more important and specific in the evaluation of prognosis. The inflammatory response that develops throughout the clinical process can cause the release of several biomarkers. This study aimed to evaluate the inflammatory biomarker "mid-regional pro-adrenomedullin (MR-proADM)" levels by distribution of lower respiratory tract complications. Plasma MR-proADM levels were measured in children with (n = 52) and without (n = 103) lower respiratory tract complications. The complicated group was also evaluated as "infective and non-infective" groups. The median MR-proADM levels were higher in the complicated cases (p = 0.175). It was 205.5 (73.4- 562.6) ng/L in the infective group while it was 96.1 (26.1-43.3) ng/L in the non-infective group and the difference between the two groups was statistically significant (p = 0.003). The predictive value of MR-proADM (AUC = 0.749, p = 0.003) was statistically significant compared to CRP (AUC = 0.330, p = 0.040) and SAA (AUC = 0.261, p = 0.004) in the infective group. This study evidences that the MR-proADM levels are higher in PID cases with infective pulmonary complications. Among other markers, MR-proADM appears to be a particularly good predictive inflammation marker for these children. Supplementary Information: The online version contains supplementary material available at 10.1007/s12291-022-01061-9.

Alterations in B and NK cells highly correlate with disease severity in children with COVID-19.

Background/aim: Children with coronavirus disease 2019 (COVID-19) present milder symptoms than adults and are at lower risk of hospitalization and life-threatening complications. However, the kinetics of lymphocyte subsets and serum immunoglobulins in the peripheral blood during COVID-19 infection remains unclear. In this study, it was aimed to determine the changes in hematological and immunological parameters, especially in the lymphocyte subsets, in the peripheral blood of children with different COVID-19 disease severity. Materials and methods: The study was planned as a prospective cohort and included 68 children aged 0-18 years who were admitted to Ege University Faculty of Medicine Department of Pediatrics and diagnosed with COVID-19 infection between May 2020 and December 2021. In addition to demographic characteristics, clinical findings, and severity criteria, hematological, biochemical, and immunological laboratory (T/B lymphocyte subgroups, serum immunoglobulins) results were noted and examined if there were some correlations between disease severity and the laboratory values. Results: In the study group, while 60.6% (n = 40) of the patients received treatment in the hospital, 10.6% (n = 7) needed intensive care treatment. Lymphopenia (35.3%) was more common than neutropenia (14.7%) in the COVID-19-infected children. CD19+ B cells were low in a very high percentage of patients (26.5%), and 16.2% had low levels of NK cells. Significant correlation between disease severity and CD19+lymphocytes, CD19+CD38+IgMlow lymphocytes, CD19+CD38+CD27highIgMhigh lymphocytes, CD19+CD81+ lymphocytes (p = 0.001, p = 0.008, p = 0.014, p = 0.025, and rs = 0.394, rs = 0.326, rs = 0.303, rs = 0.280, respectively), significant inverse correlation between disease severity and absolute lymphocytes counts and CD3-CD16+CD56+ lymphocytes (p = 0.004, 0.014, and rs = -0.353, rs = -0.304, respectively) were observed. The percentage of hospitalized patients with low CD3 levels (15%) was significantly higher than that of the outpatients with low CD3 levels. Conclusion: As the severity of the disease increased, the CD19+, CD19+CD38+IgMlow, CD19+CD38+CD27highIgMhigh, and CD19+CD81+ lymphocytes percentages increased, while the lymphocyte count and NK cell percentage decreased. Therefore, detecting these prognostic immunobiomarkers related to the severity of the disease may contribute considerably to management of the illness.

Clinical, immunological, molecular and therapeutic findings in monogenic immune dysregulation diseases: Middle East and North Africa registry.

Monogenic immune dysregulation diseases (MIDD) are caused by defective immunotolerance. This study was designed to increase knowledge on the prevalence and spectrum of MIDDs, genetic patterns, and outcomes in Middle East and North Africa (MENA). MIDD patients from 11 MENA countries (Iran, Turkey, Kuwait, Oman, Algeria, Egypt, United Arab Emirates, Tunisia, Jordan, Qatar, and Azerbaijan) were retrospectively evaluated. 343 MIDD patients (58% males and 42% female) at a median (IQR) age of 101 (42-192) months were enrolled. The most common defective genes were LRBA (23.9%), LYST (8.2%), and RAB27A (7.9%). The most prevalent initial and overall manifestations were infections (32.2% and 75.1%), autoimmunity (18.6% and 41%), and organomegaly (13.3% and 53.8%), respectively. Treatments included immunoglobulin replacement therapy (53%), hematopoietic stem cell transplantation (HSCT) (14.3%), immunosuppressives (36.7%), and surgery (3.5%). Twenty-nine (59.2%) patients survived HSCT. Along with infectious complications, autoimmunity and organomegaly may be the initial or predominant manifestations of MIDD.

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.

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.

Immunologic changes during desensitization with cow's milk: How it differs from natural tolerance or nonallergic state?

BACKGROUND: Oral immunotherapy (OIT) is a novel allergen-specific treatment for food allergies. OBJECTIVE: To investigate the effect of OIT on blocking antibodies, T cell regulation, and cytokine response during immunoglobulin (Ig)E-mediated cow's milk allergy (CMA) treatment. METHODS: A total of 59 children with IgE-mediated CMA who were followed in pediatric allergy outpatient clinic and 18 healthy children were included. The children were evaluated in the following 4 groups: OIT group, elimination group (patients receiving dairy elimination diet), tolerance group (patients who developed tolerance), and healthy control group. Milk-specific IgE, IgG4, and IgA levels, cow's milk induration diameters in skin prick test, CD4 + CD25 + FoxP3 + Treg cell percentages, messenger RNA (mRNA) expressions, and interleukin (IL)-10, transforming growth factor-beta (TGF-ß), IL-2, IL-4, and IL-13 cytokine levels were compared between the groups. RESULTS: The mean age of the patients was 42.6 ± 39 (6-201) months, and 63.6% (n = 49) of the patients were girls. We observed an increase in total IgE levels (P = .02), a decrease in cow's milk sIgE (P = .08, NS), and an increase in cow's milk component (ß-lactoglobulin and casein) specific IgA (P < .05) and IgG4 (P < .001) levels at 2 months after the maintenance phase of OIT. In addition, the immune response after OIT treatment, which had a 100% clinical success rate, was notable for similar CD4 + CD25 + FoxP3 + cell percentages (P = .8), and increased IL-10 (P = .04) levels and increased but statistically nonsignificant TGF-ß levels (P = .17) compared with those before treatment. FoxP3 mRNA expression was similar to that of patients who developed natural tolerance. Pretreatment and post-treatment FoxP3 mRNA-FoxP3 flow cytometric expressions were positively correlated with TGF-ß concentrations in the OIT group. CONCLUSION: A successful immune response to OIT was found, possibly through the blockage of IgE-mediated allergen presentation by blocking antibodies, marked IL-10 cytokine response, and TGF-ß response. FoxP3 mRNA expression was similar to the natural tolerance mechanism, but more studies are needed.

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.

Simple Measurement of IgA Predicts Immunity and Mortality in Ataxia-Telangiectasia.

Patients with ataxia-telangiectasia (A-T) suffer from progressive cerebellar ataxia, immunodeficiency, respiratory failure, and cancer susceptibility. From a clinical point of view, A-T patients with IgA deficiency show more symptoms and may have a poorer prognosis. In this study, we analyzed mortality and immunity data of 659 A-T patients with regard to IgA deficiency collected from the European Society for Immunodeficiencies (ESID) registry and from 66 patients with classical A-T who attended at the Frankfurt Goethe-University between 2012 and 2018. We studied peripheral B- and T-cell subsets and T-cell repertoire of the Frankfurt cohort and survival rates of all A-T patients in the ESID registry. Patients with A-T have significant alterations in their lymphocyte phenotypes. All subsets (CD3, CD4, CD8, CD19, CD4/CD45RA, and CD8/CD45RA) were significantly diminished compared to standard values. Patients with IgA deficiency (n = 35) had significantly lower lymphocyte counts compared to A-T patients without IgA deficiency (n = 31) due to a further decrease of naïve CD4 T-cells, central memory CD4 cells, and regulatory T-cells. Although both patient groups showed affected TCR-ß repertoires compared to controls, no differences could be detected between patients with and without IgA deficiency. Overall survival of patients with IgA deficiency was significantly diminished. For the first time, our data show that patients with IgA deficiency have significantly lower lymphocyte counts and subsets, which are accompanied with reduced survival, compared to A-T patients without IgA deficiency. IgA, a simple surrogate marker, is indicating the poorest prognosis for classical A-T patients. Both non-interventional clinical trials were registered at clinicaltrials.gov 2012 (Susceptibility to infections in ataxia-telangiectasia; NCT02345135) and 2017 (Susceptibility to Infections, tumor risk and liver disease in patients with ataxia-telangiectasia; NCT03357978).

A Novel Homozygous TRNT1 Mutation in a Child With an Early Diagnosis of Common Variable Immunodeficiency Leading to Mild Hypogammaglobulinemia and Hemolytic Anemia.

Although sideroblastic anemias (SAs) may be associated with different etiologies, deterioration of mitochondrial heme biosynthesis in bone marrow erythroid cells is a general abnormality. Congenital SA associated with immunodeficiency, periodic fever, and developmental delay is because of loss-of-function mutations in the TRNT1 gene. We report a patient with a novel homozygous mutation in the TRNT1 gene presenting with anemia with siderocytes, hypogammaglobulinemia, hepatosplenomegaly, and brittle hair but without periodic fever or developmental delay. The patient was presented to emphasize the power of reverse phenotyping in the differential diagnosis of primary immunodeficiency patients with atypical features and to raise awareness for TRNT1 disease in case of coexistent SA and hypogammaglobulinemia.

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.

Combined immunodeficiency with marginal zone lymphoma due to a novel homozygous mutation in IL-21R gene and successful treatment with hematopoietic stem cell transplantation.

Mutations in the interleukin-21 receptor (IL-21R) gene are recently defined as primary immunodeficiency diseases. IL-21R defects result in combined immunodeficiency by affecting the functions of innate and adaptive immune system components.A six-year-old girl was admitted to our hospital with complaints of chronic diarrhea that started after the newborn period and generalized rash over the last three months. She had severe respiratory distress due to Cytomegalovirus (CMV) pneumonia requiring mechanical ventilation and was diagnosed as combined immunodeficiency at another hospital at the age of four. Her physical examination on admission revealed erythematous rash on cheeks, extremities, gluteal region, and lymph node enlargements in cervical, axillary, and inguinal regions. CMV DNA and stool Cryptosporidium parvum were positive. Marginal zone lymphoma -negative for Epstein-Bar virus- was reported in the lymph node biopsy. Targeted next-generation sequencing Ion AmpliSeq™ primary immunodeficiency panel revealed a novel homozygous IL21R c.132delC (p.Ser45fs) mutation.This case is presented to emphasize that IL21R defects should be considered in the differential diagnosis of the patients with recurrent respiratory infections, chronic diarrhea, C. parvum infection, chronic liver disease, sclerosing cholangitis, and malignancy where early hematopoietic stem cell transplantation (HSCT) is life-saving. A total of eight cases with IL21R gene defects have been reported so far. The significance of this case is that it is the first case of malignancy among the published IL-21R deficient patients successfully treated with HSCT.

Long-term outcome of LRBA deficiency in 76 patients after various treatment modalities as evaluated by the immune deficiency and dysregulation activity (IDDA) score.

BACKGROUND: Recent findings strongly support hematopoietic stem cell transplantation (HSCT) in patients with severe presentation of LPS-responsive beige-like anchor protein (LRBA) deficiency, but long-term follow-up and survival data beyond previous patient reports or meta-reviews are scarce for those patients who do not receive a transplant. OBJECTIVE: This international retrospective study was conducted to elucidate the longitudinal clinical course of patients with LRBA deficiency who do and do not receive a transplant. METHOD: We assessed disease burden and treatment responses with a specially developed immune deficiency and dysregulation activity score, reflecting the sum and severity of organ involvement and infections, days of hospitalization, supportive care requirements, and performance indices. RESULTS: Of 76 patients with LRBA deficiency from 29 centers (median follow-up, 10 years; range, 1-52), 24 underwent HSCT from 2005 to 2019. The overall survival rate after HSCT (median follow-up, 20 months) was 70.8% (17 of 24 patients); all deaths were due to nonspecific, early, transplant-related mortality. Currently, 82.7% of patients who did not receive a transplant (43 of 52; age range, 3-69 years) are alive. Of 17 HSCT survivors, 7 are in complete remission and 5 are in good partial remission without treatment (together, 12 of 17 [70.6%]). In contrast, only 5 of 43 patients who did not receive a transplant (11.6%) are without immunosuppression. Immune deficiency and dysregulation activity scores were significantly lower in patients who survived HSCT than in those receiving conventional treatment (P = .005) or in patients who received abatacept or sirolimus as compared with other therapies, and in patients with residual LRBA expression. Higher disease burden, longer duration before HSCT, and lung involvement were associated with poor outcome. CONCLUSION: The lifelong disease activity, implying a need for immunosuppression and risk of malignancy, must be weighed against the risks of HSCT.