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.

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.

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.

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.

The evaluation of malignancies in Turkish primary immunodeficiency patients; a multicenter study.

BACKGROUND: There are no data regarding the prevalence of malignancies in patients with primary immunodeficiency (PID) in Turkey. Along with the prevalence of malignancy, we aimed to present the types of malignancy and define the underlying immune deficiency of the patients. METHOD: Between the years 1992 and 2018, from five tertiary immunology clinics, fifty-nine patients with PID who developed malignancy were included. All patients were evaluated for demographics, clinical features, and prognosis. RESULTS: The prevalence of malignancy in our cohort was detected as 0.9% (59/6392). The male-to-female ratio was 1.8 (38/21), and the median age of patients was 14 years (range: 1.5-51). The median age at diagnosis of malignancy was 10 years (range: 1.5-51). Ataxia-telangiectasia was the most frequent PID in patients with malignancy (n = 19, 32.2%), and non-Hodgkin lymphoma was the most common malignancy (n = 32, 51.6%). The rate of malignancy in DOCK8 deficiency (n = 7/43, 16.3%) was higher than AT (n = 19/193, 9.8%), Wiskott-Aldrich syndrome (n = 2/22, 9.1%), and common variable immunodeficiency (n = 11/205, 5.4%). EBV quantitative PCR was positive in 16 out of 53 patients (30.2%). Three patients had secondary malignancies. Remission was achieved in 26 patients (44.1%). However, 31 patients (52.5%) died. Two patients (3.4%) are still on chemotherapy. CONCLUSION: This study is the largest cohort investigating the association of malignancy in patients with PID in Turkey. While lymphoid malignancies were the most common malignancy and observed more frequently in AT patients, the risk for malignancy was higher in patients with DOCK8 deficiency compared to AT.

Gain-of-Function Mutations in STAT1: A Recently Defined Cause for Chronic Mucocutaneous Candidiasis Disease Mimicking Combined Immunodeficiencies.

Chronic Mucocutaneous Candidiasis (CMC) is the chronic, recurrent, noninvasive Candida infections of the skin, mucous membranes, and nails. A 26-month-old girl was admitted with the complaints of recurrent oral Candidiasis, diarrhea, and respiratory infections. Candida albicans grew in oral mucosa swab. CMV and EBV DNA titers were elevated. She had hypergammaglobulinemia; IgE level, percentages of lymphocyte subgroups, and in vitro T-cell proliferation responses were normal. She had parenchymal nodules within the lungs and a calcific nodule in the liver. Chronic-recurrent infections with different pathogens leading to significant morbidity suggested combined immunodeficiency, CMC, or Mendelian susceptibility to mycobacterial diseases. Genetic analysis revealed a predefined heterozygous gain-of-function mutation (GOF) (c.1154 C>T, p.Thr385Met) in the gene coding STAT1 molecule. Hematopoietic stem cell transplantation (HSCT) was planned because of severe recurring infections. Patients with STAT1 GOF mutations may exhibit diverse phenotypes including infectious and noninfectious findings. HSCT should be considered as an early treatment option before permanent organ damage leading to morbidity and mortality develops. This case is presented to prompt clinicians to consider STAT1 GOF mutations in the differential diagnosis of patients with chronic Candidiasis and recurrent infections with multiple organisms, since these mutations are responsible for nearly half of CMC cases reported.

An unusual manifestation: Papillary thyroid carcinoma in a patient with ataxia-telengiectasia.

Ataxia-telangiectasia (A-T) is a rare autosomal recessive, multisystem, neurodegenerative disorder, characterized by oculocutaneous telangiectasias, variable immunodeficiency and progressive neurological impairment. Definitive diagnosis is made by revealing a disease causing mutation on ATM gene. Missense mutations and polymorphisms of ATM gene can play a role in the development of thyroid papillary carcinoma. A 13-year-old Turkish girl was diagnosed with ataxia telengiectasia at the age of 8 years. When she was 12 years old, multi-nodular goiter was detected by physical examination and ultrasonography. She underwent thyroidectomy and histopathologic investigation revealed a papillary carcinoma with follicular variant. The patient received post-operative radioiodine therapy as well as L-thyroxine treatment because she had residual lesions. Up until now, she is the first Turkish child wit A-T and thyroid carcinoma described in the literature.

[Rifampicin-resistant Mycobacterium bovis BCG strain isolated from an infant with NEMO mutation]. / NEMO mutasyonlu bir bebekten izole edilen rifampisine dirençli Mycobacterium bovis BCG susu.

It is well known that disseminated Mycobacterium bovis BCG infection is developed after BCG vaccination in infants with congenital cellular immune deficiencies such as mutations in genes along the interleukin (IL)-12/interferon (IFN)-γ pathway and mutations in nuclear factor-kB essential modulator (NEMO). In this report, a rifampicin-resistant M.bovis BCG strain isolated from an infant with NEMO defect was presented. An 8-month-old male infant with NEMO defect admitted to the pediatric outpatient clinic of our hospital with fever, generalized lymphadenopathy and hepatosplenomegaly. Microscopic examination of the smears prepared from lymph node and liver biopsy specimens revealed abundant amount (3+) of acid-fast bacilli (AFB). Rifampicin-susceptible Mycobacterium tuberculosis complex (MTC) was detected by real-time PCR (GeneXpert MTB/RIF; Cepheid, USA) in the samples. The growth of mycobacteria was determined on the 20th day of culture performed in MGIT960 system (Becton Dickinson, USA). The isolate was identified as M.bovis BCG by GenoType MTBC kit (Hain Lifescience, Germany) and defined as M.bovis BCG [SIT 482 (BOV_1)] by spoligotyping. In the primary anti-tuberculosis drug susceptibility test performed by MGIT960 system, the isolate was found susceptible to rifampicin (RIF), isoniazid (INH), streptomycin (STM) and ethambutol (EMB). Then anti-tuberculosis treatment was started to the patient. However, the patient at the age of 2 years, re-admitted to the hospital with the complaint of hepatosplenomegaly. Smear of spontaneously draining abscess material obtained from subcutaneous nodules revealed intensive AFB positivity (3+) once again. In the present instance RIF-resistant MTC was detected with GeneXpert system in the specimen. The growth of mycobacteria was determined on the 13th day of culture and isolate was identified as M.bovis BCG. The present isolate was found susceptible to INH, STM and EMB but resistant to RIF. A mutation in the rpoB gene (codon 531, S531L) associated with RIF resistance was detected by using the partial sequencing of the rpoB gene. Patient died due to disseminated bovis BCG infection and multiple organ failure. To our knowledge, there are only six RIF-resistant M.bovis BCG strains isolated from patients in the literature. However, this is the first RIF-resistant M.bovis BCG strain isolated from a NEMO-deficient patient.

Granulomatous skin lesions, severe scrotal and lower limb edema due to mycobacterial infections in a child with complete IFN-γ receptor-1 deficiency.

Interferon-γ receptor-1 (IFNγR1) deficiency is caused by mutations in the IFNγR1 gene and is characterized mainly by susceptibility to mycobacterial disease. Herein, we report an 8-month-old boy with complete recessive IFNγR1 deficiency, afflicted by recurrent mycobacterial diseases with Mycobacterium bovis, Mycobacterium tuberculosis, Mycobacterium avium intracellulare and Mycobacterium fortuitum. Genetic analysis showed a homozygous mutation (106insT) in the IFNγR1 gene leading to complete IFNγR1 deficiency. In addition, he had atypical mycobacterial skin lesions caused by M. avium intracellulare and developed scrotal and lower limb lymphedema secondary to compression of large and fixed inguinal lymphadenopathies. Hematopoietic stem cell transplantation was performed from a matched unrelated donor at 5 years of age; however, he died at 9 months post-transplant. To our knowledge, the patient is the first case with IL-12/IFN-γ pathway defect and severe lymphedema. We have also reviewed and summarized the literature related with IFNγR1 deficiency.

Consanguinity rate and delay in diagnosis in Turkish patients with combined immunodeficiencies: a single-center study.

Combined immunodeficiency diseases comprise a group of disorders with different molecular basis. Clinical and immunological phenotypes for each group are extremely heterogenous. The frequency of combined immunodeficiencies may vary in different countries. The most frequent forms of combined immunodeficiency show inherited defects in development of T and/or B lymphocytes. These defects are classified according to immunologic phenotype and are categorized into T-B+ or T-B- including forms with or without natural killer lymphocytes. We report here twenty-three patients (female/male: 12/11) with combined immunodeficiency showing different immunological and clinical phenotypes, majority of whom were admitted because of severe upper and lower respiratory tract infections. Mean age of the study group, mean age at onset of the symptoms, and diagnosis were 47.5 ± 42.2, 11.2 ± 17.3, and 19.5 ± 23.8 months, respectively. There was nearly 8 months time delay between beginning of symptoms and diagnosis. Within the combined immunodeficiency phenotypes, T-B-NK+ category was the most frequent phenotype. Consanguinity was positive in 73.9% (n = 17) of patients while it was about 80.0% (n = 8) in deceased ten children. Bone marrow or umblical cord stem cell transplantation was applied to 11 of them. Three patients deceased after transplantation and seven patients deceased without transplantation. Twelve patients are being followed by prophylactic treatment. In conclusion; combined immunodeficiencies are frequent in our country because of high rate of consanguinity. T-B- combined immunodeficiencies are more often observed, and infants presenting severe infections beginning in the first 3 months of life have to be examined for combined immunodeficiencies. Shortening of time delay in diagnosis will increase success of life-saving treatment.