Thymic output changes in children with clinical findings signaling a probable primary immunodeficiency.

Karaca N, Azarsiz E, Akarcan SE, Aksu G, Kütükçüler N. Thymic output changes in children with clinical findings signaling a probable primary immunodeficiency. Turk J Pediatr 2019; 61: 885-894. Thymic maturation evaluation is inevitable for patients with clinical and laboratory findings for a primary immunodeficiency, as the T cellimmunodeficiencies are the most severe type. In this study, we aimed to show the usage of T cell surface molecule `CD31` for the evaluation of thymic output in patients (n: 66) with a large spectrum of findings signing a probable primary immunodeficiency. Besides the classical clinical and laboratory approach for these patients, T cell subpopulations as naive, memory, recent thymic emigrant cells were also investigated. The humoral immunodeficiency (34.8%), combined immunodeficiency (34.8%) and cardiopathy (7.6%) were the most frequent diagnosis groups. CD4+CD45RA+ naive T-cells percentages (p: 0.011) and absolute counts (p: 0.004) and absolute CD4+CD45RA+CD31+ RTE (recent thymic emigrant) cell counts (p: 0.007) were significantly lower in combined immunodeficiency group. Naive T-cells (p: 0.037) and RTE cells (p: 0.032) were also lower in patients who had cardiac surgery in the past. In conclusion, flow cytometric CD31+thymic naive RTE cell evaluation may provide rapid clinical information especially on T-cell immune dysfunction and CD4+CD45RA+CD31+ RTE cells may be used as an alternative to TRECs in the diagnosis of combined immunodeficiencies.

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.

Necrotizing Liver Granuloma/Abscess and Constrictive Aspergillosis Pericarditis with Central Nervous System Involvement: Different Remarkable Phenotypes in Different Chronic Granulomatous Disease Genotypes.

Chronic granulomatous disease (CGD) is a primary immune deficiency causing predisposition to infections with specific microorganisms, Aspergillus species and Staphylococcus aureus being the most common ones. A 16-year-old boy with a mutation in CYBB gene coding gp91phox protein (X-linked disease) developed a liver abscess due to Staphylococcus aureus. In addition to medical therapy, surgical treatment was necessary for the management of the disease. A 30-month-old girl with an autosomal recessive form of chronic granulomatous disease (CYBA gene mutation affecting p22phox protein) had invasive aspergillosis causing pericarditis, pulmonary abscess, and central nervous system involvement. The devastating course of disease regardless of the mutation emphasizes the importance of early diagnosis and intervention of hematopoietic stem cell transplantation as soon as possible in children with CGD.

Early Diagnosis and Hematopoietic Stem Cell Transplantation for IL10R Deficiency Leading to Very Early-Onset Inflammatory Bowel Disease Are Essential in Familial Cases.

Alterations of immune homeostasis in the gut may result in development of inflammatory bowel disease. A five-month-old girl was referred for recurrent respiratory and genitourinary tract infections, sepsis in neonatal period, chronic diarrhea, perianal abscess, rectovaginal fistula, and hyperemic skin lesions. She was born to second-degree consanguineous, healthy parents. Her elder siblings were lost at 4 months of age due to sepsis and 1 year of age due to inflammatory bowel disease, respectively. Absolute neutrophil and lymphocyte counts, immunoglobulin levels, and lymphocyte subsets were normal ruling out severe congenital neutropenia and classic severe combined immunodeficiencies. Quantitative determination of oxidative burst was normal, excluding chronic granulomatous disease. Colonoscopy revealed granulation, ulceration, and pseudopolyps, compatible with colitis. Very early-onset colitis and perianal disease leading to fistula formation suggested probability of inherited deficiencies of IL-10 or IL-10 receptor. A mutation at position c.G477A in exon of the IL10RB gene, resulting in a stop codon at position p.W159X, was identified. The patient underwent myeloablative hematopoietic stem cell transplantation from full matched father at 11 months of age. Perianal lesions, chronic diarrhea, and recurrent infections resolved after transplantation. IL-10/IL-10R deficiencies must be considered in patients with early-onset enterocolitis.