Alisan Yildiran

Inherited and acquired immunodeficiencies underlying tuberculosis in childhood.

Tuberculosis (TB), caused by Mycobacterium tuberculosis (M.tb) and a few related mycobacteria, is a devastating disease, killing more than a million individuals per year worldwide. However, its pathogenesis remains largely elusive, as only a small proportion of infected individuals develop clinical disease either during primary infection or during reactivation from latency or secondary infection. Subacute, hematogenous, and extrapulmonary disease tends to be more frequent in infants, children, and teenagers than in adults. Life‐threatening primary TB of childhood can result from known acquired or inherited immunodeficiencies, although the vast majority of cases remain unexplained. We review here the conditions conferring a predisposition to childhood clinical diseases caused by mycobacteria, including not only M.tb but also weakly virulent mycobacteria, such as BCG vaccines and environmental mycobacteria. Infections with weakly virulent mycobacteria are much rarer than TB, but the inherited and acquired immunodeficiencies underlying these infections are much better known. Their study has also provided genetic and immunological insights into childhood TB, as illustrated by the discovery of single‐gene inborn errors of IFN‐γ immunity underlying severe cases of TB. Novel findings are expected from ongoing and future human genetic studies of childhood TB in countries that combine a high proportion of consanguineous marriages, a high incidence of TB, and an excellent clinical care, such as Iran, Morocco, and Turkey.

Clinical, functional, and genetic characterization of chronic granulomatous disease in 89 Turkish patients

BACKGROUND Chronic granulomatous disease (CGD) is a rare primary immunodeficiency disorder of phagocytes resulting in impaired killing of bacteria and fungi. A mutation in one of the 4 genes encoding the components p22(phox), p47(phox), p67(phox), and p40(phox) of the leukocyte nicotinamide dinucleotide phosphate reduced (NADPH) oxidase leads to autosomal recessive (AR) CGD. A mutation in the CYBB gene encoding gp91(phox) leads to X-linked recessive CGD. OBJECTIVE The aim of this study is to show the correlation between clinical, functional, and genetic data of patients with CGD from Turkey. METHODS We report here the results of 89 patients with CGD from 73 Turkish families in a multicenter study. RESULTS Most of the families (55%) have an AR genotype, and 38% have an X-linked genotype; patients from 5 families with a suspected AR genotype (7%) were not fully characterized. We compared patients with CGD according to the severity of NADPH oxidase deficiency of neutrophils. Patients with A22(0), A67(0) or X91(0) phenotypes with a stimulation index of 1.5 or less have early clinical presentation and younger age at diagnosis (mean, 3.2 years). However, in p47(phox)-deficient cases and in 5 other AR cases with high residual oxidase activity (stimulation index ≥ 3), later and less severe clinical presentation and older age at diagnosis (mean, 7.1 years) were found. Pulmonary involvement was the most common clinical feature, followed by lymphadenitis and abscesses. CONCLUSION Later and less severe clinical presentation and older age at diagnosis are related to the residual NADPH oxidase activity of neutrophils and not to the mode of inheritance. CGD caused by A22(0) and A67(0) subtypes manifests as severe as the X91(0) subtype.

An unconditioned bone marrow transplantation in a child with purine nucleoside phosphorylase deficiency and its unique complication

Abstract:  Purine nucleoside phosphorylase deficiency is a rare immunodeficiency syndrome characterized by recurrent infections, neurological dysfunction, and autoimmunity. Early diagnosis and hematopoietic stem cell transplantation may reverse the dismal prognosis in PNP deficiency. This report presents a new PNP deficiency case successfully transplanted without a conditioning regimen from an HLA‐identical family donor, who developed a complication of disseminated BCG infection.

Randomized, Double-blinded, Placebo-controlled Trial of Early Administration of Recombinant Human Granulocyte Colony-stimulating Factor to Non-neutropenic Preterm Newborns Between 33 and 36 Weeks with Presumed Sepsis

A randomized, double-blinded, placebo-controlled trial was conducted of early administration of recombinant granulocyte colony-stimulating factor (rGCSF) to 40 non-neutropenic, preterm infants between 33 and 36 weeks of gestational age with the diagnosis of presumed sepsis. The treatment group (n = 20) received 5 μg/kg per day of intravenous rGCSF once daily for 3 d and the control group (n = 20) received the same volume of physiological serum. Immediately before the first dose and on the 4th day, plasma levels of GCSF and tumour necrosis factor-α (TNF-α), absolute neutrophil counts (ANC), immature neutrophil count (INC), immature/total neutrophil (I/T) ratios and platelet counts were determined. At study entry, the plasma GCSF and TNF-α levels were similar. On day 4, there was no significant change in GCSF levels in either groups, whereas there was a significant decrease in TNF-α levels in the treatment group. ANC and INC of the treatment group also increased significantly. The I/T ratio continued at the same level in the treatment group, but decreased significantly on days 4 and 7 day in the control group. The length of time on the neonatal intensive care unit (NICU) was significantly shorter in the treatment group. In conclusion, early administration of 3 daily doses of rGCSF (5 μg/kg per day) to non-neutropenic, preterm infants who had presumed sepsis increased circulating ANC and INC, decreased plasma TNF-α levels and shortened the length of time on the NICU.

Novel NLRP12 mutations associated with intestinal amyloidosis in a patient diagnosed with common variable immunodeficiency.

Heterozygous mutations in the NLRP12 gene have been found in patients with systemic auto-inflammatory diseases. However, the NLRP12-associated periodic fever syndromes show a wide clinical spectrum, including patients without classical diagnostic symptoms. Here, we report on a 20-year-old female patient diagnosed with common variable immunodeficiency (CVID), who developed intestinal amyloidosis and carried novel compound heterozygous mutations in NLRP12, identified by whole exome and transcriptome sequencing. CVID is a primary immunodeficiency characterized by low serum immunoglobulins, recurrent bacterial infections and development of malignancy, but it also presents with a magnitude of autoimmune features. Because of the unspecific heterogeneous clinical features of the disease, a delay in diagnosis is common. Secondary, inflammatory (AA type) amyloidosis has infrequently been observed in CVID patients. Based on our case observation and a critical review of the literature, we suggest that NLRP12 mutations might account for a small fraction of CVID patients with severe auto-inflammatory complications.

Could familial Mediterranean fever gene mutations be related to PFAPA syndrome

The cause and pathophysiology of PFAPA syndrome is unknown. The aim of this study was to determine all MEFV gene variants relevant to familial Mediterranean fever in children with PFAPA syndrome.

Comparison of major lymphocyte subpopulations and recent thymic emigrants in patients with ataxia telangiectasia and age-matched healthy groups.

BACKGROUND Ataxia telangiectasia (A-T) is a genetic disorder caused by the homozygous mutation of the A-T mutated gene. It is frequently associated with variable degrees of cellular and humoral immunodeficiency. However, the immune defects in A-T patients are not well characterized. To the best of our knowledge, no studies have focused on the major lymphocyte subpopulations and recent thymic emigrants of A-T patients in comparison with age-matched healthy controls. METHODS Following the European Society for Immunodeficiencies criteria, 17 patients diagnosed with A-The, and 12 age-matched healthy children were assigned to the study. Both patients and healthy controls were grouped as 1-5, 6-10, 11-15, and 15+ years. By using a flow cytometer, major lymphocyte subpopulations and CD4+CD45RA+CD31+ recent thymic emigrants were determined as percentage and absolute cell numbers and compared. RESULTS No significant differences in all lymphocyte subpopulations were observed between the age groups of A-T patients. Compared to the healthy controls, there was a decrease in T cells, effector memory T4 cells, B cells, naïve B cells, naïve T4 cells, switched B cells, and recent thymic emigrants and an increase in active T8 cells and non-switched B cells in the percentage and absolute number of some cell populations in the A-T group. CONCLUSIONS This study showed that effector functions in some cell lymphocyte populations were decreased in A-T patients.

An evaluation of vitamin D levels in children with seasonal allergic rhinitis during pollen season

Serum vitamin D levels have not been studied in children with seasonal allergic rhinitis (SAR). The aim of this study was to evaluate the vitamin D levels of children with SAR and to compare them to levels in healthy children during pollen season.

Vesicourethral reflux-induced renal failure in a patient with ICF syndrome due to a novel DNMT3B mutation.

ICF syndrome is a primary immunodeficiency disease characterized by hypo‐ or agammaglobulinemia, centromeric instability mainly on chromosomes 1, 9, and 16 and facial anomalies. ICF syndrome presents with frequent respiratory tract infections in infancy. A 20‐month‐old female patient was referred to our clinic due to frequent lower respiratory tract infections. ICF syndrome was considered because of comorbidity of hypogammaglobulinemia, facial anomalies, and neuromotor growth retardation. Metaphase chromosome analysis revealed centromeric instability on chromosomes 1, 9, and 16 and through Sanger a previously unreported homozygous missense mutation (c.1805T>C; [p.V602A]) was identified in the DNMT3B, confirming ICF1. The patient was found to have a breakdown in renal function 1 year later; the urinary system was examined and bilateral vesicoureteral reflux was found, warranting the need for dialysis in time. This report expands the mutation spectrum of ICF1 and is the first to describe bilateral vesicoureteral reflux accompanying ICF syndrome.

Effects of circulating endothelial progenitor cells, serum vascular endothelial growth factor and hypogammaglobulinemia in Perthes disease

OBJECTIVE The aim of this study was to investigate Legg-Calvé-Perthes disease (PD) pathogenesis by comparing absolute circulating endothelial progenitor cell (EPC) counts, serum levels of vascular endothelial growth factor-A (VEGF-A) and immunoglobulins between PD patients and controls. METHODS The study included 28 PD cases (mean age: 8 ± 3.8) and 25 healthy age-matched control subjects. EPC, serum VEGF-A and immunoglobulin levels were measured in peripheral blood samples. Comparisons and correlation analysis were performed. RESULTS In the PD group, 17 subjects were in the fragmentation stage and 11 in the healing stage. Four patients had bilateral disease and 14 had hypogammaglobulinemia. Median EPC count of the PD group was 80 and was significantly higher than those of the control group (p=0.011). No significant difference was determined in serum VEGF-A levels (p=0.354). EPC count were inversely correlated with serum IgG levels of the PD group (r=0.403, p=0.03). Absolute EPC count was also significantly higher in the fragmentation stage than in the healing stage and were also greater in bilaterally affected than in unilaterally affected patients. Circulating EPC count was correlated to the serum VEGF-A levels in patients with fragmentation stage of PD (r=0.605, p=0.01) and in those with hypogammaglobulinemia (r=0.599, p=0.001). CONCLUSION High EPC count at the fragmentation stage of PD and relatively higher counts in bilateral disease suggest that EPC may be a valuable marker in the diagnosis and follow-up of PD. Additional studies are needed to explain the strong correlation between EPC and serum VEGF-A level in the fragmentation stage and in the presence of hypogammaglobulinemia.