Allogeneic hematopoietic stem cell transplantation outcome in oldest known surviving patients with Wiskott-Aldrich syndrome

Regardless of their age, adult patients with Wiskott-Aldrich syndrome should be considered for hematopoietic stem cell transplantation if clinically indicated

Loss of function NFKB1 variants are the most common monogenic cause of CVID in Europeans.

BACKGROUND: The genetic etiology of primary immunodeficiency disease (PID) carries prognostic information. OBJECTIVE: We conducted a whole-genome sequencing study assessing a large proportion of the NIHR-BioResource - Rare Disease cohort. METHODS: In the predominantly European study population of principally sporadic unrelated PID cases (n=846), a novel Bayesian method identified NFKB1 as one most strongly associated with PID, and the association was explained by 16 novel heterozygous truncating, missense and gene deletion variants. This accounted for 4% of common variable immunodeficiency (CVID) cases (n=390) in the cohort. Amino-acid substitutions predicted to be pathogenic were assessed by analysis of structural protein data. Immunophenotyping, immunoblotting and ex vivo stimulation of lymphocytes determined the functional effects of these variants. Detailed clinical and pedigree information was collected for genotype-phenotype co-segregation analyses. RESULTS: Both sporadic and familial cases demonstrated evidence of the non-infective complications of CVID, including massive lymphadenopathy (24%), unexplained splenomegaly (48%) and autoimmune disease (48%), features prior studies correlate with worse clinical prognosis. Although partial penetrance of clinical symptoms was noted in certain pedigrees, all carriers have a deficiency in B lymphocyte differentiation. Detailed assessment of B lymphocyte numbers, phenotype and function identifies the presence of a raised CD21lowB cell population: combined with identification of the disease-causing variant, this distinguishes between healthy individuals, asymptomatic carriers and clinically affected cases. CONCLUSION: We show that heterozygous loss-of-function variants in NFKB1 are the most common known monogenic cause of CVID that results in a temporally progressive defect in the formation of immunoglobulin-producing B cells.This study was supported by The National Institute for Health Research England (grant number RG65966), and by the Center of Immunodeficiencies Amsterdam (CIDA). JET is supported by an MRC Clinician Scientist Fellowship (MR/L006197/1). AJT is supported by both the Wellcome Trust (104807/Z/14/Z) and by the National Institute for Health Research Biomedical Research Centre at Great Ormond Street Hospital for Children NHS Foundation Trust and University College London. EO receives personal fees from CSL Behring and MSD

First case series of clozapine induced hypogammaglobulinaemia in England

Evidence is emerging that clozapine can adversely affect immunoglobulin levels. We present a case series of 17 clozapine-treated patients referred to clinical immunology centres in the north west of England with otherwise-unexplained hypogammaglobulinaemia. This adds to existing evidence and suggests that clozapine can cause clinically significant antibody deficiency that will sometimes require specialist intervention. We speculate that this putative drug toxicity could be mediated via interaction with PI3K (phosphatidylinositol-3-kinase) signalling pathways involved in the development and homeostasis of B cells. It may be advisable to monitor immunoglobulin levels in patients being treated with clozapine.</p