Clinical immunology : the official journal of the Clinical Immunology Society
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Common variable immunodeficiency (CVID), the most common symptomatic primary antibody deficiency, is accompanied in some patients by a duodenal inflammation and malabsorption syndrome known as CVID enteropathy (E-CVID). The goal of this study was to investigate the immunological abnormalities in CVID patients that lead to enteropathy as well as the contribution of intestinal microbiota to this process. ⋯ Finally, we found that E-CVID patients exhibit a pronounced activation of immune genes and down-regulation of epithelial lipid metabolism genes. We conclude that in the virtual absence of mucosal IgA, pathobionts such as A. baumannii, may induce inflammation that re-directs intestinal molecular pathways from lipid metabolism to immune processes responsible for enteropathy.
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Activated phosphoinositide 3-kinase δ (PI3Kδ) syndrome is a newly defined and relatively common primary immunodeficiency, which is caused by heterozygous gain-of-function (GOF) mutations in PIK3CD or PIK3R1. Here, we report a novel de novo GOF mutation (c.1570 T > A, p. Y524N) in PIK3CD in a 6-year-old Chinese girl. ⋯ Hyperactivation of the PI3Kδ-Akt-mTOR signaling pathway was also confirmed. Treatment with rapamycin ameliorated the lymphoproliferative immunodeficiency caused by hyperactivation of mTOR. These results expand genetic spectrum of APDS and will facilitate further study of the genotype-phenotype correlation in those with PIK3CD mutations.