Phenotypic and Genotypic Changes in CVID Patients

Abstract

Common variable immunodeficiency (CVID) is a humoral immunodeficiency. In recent years, the discovery of related genes has broadened, including TACI, ICOS, CD19, CD20, CD81 and BAFF-R. We selected 20 CVID patients and 20 controls. We evaluated CD154 in T cells, markers in B cells (CD19, CD20, CD21, CD40, BAFF-R, CD5, CD27, IgM and IgD), PBMC cultures, and sequencing of the TACI, BAFF and BAFF-R genes. The genotyping of TACI showed 5/17 patients presented allelic variants: a non-pathogenic allelic variant in exon 2 (G>A in g19525, c94), a previously described mutation in exon 3 (g23216T>C; c310 T>C; p C104R), one intronic SNP in g23376 A>C, a heterozygous SNP at position g31695 A>T, possibly pathogenic and not previously described in exon 4, and a heterozygous SNP g32491T>C. The genotyping of BAFF showed one previously unpublished heterozygous allelic variant (g336A>G, c69A>G), but predicted to be a non-pathogenic polymorphism. The evaluation of BAFF-R genotype showed an intronic homozygous genetic variant in g1027T>A, between exons 2 and 3, not previously described and predicted as pathogenic, affecting the splice-site of exon 3.