To clarify the pathogenesis of CVID and IgAD of Japanese patients, we investigated the mutations of TNF family members TACI, APRIL, B-cell activating factor (BAFF), B-cell maturation antigen (BCMA) and BAFF receptor (BAFF-R) genes and the expression levels of BAFF and APRIL in patients with CVID, IgAD and X-linked agammaglobulinaemia (XLA).
sBCMA level is profoundly reduced in patients with severe PAD, including those with CVID and XLA and those with IgG levels of less than 600 mg/dL. sBCMA level measurement has potential to augment clinical evaluation of PAD.