Mild Hypogammaglobulinemia Can Be a Serious Condition.

Most patients with primary antibody deficiency (PAD) suffer from less well-described and understood forms of hypogammaglobulinemia (unclassified primary antibody deficiency, unPAD). Because of the moderately decreased immunoglobulin levels compared to CVID, unPAD is generally considered to be clinically mild and not very relevant. To describe our cohort of-mainly-unPAD patients, and to analyze whether subgroups can be identified.