Late‐Onset Combined Immune Deficiency: A Subset of Common Variable Immunodeficiency with Severe T Cell Defect

BACKGROUND Common variable immunodeficiency (CVID) is a primary immune deficiency defined by defective antibody production. In most series, a small proportion of patients present with opportunistic infections (OIs). METHODS The French DEFI study has enrolled patients with primary hypogammaglobulinemia and allows a detailed clinical and immunologic description of patients with previous OIs and/or at risk for OIs. RESULTS Among 313 patients with CVID, 28 patients (8.9%) presented with late-onset combined immune deficiency (LOCID), defined by the occurrence of an OI and/or a CD4(+) T cell count