Use

This test is used for screening common variable immunodeficiency (CVID) and hyper-IgM syndromes. It also assesses B-cell subset reconstitution following stem cell or bone marrow transplant and the response to B-cell-depleting immunotherapy. CVID is the most common primary immunodeficiency characterized by hypogammaglobulinemia and impaired functional antibody responses, often with recurrent sinopulmonary infections. The test helps in diagnosing hyper-IgM syndromes, which feature defective isotype class-switching and reduced class-switched memory B cells. This test is not suitable for evaluating lymphoproliferative disorders such as leukemia, lymphoma, and multiple myeloma.