The
primary antibody deficiency syndromes are a group of rare disorders characterized by an inability to produce clinically effective
immunoglobulin responses. Some of these disorders result from genetic mutations in genes involved in B cell development, whereas others appear to be complex polygenic disorders. They most commonly present with
recurrent infections due to encapsulated bacteria, although in the most common antibody deficiency,
Common Variable Immunodeficiency, systemic and organ-specific autoimmunity can be a presenting feature. Diagnostic delay in this group of disorders remains a problem, and the laboratory has a vital role in the detection of abnormalities in
immunoglobulin concentration and function. It is critical to distinguish this group of disorders from secondary causes of hypogammaglobulinaemia, in particular lymphoid
malignancy, and appropriate laboratory investigations are of critical importance. Treatment of
primary antibody deficiencies involves
immunoglobulin replacement
therapy, either via the intravenous or subcutaneous route. Patients remain at risk of a wide variety of complications, not all linked to diagnostic delay and inadequate
therapy. In
common variable immunodeficiency (CVID) in particular, patients remain at significantly increased risk of lymphoid
malignancy, and regular clinical and laboratory monitoring is required. This review aims to give an overview of these conditions for the general reader, covering pathogenesis, clinical presentation, laboratory investigation,
therapy and clinical management.