The Diagnosis of Common Variable Immunodeficiency After Multisystem Dysfunction.

Common variable immunodeficiency (CVID) is a primary immunodeficiency caused by the lack of B cell differentiation into plasma cells, thereby leading to decreased serum immunoglobulins. Patients with this condition are predisposed to recurrent infections and are more likely to develop certain cancers and autoimmune diseases. We report the case of a 53-year-old female suffering from recurrent pulmonary infections and a history of non-Hodgkin lymphoma (NHL) who had a poor response to the measles, mumps, and rubella (MMR) and varicella vaccines as a child, and was infected with coronavirus disease 2019 (COVID-19) twice in 2020. Testing of her antibody titers in order to determine suitability for vaccination found an overall decrease in major immunoglobulin classes (IgG, IgM, and IgA) and B cells with normal morphology. The diagnosis of CVID was made, and prompt treatment with intravenous immunoglobulins (IVIG) brought her IgG levels up from 282 to 680 mg/dL within three months. This case highlights the importance for providers to keep immunological dysfunction on their differentials for patients with atypical presentations involving multiple organ systems.