A CASE WITH YEARS IN THE MAKING

Introduction The immune system dysregulation that occurs in some cases of immunodeficiency manifests itself by autoimmunity and malignancy. These complications may be more likely to occur in patients with specific genetic defects that lead to common variable immunodeficiency (CVID). Case Description A 48-year-old woman with a history of frequent respiratory tract infections and CVID on immunoglobulin replacement has been followed in our immunology clinic for 11 years. In the 18 years since diagnosis of CVID, she has also been diagnosed with type 1 diabetes mellitus, hypothyroidism, rheumatoid arthritis, Non-Hodgkin's Lymphoma, and enteropathy. An immunoglobulin G level obtained at the age of 30 revealed an IgG of 672 mg/dL (low). At age 38, she had the following findings: IgG Discussion CTLA4 plays an active role in self-tolerance, as it is an inhibitory molecule located on T cells to help regulate T cell responses. Mutations in this protein can lead to improper regulation, and therefore, autoimmunity and organ infiltration by T cells. CTLA4 haploinsufficiency has been identified as one of the mutations which may lead to a CVID phenotype.