Risk is slightly increased in people with Certain types of immunosuppression (eg, posttransplant patients taking immunosuppressants) Congenital immunodeficiency disorders (eg, ataxia-telangiectasia, Klinefelter syndrome, Chédiak-Higashi syndrome, Wiskott-Aldrich syndrome) Certain autoimmune disorders (rheumatoid arthritis, celiac disease, Sjögren syndrome, systemic lupus erythematosus) Most patients also develop a slowly progressive defect in cell-mediated immunity (T-cell function) that, in advanced disease, contributes to common bacterial and unusual fungal, viral, and protozoal infections.