Acquired immunodeficiency syndrome cause(s) still elusive

More than a year after the first reports of opportunistic infections and Kaposi's sarcoma (KS) among homosexual men and intravenous (IV) drug abusers, the medical community still is baffled by the alarming number of cases of acquired immunodeficiency syndrome (AIDS). Acquired immunodeficiency syndrome is the term that now is used to describe a diverse array of problems that may include the heretofore rare KS and other malignant neoplasms such as squamous cell carcinoma of the anus, as well as such opportunistic infections as pneumonia fromPneumocystis carinii(which generally attacks persons with deficient immune systems), cryptococcosis, or toxoplasmosis. The underlying defect appears to be one of diminished cellular immunity, although patients have no histories of immunodeficiencies, immunosuppressive therapies, or diseases that might affect the immune system. The diagnosis presently is considered only in persons younger than 60 years, because KS long has been known to occur in some older populations.