Immunological studies on opportunistic infection and the development of adult T-cell leukemia.

Three patients with opportunistic infection preceding adult T-cell leukemia (ATL) are presented: a 66-year-old woman with cryptococcosis and Pneumocystis carinii pneumonia, a 46-year-old man with Pneumocystis carinii pneumonia, and a 55-year-old woman with cryptococcosis. Although, at the first examination, the first two had smoldering type ATL and the third case was an HTLV-I carrier, all three developed overt ATL 14-16 months after the onset of opportunistic infection. It is considered that there is immune suppression already present in HTLV-I carriers and in patients with smoldering ATL, and opportunistic infection is predictive of the development of ATL.