[Pneumocystis carinii pneumonia in a HTLV-I carrier with monoclonal proliferation of HTLV-I infected lymphocyte].

A 63-year-old woman had Pneumocystis carinii pneumonia without any apparent underlying disease such as cancers or HIV infection. Although she reacted positively for HTLV-I antibody, hematological findings and clinical symptoms did not suggest that this patient had an ATL. Southern blot analysis revealed that HTLV-I infected lymphocytes had already proliferated monoclonally. The development of overt ATL should be carefully monitored in this type of patient as Pneumocystis carinii infection in HTLV-I carriers were reported to be a predictive sign of ATL and the monoclonal integration of a HTLV-I genome in the lymphocytes in this patient also suggests the presence of neoplastic clone.