Expression of Proviral DNA Integration in Peripheral Blood Mononuclear Cells and Skin Lesions Derived from HTLV-1 infected Patients at Nagasaki University Hospital

Abstract

We used Southern blot to analyse HTLV-1 proviral DNA integration in peripheral blood mononuclear cells (PBMC) and skin lesion from 15 HTLV-1 antibody positive cases. Seven cases were positive for HTLV-1 proviral DNA integration in both PBMC and skin lesions, 5 cases were positive in the skin lesion only, and 3 cases were negative in both PBMC and skin lesions. The patients with positive HTLV-1 proviral DNA integration only in the skin lesion were older than those with positive results in both samples and showed rapid progression with a short clinical history of active skin lesions. No significantly different histopathological findings were obtained among the 3 groups. Elevated sIL-2R was observed in the patients with positive HTLV-1 proviral DNA integration in both tissues. The three of the cases with positive integration only in skin lesions had a poorer prognosis. Four out of the 5 cases with positive HTLV-1 proviral DNA integration only in the skin died after a short clinical course, contrasting with the good prognosis for the cases with positive HTLV-1 proviral DNA integration in both PBMC and skin lesions. These results indicate that the cutaneous type of ATL should be more widely recognized and more effective therapy is required to control skin lesions and prevent acute transformation to the leukemic stage.