Differences in HTLV-I integration patterns between skin lesions and peripheral blood lymphocytes of HTLV-I seropositive patients with cutaneous lymphoproliferative disorders.

We examined HTLV-I integration patterns in nine cases of HTLV-I-seropositive patients with cutaneous lymphoproliferative disorders. The Southern blot on EcoRI digests of DNA revealed a discrete band of HTLV-I provirus (monoclonal integration) in either skin lesions or peripheral blood lymphocytes (PBL). Four cases showed the monoclonal integration of HTLV-I provirus only in skin lesions: one case showed only in PBL and two cases showed in both skin and PBL. The Southern blot on PstI digests of DNA revealed a 2.4 Kb band of the internal construct of HTLV-I provirus (polyclonal integration) in the PBL of EcoRI-negative samples. The difference in HTLV-I integration patterns between skin lesions and PBL in these cases suggests that the monoclonal outgrowth of HTLV-I-infected cells in the skin is causatively associated with the pathogenesis of cutaneous ATL.