[Treatment of adult T-cell leukemia with intravenous administration of IFN-gamma-immunohistochemical studies of infiltrating cells in cutaneous lesions].

Three cases of adult T-cell leukemia (ATL) with cutaneous lesions of disseminated papules or nodules were treated with recombinant human interferon-gamma (IFN-gamma) by intravenous administration. Clinical stage of each case was different, i.e., 1) preleukemic state of ATL (pre-ATL), 2) chronic-type ATL, and 3) crisis-type ATL. We evaluated clinical efficacy of IFN-gamma, and performed immunohistochemical analysis of biopsy specimens derived from cutaneous lesions of the patients both before and during treatment. The case of pre-ATL achieved a complete remission of cutaneous lesions for 18 months. The other cases also obtained clinical responses with a shorter duration, but relapsed while they are still on IFN-gamma therapy. The cutaneous lesions reduced in size during the therapy associated with a decrease in the ratio of Leu3a + 3b (CD4)+ cells in all three cases. After the therapy, Leu7 (HNK-1)+ cells increased in all cases, and LeuM5 (CD11)+ cells did in two. These results suggested that IFN-gamma enhanced tumor immunity although its clinical effect was less clear. Only in the cutaneous lesions of pre-ATL case an increased number of LeuM5+ cells, probably monocyte-macrophage series in host defence, were seen before the therapy. And IFN-gamma was useful for this case after all.