RESUMEN
Six Black patients (five born in the West Indies and one in Guyana), aged 21-55 years, had adult T-cell lymphoma-leukaemia diagnosed in the U.K. This disorder is rare in Europe and the U.S.A., but is more common in Japan. Five patients had severe hypercalcaemia which correlated with disease activity, although osteolytic lesions were found in only one. Other clinical features were lymphadenopathy and a high white blood-cell count (range 27-67 X 10(9)/l) with a predominance of pleomorphic lymphoid cells with pronounced nuclear irregularities prominent at ultrastructural level. The cells in all cases formed rosettes with sheep red blood-cells and lacked terminal transferase. Analysis with OKT monoclonal antibodies in four cases confirmed a mature T-cell phenotype defined as helper/inducer (T4+, T6-, T8-) in three. Combination chemotherapy resulted in short-lived remissions; four patients died and two have survived 3-6 months. The disease in these patients is indistinguishable on clinical and pathological grounds from adult T-cell leukaemia/lymphoma in Japan. Geographical clustering among certain racial groups suggests common aetiological factors in the pathogenesis of this disease. The finding of high titre antibody against the structural core protein (p24) of a new human C-type leukaemia virus (human T-cell leukaemia/lymphoma virus) in all tested cases from this series and data from all but one case from Japan suggest that one such factor may be viral.