Spontaneous regression associated with apoptosis in a patient with acute-type adult T-cell leukemia

We describe a 76-year-old man with acute-type adult T-cell leukemia, who de monstrated a spontaneous decrease in leukemic cell number, apparently coinc ident with apoptotic cell death. On admission the patient's white blood cel l count was 38.9 x 10(9)/l with 97% abnormal lymphocytes, He also had hypop roteinemia (4.3 g/dl) from protein losing enteropathy, After admission the leukemic cell count decreased without chemotherapy, reaching 5.9 x 10(9)/l after 2 months. Studies of peripheral lymphocytes demonstrated appearance o f the apoptotic cells and DNA ladder formation from the beginning of regres sion. Same truncated proviral DNA was recognized in primary ATL cells throu gh the whole clinical course. The hypoproteinemia improved with intravenous nutrition, followed by increase of the leukemic cells. This case is the fi rst report that demonstrates tumor-cell apoptosis induced clinical regressi on in adult T-cell leukemia, Further, we speculate that the hypoproteinemia may have been involved in the leukemic cell apoptosis. Am. J, Hematol. 61: 144-148, 1999, (C) 1999 Wiley-Liss, Inc.