Clinical description of 44 patients with acute promyelocytic leukemia who developed the retinoic acid syndrome

We examined the incidence, clinical course, and outcome of patients with ne wly diagnosed acute promyelocytic leukemia (APL) who developed the retinoic acid syndrome (RAS) treated on the intergroup Protocol 0129, which prospec tively evaluated the role of all-trans retinoic acid (ATRA) alone during in duction and as maintenance therapy. Forty-four of 167 (26%) patients receiv ing ATRA for induction developed the syndrome at a median of 11 days of ATR A (range, 2-47), The median white blood cell (WBC) count was 1450/mu L at d iagnosis and was 31 000/mu L (range, 6800-72 000/mu L) at the time the synd rome developed. ATRA was discontinued in 36 of the 44 patients (82%) and co ntinued in 8 patients (18%), with subsequent resolution of the syndrome in 7 of the 8. ATRA was resumed in 19 of the 36 patients (53%) in whom ATRA wa s stopped and not in 17 (47%). The syndrome recurred in 3 of those 19 patie nts, with 1 death attributable to resumption of the drug. Ten of these 36 p atients received chemotherapy without further ATRA, and 8 achieved complete remission (CR), Among 7 patients in whom ATRA was not restarted and were n ot treated with chemotherapy, 5 achieved CR and 2 died. Two deaths were def initely attributable to the syndrome. No patient receiving ATRA as maintena nce developed the syndrome. (C) 2000 by The American Society of Hematology.