OBJECTIVE: To study the morphologic and cytogenetic change in acute promyelocytic leukemia (APL) patients during the tetra-arsenic tetra-sulfide (TATS) treatment and the mechanism of TATS. METHODS: The bone marrow cells of 13 newly diagnosed and 7 recurrent APL patients were studied through FISH and morphology during the TATS treatment by special and repeated marrow culture. RESULTS: Cytomorphological study of 8 cases (6 untreated and 2 recurrent) showed that TATS could differentiate APL cells forward to mature granulocytes. There was obvious correlation between the reduced t (15; 17) positive cells and the reduced APL cells (r range 0.7298 - 0.9989). Except one patient with t (11; 17), 19 (13 untreated and 7 recurrent) with translocation t (15; 17) achieved clinical CR including 16 who achieved cytogenetic CR. CONCLUSION: TATS has a differentiation-inducing effect on untreated and recurrent APL, with haematological CR and cytogenetic CR achieved. Measurement of t (15; 17) positive cells by FISH technique can reflect the change of APL cells objectively.
OBJECTIVE: To study the morphologic and cytogenetic change in acute promyelocytic leukemia (APL) patients during the tetra-arsenic tetra-sulfide (TATS) treatment and the mechanism of TATS. METHODS: The bone marrow cells of 13 newly diagnosed and 7 recurrent APL patients were studied through FISH and morphology during the TATS treatment by special and repeated marrow culture. RESULTS: Cytomorphological study of 8 cases (6 untreated and 2 recurrent) showed that TATS could differentiate APL cells forward to mature granulocytes. There was obvious correlation between the reduced t (15; 17) positive cells and the reduced APL cells (r range 0.7298 - 0.9989). Except one patient with t (11; 17), 19 (13 untreated and 7 recurrent) with translocation t (15; 17) achieved clinical CR including 16 who achieved cytogenetic CR. CONCLUSION:TATS has a differentiation-inducing effect on untreated and recurrent APL, with haematological CR and cytogenetic CR achieved. Measurement of t (15; 17) positive cells by FISH technique can reflect the change of APL cells objectively.