Glutathione S-transferase activity of leukemic cells as a prognostic factor for response to chemotherapy in acute leukemias.

This paper presents an analysis of glutathione S-transferase (GST) activity of leukemic cells in 30 patients with acute leukemias and its predictive value for therapy. Blast cells were isolated from peripheral blood or bone marrow before induction therapy using Ficoll density gradient. GST activity was measured according to the spectrophotometric assay based on the use of 1-chloro-2,4-dinitrobenzene as a substrate. The results did not show any significant differences between activities of the enzyme within the different leukemia types according to the French-American-British (FAB) classification. The patients who achieved complete remission demonstrated the lowest value of enzyme activity. The highest enzyme activity was observed in those patients who achieved partial remission and the non-responsive patients presented a GST value within the median of these two groups. Two categories of patients were represented within the non-responsive treatment group. One was resistant to the conventional therapy and in the other death was caused by infectious or hemorrhagic complications. The mean GST activity in these two groups of patients differ greatly. These results suggest that low GST activity of leukemic cells could be a favourable prognostic factor whereas high GST values could help to find out the group of patients who should be further analysed prior to induction therapy.