Existence of tartaric acid-resistant acid phosphatase in adult T cell leukemia and B-CLL and its significance

Acid phosphatase isozyme patterns in normal peripheral lymphocytes and various lymphoid leukemia cells were examined by polyacrylamide gel electrophoresis. Five fractions (F-I, F-II, F-III, F-IV, F-V) were separated by this method. F-V activity was different from the others in its resistance to L(+)-tartaric acid treatment. It was generally accepted that F-V was characteristic of hairy cell leukemia; however, our results revealed that F-V existed not only in hairy cell leukemia cells but also in adult T-cell leukemia cells, B-CLL cells, and normal T-enriched and T-depleted cell populations. F-V existed neither in null-ALL, T-ALL nor in B-ALL, which might deviate from immature lymphocytes. From the above results, we suggest that tartaric acid-resistant acid phosphatase activity (F-V) may be one of the markers of the differentiation of lymphocytes.