Isoenzymatic study of leucocytic acid phosphatase in haematologic diagnosis.

Isoenzymatic study of leucocytic acid phosphatase under normal conditions identifies 3 isoenzymatic bands, which exhibit a noticeable cell specificity. Band 2 is granulocytic, band 3 lymphocytic and band 4 monocytic in origin. Pathologic deviations in the isoenzymatic pattern are both qualitative and quantitative. For some diseases such as chronic lymphocytic leukaemia there is a well-defined, differential pattern according to immunological B- or T-cell origin. The more significant qualitative aspects are related to the appearance of abnormal bands, especially band 3b, indicating blastic cellularity, and 5, corresponding to hairy cells. The isoenzymatic analysis of acid phosphatase activity is a simple haematologic complementary test, particularly useful in the differential diagnosis of lymphoproliferative disorders with peripheral blood manifestations.