Effect of indomethacin on lysosomal acid phosphatase activity in peripheral blood lymphocytes.

In 25 patients with discopathies and degenerative disease of the vertebral column, treated with indomethacin (Metindol, Polfa) in a dose of 100 mg per day during 10 days, the acid phosphatase (AP) activity was determined in the peripheral blood lymphocytes by means of the cytochemical method of Barka and Anderson. Indomethacin administration induced an increase of total lymphocytosis related to the elevation of the AP-negative lymphocyte count. These changes were accompained by an increased lymphocyte count including enzyme-positive lysosomal granules within their cytoplasm and a decrease of those showing diffuse enzymatic reaction and no granules. In the author's opinion, such changes reflect the stabilizing effect of indomethacin on lysosomal membranes within lymphocytes and a diminished release of this enzyme from lysosomes to the cytoplasm.