Isoenzymes of lactate dehydrogenase in T lymphocytes in systemic lupus erythematosus

Active forms of systemic lupus erythematosus (SLE) are accompanied by a decrease in the number of T lymphocytes in the peripheral blood. This association may be related to an immunoregulatory disorder in SLE. Plum and Ringoir reported that lactate dehydrogenase (LDH) is a reliable marker for T and B lymphocytes in humans. In comparison with B lymphocytes, T lymphocytes have significantly greater LDH1 activity. The aim of our study was to investigate the activity of LDH isoenzymes in peripheral blood T lymphocytes of SLE patients. Since LDH1 is present in mature and fully functioning cells and LDH3 is typical in young functionally immature cells, the results indicate impaired T lymphocyte maturation in SLE patients and may be a sensitive reflection of the activity of the immune system. The decrease of activity of LDH1 isoenzymes may also imply impairment of aerobic glycolysis in the T lymphocytes in SLE patients.