Changes of lactate dehydrogenase and its isoenzyme activity in renal diseases

Analysis of the five different serum isoenzymes of lactate dehydrogenase (LDH) is of great value in the differential diagnosis of various diseases. In order to investigate the changes of serum LDH isoenzymes in several renal diseases, 44 patients with Korean hemorrhagic fever, 10 patients with chronic renal failure, 10 patients with nephrotic syndrome, and 15 healthy subjects were studied. The isoenzymes of LDH were determined by the Helena LDH isoenzyme electrophoresis procedure. LDH1 was 22.3 +/- 2.8, LDH2 29.4 +/- 5.1, LDH3 20.8 +/- 4.5, LDH4 9.0 +/- 2.7 and LDH5 8.8 +/- 3.2 mU/ml in healthy subjects. In patients in the oliguric stage of Korean hemorrhagic fever, LDH1 was 63.4 +/- 28.5, LDH2 99.7 +/- 40.7, LDH3 107.5 +/- 39.0, LDH4 41.9 +/- 32.8 and LDH5 37.2 +/- 26.3 mU/ml, while LDH1 was 23.8 +/- 11.7, LDH2 38.9 +/- 14.6, LDH3 36.0 +/- 18.7, LDH4 13.8 +/- 13.0 and LDH5 12.7 +/- 7.6 mU/ml in nonoliguric patients. In patients with chronic renal failure LDH1 was 33.2 +/- 10.8, LDH2 41.9 +/- 13.3, LDH3 27.7 +/- 8.5, LDH4 12.1 +/- 6.2 and LDH5 12.3 +/- 5.8 mU/ml. In patients with nephrotic syndrome, LDH1 was 25.1 +/- 4.3, LDH2 33.5 +/- 4.9, LDH3 23.1 +/- 6.2, LDH4 8.4 +/- 3.7 and LDH5 8.4 +/- 3.4 mU/ml. In summary, LDH3 activity was elevated in the oliguric stage of Korean hemorrhagic fever and LDH2 was elevated in chronic renal failure; those values were correlated with the BUN level.