Effect of reticulocytosis on lactate dehydrogenase isoenzyme distribution in serum: in vivo and in vitro studies.
We investigated the effect of reticulocytosis on the lactate dehydrogenase (LD; EC 1.1.1.27) isoenzyme LD1/LD2 ratio in patients with and without evidence of hemolytic disease. Analysis of sera from patients with reticulocytosis and in vivo hemolysis showed a mean LD1/LD2 ratio of 0.92 compared with a ratio of 0.69 in patients with in vivo hemolysis and normal reticulocyte counts. Determination of LD isoenzymes in erythrocyte lysate revealed significantly increased LD1/LD2 ratios for patients with marked reticulocytosis compared with those for patients with normal-to-minimal increases in reticulocytes. Finally, separation of mature erythrocytes and reticulocytes by flow cytometry revealed marked differences in the LD1/LD2 isoenzyme distribution between these two cell types. The ability of hemolysis to cause a "flipped" LD1/LD2 ratio is dependent on the proportion of the hemolyzed cells that are reticulocytes.
Department of Clinical Pathology, East Carolina University School of Medicine, Greenville, NC 27858.
S C
SC
Kazmierczak
W J
WJ
Castellani
F
F
Van Lente
E D
ED
Hodges
B
B
Udis
D002478:Cells, Cultured; D004906:Erythrocyte Count; D004912:Erythrocytes / Q000201:enzymology; D005434:Flow Cytometry; D006242:Haptoglobins / Q000032:analysis; D006402:Hematologic Diseases / Q000097:blood* / Q000201:enzymology; D006461:Hemolysis / Q000502:physiology; D006801:Humans; D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase / Q000097:blood*; D012156:Reticulocytes / Q000201:enzymology*
D006242:Haptoglobins; D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase