We investigated the effect of reticulocytosis on the lactate dehydrogenase (LD;EC 22.214.171.124) 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.
All Science Journal Classification (ASJC) codes
- Clinical Biochemistry
- Biochemistry, medical