Abstract: Objective To evaluate the significance of activity ratio of pyruvate kinase （PK） to glucose-6-phosphate dehydrogenase（G6PD）in the diagnosis of PK deficiency. Methods A total of 40 patients diagnosed with pyruvate kinase deficiency（PKD）in the department of blood transfusion at our hospital from January 2015 to January 2022 were retrospectively analyzed. Healthy peoples made up the control group. The differences between the two groups in blood count, reticulocyte percentage（Ret）, peripheral blood smear and PK/G6PD activity ratio（recommended by ICSH） were compared, and the relationship between each index and PKD was analyzed. Results Compared with the control group, RBC decreased, Ret increased and PK/G6PD ratio decreased significantly in the PKD group（P<0.05）. The Pearson correlation coefficient between PK/G6PD ratio and PK activity was 0.913, and the area under the ROC curve when evaluating the diagnosis of PKD was 0.972（95% CI: 0.941~1.002）. The decrease of PK/G6PD ratio in heterozygotes was more severe than that in non-heterozygotes. Conclusion The ratio of PK/G6PD and the activity of PK have the same diagnostic value, especially for patients with increased reticulocyte and transfusion dependence. For PKD with recessive genetic defects, pedigree analysis is strong evidence for diagnosis.

Key words: Pyruvate kinase deficiency, PK/G6PD ratio, Reticulocyte, Family heterozygote