Diagnostic value of lactate dehydrogenase isoenzymes in children with refractory mycoplasma pneumoniae pneumonia / 中国医师进修杂志

ABSTRACT

Objective To investigate the diagnostic value of lactate dehydrogenase (LDH) isoenzymes in children with refractory mycoplasma pneumoniae pneumonia (RMPP). Methods One hundred and forty-seven children with mycoplasma pneumoniae pneumonia (MPP) in Children′s Medical Center, Dongfeng Hospital Affiliated to Hubei University of Medicine from July 2016 to July 2018 were selected. Among them, RMPP was in 54 cases (RMPP group), and non-RMPP was in 93 cases (non-RMPP group). The white blood cell count (WBC), C- reactive protein (CRP), erythrocyte sedimentation rate (ESR), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and creatine kinase (CK) were detected; meanwhile, the serum levels of total LDH and LDH isoenzymes (LDH1, LDH2, LDH3, LDH4 and LDH5) were measured by radioimmunoassay. Results The ESR, AST, ALT, LDH1, LDH2, LDH4, LDH5 and total LDH in RMPP group were significantly higher than those in non-RMPP group(23.15 ± 3.62) mm/h vs. (19.45 ± 3.04) mm/h, (37.20 ± 6.82) U/L vs. (31.49 ± 4.70) U/L, (35.48 ± 5.72) U/L vs. (27.31 ± 7.22) U/L, (89.77 ± 5.26) U/L vs. (85.01 ± 7.65) U/L, (154.60 ± 22.30) U/L vs. (133.17 ± 32.82) U/L, (61.51 ± 10.09) U/L vs. (47.74 ± 11.22) U/L, (78.99 ± 12.86) U/L vs. (64.98 ± 7.14) U/L and (511.49 ± 38.90) U/L vs. (450.19 ± 47.63) U/L, and there were statistical differences (P＜0.05); there were no statistical differences in WBC, CRP, CK and LDH3 between 2 groups (P＞0.05). Logistic regression analysis result showed that the ESR, AST, ALT, LDH1, LDH4 and LDH5 were the risk factors of RMPP ( OR=0.618, 0.735, 0.785, 0.769, 0.866, 0.880; 95% CI 0.430 to 0.888, 0.596 to 0.906, 0.665 to 0.926, 0.646 to 0.917, 0.781 to 0.961, 0.803 to 0.965; P<0.01). Receiver operating characteristic curve analysis result showed that the area under curve (AUC) of RMPP predicted by LDH5 was the largest (0.857), and then by LDH4 (0.819). The critical values were 70.74 and 53.14 U/L respectively; the AUC of RMPP predicted by LDH4 combined with LDH5 was 0.914, and the critical values was 130.10 U/L, with a sensitivity of 83.3% and a specificity of 92.5% , 95% CI 0.856 to 0.954. Conclusions Serum levels of LDH4 and LDH5 are significantly increased in children with RMPP. LDH4 combine with LDH5 detection might be useful in predicting the occurrence of RMPP.