Lactate dehydrogenase, an independent risk factor of severe COVID-19 patients: a retrospective and observational study

Abstract

Background: The World Health Organization has declared coronavirus disease 2019 (COVID-19) a public health emergency of global concern. Updated analysis of cases might help identify the risk factors of illness severity.

Results: The median age was 63 years, and 44.9% were severe cases. Severe patients had higher APACHE II (8.5 vs. 4.0) and SOFA (2 vs. 1) scores on admission. Among all univariable parameters, lymphocytes, CRP, and LDH were significantly independent risk factors of COVID-19 severity. LDH was positively related both with APACHE II and SOFA scores, as well as P/F ratio and CT scores. LDH (AUC = 0.878) also had a maximum specificity (96.9%), with the cutoff value of 344.5. In addition, LDH was positively correlated with CRP, AST, BNP and cTnI, while negatively correlated with lymphocytes and its subsets.

Conclusions: This study showed that LDH could be identified as a powerful predictive factor for early recognition of lung injury and severe COVID-19 cases.

Methods: We extracted data regarding 107 patients with confirmed COVID-19 from Renmin Hospital of Wuhan University. The degree of severity of COVID-19 patients (severe vs. non-severe) was defined at the time of admission according to American Thoracic Society guidelines for community acquired pneumonia.

Keywords: COVID-19; coronavirus disease 2019; inflammatory response; lactate dehydrogenase (LDH); lung injury.

Figure 1

Predictive factors correlated with severity of COVID-19 patients. Correlation analysis was performed between candidate indicators with APACHE II score. (A) Lymphocyte counts was negatively correlated with APACHE II; (B–D) AST, CRP and LDH were positively correlated with APACHE II.

Figure 2

Predictive factors correlated with lung injury of COVID-19 patients. Correlation analysis was performed between the indicators with P/F ratio. (A–C) Lymphocyte counts, AST and CRP were not correlated with P/F ratio; (D), LDH was negatively correlated with P/F ratio.

Figure 3

ROC curve and cutoff value of predictive factors. The factors for the prediction of COVID-19 patients getting severe condition. (A–F) ROC curve of lymphocytes, AST, CRP, LDH, P/F ratio, and APACHE II. AUC, area under curve.

Figure 4

Relationship between LDH and inflammation, cardiac and liver injury. Pearson correlation analysis was performed between the indicators with the serum LDH level. (A–D) LDH was negatively correlated with lymphocyte and its subsets; (E–H) LDH was positively correlated with AST, CRP, BNP and cTnI.