Diagnostic value of lactate dehydrogenase in COVID-19: A systematic review and meta-analysis.

Background: This meta-analysis outlines the role of elevated lactate dehydrogenase (LDH) levels in assessing the severity of coronavirus disease 2019 (COVID-19).

Methods: The current study was designed as a systematic review and meta-analysis. Embase, Pub- Med, Web of Science, Scopus and Cochrane Central Register of Controlled Trials were searched to identify the usefulness of LDH as a marker of COVID-19 severity. All extracted data were analyzed using RevMan V.5.4 or STATA V.14 software.

Results: A total of 264 records were selected for this meta-analysis. Pooled analysis showed that LDH levels were statistically significantly lower in the group of survivors compared to patients who died in hospital (standardized mean differences [SMD] = -3.10; 95% confidence interval [CI]: -3.40 to -2.79; I2 = 99%; p < 0.001). Lower LDH levels were observed in non-severe groups compared to severe course of COVID-19 (SMD = -2.38; 95% CI: -2.61 to -2.14; I2 = 99%; p < 0.001). The level of LDH was statistically significantly lower in the severe group compared to the critical group (SMD = -1.48; 95% CI: -2.04 to -0.92; I2 = 98%; p < 0.001). Patients who did not require treatment in the intensive care unit (ICU) showed significantly lower levels of LDH compared to patients who required treatment in the ICU (SMD = -3.78; 95% CI: -4.48 to -3.08; I2 = 100%; p < 0.001).

Conclusions: This meta-analysis showed that elevated LDH was associated with a poor outcome in COVID-19.