Lactate dehydrogenase contribution to symptom persistence in long COVID: A pooled analysis

Abstract

AbstractThere's critical need for risk predictors in long COVID. This meta‐analysis evaluates the evidence for an association between plasma lactate dehydrogenase (LDH) and long COVID and explores the contribution of LDH to symptoms persistent across the distinct post‐acute sequelae of COVID‐19 (PASC) domains. PubMed, EMBASE, Web of Science, and Google Scholar were searched for articles published up to 20 March 2023 for studies that reported data on LDH levels in COVID‐19 survivors with and without PASC. Random‐effect meta‐analysis was employed to estimate the standardized mean difference (SMD) with corresponding 95% confidence interval of each outcome. There were a total of 8289 study participants (3338 PASC vs. 4951 controls) from 46 studies. Our meta‐analysis compared to the controls showed a significant association between LDH elevation and Resp‐PASC [SMD = 1.07, 95%CI = 0.72, 1.41, p = 0.01] but not Cardio‐PASC [SMD = 1.79, 95%CI = −0.02, 3.61, p = 0.05], Neuro‐PASC [SMD = 0.19, 95%CI = −0.24, 0.61, p = 0.40], and Gastrointestinal‐PASC [SMD = 0.45, 95%CI = −1.08, 1.98, p = 0.56]. This meta‐analysis suggests elevated LDH can be used for predicting Resp‐PASC, but not Cardio‐PASC, Neuro‐PASC or gastrointestinal‐PASC. Thus, elevated plasma LDH following COVID infection may be considered as a disease biomarker.