Blood biochemical parameters as predictors of disease severity and mortality in COVID-19 patients- an updated systematic review and meta-analysis

BackgroundThe outbreak of coronavirus disease 2019 (COVID-19) has been rapidly spreading across the globe and poses a great risk to human health. Patients with abnormalities in laboratory parameters are more susceptible to COVID-19. Therefore, we explored the association of blood biochemical parameters with severity and mortality of COVID-19 amongst 3695 patients across seventeen studies. MethodsWe searched PubMed, Cochrane library and LitCOVID database until February 28, 2021. Seventeen studies were included in the meta-analysis with 3695 COVID-19 patients. ResultsThe pooled analysis showed that compared to non-severe group, severe group was characterised by significantly elevated alanine aminotransferase (ALT) (standardised mean difference [SMD]: 0.65, 95% confidence interval [CI]: 0.23 to 1.06; p<0.001, erythrocyte sedimentation rate (ESR) (SMD: 0.55, 95%CI: 0.02 to 1.07 p=0.004) and lymphopenia (SMD: -1.22, 95% CI: -2.15 to -0.30; p<0.01), decreased serum albumin (SMD: -1.60, 95% CI: -2.96 to -0.22 ; p<0.001), creatinine (SMD: 0.54, 95% CI: 0.17 to 0.90; p<0.001), lactate dehydrogenase (LDH)(SMD: -1.54, 95% CI: - 2.27 to -0.80; p=0.002) and haemoglobin (SMD:-0.89, 95% CI: ; p<0.001). Additionally, in the non-survivor group, elevated lactate dehydrogenase (LDH) (SMD: 1.54 95% CI: -2.27 to 0.80; p=0.002), decreased serum albumin (SMD: 1.08, 95% CI: 0.75 to 1.42; p<0.001) were reported. There was no comorbidity which was found to be significant in the severe group. ConclusionSerum albumin, ALT, ESR, lymphopenia, haemoglobin, and leucocytosis can reflect the severity of COVID-19, while the LDH, leucocytosis and albumin can be considered as risk factor to higher mortality. SummaryOur manuscript discusses the various blood biochemical markers as potential predictors of disease severity and mortality in COVID-19 patients. The timely detection of these parameters can help in providing appropriate course of treatment and reducing the mortality rate in the patients. We have found an association between the blood biochemical markers and disease severity and mortality in COVID-19 patients. Serum albumin, alanine aminotransferase (ALT), Erythrocyte Sedimentation Rate (ESR), lymphopenia, hemoglobin, and leukocytosis can reflect the severity of the disease, while the LDH, leukocytosis and albumin can be considered as risk factor to higher mortality.