Correlation of Viral Load With the Clinical and Biochemical Profiles of COVID-19 Patients.

Background/objective Coronavirus infectious disease (COVID-19) is a novel disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-COV-2). Some studies have shown that disease severity according to clinical and biochemical parameters are in direct relation to viral load while others have found no direct correlation. In this study, the COVID-19 cycle threshold (Ct) value, which is taken as a direct indicator of the viral load, has been correlated with the biochemical and clinical parameters in COVID-19 patients. Methods In this cross-sectional, retrospective, and single-center study, 365 patients admitted with COVID 19 were divided into three groups according to their Ct values obtained from reverse transcription-polymerase chain reaction RT-PCR as 1 (9-20), 2 (21-30), and 3 (31-40). The correlation of the COVID-19 Ct value with biochemical parameters and clinical presentation (taken as mild, moderate, and severe) was done and analyzed. The chi-square test was used for the correlation and calculated by using SPSS V-24.0 (IBM Corp., Armonk, NY). p-value <0.05 was considered significant statistically. Results Disease severity levels (mild, moderate, and severe) correlated in group 1 (Ct value 9 to 20), 2 (Ct value 21 to 30), and 3 (Ct value 31 to 40) but no significance was found between disease severity levels and the Ct value groups' p-value (>0.05). All the biochemical parameters analyzed (alanine transaminase (ALT), aspartate aminotransferase (AST), albumin, bilirubin, c-reactive protein (CRP), lactate dehydrogenase (LDH), ferritin, D-dimer, and total leucocyte count (TLC)) showed a significant p-value (<0.05) in all the three groups studied. Procalcitonin (PCT), however, did not show any significant value in any of the groups studied. In the intergroup assessment, it was found that the values of ALT, AST, albumin, CRP, ferritin, bilirubin, and TLC are maximum in group 2 with a downward trend in groups 1 and 2. Neutrophils and lymphocytes did not show any variations. LDH did not follow the trend of increasing viral load. Conclusions The severity of the disease was not statistically significant in the Ct value groups (p> 0.05). However biochemical parameters, i.e. ALT, AST, ALP, CRP, and bilirubin were statistically significant (p<0.05). Patients with COVID-19 should be closely monitored for the assessment of disease progression according to the above-mentioned biochemical parameters.