Biochemical Profile of Recovered Individuals with Mild COVID-19: A Cross-Sectional View at Two Different Time Points

This study was designed to cross-sectionally evaluate the frequency of long COVID-19, along with their hematological and biochemical parameters in survivors of mild COVID-19 after 6-15 months of acute infection.

We recruited 75 age-matched healthy controls (HC) and 150 individuals who had recovered from mild cases of COVID-19. The recovered individuals were grouped according to the time elapsed since acute infection: 6-10 month (CoV_A) and >10-15 month of recovery (CoV_B). A brief clinical history was taken and detailed hematological and biochemical blood parameters were measured.

In our study, 64% of individuals had symptoms of long COVID. There were differential symptoms and presenting complaints associated with time since acute infection. The recovered group had significantly different hemoglobin concentration, red blood cell (RBC) count, white blood cell (WBC) count, lymphocyte, interleukin-6 (IL-6), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and vitamin D3 levels, compared with the healthy controls (p <0.05). Differences were also found between the 6-10 months and the >10-15 month recovery groups (p <0.05).

Differential biochemical markers related to the time elapsed since acute infection show a different metabolic and biochemical status of the host at different time points after infection. Moreover, the pathophysiological pathways involved in these dysregulated biochemical markers should also be studied in relation to the long term impact of COVID-19 infection.