Relationship of Viral Load with the Laboratory Markers and Prognosis in COVID-19 Patients

Coronavirus disease 2019 (COVID-19) viral load determined from the cycle threshold (CT) values may be a marker of disease severity and predict disease progression. Our study aimed to investigate the relationship between SARS-CoV-19 cycle thresholds or viral load, laboratory markers, and patient prognosis.
  

Patients who were admitted to Imam Reza Hospital at Mashhad University of Medical Sciences between March 2020 and March 2021 and had COVID-19 polymerase chain reaction (PCR)-confirmed at random were included in this cross-sectional study. Patients were randomly selected from those who tested positive on nasopharyngeal and oropharyngeal reverse transcription-PCR samples. The inclusion criteria were all patients older than 16 years with positive COVID-19 PCR results. Samples with Ct values of ≤36 were considered positive for SARS-CoV-2 RNA. Patients who did not have laboratory markers were excluded. We used SPSS Version 16 (Pearson correlation, analysis of variance, and logistic regression tests) to analyze the data. A P ≤ 0.05 was considered statistically significant.
  

In our study, serum lactate dehydrogenase and aspartate aminotransferase were found to be laboratory biomarkers inversely correlated with COVID-19 Ct values, indicating higher viral load (r = -0.14; P = 0.024 and r = -0.12; P = 0.053, respectively). Also, the platelet count is lower in patients with higher viral loads (r = 0.18;  P < 0.001). However, we found no correlation between the viral load and some laboratory biomarkers such as ferritin, white blood cell and lymphocyte count, alanine transaminase, and c-reactive protein (P > 0.05). The patient’s length of hospital stay was not correlated with their viral load (P > 0.05).
  

The COVID-19 viral load has been linked to some laboratory indicators and may be used to predict patient death. These discoveries might help in the treatment of COVID-19 disease.