Effect of the SARS-CoV-2 viral load on hematological and biochemical parameters

Gustavo Caires Neves Magalhães; Clayson  Moura Gomes; Leandro do Prado Assunção; Sérgio Henrique Nascente Costa; Fernando Antônio Vinhal dos Santos; Keila Correia de Alcântara

doi:10.15448/1980-6108.2025.1.46366

Authors

Gustavo Caires Neves Magalhães Federal University of Goiás, Goiânia, GO, Brazil. https://orcid.org/0000-0001-7006-6732
Clayson Moura Gomes Pontifical Catholic University of Goiás, Goiânia, GO, Brazil. https://orcid.org/0000-0001-8827-8274
Leandro Assunção Federal University of Goiás, Goiânia, GO, Brazil. https://orcid.org/0000-0002-1743-8151
Sérgio Nascente Costa Federal University of Goiás, Goiânia, GO, Brazil. https://orcid.org/0000-0002-4225-6368
Fernando dos Santos Transplant Immunology Laboratory – Hlagyn, Aparecida of Goiânia, GO, Brazil https://orcid.org/0009-0008-9047-9700
Keila Correia de Alcântara Federal University of Goiás, Goiânia, GO, Brazil. https://orcid.org/0000-0002-4477-2833

DOI:

https://doi.org/10.15448/1980-6108.2025.1.46366

Keywords:

COVID-19. RTq-PCR. Biomarkers.

Abstract

Objective: the viral load is determined by the cycle threshold (Ct), which is inversely proportional to the amount of target sequences present in the sample. In various viral diseases, the induction of inflammatory cytokines is strongly correlated with the viral load. However, the viral kinetics of SARS-CoV-2 remain poorly characterized, and its association with disease progression remains controversial. This study aimed to understand the correlation between the SARS-CoV-2 viral load and the biochemical and hematological markers in COVID-19-positive patients.

Methods: data from patients with detectable viral load for SARS-CoV-2 treated between March 2020 and May 2021 were collected between Jan/2023 and Jan/2024. Data were analyzed using Pearson's correlation, Student's t-test, and analysis of variance.

Results: the mean Ct values for the N and ORF1AB genes were 26.73 (±3.95) and 25.93 (±4.75), respectively. A Ct value below the mean for the N and ORF1AB genes, suggesting a higher viral load, was observed in 17.8% (n=152) and 18.4% (n=157) of the patients. There was no correlation between the mean Ct and hematological or biochemical parameters, but the monocyte-to-lymphocyte ratio (MLR) was below the reference value for COVID-19-negative patients (P<0.0001). The C-reactive protein and ferritin levels were higher in patients with COVID-19 (P<0.05). Leucopenia (P<0.001), lymphocytopenia (P<0.001), neutropenia (P<0.001), and thrombocytopenia (P=0.003) were observed more frequently in patients with COVID-19.

Conclusion: the MLR below the reference value was more frequent observed in patients with a higher Ct value (lower viral load).

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Author Biographies

Gustavo Caires Neves Magalhães, Federal University of Goiás, Goiânia, GO, Brazil.

MsC in Healthcare and Evaluation in Health from the Postgraduate Program in Healthcare and Evaluation
in Health from Federal University of Goiás (UFG), in Goiânia, GO, Brazil.

Clayson Moura Gomes, Pontifical Catholic University of Goiás, Goiânia, GO, Brazil.

PhD in Tropical Medicine and Public Health from the Federal University of Goiás (UFG), in Goiânia, GO, Brazil. Professor at Pontifical Catholic University of Goiás (PUC-GO) in Goiânia, GO, Brazil.

Leandro Assunção, Federal University of Goiás, Goiânia, GO, Brazil.

PhD in Tropical Medicine and Public Health from the Federal University of Goias (UFG) in Goiânia, GO, Brazil.

Sérgio Nascente Costa, Federal University of Goiás, Goiânia, GO, Brazil.

PhD in Health Science from Federal University of Goias (UFG), in Goiânia, GO, Brasil. Professor at the
Pharmacy Faculty from Federal University of Goias (UFG), in Goiânia, GO, Brasil.

Fernando dos Santos, Transplant Immunology Laboratory – Hlagyn, Aparecida of Goiânia, GO, Brazil

PhD in Aplicable Immunology and Parasitology from the Federal University of Uberlândia (UFU), in Uberlândia, MG, Brazil. Technical Director of the Transplant Immunology Laboratory – Hlagyn, in Aparecida of Goiânia, GO, Brazil.

Keila Correia de Alcântara, Federal University of Goiás, Goiânia, GO, Brazil.

PhD in Tropical Medicine and Public Health from the Federal University of Goias (UFG), in Goiânia, GO,
Brasil. Professor at the Pharmacy Faculty from Federal University of Goias (UFG), in Goiânia, GO, Brasil.

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