SARS-CoV-2 RT-PCR Ct Value and Laboratory Tests

Clinicopathologic Characteristics among Adult Filipino Inpatients diagnosed with COVID-19 in a Tertiary Medical Center




Introduction. The role of the laboratory during the COVID-19 pandemic is not limited to just diagnosis of the disease, but also in clinical decision-making, by providing information on relevant laboratory biomarkers. Clinicians also use Ct value to guide patient management. There are limited studies available locally regarding the significance of Ct value and pertinent laboratory biomarkers in COVID-19 patients. This study aimed to assess the aforementioned laboratory data, along with the clinicopathologic characteristics of affected patients, and determined if this information may be useful for robust clinical decision-making.  

Methodology. In this retrospective analytic study, we identified 325 out of 1,049 adult Filipino inpatients diagnosed with COVID-19 and analyzed their Ct values and pertinent laboratory biomarkers such as neutrophil and lymphocyte count, platelet count, LDH, ferritin, procalcitonin, CRP, AST/SGOT, ALT/SGPT, PT/INR, and D-dimer, and correlated them with the severity of the disease.

Results. Two hundred twenty (67.7%) patients had non-severe disease, while 105 (32.3%) had severe disease. Lower Ct values of ORF1ab (median = 26.4) and N (median = 24.8) genes were seen in the severe group compared to the non-severe group and were found to be significant (p<0.001). Laboratory markers (neutrophil, platelet counts, LDH, ferritin, procalcitonin, CRP, AST, PT/INR, and D-dimer) were associated with severe COVID-19. On the other hand, ALT was not associated with severe disease.

Conclusion. The laboratory biomarkers together with Ct value and overall clinical picture may provide valuable information to physicians for more robust clinical decision-making.


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Author Biographies

Carolyn Marie Legaspi, The Medical City, Ortigas Avenue, Pasig City, Philippines

Department of Laboratory Medicine and Pathology

David Jerome Ong, The Medical City, Ortigas Avenue, Pasig City, Philippines

Department of Laboratory Medicine and Pathology

Jose Iñigo Remulla, The Medical City, Ortigas Avenue, Pasig City, Philippines

Department of Laboratory Medicine and Pathology

Rose Lou Marie Agbay, The Medical City, Ortigas Avenue, Pasig City, Philippines

Department of Laboratory Medicine and Pathology


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How to Cite

Legaspi, C. M., Ong, D. J., Remulla, J. I., & Agbay, R. L. M. (2023). SARS-CoV-2 RT-PCR Ct Value and Laboratory Tests: Clinicopathologic Characteristics among Adult Filipino Inpatients diagnosed with COVID-19 in a Tertiary Medical Center. PJP, 8(1), 32–40.



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