Is There a Correlation Between the Cycle Threshold of SARS-CoV-2 RT-PCR and the Clinical Course of COVID-19?

Abstract

Objectives: Many parameters are studied in coronavirus disease-2019 (COVID-19) to predict the progress of the disease. One of these parameters is the clinical significance of the reverse transcriptase-polymerase chain reaction (RT-PCR) cycle threshold (CT) value used in diagnostic tests. In this study, we evaluated the relationship between RT-PCR CT values and the clinical course of COVID-19. Materials and Methods: Symptomatic patients over the age of 18 years, who had positive severe acute respiratory syndrome-coronavirus-2 RT-PCR test results between June 1, 2020 and December 1, 2020, were screened retrospectively. Patients’ CT values and other data were collected from the hospital’s information management system. Results: The study included the data of 880 patients. The median age was 63 years, and 47% (415) were female. The severity of COVID-19 was mild in 69.7% (614), moderate in 20.4% (180), and severe/critical in 9.7% (86). There was no significant difference between median CT (mCT) levels of disease severity (mCT=22 in mild group; mCT=23 in moderate group; mCT=22 in severe/critical group, p=0.882). The results showed no correlation between these CT values and COVID-19’s severity, prognosis, or laboratory values. Conclusion: Although there are some reports that propose a relationship between CT values and viral load, we believe that these test results cannot be considered quantitative and cannot be generalized because of the many factors known to affect CT values.

Keywords

• Viral Load
• Cycle Threshold
• COVID-19

SARS-CoV-2 RT-PCR’nin Döngü Eşiği ile COVID-19’un Klinik Seyri Arasında Bir Korelasyon Var mıdır?

Abstract

Amaç: Hastalığın progresyonunu tahmin etmek için koronavirüs hastalığı-2019’da (COVID-19) birçok parametre incelenmektedir. Bu parametrelerden biri, tanısal testlerde kullanılan ters transkriptaz-polimeraz zincir reaksiyonu (RT-PCR) döngü eşiği (CT) değerinin klinik önemidir. Bu çalışmada RTPCR CT değerleri ile COVID-19’un klinik seyri arasındaki ilişkiyi değerlendirdik. Gereç ve Yöntem: 1 Haziran 2020 ile 1 Aralık 2020 tarihleri arasında şiddetli akut solunum sendromu-koronavirüs-2 RT-PCR testi pozitif çıkan 18 yaş üstü ve semptomatik hastalar geriye dönük olarak tarandı. Hastaların CT değerleri ve diğer verileri hastanenin bilgi yönetim sisteminden toplandı. Bulgular: Çalışmaya 880 hastanın verileri dahil edildi. Hastaların yaş ortancası 63 idi ve %47’si (415) kadındı. COVID-19 hastalığının şiddeti hastaların %69,7’sinde (614) hafif, %20,4’ünde (180) orta ve %9,7’sinde (86) şiddetli/kritik idi. Medyan CT (mCT) değerleri ile hastalık şiddeti arasında anlamlı bir fark yoktu (hafif hastalık grubunda mCT=22; orta hastalık grubunda mCT=23; şiddetli/kritik hastalık grubunda mCT=22, p=0,882). Çalışmamızın sonuçları, CT değerleri ile COVID-19’un şiddeti, prognozu veya laboratuvar değerleri arasında bir ilişki olmadığını gösterdi. Sonuç: Pratikte CT değerleri ile viral yük arasında göreceli bir ilişki olmasına rağmen, CT değerlerini etkilediği bilinen birçok analitik ve klinik faktör nedeniyle bu test sonuçlarının nicel olarak kabul edilemeyeceğine ve genellenemeyeceğine inanmaktayız.

Keywords

• Viral Yük
• Siklus Eşiği
• COVID-19

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