Lack of correlation between the SARS‐CoV‐2 cycle threshold (C (t)) value and clinical outcomes in patients with COVID‐19

Camargo, Jose F.; Lin, Rick Y.; Komanduri, Krishna V.

PROBLEM: The utility of the polymerase chain reaction (PCR) cycle threshold (C (t)) values in the management of patients with coronavirus disease 2019 (COVID‐19) remains controversial. METHODS: We assessed the correlation of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) C (t) values in nasopharyngeal swab samples with the oxygen requirements at the time of sample collection. Specimens were tested with the Simplexa PCR platform, which targets the SARS‐CoV‐2 ORF1ab and S genes. RESULTS: We identified 23 COVID‐19 patients with 49 C (t) values available. While C (t) values from ORF1ab and S genes were highly correlated for a given specimen, there was no correlation between C (t) values for any of these target genes and the oxygen requirements of the patient at the time of sample collection. We found no differences in the initial nor the nadir C (t) values between survivors and non‐survivors or mild/moderate versus severe/critical illness at the maximum point of illness. CONCLUSION: SARS‐CoV‐2 C (t) values have limited value in the management of COVID‐19.