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

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.