Trajectories of the SARS-CoV-2 RNA load in patients with hematological malignancy

The higher risk of prolonged viral shedding in coronavirus disease (COVID-19) patients with hematological malignancies (HM) necessitates test-based de-isolation strategies. However, evidence to establish their appropriate isolation period is insufficient. This study investigated the factors affecting prolonged viral shedding and the requisite isolation period in these patients.

We retrospectively reviewed 14 COVID-19 patients with HM between January and April 2022, who were subjected to our test-based de-isolation strategy, followed by analysis of the viral load trajectory. The viral loads of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were evaluated using the cycle threshold (C_t ) of the reverse-transcription quantitative polymerase chain reaction. The trajectories were classified according to the time-interval from COVID-19 onset to the attainment of C_t values >30.

The median interval between onset and attainment of a C_t value >30 was 22 days. Five patients with mild or moderate COVID-19 without intense treatment histories achieved C_t values >30 within 20 days. The other nine patients needed more than 20 days, including three patients who did not meet this criterion during the observation period.

The SARS-CoV-2 viral load trajectories in patients with HM can be stratified by treatment history for the underlying HM and severity of COVID-19.