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

Objectives: 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. Methods: 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. Results: 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. Conclusions: 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.