# SARS-CoV-2 Polymerase Chain Reaction Cycle Threshold Trends in Patients Who Are Immunocompromised and Implications for Isolation Precautions

## TL;DR

Immunocompromised patients with certain blood cancers may remain infectious longer, suggesting a need for extended isolation precautions.

## Contribution

The study identifies a higher frequency of prolonged PCR positivity in hematologic cancer patients, particularly those on B-cell therapies.

## Key findings

- PCR cycle thresholds remained below 33 beyond 20 days in 26% of hematologic malignancy patients.
- This was significantly higher compared to 5% in solid organ malignancy patients.
- B-cell depleting or Bruton tyrosine kinase inhibitor therapy was associated with prolonged positivity.

## Abstract

Among 495 patients who were immunocompromised and tested positive for SARS-CoV-2, polymerase chain reaction cycle thresholds remained <33 beyond 20 days more frequently in patients with hematologic malignancies, particularly those receiving B-cell–depleting or Bruton tyrosine kinase inhibitor therapy, as compared with those with solid organ malignancy (26% vs 5%).

Among 495 immunocompromised patients positive for SARS-CoV-2, PCR cycle thresholds remained <33 beyond 20 days more frequently in patients with hematologic malignancies, particularly those receiving B-cell depleting or BTKi therapy, compared to those with solid organ malignancy (26% vs 5%).

Graphical Abstract