Changes in C-Reactive Protein Forecast Infection Risk Following Treatment with Chimeric Antigen Receptor T Cells

Background. Immunosuppressive conditioning regimens for chimeric antigen receptor-modified T cell immunotherapy (CARTx) and subsequent T cell dysfunction increase risk for infection. However, it is difficult to discern infection from CRS in the early (up to Day 30) and late (Days 31–180) periods after CARTx due to overlapping signs and symptoms. Methods. We analyzed infectious complications and predictors of infection during the early and late periods after CARTx in 213 adult patients with malignancies over a 5-year period. Results. Overall, 75 patients (35%) had at least one infection, mostly within the first 30 days after CARTx. Infections occurring early after CARTx were mostly bacterial, whereas viral infections predominated after Day 30. In multivariate analyses, a high baseline CRP (≥5 mg/dL) was significantly associated with increased risk of infection in the early period after CARTx, and a Day-5-to-baseline-CRP ratio of <1.5 was significantly associated with a higher risk of infection through all 180 days after CARTx and during the late period after CARTx. Conclusions. Infections in adult patients are common up to 180 days after receiving CARTx. High baseline CRP without significant temporal changes may predict risk of infection. Tracking CRP trends may be a useful clinical tool for discerning causes of fever and guiding antibiotic stewardship in this population at high risk for infections.