Infectious complications among CD19 CAR‐T cell therapy recipients: A single‐center experience

Background CD19 chimeric antigen receptor (CAR)‐T cell therapy has emerged as an effective treatment in those with refractory or relapsed lymphoma. CD19 CAR‐T cell therapy can cause direct and indirect toxic adverse effects and increased risk for infection. Infectious complications and optimal antimicrobial prophylaxis strategies are an ongoing area of investigation. Methods A single‐center retrospective cohort study was conducted to review recipients of CD19 CAR‐T cell therapy between April 2018 and December 2020. Patient characteristics and clinical outcomes were extracted from the electronic health records. Results Infectious complications were identified in 18/50 (36%) recipients with 31 episodes of infection. The median time to infection was 225 days (range 0–614). Bacterial infections were most common with bloodstream infection followed by sinusitis and skin and soft tissue infection. Eight viral infections were identified, most being respiratory viral illnesses. Two fungal infections were identified: Pneumocystis jirovecii pneumonia (PJP) and disseminated fusariosis. Seventeen infections (54.8%) were classified as severe: leading to death, requiring hospitalization, need for empiric intravenous antibiotics, or significant alteration in hospital course. No characteristics were found to be statistically significant risks for infection, although a trend toward significance was seen in prior autologous stem cell transplant recipients (p = .12) and those with recurrent neutropenia (p = .14). Three patients (6%) died from infection. Conclusion Infections were common after CD19 CAR‐T cell therapy and occurred beyond the first year. Further multicenter studies are needed to define infectious risks and optimize antimicrobial prophylaxis recommendations in recipients of CD19 CAR‐T cell therapy. We reviewed infectious complications in patients up to 2 years after receiving CD19 CAR T‐cell therapy. Infectious complications were common after receiving CD19 CAR T‐cell therapy, occurred frequently beyond the first year, and additional studies are needed to optimize antimicrobial prophylaxis in this patient population.