Outcome of Human Parainfluenza Virus infection in allogeneic stem cell transplantation recipients: possible impact of ribavirin therapy

This retrospective study focused on analyzing community-acquired respiratory virus (CARV) infections, in particular human parainfluenza virus (hPIV) after allogeneic stem cell transplant (allo-SCT) in adults recipients. It aimed to assess the impact of ribavirin treatment, clinical characteristics, and risk factors associated with lower respiratory tract disease (LRTD) progression and all-cause mortality.

The study included 230 allo-SCT recipients diagnosed with hPIV between December 2013 and June 2023. Risk factors for the development of LRTD, disease severity, and mortality were analyzed. Ribavirin treatment was administered at physician discretion in 61 out of 230 cases (27%).

Risk factors for LRTD progression in multivariate analysis were corticosteroids > 30 mg/day (Odds ratio (OR) 3.5, 95% Confidence Interval (C.I.) 1.3–9.4, p = 0.013), fever at the time of hPIV detection (OR 3.89, 95% C.I. 1.84–8.2, p < 0.001), and absolute lymphocyte count (ALC) < 0.2 × 10⁹/L (OR 4.1, 95% C.I. 1.42–11.9, p = 0.009). In addition, the study found that ribavirin therapy significantly reduced progression to LRTD [OR 0.19, 95% C.I. 0.05–0.75, p = 0.018]. Co-infections (OR 5.7, 95% C.I. 1.4–23.5, p = 0.015) and ALC < 0.2 × 10⁹/L (OR 17.7, 95% C.I. 3.6–87.1, p < 0.001) were independently associated with higher day + 100 after hPIV detection all-cause mortality. There were no significant differences in all-cause mortality and infectious mortality at day + 100 between the treated and untreated groups.

ALC, corticosteroids, and fever increased the risk for progression to LRTD while ribavirin decreased the risk. However, mortality was associated with ALC and co-infections. This study supports further research of ribavirin therapy for hPIV in the allo-HSCT setting.