Adjunctive palivizumab with ribavirin for respiratory syncytial virus infection during the early peri-transplant period in adult allogenic hematopoietic stem cell transplant recipients: Case series.

Background: Respiratory syncytial virus (RSV) is associated with significant morbidity and mortality in hematopoietic stem cell transplant (HSCT) recipients, particularly during the peri-transplant period. Therapeutic options remain limited, and the role of adjunctive RSV-specific immunotherapy is unclear. We evaluated the outcomes of palivizumab combined with ribavirin in high-risk adult HSCT recipients with RSV infection. Methods: We retrospectively reviewed adult HSCT recipients with RT-PCR-confirmed RSV infection who received palivizumab and ribavirin. Clinical characteristics, treatment timing, outcomes, adverse events, and mortality were assessed. Results: Three adult allogeneic HSCT recipients who developed RSV infection between (day - 4 to day +2) were identified. Two patients survived, who had moderate- to high-risk disease according to the Immunodeficiency Scoring Index (ISI-RSV), while one patient with high-risk disease developed progressive respiratory failure and died despite intensive therapy, likely due to concomitant mucormycosis. No treatment-related adverse events were observed. Earlier initiation of ribavirin and palivuzumab, and the intravenous route of palivuzumab, were observed in the two cases who achieved complete recovery. Conclusions: Adjunctive palivizumab appears to be safe and may be a useful therapeutic option for HSCT recipients with RSV infection during the peri-transplant period. Larger prospective studies are needed to define the optimal role, timing, and route of palivizumab administration in this high-risk population.