Infections after T-replete haploidentical transplantation and high-dose cyclophosphamide as graft-versus-host disease prophylaxis

Background: Recently, a platform of T-cell replete haploidentical hematopoietic stem cell transplantation (haplo-HSCT) using post-transplant cyclophosphamide (Cy) has shown high reproducibility and acceptable safety profile. Method: This prospective cohort analysis allowed us to collect data on infections among 70 consecutive recipients of haplo-HSCT affected by various hematologic malignancies. Results: After a median follow-up of 23 months, cumulative incidence of viral infections was 70% (95% confidence interval [CI] 59-81) at 100 days and 77% (95% CI 67-87) at 1 year; 35 of 65 patients at risk had CMV reactivation (54%) and the rate of polyomavirus-virus-associated cystitis was 19% (13/70). Cumulative incidence of bacterial and fungal infections at 1 year were 63% (95% CI 51-75) and 12% (95% CI 4-19), respectively. Of note, only 1 invasive fungal infection occurred beyond 1 year after transplant (day +739). Conclusion: In conclusion, despite a high rate of viral infections in the early period, present data suggest a satisfactory infectious profile after T-cell replete haplo-HSCT using post-transplant Cy. These results may help clinicians to improve both prophylactic and therapeutic antimicrobial strategies in this emerging haploidentical setting.