Validation of a multivariable prediction model for post-engraftment invasive fungal disease in 465 adult allogeneic hematopoietic stem cell transplant recipients.

BACKGROUND: Recently, we reported a simple prognostic score for post-engraftment invasive fungal disease (IFD) obtained in 404 adult allogeneic hematopoietic stem cell transplant (alloSCT) (training cohort). OBJECTIVES: We aim to validate this score in an external cohort assessing the 1-year cumulative incidence (CI) of post-engraftment IFD. Additionally, we analyse the type of IFD and incidence of IFD according to type of prophylaxis. PATIENTS/METHODS: We included 465 consecutive adult recipients surviving >40 days who engrafted and were discharged without prior IFD (median age 45 years, range, 14-69). RESULTS: Patients classified as low-risk, 139; intermediate-risk, 162; and high-risk, 164 (35% vs 27% in the training cohort, P = 0.03). The CI of probable/proven IFD in the validation cohort was 8% vs 11% in the training cohort (P = 0.006). The only voriconazole prophylaxis used in the training cohort was 100 mg/12 h, 65% vs 27% in the validation cohort, but 38% received 200 mg/12 h. Thus, the validation cohort showed a lower CI of IFD (P = 0.009). The post-engraftment IFD score was validated, showing a CI of IFD for low-, intermediate- and high-risk of 3%, 6% and 14%, respectively (P < 0.001). CONCLUSION: To our knowledge, this is the first prognostic index to predict the occurrence of post-engraftment IFD after alloSCT that has been validated in an external cohort.