A grading system based on severity of infection to predict mortality in allogeneic stem cell transplant recipients

There is, until now, no prognostic grading system for infections occurring in allogeneic stem cell transplant (SCT) recipients. The aim of this study was to determine the prognostic value of a grading system of infectious complications in predicting death.

For the purposes of a prospective allogeneic SCT trial, we classified severity of infections in 3 grades according to expected rates of mortality (>or= 60% for grade 3). We prospectively recorded the type and time of occurrence of 440 infectious events in 190 consecutive patients until 6 months after transplant. We used multivariate Cox models with time-dependent covariates to analyze the relationship between the grade of severity of each infectious episode and mortality due or not due to infection, adjusting for possible confounders.

Only patients with grade 3 infections had a significantly increased risk of death (P<.0001). The risk was not modified when the occurrence of acute graft-versus-host disease or the dose of IVIg administered were considered. Occurrence of a grade 1 and 2 infection had no additional influence.

Our grading system identifies the most medically important, life-threatening infections and allow high-risk patients to be identified. We suggest grade 3 infections should be given priority in the evaluation of anti-infectious strategies.