Early predictors of transplant-related mortality (TRM) after allogeneic bone marrow transplants (BMT): blood urea nitrogen (BUN) and bilirubin

Transplant-related mortality (TRM) following allogeneic bone marrow transpl antation (BMT) remains a major concern and early identification of patients at risk may be clinically relevant. In this study we describe a predictive score based on bilirubin and blood urea nitrogen (BUN) levels on day +7 af ter BMT, The patient population consisted of 309 consecutive patients who u nderwent BMT from sibling (n = 263) or unrelated donors (n = 46) for hemato logic disorders between December 1990 and December 1996, Of 27 laboratory t ests taken on day +7 after BMT, serum bilirubin (P = 0.02) and BUN (P = 0.0 07) were found to be independent predictors of TRM in multivariate analysis , The median levels of bilirubin (0.9 mg/dl) and of BUN (21 mg/dl) were the n used as a cut-off and a score of 1 was given for values equal/greater tha n the median. There were 216 patients with scores 0-1 (low risk) on day +7 (bilirubin <0.9 and/or BUN <21) and 93 patients with score 2 thigh risk) (b ilirubin greater than or equal to 0.9 and BUN greater than or equal to 21): the latter had more grade III-IV acute graft-versus-host disease (P = 0.03 ), slower neutrophil (P = 0.02) and slower platelet engraftment (P = 0.002) . The actuarial 5 year TRM is 22% for low risk vs 44% for high risk patient s (P = 0.0003). For HLA-identical siblings TRM is 20% vs 35% (P = 0.01), fo r unrelated donors it is 20% vs 65% (P = 0.01). Day +7 score was highly pre dictive of TRM on multivariate analysis (hazard ratio 1.9, P < 0.01), after adjustment for year of transplant (P < 0.00001), unrelated vs sibling dono rs (P = 0.001), patient age (P = 0.01) and diagnosis (P = 0.01). These resu lts were validated on an independent group of 82 allogeneic BMT recipients in a pediatric Unit who showed an actuarial TRM of 16% for low risk vs 46% for high risk patients (P = 0.002). This study suggests that it may be poss ible to identify patients with different risks of TRM on day +7 after BMT: high risk patients could be eligible for programs designed to intensify pro phylaxis of post-transplant complications.