IBMTR SEVERITY INDEX FOR GRADING ACUTE GRAFT-VERSUS-HOST DISEASE - RETROSPECTIVE COMPARISON WITH GLUCKSBERG GRADE

Acute graft-versus-host disease (GVHD) severity is graded by pattern o f organ involvement and clinical performance status using a system int roduced by Glucksberg and colleagues 21 years ago. We examined how wel l Glucksberg grade predicted transplant outcome and constructed a Seve rity Index not requiring subjective assessment of performance in 2881 adults receiving an HLA-identical sibling T-cell-depIeted (n = 752) or non-T-cell-depleted (n = 2123) bone marrow transplant for leukaemia b etween 1986 and 1992. Relative risks (RR) of relapse, treatment-relate d mortality (TRM) and treatment failure (TF) (relapse or death) were c alculated for patients with Glucksberg Grade I, II or III/IV acute GVH D Versus those without acute GVHD and for patients with distinct patte rns of organ involvement regardless of Glucksberg grade. Using data fo r non-T-cell-depleted transplants, a Severity Index was developed grou ping patients with patterns of organ involvement associated with simil ar risks of TRM and TF. Higher Glucksberg grade predicted poorer outco me; however, patients with the same grade but different patterns of sk in, liver or gut involvement often had significantly different outcome s. The revised Severity Index groups patients in four categories, A-D. Compared to patients without acute GVHD, RRs (95% confidence interval ) of TF were 0.85 (0.69, 1.05) for patients with Index A, 1.21 (1.02, 1.43) with B, 2.19 (1.78, 2.71) with C and 5.69 (4.57, 7.08) with D. P rognostic utility of the Index was tested in patients receiving T-cell -depleted transplants; similar RRs of TP were observed. An acute GVHD Severity Index is proposed to enhance design and interpretation of cli nical trials in the current era of allogeneic blood and bone marrow tr ansplantation.