Improvement of lesion quantitation for the Banff schema for renal allograft rejection

The Banff Working Formulation provides objective criteria for diagnosis and grading of acute rejection in renal allografts and should be a reliable tool in the hands of most pathologists. However, as with any such schema, improvement and refinement are both possible and desirable. Agreement should be enhanced by more careful definitions of morphologic criteria, a process which is already underway. In addition, immunostaining, even nonspecific staining for common leukocyte antigen, would be useful in particular for identifying and quantitating glomerular and tubulitis. More specific immunostains, eg, for effector cell populations, cytokines, and/or adhesion molecules will doubtless also be validated by ongoing and future studies, and be incorporated into this rejection assessment schema.