BACKGROUND: Arteritis and tubulitis, the diagnostic features of acute renal allograft rejection, are typically focal lesions. To avoid under-diagnosis, the Banff '97 schema recommends the preparation of multiple slides, of which three should be stained with hematoxylin and eosin (H&E) and three with periodic acid-Schiff (PAS) or silver. In this study, we examine the validity of the Banff '97 recommendations and determine how widely these recommendations are applied. METHODS: We reviewed 52 consecutive renal transplant biopsy specimens showing both acute tubulointerstitial and vascular rejection. Arteritis was graded for each H&E slide, and tubulitis was graded for each H&E and PAS/silver. The handling of renal allograft biopsy specimens in the U.K. was determined by means of a questionnaire. RESULTS: When two, as opposed to three, H&E slides were examined, arteritis was missed in 11.4% of cases; when only one H&E slide was examined, arteritis was missed in 33.3% of cases. When only one, as opposed to three, PAS/silver slide was examined, tubulitis was under-graded in 33.3% of cases. In the U.K., 40% of laboratories stain at least three slides with H&E, and 42% stain at least three slides with PAS/silver. Only 30% of laboratories conform to all the Banff guidelines for slide preparation. CONCLUSIONS: There is likely to be significant under-diagnosis and under-grading of acute rejection if the Banff '97 guidelines for slide preparation are not implemented. Most laboratories in the U.K. do not conform to these guidelines.
BACKGROUND:Arteritis and tubulitis, the diagnostic features of acute renal allograft rejection, are typically focal lesions. To avoid under-diagnosis, the Banff '97 schema recommends the preparation of multiple slides, of which three should be stained with hematoxylin and eosin (H&E) and three with periodic acid-Schiff (PAS) or silver. In this study, we examine the validity of the Banff '97 recommendations and determine how widely these recommendations are applied. METHODS: We reviewed 52 consecutive renal transplant biopsy specimens showing both acute tubulointerstitial and vascular rejection. Arteritis was graded for each H&E slide, and tubulitis was graded for each H&E and PAS/silver. The handling of renal allograft biopsy specimens in the U.K. was determined by means of a questionnaire. RESULTS: When two, as opposed to three, H&E slides were examined, arteritis was missed in 11.4% of cases; when only one H&E slide was examined, arteritis was missed in 33.3% of cases. When only one, as opposed to three, PAS/silver slide was examined, tubulitis was under-graded in 33.3% of cases. In the U.K., 40% of laboratories stain at least three slides with H&E, and 42% stain at least three slides with PAS/silver. Only 30% of laboratories conform to all the Banff guidelines for slide preparation. CONCLUSIONS: There is likely to be significant under-diagnosis and under-grading of acute rejection if the Banff '97 guidelines for slide preparation are not implemented. Most laboratories in the U.K. do not conform to these guidelines.