Acute renal allograft rejection with severe tubulitis (Banff 1997 grade IB)

Recent studies have correlated renal allograft function with individual his tologic lesions defined in the Banff schema of kidney transplantation patho logy. The clinical significance of severe tubulitis (Banff 97 grade t3) has not been specifically examined. We compared the clinical course and respon se to antirejection therapy in 36 patients with t3 tubulitis, and 137 patie nts with milder grades of tubulitis and varying grades of intimal arteritis . Rejection associated with severe tubulitis (grade t3) was associated with graft outcome that was worse than mild to moderate tubulitis (grades tl or t2) and approached that seen in grade vl intimal arteritis. Rejection char acterized by grade v2 or v3 intimal arteritis had worse prognosis than vl i ntimal arteritis and all grades of tubulitis without coexisting intimal art eritis. These observations validate the Banff 97 recommendation that the se verity of both tubulitis and intimal arteritis needs to be graded in renal allograft biopsies. In addition, grade t3 tubulitis is identified as a lesi on which should be a cause for clinical concern.