Designation of T-cell-mediated rejection type Ib and IIa reflects the type of rejection rather than the severity in the Banff classification.

OBJECTIVES

Whether T-cell-mediated rejection Banff classification type Ib (severe tubulointerstitial rejection) and type IIa (mild vascular rejection) are associated with responses to antirejection therapy and long-term graft survival are unclear.

MATERIALS AND METHODS

One hundred ten patients were enrolled who had at least 1 episode of T-cell-mediated rejection and whose highest T-cell-mediated rejection severity was T-cell-mediated rejection type Ib or IIa.

RESULTS

T-cell-mediated rejection Ib occurred significantly later than T-cell-mediated rejection IIa (P < .001). The proportion of partial/no response to antirejection therapy was comparable between the 2 groups (P = .83). Up to 8-year posttransplant, death-censored graft survival rate of the T-cell-mediated rejection Ib group was similar to that of the T-cell-mediated rejection IIa group (P = .51). Early T-cell-mediated rejection IIa had a statistically higher death-censored graft survival rate than did late T-cell-mediated rejection IIa (P < .001), while no significant difference in the death-censored graft survival was found between early and late T-cell-mediated rejection Ib (P = .11) or between early T-cell-mediated rejection Ib and early T-cell-mediated rejection IIa (P = .11) or between late T-cell-mediated rejection Ib and late T-cell-mediated rejection IIa (P = .07). Furthermore, the T-cell-mediated rejection IIa with isolated v1 lesion (v1, i0-1, t0-1) showed a similar death-censored graft survival rate compared to T-cell-mediated rejection IIa with intensive tubulointerstitial inflammation (v1, i2-3, t2-3). The timing of rejection, graft number, the number of indicated biopsies and the presence of ci/ct lesions were associated with long-term graft loss.

CONCLUSIONS

The designation of T-cell-mediated rejection type Ib and IIa reflects the different type rather than the distinct severity of rejection and has no independent prognostic significance.