Impact of Banff borderline acute rejection among renal allograft recipients.

OBJECTIVE: This study was performed to determine the incidence, treatment, and outcomes of Banff borderline acute rejection (AR) among renal transplant recipients. PATIENTS AND METHODS: We reviewed the courses of adult kidney transplant recipients with borderline AR on clinically indicated biopsies performed at our center from January 2003 to July 2006. Patients with complete transplant records and serum creatinine values at 6 and 12 months were included in this study. The primary outcome measures were serum creatinine values at 1 to 2 weeks after treatment, and at 6 and 12 months after graft biopsy.
RESULTS: Among 428 renal graft biopsies, borderline AR was observed in 100 cases (23%). Patients were maintained on the same immunosuppression. The 86 who had complete data were included in the study. Seventy-eight percent of the patients received treatment with 3 days of methylprednisolone, while 22% were untreated. Mean serum creatinine values in the treated group were 2.9 +/- 1.0, 2.6 +/- 2.5, and 3.0 +/- 2.9 mg/dL at the time of biopsy, and at 6 and 12 months thereafter, respectively. In the untreated group, mean serum creatinine values were 2.2 +/- 1.0, 1.9 +/- 0.8, and 2.3 +/- 1.2 mg/dL during biopsy, and at 6 and 12 months thereafter, respectively. There was no significant difference in the serum creatinine at any of the measured time points between the 2 groups. Twelve patients had repeat renal graft biopsies which showed AR (6%), chronic allograft nephropathy (2.4%), and borderline changes (3.8%). Nine of the patients in the treated group eventually developed graft loss.
CONCLUSIONS: Patients with borderline AR showed a progressive increase in serum creatinine over time. They should be followed closely; immunosuppression may need to be intensified.