Surveillance Biopsy Driven Steroid Withdrawal in Kidney Transplantation.

Abstract

Background Surveillance biopsies (SB) can help individualized tapering of immunosuppression. In 2008, we have introduced surveillance biopsies at 3 months post kidney transplantation (KTx). Steroids were then withdrawn if the biopsy did not show any rejection. Methods All KTx performed in our center are prospectively introduced in a database since 2005. Our cohort covers 299 KTx perfomed from Jan-2008 to Jul-2013. During this period, 227 SB were performed. Reasons for not performing SB and complication rate were retrospectively assessed. SB were scored according to the Banff 07 Classification. Results Characteristics of the patients and KTx are given in the table. SB was obtained in 76% of KTx. Reasons for not proposing the SB were (n): pediatric recipient (6), primary non function or death (9), lost to follow-up (3), recent per-cause biopsy (24), mandatory anti-platelet or anticoagulation treatment (7). SB could not be performed in another 23 patients: 6 technical failures, 1 patient refusal and 16 others reasons. Among the 227 performed SB, 61 were inadequate according to Banff criteria leaving 166 for analysis. The complication rate was 3 % (mostly sever hematuria and arterio-venous fistula, no graft lost but two transient renal function deterioration). Eighty-two % of the SB were normal. Abnormal findings were distributed as follow (n): borderline (20) or sub clinical cellular (6, ranging from Ia to IIb) rejections; microcirculatory inflammation (5), sub-clinical antibody-mediated rejection (1); among those 4 presented mixed humoral and cellular reaction. IF/TA was present in 16% of SB and DSA were observed in 9% of the patients in whom it was determined. Steroids withdrawal was obtained in 66% of the KTx with normal SB. The main reason for not stopping steroids despite a normal SB was mycophenolate adverse event requiring interruption of this drug. BPAR was observed in 4 of these patients after steroid removal. Only one transplant was lost because patient died with a functioning graft for a reason not related to steroid removal.Table: No Caption available.Conclusion SB was a safe procedure that allowed selective steroid withdrawal in our population. In 18% of the cases the SB found sub clinical features that precluded steroid withdrawal.