[Limited prognostic value of surgical biopsy before transplantation of good quality renal transplants].

Objective: The purpose of this study was to assess the correlations between histological examination of surgical biopsies before transplantation of good quality donor kidneys and delayed return of renal function and renal function at 1 year in order to determine whether histology could explain the various, sometimes surprising outcomes observed with these good quality transplants.
Material and Method: From November 1999 to March 2002, 110 consecutive renal transplantations were performed in our centre from 79 different donors, not including any "borderline" donors. During preparation of each transplant, a surgical wedge biopsy of the mid-renal cortex was performed. Biopsies were paraffin-embedded then stained with P.A.S. (Periodic Acid Shiff). Histological examination was performed by a single pathologist and focused on the glomeruli (number, morphology), and the morphology of the interstitial space and vessels. Delayed return of transplant renal function was defined by the need for dialysis during the first week after renal transplantation. Immunosuppression and surveillance protocols were standardized and uniform. Transplant function at 1 year was evaluated by serum creatinine and creatinine clearance calculated according to Cockcroft's formula.
Results: The mean number of glomeruli per biopsy was 15.0 +/- 10.8. 42 renal biopsies (39.2%). Histological examination did not reveal any vascular, interstitial or glomerular lesions. Among these 42 transplants with normal biopsies, 30 (71.4%) did not develop delayed return of renal function (vs 69% of the transplants with abnormal biopsies, p > 0.05). Mean serum creatinine at 1 year (168.5 +/- 63 micromol/l vs 166.9 +/- 40.5 micromol/l, p > 0.05) and mean creatinine clearance at 1 year (53.4 +/- 17.4 ml/min. vs 48.3 +/- 14.3 ml/min, p > 0.05) were not significantly different between the normal biopsy group and the abnormal biopsy group.
Conclusion: Histological abnormalities are frequently observed in renal transplants derived from good quality donors. The biopsy result before renal transplantation from "non-borderline" donors was not significantly correlated with the risk of delayed return of transplant function or the renal function at 1 year Biopsy alone cannot constitute a reliable criterion for the selection of renal transplants from "non-borderline" donors.