[Restrospective analysis of the renal biopsy activity in Piedmont]

The Piedmont Group of Clinical Nephrology has compared the activity of 18 nephrology centers in the region Piedmont/Valle d'Aosta with regard to renal biopsy (RB). Data on the RBs performed in every nephrology unit, taking into account their entire experience (in some cases spanning more than 30 years), were analyzed. 3396 RBs were performed between 1996 and 2011. Thirty to forty percent were done in patients aged >-65 years (1568 in patients >-65 years, 29 in patients >-85 years). 598 BRs were performed in children over the last 20 years. The following contraindications to RB were considered: chronic renal failure by 8 centers (44.4%), serum creatinine (SCr >3 mg/dL) by 3 centers, longitudinal renal size <8 cm by 3 centers, and renal cortex thickness <1 cm by 2 centers. 1798 RBs were performed in patients with SCr >2 mg/dL and 275 in patients on dialysis. The percentage of RBs performed in patients with SCr >2 mg/dL ranged from 27% to 55% between centers. As regards RB in the course of acute renal failure in an ANCA-positive context, 4 centers allowed administration of corticosteroids and 8 centers administration of immunosuppressive treatment as well, even in the absence of histological data. In drug-related nephropathies, RB was considered indicated to confirm the farhypothesis of immunoallergic interstitial nephropathy either if the responsible drug was not among the traditional ones known to induce tubulo-interstitial renal disease or if the pharmacological hypothesis seemed no longer sufficient to justify the renal presentation. All centers but one were against performing RB in case of atheroembolic disease. Three centers performed RB in the intensive care unit. As regards RB in patients undergoing treatment with anticoagulants, aspirin was discontinued 5-14 days before the procedure (mean 8 days) and given again 7-15 days afterwards (mean 11.4 days). Ten centers replaced the anticoagulants with low-dose heparin, which was discontinued the day before the procedure; 11 centers asked advice from cardiologists. RB was repeated in 113 cases after a delay of 1 month to 8 years from the first RB. Our analysis shows uniformity in the approach to RB in this Italian region, with some differences compared with the literature: particular attention was paid to severely critical patients, elderly patients, and patients treated with anticoagulant drugs.