Background: The aim of this study was to investigate if specific clinical and histological findings can be related to biopsy complications to enable more closely monitoring patients at high risk.
Methods: Results from 1081 biopsies (994 patients, median age 54.5 years; 896 native and 185 transplant kidney biopsies) were included. Diagnostic quality, morphology, clinical data and complications were prospectively registered.
Results: In native kidney biopsies, the most common diagnosis was IgA-nephritis, while in transplant kidney biopsies it was rejection. Patients with IgA-nephritis had a higher risk of major complications (11.7 versus 6.4 %, Odds Ratio (OR) 1.8, Confidence Interval (CI) 1.1-3.2) when compared to patients with other diseases. In native kidney biopsies, patients who experienced major complications had higher degrees of glomerulosclerosis (31 versus 20 %, p = 0.008), whereas in transplant kidney biopsies, patients had higher degrees of interstitial fibrosis (82 versus 33 %, p < 0.001) when compared to patients without major complications. IgA-nephritis-patients had a higher risk of re-biopsies (4.7 versus 1.3 %, OR 4, CI 1.5-11) than patients with other diseases. Patients with native kidneys who needed re-biopsies were younger (42.6 versus 52.3 years, p = 0.031) and had a higher degree of interstitial fibrosis (63 versus 34 %, p = 0.046).
Conclusions: Patients with IgA-nephritis have an increased risk of major biopsy complications. The risk of re-biopsies was higher in younger individuals and in patients with IgA-nephritis.
Keywords: Biopsy complications; Glomerulosclerosis; IgA-nephritis; Interstitial fibrosis; Kidney biopsy.