RESUMO
BACKGROUND: Few studies exist about risk factors for complications in subsequent biopsies. PURPOSE: To explore risk factors for complications in initial versus subsequent biopsies in native and transplant kidneys, which may predict biopsy complications. MATERIAL AND METHODS: In a multicenter study, 2830 native kidney biopsies (4.3% subsequent) were analyzed for major complications (1251 of these were also analyzed for minor) and 667 transplant kidney biopsies (29% subsequent) were analyzed for major and minor complications. No death or nephrectomy were described. Fisher's exact test, Student's t-test, chi-square analyses, and univariate and multiple binary logistic regression analyses were employed; P < 0.05 was considered significant. RESULTS: In initial native kidney biopsies, the frequency of major complications was higher in women compared to men (odds ratio 1.6, 95% confidence interval 1.1-2.2), in younger patients (50 vs. 54 years, P = 0.007), and in patients with lower weight (78 vs. 82 kg, P = 0.005). In subsequent native kidney biopsies, patients with major complications had a higher systolic blood pressure (145 vs. 132 mmHg, P = 0.03). In initial transplant kidney biopsies, biopsies with major complications had less glomeruli in the biopsy (17 vs. 24, P = 0.046). In subsequent transplant kidney biopsies, patients with major complications had a higher mean arterial pressure (112 vs. 98 mmHg, P = 0.002). In subsequent native kidney biopsies, there was a higher number of SLE-nephritis (12% vs. 4.6%, P = 0.001) compared to initial biopsies. CONCLUSION: The different types of risk factors for complications in initial versus subsequent renal biopsies could be important for the clinicians to improve patients' safety.