RESUMO
BACKGROUND: Thrombotic microangiopathy (TMA) has been associated with diabetic nephropathy, but its pathogenesis is unknown. OBJECTIVES: To determine the role of vascular endothelial growth factor (VEGF) expression in patients with TMA and diabetes mellitus. MATERIALS AND METHODS: Retrospective cohort study, patients were divided into diabetic nephropathy patients either without thrombotic microangiopathy (DN-TMA) or with thrombotic microangiopathy (DN+TMA). VEGF levels were analyzed using immunohistochemistry. Statistical analysis was performed with SPSS 20.0 software. RESULTS: There were 36 patients included in this study with a mean age of 47.6 ± 9.3 years. The average time since the diagnosis of diabetes mellitus was 6.8 ± 4.1 years. There were 21 patients (58.3%) with DN+TMA and 15 patients (41.7%) with DN-TMA. Patients with DN+TMA had a higher systolic blood pressure (p = 0.014) and diastolic blood pressure (p < 0.001) as well as proteinuria (p = 0.006), and a lower rate of glomerular filtration at baseline (p = 0.01). VEGF assessment showed lower arteriolar and glomerular expression in patients with DN+TMA (p < 0.001). The VEGF expression levels had an inverse relationship with proteinuria (r = -0.373; p = 0.03) and were directly proportional with glomerular filtration (r = 0.712; p < 0.01). Kaplan-Meier curves showed a higher probability of end-stage renal disease in patients with DN+TMA (log-rank p < 0.012). CONCLUSION: TMA is associated with low VEGF expression and end-stage renal disease in patients with diabetic nephropathy.â©.
