Clinicopathological characteristics, risk factors and prognostic value of intrarenal vascular lesions in IgA nephropathy

Background: The aim was to study clinicopathological characteristics, risk factors and renal outcome in IgA nephropathy (IgAN) patients with vascular lesions.Methods: We enrolled a Chinese cohort with 458 biopsy-confirmed primary IgAN patients for a retrospective analysis. They were divided into three groups according to vascular lesions: no vascular lesions (n = 239), arterio-/arteriolosclerosis (n = 181) and microangiopathic lesions (n = 38). The clinicopathological features and renal outcome were recorded. In univariate and multivariate models, association between vascular lesions and renal outcome and vascular lesions associated clinical factors were analyzed.Results: Patients with vascular lesions presented worse clinical characteristics with regard to blood pressure and kidney function, and segmental glomerulosclerosis (S1), tubular atrophy/interstitial fibrosis (T1/2) and lym-phocytes and monocytes infiltration were more common. Furthermore, older age, hyperuricemia, proteinuria, global glomerulosclerosis and endocapillary hypercellularity (E1) were more severe in patients with simple arterio-/arteriolosclerosis. By multivariate logistic regression, age, MAP and eGFR were significantly associated with vascular lesions. Vascular lesions, especially arterio-/arteriolosclerosis, were significantly associated with poorer renal survival in IgAN patients, and renal survival was similar whether patients with arterio-/arterio-losclerosis received immunosuppressive therapy. In addition to eGFR, arterio-/arteriolosclerosis, along with arterial intimal fibrosis, was an independent predictor for renal survival in multivariate Cox analyses. Conclusion: IgAN patients with vascular lesions, especially with arterio-/arteriolosclerosis, presented more severe clinicopathological features. Renal function, blood pressure and age contributed to distinguishing patients with vascular lesions. Arterio-/arteriolosclerosis lesions were associated with poorer renal survival.