Abstract:

Objective: To investigate the clinicopathologic characteristics, long-term renal survival and related risk factors in the elderly patients with IgA nephropathy (IgAN). Methodology: Eighty-two patients aged ≥65years and 328 patients aged 18-64 years with IgAN undergoing renal biopsy in 2003-2012 were included this retrospective study. All patients’ clinical record were reviewed and biopsies were re-evaluated and scored according to the Oxford classification. Renal survival and the relationships between clinical parameters and renal outcomes were evaluated. The 3 and 8-year cumulative renal survival rates were calculated by Kaplan-Meier method, Results: The elderly patients had a higher MAP (P =0.001), higher urine protein excretion (P =0.011), higher serum creatinine (P <0.0001), lower eGFR (P <0.0001), higher serum uric acid (P =0.012), higher total cholesterol (P <0.0001) at time of renal biopsy compared with the control group. On histology, a higher percentage of global glomerulosclerosis (P =0.001), higher incidence of segmental glomerulosclerosis (P <0.0001), higher incidence of tubular atrophy/interstitial fibrosis (P =0.009) and higher incidence of arteriosclerosis (P <0.0001) were presented in the elderly group. During follow-up, the 3 and 8-year cumulative renal survival rates in the elderly group were 89.6% and 37.7%, which were significantly lower than that in the control group (96.5% and 79.4%, P =0.0002). For the elderly patients, multivariate Cox regression analysis showed that initial urine protein excretion (HR 1.847; P =0.011), eGFR (HR 1.080; P =0.006) and presence of tubular atrophy/interstitial fibrosis (HR 5.850; P =0.007) at the time of renal biopsy were independent predictor for renal outcome. Conclusions：Elderly patients with IgAN were more common to present with hypertension, nephrotic range proteinuria, renal dysfunction and severe chronic histologic lesions. Renal outcome was predicted by the level of urine protein excretion, eGFR and the presence of tubular atrophy/interstitial fibrosis at the time of renal biopsy.

Key words: IgA nephropathy, elderly, outcomes, risk factors