Clinical, Pathological Characteristics and Outcomes of IgA Nephropathy Patients with different ages.

Aim To determine the clinical and pathological differences in immunoglobulin A (IgA) nephropathy (IgAN) with different ages, and to determine whether age is a risk factor for progression of IgAN. Methods This was a single centre retrospective cohort study. Patients with biopsy-diagnosed primary IgAN were stratified into three groups: young-aged (14-29 years), middle-aged (30-49 years) and older-age (>= 50 years). The primary outcome was end-stage renal disease (estimated glomerular filtration rate [eGFR] <15 mL/min/1.73 m(2), dialysis or renal transplantation) or doubling of the baseline serum creatinine. Results A total of 981 patients were enrolled, including 65 (6.6%) patients in older-age group, 517 (52.7%) in middle-aged group and 399 (40.7%) in young-aged group. The older-age group had significantly higher levels of serum IgA, cholesterol, triglycerides and creatinine, and a reduced eGFR. In contrast to the young adults who had a higher percentage of crescent formation in glomeruli, the older-aged patients had more severe chronic pathological changes including global glomerulosclerosis and vascular lesions (p < .01). The cumulative renal survival in the older-age group was slightly shorter than that in the young adult or middle-aged group, but not achieving significant (p > .05). The 3- and 5-year renal survival rates were similar among the three groups. A multivariate Cox regression analysis showed that age was not an independent predictor of an unfavourable prognosis. Conclusion The IgAN patients with aged 50 years or older had different clinical pathological changes as compared with younger patients. However, aging was not found as an independently predictor of renal progression of IgAN. Prolonged follow up is necessary to confirm this trend.