Objective:To summarize the relationship between the clinicopathological features and prognosis of immunoglobulin A nephropathy (IgAN) after renal transplantation.Methods:A total of 34 patients with IgAN after renal transplantation confirmed by renal biopsy were enrolled. And another 34 patients with primary IgAN confirmed by initial renal biopsy were adopted as controls. Clinical and pathological features of two groups were compared to explore the relationship between clinicopathological features and prognosis of allograft IgAN.Results:As compared with primary IgAN group, renal function in allograft IgAN group included serum creatinine [(158.5±75.9) vs (84.8±26.8) umol/L], urea nitrogen [(9.7±6.1) vs (5.2±1.4) mmol/L], uric acid [(406.7±87.8) vs (359.0±92.6) umol/L], estimated glomerular filtration rate {(57.4±25.4) vs (91.2±28.6) [ml/(min·1.73m 2)]}. All were statistically significantly higher ( P<0.05) while other parameters showed no differences. Pathologically, the proportion of T1 type (50.0% vs 17.6%) of renal tubular atrophy/interstitial fibrosis was significantly higher in allograft IgAN group than control group ( P<0.05). Furthermore, univariate and multivariate Logistic regression analyses were performed between various pathological parameters and prognosis in allograft IgAN patients. It indicated that the degree of mesangial hyperplasia of patients with transplanted IgAN had a significantly negative impact on the prognosis. Conclusions:The clinicopathological features of patients with allograft IgAN show no difference from those of patients with primary IgAN. And among patients with allograft IgAN, those with severe mesangial hyperplasia often have a worse prognosis.