Clinicopathological and prognostic analysis of IgA nephropathy patients with anemia

Objective To analyze the clinicopathological features of IgA nephropathy (IgAN) patients with anemia and the influencing factors of prognosis. Methods The clinical and pathological data of patients diagnosed with primary IgAN at the First Affiliated Hospital of Fujian Medical University from January 1, 2006 to December 31, 2016 were retrospectively analyzed. The patients were divided into anemia group and non-anemia group according to whether the patient was anemia or not. The clinical and pathological data of the two groups were collected. All of them were followed up from the date of renal biopsy to January 1, 2018. Survival curves of the two groups were drawn by Kaplan-Meier method, and compared by Log-rank test. Multivariate Cox proportional hazards regression model was adopted to explore the influencing factors of prognosis in IgAN patients. Results A total of 231 subjects were enrolled, including 122 males (52.8%), and the male-female ratio was 1.12∶1. Their age was (34.8±10.1) years (15-68 years). There were 70 patients (30.3%) in anemia group, 161 cases (69.7%) in non-anemic group. Compared with non-anemia group, anemia group had higher proportion of females, lower serum albumin, higher proportion of tubular atrophy/interstitial fibrosis (T1/2), endothelial cell proliferation (E1) and crescent formation (C1/2), which were statistically significant (all P＜0.05). The patients had a median follow-up time as 6.3 years (0.3-12.9 years). Survival analysis showed that patients in anemia group had lower cumulative renal survival rate than that in non-anemia group ( χ2=15.234, P＜0.001). Multivariate Cox hazards regression analysis revealed that anemia (HR=3.820, 95%CI 1.674-8.719, P=0.001), tubular atrophy/interstitial fibrosis (T1/2) (HR=3.770, 95%CI 1.026-13.852, P=0.046), glomerular segmental sclerosis/adhesion (S1) (HR=4.211, 95%CI 1.139-15.576, P=0.031), hypertension (HR=2.988, 95%CI 1.276-6.999, P=0.012), increased 24 h urinary protein (HR=1.103, 95%CI 1.046-1.163, P＜0.001) and estimated glomerular filtration (eGFR)＜60 ml?min-1?(1.73 m2)-1 (HR=3.725, 95%CI 1.639-8.462, P=0.002) were the independent risk factors for poor renal prognosis in patients with IgAN. Conclusions The clinicopathological features of IgAN patients with anemia are relatively serious, and the renal cumulative survival rate is lower. Anemia, tubular atrophy/interstitial fibrosis (T1/2), glomerular segmental sclerosis/adhesion (S1), hypertension, increased urinary protein and eGFR＜60 ml?min-1?(1.73 m2)-1 are the independent risk factors for poor renal prognosis in patients with IgAN.