Analysis of the clinicopathological characteristics and prognosis of 742 cases with primary IgA nephropathy / 中华肾脏病杂志

ABSTRACT

Objective:To investigate the clinicopathological characteristics and influencing factors of kidney prognosis in primary IgA nephropathy (IgAN) patients.Methods:The data of primary IgAN patients diagnosed with renal biopsy in the First Affiliated Hospital of Anhui Medical University from January 2015 to September 2019 were retrospective analyzed. According to the level of baseline estimated glomerular filtration rate (eGFR) when performing renal biopsy, the patients were divided into group A[eGFR≥90 ml·min -1·(1.73 m 2) -1], group B[eGFR 61-89 ml·min -1·(1.73 m 2) -1] and group C[eGFR≤60 ml·min -1·(1.73 m 2) -1]. The clinical and pathological data were collected and compared among the three groups. Kaplan-Meier method was conducted for renal results, whereas the Cox proportional-hazards regression model was exploited to analyze the influencing factors of kidney prognosis in IgAN patients. Results:A total of 742 patients were included in the study, including 394 cases (53.1%) in group A, 203 cases (27.4%) in group B, and 145 cases (19.5%) in group C. There were 325 males (43.8%) and 417 females (56.2%). The median duration of renal biopsy was 6 (1, 24) months, and the median age was 36 years old (18-68 years old). As the baseline level of renal function decreased, the proportion of patients with nephrotic syndrome, hypertension, anemia and hyperuricemia and the levels of 24 h urinary protein, serum triglyceride and total cholesterol increased significantly (all P<0.05), while the proportion of gross hematuria episodes and the ratio of serum albumin to globulin significantly decreased (all P<0.05). For the aspect of pathological manifestations, the proportions of cell proliferation in capillaries (E1), segmental sclerosis or adhesion (S1), renal tubular atrophy or interstitial fibrosis (T1/2), globular sclerosis, renal arteriole wall thickening and vitreous degeneration, Lee's grade Ⅳ and Ⅴ increased with the decrease of baseline renal function (all P<0.05). Kaplan-Meier analysis showed that the cumulative renal survival rate decreased with the decline of baseline renal function (Log-rank χ2=88.510, P<0.001). As a result of multivariate Cox regression analysis, nephrotic syndrome ( HR=2.399, 95% CI 1.054-5.459, P=0.037), hypertension ( HR=1.806, 95% CI 1.071-3.048, P=0.027), low baseline eGFR (taking group A as the reference, group B HR=2.383, 95% CI 1.053-5.392, P=0.037; group C HR=6.878, 95% CI 3.074-15.393, P<0.001), IgG deposition ( HR=2.224, 95% CI 1.384-3.574, P=0.001) and globular sclerosis ( HR=2.075, 95% CI 1.230-3.501, P=0.006) were the independent influencing factors for renal progression in primary IgAN patients. Conclusions:The level of baseline renal function in primary IgAN patients can be used to predict the extent of clinic-pathological damage. Nephrotic syndrome, hypertension, low baseline eGFR, IgG deposition and globular sclerosis are the independent influencing factors for renal progression in primary IgAN patients.