Abstract:

Objective: To observe the clinicopathologic features and prognostic of the patients with IgA nephropathy superimposed on diabetic nephropathy (DN+IgAN). Methodology: Patients with T2DM and renal biopsy from 2003 to 2011 were reviewed. All patients were followed for at least a year after biopsy. All renal biopsies were reviewed according to the pathologic classification of Tervaert et al. Fifty cases with DN+IgAN were diagnosed, and 418 cases with DN only were enrolled as the control group. A renal event was defined as eGFR<15ml/min/1.73m2. Their clinicopathologic features and prognosis were analyzed and compared between two groups. Results: At the time of renal biopsy, the median duration of diabetes was shorter in the DN+IgAN than that in the DN group (44 VS 84 months, P=0.005), however, the ages, sex ratio and the kidney disease duration of the two groups had no difference. Compared with the DN group, the level of urinary protein excretion <1g/24h in the DN+IgAN was 64.0% vs 41.1% cases, and >3.5g/24h was 12% vs 23.4% cases (P=0.008). While the renal function had no differences between two groups. Additionally, the rate of hypertension and diabetic retinopathy in the DN+IgAN group was 66.0% and 24.0% respectively, and lower than those in the DN group. Histologically, most patients presented as class Ⅱa (68.0%) in the DN+igAN group, while as class Ⅲ (40.0%)in the DN group. The lesion of segmental glomerulosclerosis and crescent formation was 66.0% and 28.0% respectively in the DN+IgAN group, and higher than those in the DN group (P<0.001). Typical glomerular lesions of DN, such as nodule lesions, microaneurysms, atubular glomeruli, were presented in fewer patients of the DN+IgAN group. Calculated by Kaplan-Meier method, the outcome of the DN+IgAN group had no difference with the DN group. Conclusion: Compared with DN only, the patients with DN+IgAN had shorter duration of diabetes, lower level of proteinuria, fewer with hypertension and diabetic retinopathy, milder glomerular lesions and some histological features of IgAN. The prognosis of the patients with DN+IgAN had no difference to the patients with DN.

Key words: Keywords: Diabetic nephropathy, IgA nephropathy, Clinical features, Pathological features, Prognosis