Clinicopathologic features and prognosis of patients with IgA nephropathy superimposed on transplant glomerulopathy

Abstract

Objective: To observe the clinicopathologic features and prognostic of patients with IgA nephropathy (IgAN) superimposed on transplant glomerulopathy (TG+ IgAN). Methods: Electronic medical records of Jinling Hospital were searched for TG+ IgAN patients that was diagnosed during January 2004 to December 2016. Clinicopathologic features and prognoses information were retrieved and analyzed. The primary outcome was initiation of replacement therapy or an eGFR declined to<15 ml·min(-1)·(1.73m(2))(-1). Results: A total of 49 patients with pathologically confirmed TG+ IgAN were enrolled in this study. The median time from renal transplantation to allograft biopsy was 85 months. There were 131 patients with TG in the control group. There was no statistical difference in the age, gender, and immunosuppressive regimen during renal biopsy in the two groups. In TG+ IgAN patients, the median serum creatinine level was 175 μmol/L, the median urinary protein was 1.45 g/24 h, and 16.3% of the patients had nephrotic range proteinuria, the incidence of microscopic hematuria was 40.8%, and the average hemoglobin was 105 g/L. In terms of pathology, the degree of glomerular mesangial matrix hyperplasia in the TG+ IgAN group was significantly heavier compared with TG group (P=0.004), and the degree of hyaline degeneration of the small arteries was lighter (P=0.043). There was no significant difference in interstitial inflammation (i), tubulitis (t), glomerulitis (g), peritubular capillaritis (ptc) and intimal arteritis (v). Calculated by Kaplan-Meier method, the median survival time of 49 patients with TG+ IgAN was 36.9 months, and there was no difference in survival rate of allografts compared with TG group. Conclusions: Compared with TG patients without IgA, TG+ IgAN patients had higher incidence of microscopic hematuria, more severe glomerular mesangial matrix hyperplasia, and no significant differences in other clinicopathological features. The prognosis of TG+ IgAN patients was not significantly different from those without IgAN.