Long-term prognosis of clinically early lgA nephropathy is not always favorable

Abstract

Background: The long-term prognosis of clinically early lgA nephropathy (lgAN) patients remains to be clarified. We investigated the long-term outcomes of lgAN patients with an apparently benign presentation and evaluated prognostic factors for renal survival. Methods: We included patients with biopsy-proven lgAN who had estimated glomerular filtration rates (eGFR) >= 60 mL/min/1.73 m(2), normal blood pressure, and proteinuria <0.5 g/day at the time of biopsy. The primary outcome was progression to end-stage renal disease (ESRD). The secondary outcome was a 50% increase in serum creatinine level or an increase in proteinuria to >1 g/day. Results: The analysis included 153 patients who met the inclusion criteria. At diagnosis, their median systolic blood pressure was 120 (110-130) mmHg, eGFR was 85.9 (74.9-100.1) mL/min/1.73 m(2), and proteinuria was 0.25 (0.13-0.38) g/day. Of these, 4 patients died and 6 reached ESRD. The 30-year renal survival rate was 85.5%. Three patients had increased serum creatinine levels and 11 developed proteinuria. Remission was observed in 35 (22.9%) patients. A moderate or severe degree of interstitial fibrosis (adjusted odd ratio [OR] 5.93, 95% confidence interval [CI] 1.44-24.45, P = 0.014) and hypoalbuminemia (adjusted OR 6.18, 95% CI 1.20- 31.79, P = 0.029) were independent predictors of the secondary outcome. Conclusions: This study showed that the prognosis of early lgAN was not always favorable, even resulting in progression to ESRD in some cases. Hypoalbuminemia and interstitial fibrosis should also be considered important prognostic factors in clinically early lgAN patients.