Progression of IgA Nephropathy under Current Therapy Regimen in a Chinese Population

Abstract

Background and objectives Current therapy for IgA nephropathy mainly includes renin-angiotensin system inhibitors and adding steroids for patients with persistent proteinuria. This study aimed to evaluate kidney disease progression and its risk factors in a Chinese cohort under current therapy.Design, setting, participants, & measurements Patients with IgA nephropathy followed up for at least 12 months from a prospective database were involved. Renal survival and the relationship between clinical parameters and composite kidney failure events (defined as end stage kidney failure or eGFR halving) were assessed.Results Overall, 703 patients between 2003 and 2011 were enrolled in this study, with a mean follow-up time of 45 months. Mean eGFR was 84.0 ml/min per 1.73 m 2 , systolic BP was 124 mmHg, and time-averaged mean arterial pressure was 90.0 mmHg. Median proteinuria at baseline was 1.60 g/d, and time-averaged proteinuria was 0.80 g/d. The mean rate of eGFR decline was 23.12 ml/min per 1.73 m 2 per year (95% confidence interval, 219.07 to 11.80), and annual end stage kidney failure rate was 2.3%. Multivariate Cox regression analyses revealed that baseline eGFR (hazard ratio, 0.76 per 10 ml/min per 1.73 m 2 ; 95% confidence interval, 0.66 to 0.91), proteinuria at 6 months (hazard ratio, 1.53 per g/d; 95% confidence interval, 1.27 to 1.84), and systolic BP control at 6 months (hazard ratio, 1.36 per 10 mmHg; 95% confidence interval, 1.05 to 1.77) were associated with composite kidney failure events. Baseline eGFR (regression coefficient, 20.06; 95% confidence interval, 20.07 to 20.04), time-averaged proteinuria (regression coefficient, 20.21; 95% confidence interval, 20.25 to 20.16), and time-averaged mean arterial pressure (regression coefficient, 20.15; 95% confidence interval, 20.21 to 20.09) were independent predictors of the slope of eGFR by linear regression.Conclusion Lower proteinuria and lower BP were associated with slower eGFR decline and lower risk of end stage kidney failure in patients currently being treated for IgA nephropathy.

Effect of Oral Methylprednisolone on Clinical Outcomes in Patients With IgA Nephropathy

“…A 30% risk reduction was selected because it was the upper bound of the 95% confidence interval in a meta-analysis of previous trials assessing steroids for IgA nephropathy. 9 After the primary end point was modified to include a 40% reduction in eGFR, the estimated annual event rate increased to 12% based on data from a large Chinese cohort 18 and a previous trial, 10 and the required sample size was reduced to 750 participants to provide more than 90% power to detect a 30% risk reduction with methylprednisolone. The trial was event-driven throughout, with a total of 335 primary outcomes expected over a mean follow-up of 5 years.…”

Effects of Hydroxychloroquine on Proteinuria in Immunoglobulin A Nephropathy

“…Most affected patients develop chronic, slowly progressive renal injury, and proteinuria is one of the strongest risk factors for the rate of renal function decline [2]. The recent Kidney Disease: Improving Global Outcomes (KDIGO) guidelines recommend that patients with persistent proteinuria greater than 1 g/day despite optimized renin-angiotensin-aldosterone system (RAAS) inhibition receive corticosteroid therapy [3].…”

Association of Relapse with Renal Outcomes under the Current Therapy Regimen for IgA Nephropathy: A Multi-Center Study

“…The prevalence and significance of disease relapse and the impact of available treatments are poorly understood. Many studies have been published on predictive factors related to renal progression in IgAN [ 3 , 9 – 11 ], but there are few data on predictive factors related to relapse. Most published studies are small, single-center investigations, and outcome data are often difficult to generalize to populations that are demographically diverse [ 9 ].…”