A multidrug, antiproteinuric approach to alport syndrome: a ten-year cohort study

Abstract

Background/aims: Combined ACE inhibitor, angiotensin-receptor-blocker, non-dihydropyridine calcium-channel-blocker, and statin therapy (Remission Clinic) reduced proteinuria and halted progression in non-diabetic nephropathies, but their efficacy in Alport syndrome (AS) nephropathy is unknown.

Methods: From February 2004 to September 2007, we included nine albuminuric AS adults with creatinine clearance >20 ml/min/1.73 m(2) in a single-center, open-label, prospective, off-on-off academic study. After the 1-month wash-out from RAS inhibition (Run-in), patients entered the 4-month, add-on, treatment period with benazepril (10-20 mg/day), valsartan (80-160 mg/day), diltiazem (60-120 mg/day), and fluvastatin (40-80 mg/day) followed by the 1-month wash-out (Recovery). The primary outcome was albuminuria at month 4. After recovery, patients were kept on the Remission Clinic protocol and followed until July 2014 (Extension).

Results: The median (IQR) albuminuria progressively declined from 657.7 (292.7-1,089.6) μg/min at baseline to 71.4 (21.7-504.9) μg/min at treatment end (p = 0.009) and raised to 404.3 (167.9-446.8) μg/min after recovery. Albumin and IgG fractional clearances significantly (p ≤ 0.005) decreased from 66.9 (53.6-80.8) to 9.4 (4.6-26.0) and from 5.1 (3.0-8.4) to 1.1 (0.6-3.2), and then recovered toward baseline. Blood pressure and lipids significantly decreased on treatment, without changes in inulin-measured GFR or para-aminohippuric-measured RPF. After recovery, one patient refused to enter the extension, one with severe renal insufficiency at baseline reached ESRD, and seven retained normal serum creatinine until the end of the study. At the final visit, three were microalbuminuric and one was normoalbuminuric. Treatment was well tolerated.

Conclusion: The Remission Clinic approach safely ameliorated albuminuria, blood pressure, lipids, and glomerular selectivity in AS patients and halted long-term progression in those without renal insufficiency to start with.

Figure 1

Study flow chart.

Figure 2

Changes in overnight UAE (upper panel) and spot morning urinary A/C ratio during the Treatment, Recovery, and Extension phases as compared to baseline (month 0). Data are Median (IQR). *p<0.05 vs. month 0 **p<0.01 vs. month 0 and 1.

Figure 3

Albumin (left panel) and IgG (right panel) fractional clearances at baseline and at the end of the 4-month Treatment period and of the Recovery period. Data are median (IQR).