A combination of two types of blood pressure-lowering drugs, an angiotensin-converting enzyme inhibitor (ACEI) plus an angiotensin-receptor blocker (ARB), added to enzyme replacement therapy (ERT) with agalsidase-beta (Fabrazyme, Genzyme Corporation, Cambridge, MA) is the first treatment shown to stop progressive loss of kidney function in patients with severe kidney involvement due to the rare genetic disorder Fabry disease, reports a study in the September Journal of the American Society of Nephrology.
"While Fabry disease is very rare, our study shows that controlling urine protein excretion will slow progression of kidney disease, even though the achieved blood pressures were lower than are usually targeted in treating chronic kidney disease," says Dr. David Warnock of University of Alabama, Birmingham, one of the study authors.
Dr. Warnock and colleagues report encouraging results with ACEI/ARB therapy in eleven patients with progressive loss of kidney function related to Fabry disease (Fabry nephropathy). Fabry disease is a rare genetic disorder caused by problems with an enzyme called alpha-galactosidase-A, which the body needs to metabolize lipids (fatty substances). Even with treatment to replace the missing enzyme, buildup of lipids can cause progressive kidney, brain, and heart disease. In the current study, four patients had relatively mild kidney disease (stage 1 to 2), while seven had more severe loss of kidney function (stage 3 to 4).
All patients received ERT and combined ACEI/ARB treatment. The ACEIs and ARBs are widely used in patients with chronic kidney disease and proteinuria "leakage" of protein into the urine associated with progressive loss of kidney function. Treatment is usually based on the patient's blood pressure. However, the situation is different in patients with Fabry disease, who often have low to normal blood pressure despite kidney disease.