Concurrent Fabry disease and Hepatitis-B virus-associated IgA nephropathy: A case report with pain as a precursor

Abstract

We report a 35-year-old man with Fabry disease coexisting with Hepatitis-B virus (HBV)-associated IgA nephropathy who had been treated for “rheumatism” for many years. He presented with severe burning pain in his extremities, microscopic hematuria and nephrotic-range proteinuria, while kidney function was preserved. Autoimmune tests were negative, but HBV markers were positive. Renal biopsy showed IgA-dominant mesangial proliferative glomerulonephritis with mesangial HBsAg deposits, and electron microscopy revealed myelin-like inclusions in podocytes and tubules. Markedly reduced α-galactosidase A activity, elevated lyso-GL-3 and a splice-site GLA mutation confirmed Fabry disease. Treatment with renin-angiotensin blockade, entecavir and enzyme replacement improved pain and proteinuria and stabilized renal function. This case illustrates that Fabry disease coexisting with HBV-associated IgA nephropathy is uncommon and easily underdiagnosed, and that persistent neuropathic pain with proteinuria should prompt consideration of metabolic and genetic renal disorders.