Autosomal Dominant Polycystic Kidney Disease With Idiopathic Membranous Nephropathy: An Unusual Association?

Abstract

Autosomal dominant polycystic kidney disease (ADPKD) is usually characterized by proteinuria less than 1 g/24 hours and only anecdotal cases of associated nephrotic syndrome have been reported. We report another case of ADPKD with nephrotic syndrome, where histological examination showed features of membranous glomerulonephritis. Serologic tests for hepatitis B surface antigen and anti-hepatitis C antibodies were negative. Antinuclear antibody and anti-neutrophil cytoplasmic antibody were negative. Serum complement fraction, C3 and C4, were within normal range. Abdominal ultrasound examination showed both enlarged liver and kidneys, both with multiple cysts of varying sizes. Nevertheless renal parenchyma between cysts was not yet widely interested. Family history revealed ADPKD affecting the mother. Considering nephrotic proteinuria, a percutaneous biopsy was performed, and a diagnosis of idiopathic membranous nephropathy associated with ADPKD was made. Our patient was managed with salt restriction, diuretics and antihypertensive drugs (ACE-I and ARB) and started therapy according to Ponticelli's Protocol. At 12 week follow up proteinuria dropped to less than 1 g/24 hours, with normalization of renal function. Our case confirmed the importance of kidney biopsy even in patients with ADPKD and nephrotic syndrome, in order to demonstrate any coexisting glomerular disease, make an accurate diagnosis and plan appropriate treatment.




J Med Cases. 2011;2(2):94-96
doi: https://doi.org/10.4021/jmc144w