Polycystic kidney syndrome in New Zealand White rabbits resembling human polycystic kidney disease

Abstract

Cystic kidney diseases are an important cause of morbidity and mortality in humans. Small animal models are needed to more fully explore the complex expression patterns and pathobiology of this group of heritable diseases. We performed a 15-year retrospective analysis of cases in our laboratory animal diagnostic archives to determine the prevalence of cystic kidney disease in New Zealand White rabbits. Out of 203 records with documented renal histopathology, we identified and defined 7 cases of polycystic kidney syndrome (PKS) by 3 morphologic criteria: (1) cysts or microcysts derived from tubules, glomeruli, or both; (2) loose mesenchymal expansion of cortical and/or medullary interstitium; and (3) irregular thickening, thinning, and splitting of basement membranes. PKS was associated with hypercalcemia and hypercreatinemia (P < 0.01), and arterial mineralization resembling Mönckeberg's medial calcific sclerosis. In the liver, mild chronic cholangitis with cholangiodysplasia and fibrosis was common. Anorexia and lethargy were the clinical signs most often reported. Clinicopathologic characterization of PKS in New Zealand White rabbits revealed similarities to both autosomal-dominant and autosomal-recessive polycystic kidney diseases of humans. Awareness of polycystic kidney syndrome in New Zealand White rabbits will allow investigators to avoid using affected animals in unrelated renal research. Prospective studies are needed to define the underlying cause(s) of polycystic kidney syndrome in New Zealand White rabbits, which may be an important new small animal model of human cystic kidney diseases.