Hepatic copper and iron accumulation and histologic findings in 104 feline liver biopsies

Abstract

Abstract. In contrast to dogs, the role of copper and iron accumulation in feline hepatic disease remains poorly characterized. Therefore, the objective of the current study was to compare the amount and distribution of copper and iron accumulation for different disease processes in feline liver biopsies. Liver biopsies (from 104 privately owned cats) were categorized by primary histopathologic lesion. Copper (by rubeanic acid) and iron (by Prussian blue) accumulation were graded by amounts (0-3) and location (centrilobular, midzonal, periportal, random). The Kruskal-Wallis test and Pearson chi-square test were used to assess differences in metal grade and location, respectively, between diagnostic categories. Histologic diagnoses were normal (n = 12), congenital (n = 6), neoplastic (n = 16), infectious and/or inflammatory (n = 39), and other (n = 31). Hepatocellular iron staining was negative in 18 samples; remaining samples had grade 1 (n = 38), 2 (n = 40), and 3 (n = 8) accumulation. Ninety-two samples were negative for copper; remaining samples had grade 1 (n = 5), 2 (n = 6), and 3 (n = 1) accumulation. No significant differences were found in the amount of iron or copper accumulation between the different diagnostic categories. Diagnostic category and the location of copper or iron accumulation were not associated. Hepatic iron accumulation was common and not associated with histologic diagnosis. Hepatocellular copper accumulation was more common in cats than previously reported, had a similar pattern of distribution to fibrotic changes, and was not present in histologically normal liver biopsies.

Hepatic Lesions in 90 Captive Nondomestic Felids Presented for Autopsy

“…Copper accumulation was uncommon in our study (11%) but had a similar prevalence as was reported in domestic cats 27 and snow leopards with veno-occlusive disease. 17 The 1 case with veno-occlusive disease in our study did not have copper accumulation.…”

“…7,14 A recent study of a large group of domestic cats found no association between histologic abnormalities and the presence or quantity of hepatic iron. 27 Studies of iron and copper accumulation in the liver of snow leopards with veno-occlusive disease have been performed; 17 however, studies looking at hepatic iron and copper accumulation in a large group of nondomestic felids have not been performed. This study describes postmortem histologic findings in liver tissues of nondomestic felids.…”

Presumed primary and secondary hepatic copper accumulation in cats

“…7,8,12 In cats, copper concentrations in the liver, rather than other tissues or plasma, reflect dietary copper intake; results of 1 study 12 suggest that liver is the preferential site for copper accumulation in this species. In a recent retrospective study 11 of the results of histologic examination of feline liver samples stained with rubeanic acid for detection of copper without correlative copper quantification, copper was detected in only 12 of 104 (11.5%) samples. 11 Results of that study 11 indicate histologic distribution of copper in livers of cats is variable (periportal in some cats and centrilobular in others).…”

“…In a recent retrospective study 11 of the results of histologic examination of feline liver samples stained with rubeanic acid for detection of copper without correlative copper quantification, copper was detected in only 12 of 104 (11.5%) samples. 11 Results of that study 11 indicate histologic distribution of copper in livers of cats is variable (periportal in some cats and centrilobular in others).…”

“…7,8 Compared with humans, dogs seem to be resistant to hepatocellular copper accumulation as an epiphenomenon of cholestasis 6,9 ; however, the frequency of development and pattern of secondary hepatic copper accumulation in cats are not known. The authors and others investigators 10,11 have detected copper accumulation in the periportal regions of livers in some cats with nonsuppurative cholangiohepatitis.…”