Domestic cat hepadnavirus associated with hepatopathy in cats: A retrospective study.

BACKGROUND: Whether domestic cat hepadnavirus (DCH) infection is associated with clinical disease remains to be determined. OBJECTIVES: To determine the relationship between DCH detection, hematology, serum bichemistry and liver histology in DCH-positive cats. ANIMALS: One thousand twenty-two cats in Thailand without concurrent diseases and not undergoing treatments adversely affecting the liver. METHODS: Retrospective cross-sectional study. Samples derived from cats with concurrent virus detection were excluded. DCH detection was determined in blood and fresh-frozen liver by quantitative polymerase chain reaction (qPCR) and further investigated in liver sections showing histological parenchymal disorders (HPD) and normal liver (HNL) using in situ hybridization (ISH). Proliferative/apoptotic activities were determined using immunohistochemistry and ISH panels. Biochemical variables and risk factors for DCH infection were investigated. RESULTS: Six hundred sixty-one (557 blood and 119 liver samples) cats were included. DCH was detected in 18.50% (103/557), 13.85% (9/65), and 3.70% (2/54) of the blood, HPD, and HNL groups, respectively. Cats with DCH revealed abnormally high activity of aspartate aminotransferase (AST) (P = .001) and alanine aminotransferase (ALT) (P < .001). Among DCH-positive HPD case 2/9 an 7/9 were acute and chronic hepatitis, of which 4/7 had hepatitis. Log viral copy number (LVCN) was positively correlated with ALT (P < .001), triglyceride (P < .001), and gamma-glutamyl transpeptidase (GGT) (P = .022). The LVCN also had a positive association with degree of hepatitis (P < .05). There was hepatocyte proliferation activity in DHC positive cats. CONCLUSION AND CLINICAL IMPORTANCE: Domestic cat hepadnavirus infection was associated with high serum activity of liver enzymes and chronic lymphoplasmacytic hepatitis (LPH).