Cfa-miRNAs-122 and -21 as modern biomarkers of primary hepatitis in dogs

Primary hepatitis (PH) is one of the most frequently diagnosed hepatic diseases in dogs. Its popular forms are acute hepatitis (AH) and chronic active hepatitis (CAH) which can progress to hepatic fibrosis and cirrhosis. This investigation aimed to evaluate the use of hepatocyte released Canine familiaris miRNAs(cfamiR)-122 and -21 as serum biological markers for the early and reliable diagnosis of PH and to reveal the onset of hepatic fibrosis. After the ultrasonographic and histological examination, fifteen healthy dogs were involved in the study as control group to compare with other thirty dogs confirmed to have AH or CAH (n = 15). Activity of liver enzymes as well as serum level of globulin and total bilirubin were significantly elevated in AH (P < 0.001) and CAH (P < 0.01) groups whereas, serum level of total protein, albumin, BUN and A/G ratio were significantly lowered in both PH groups (P < 0.01) compared to control. Cfa-miR-122 significantly expressed in AH (P < 0.001) and CAH (P < 0.01) and exhibited a potential significance in distinguishing these groups from control with an area under the curve (AUC) of 0.98 and 0.96, respectively. Additionally, cfa-miR-122 displayed a potential role in distinguishing AH (P < 0.05) from CAH group with an AUC of 0.85. Cfa-miR-21 was only expressed in dogs of CAH group and displayed a potential role in distinguishing this group (P < 0.001) from AH and healthy groups with an AUC of 0.99 and 0.88, respectively. Therefore, cfa-miR-122 can be significantly expressed in dogs with two forms of PH whereas, cfa-miR-21 could be potentially enhanced only in chronic form of PH and may act as new non-invasive biomarker for distinguishing AH from CAH.