Sensitivity and specificity of microRNA‐122 for liver disease in dogs

Abstract

BackgroundCurrent tests for diagnosing liver disease in dogs are sub‐optimal. MicroRNA‐122 (miR‐122) is a sensitive and specific biomarker of liver injury in humans and rodents. Circulating miR‐122 could have utility in identifying dogs with liver disease.ObjectiveEstablish the reference interval for miR‐122 in healthy dogs and determine performance in a range of dog breeds with liver disease and control animals with non‐liver disease.AnimalsStored serum from 120 healthy dogs, 100 dogs with non‐liver diseases, and 30 dogs with histologically confirmed liver disease was analyzed.MethodsRetrospective study. Medical records of dogs with liver disease, non‐liver disease and healthy dogs were reviewed. Serum miR‐122 concentrations were measured by PCR and compared with the characteristics of the dogs and their conventional clinical measurements.ResultsIn healthy dogs the 2.5th, 50th, and 97.5th quartiles of miR‐122 were 110 (90% CI 80‐114), 594 (505‐682), and 3312 (2925‐5144) copies/μL, respectively. There was no difference between healthy dogs and dogs with non‐liver disease (median ± IQR: healthy dogs 609 [327‐1014] copies/μL; non‐liver disease 607 [300‐1351] copies/μL). miR‐122 was higher in dogs with liver disease (11 332 [4418‐20 520] copies/μL, P < .001 compared to healthy dogs). miR‐122 identified dogs with liver disease with high accuracy (receiver operating characteristic area under curve for comparison with healthy dogs: 0.93 [95% CI 0.86‐0.99]). The upper limit of normal for healthy dogs (3312 copies/μL) had a sensitivity of 77% and specificity of 97% for identifying liver disease.Conclusion and Clinical ImportanceLiver disease can be sensitively and specifically diagnosed in dogs by measurement of miR‐122.

Direct detection of circulating microRNA-122 using dynamic chemical labelling with single molecule detection overcomes stability and isomiR challenges for biomarker qualification

“…We compared serum from healthy dogs to dogs with a range of biopsy diagnosed liver diseases (n = 12 per group). The clinical characteristics of the liver disease group are presented in Supplementary Table 4 Consistent with our previous published data using PCR 16 , miR--122 was significantly higher in the liver disease group when measured using the DCL assay ( Supplementary Figure 3).…”

ACVIM consensus statement on the diagnosis and treatment of chronic hepatitis in dogs

“…Serum ALT activity thus is the best screening test for CH. However, histopathologic evidence of CH can exist in the absence of increased serum liver enzyme activity . Increased serum alkaline phosphatase (ALP) activity occurs later in CH.…”

“…Less information is available regarding serum aspartate aminotransferase and GGT activities in CH, but they tend to mirror serum ALT and ALP activities, respectively, although both are less sensitive. Evidence suggests that serum concentrations of some microRNAs, particularly miR‐122, are increased with minimal liver injury in the dog in the absence of increases in ALT activity, and thus may have superior sensitivity over standard serum liver enzymology in detecting early CH …”

“…However, histopathologic evidence of CH can exist in the absence of increased serum liver enzyme activity. 192,193,195,196 Increased serum alkaline phosphatase (ALP) activity occurs later in CH. If both ALT and ALP activities are increased, the magnitude of ALT increase often exceeds that of ALP.…”

“…Evidence suggests that serum concentrations of some microRNAs, particularly miR-122, are increased with minimal liver injury in the dog in the absence of increases in ALT activity, and thus may have superior sensitivity over standard serum liver enzymology in detecting early CH. [192][193][194][195][196]…”