Concordance between hepatic biopsy and the APRI index (Ast to Platelet Ratio Index) for the diagnosis of cirrhosis in patients with autoimmune liver disease

Introduction and objectives: It has been proposed that non-invasive methods may replace liver biopsy for the diagnosis of tissue damage in patients with autoimmune liver disease (ALD). The aim of this study was to determine diagnostic performance and degree of concordance between the APRI index and liver biopsy for diagnosing cirrhosis in these patients. Material and methods: In a cohort of patients with ALD, the value of the APRI index and liver biopsy results were determined according to the METAVIR score. The AUC and the degree of concordance between an APRI value >2 and a METAVIR score of F4 were evaluated as markers of liver cirrhosis, through a kappa statistic. Results: In total, 70 patients (age 51 ± 13 years) were included. The most common autoimmune liver diseases were primary biliary cirrhosis (PBC) (40%), autoimmune hepatitis (AIH) (24.3%) and AIH-PBC overlap syndrome (32.9%). Cirrhosis was confirmed by biopsy in 16 patients (22.9%). 15 patients (21.4%) had an APRI index >2 (Cirrhosis) and only six met both criteria. The AUC of the APRI was 0.77 (95% CI 0.65-0.88). The degree of concordance between the tests was low for an APRI cut-off point >2 (kappa 0.213; 95% CI 0.094-0.332), as well as for cut-off points >1.5, >1 and >0.5 (kappa 0.213, 0.255, 0.257, respectively) Conclusion: Our results suggest that there is little concordance between APRI and liver biopsy for the diagnosis of cirrhosis in patients with ALD. It should therefore not be used as a single diagnostic method to determine cirrhosis.