The Diagnostic Value of ANA and Anti-SMA in Suspected Patients with Autoimmune Hepatitis

Abstract

BACKGROUND: Autoimmune hepatitis (AIH) is an unknown chronic disease characterized by hepatocellular inflammation with a tendency to progress to cirrhosis. AIH can present with symptoms of acute hepatitis with symptoms of chronic liver disease. AIH occurs globally; it is more commonly found in females. Autoantibodies such as antinuclear, smooth muscle, liver kidney microsome, and soluble liver antigen are used to aid in the diagnosis of AIH, which presents with a variety of symptoms that also contribute to the classification of AIH. AIM: Evaluation of anti-nuclear antibodies (ANA) and anti-smooth muscle antibodies (SMA) positivity in hepatic diseases, gastrointestinal diseases, viral hepatitis, and extra-hepatic diseases, providing better markers for the early diagnosis of AIH-type 1. MATERIALS AND METHODS: The study included 207 individuals. 62.4% of them were female. Regarding the diagnoses, we grouped them into 4 groups: hepatic diseases (n = 73), viral hepatitis B and C (n = 54), gastrointestinal diseases (n = 34), and extra-hepatic diseases (n = 46). Serum levels of ANA and anti-SMA were measured using an indirect immunofluorescence method following the manufacturer’s instructions (Aesku Diagnostics, Germany). Fluorescence intensity was interpreted semi-quantitatively based on negative control (0) and positive control (+4). RESULTS: The positivity of ANA and anti-SMA resulted as follows: In hepatic diseases 34.2% and 48%, in viral hepatitis B and C, ANA positivity was 14.8% and SMA positivity was 22.2%; in gastrointestinal diseases, ANA and SMA positivity were, respectively, 11.8% and 20.6%; and in  extrahepatic diseases, positivity of ANA resulted in 32.6% and SMA in 26%. When compared to the viral hepatitis patient group, the ANA specificity for hemagglutination inhibition (HAI) was 85.2% and that of anti-SMA was 77.8%. The analysis of 46 extrahepatic patient groups provided an ANA specificity of 67.4% and an anti-SMA specificity of 74% for HAI. The comparison to gastrointestinal disease showed that ANA specificity for HAI was 88.2% and anti-SMA specificity was 79.4%. CONCLUSION: Diagnosing AIH is difficult because the clinical spectrum ranges from an asymptomatic presentation to an acute and severe disease. So in all cases, AIH must be suspected. Both males and females can develop AIH, but the disease is more common in females. Based on our diagnostic parameters, we can say that ANA and anti-SMA provide moderate sensitivity for AIH, but they are more specific to AIH type 1.