Introduction: Antinuclear antibody (ANA) testing using indirect immunofluorescence assay (IIFA) is a common and economical method which contributes to detect systemic autoimmune diseases (SARD) and autoimmune liver diseases (AILD). The primary aim of our study was to investigate ANA positivity and their patterns in multiple liver diseases, including primary biliary cirrhosis (PBC), autoimmune hepatitis (AIH), hepatitis B virus infection (HBV), hepatitis C virus infection (HCV), and hepatic carcinoma (HCC). Besides, we also compared the ANA titers and patterns in patients with liver disease, SARD, and healthy controls (HC).
Methods: A total of 2537 patients with SARD, 137 PBC cases, 57 AIH cases, 3420 HBV cases, 769 HCV cases, 268 HCC cases, and 1073 HC were retrospectively assessed. The titers and patterns of ANA were detected with the IIFA method.
Results: ANA positivity rate was considerably discernible between these diseases, which is 90.1% in SARD, 93.4% in PBC, 49.1% in AIH, 19.1% in HBV, 13.9% in HCV, and 23.5% in HCC. Moreover, only 4.9% of HCC cases, 2.5% of HBV patients, and 1.6% of HCV patients had an ANA titer ≥ 1:320. The mixed pattern which composed of at least two patterns majorly lied in PBC. AC-15 and AC-21 was frequently related to liver diseases; the former pattern was more frequently found in AIH (84.2%) and PBC (8.8%), and the latter pattern was easily seen in PBC (62.2%) and HCC (22.6%). The positive rate of ANA in HC was 12.2%, and its major pattern was AC-2.
Conclusions: There are differences in ANA positivity among patients with SARD and various liver diseases. Some mixed patterns may provide important evidence for the diagnosis of PBC. Clinicians should pay attention to ANA patterns and titer during the interpretation of this test. Key Points • Defining the clinical relevance of antinuclear antibody (ANA) using indirect immunofluorescence assay in the context of diseases can be an important tool for the clinician in the diagnostic work-up of patients with liver diseases. • The mixed pattern of ANA is majorly found in primary biliary cirrhosis (PBC). ANA patterns including AC-15 and AC-21 are frequently related to liver diseases. AC-15 is more often found in autoimmune hepatitis (AIH) (84.2%) and PBC (8.8%), and AC-21 is easily found in PBC (62.2%, and hepatic carcinoma (HCC) (22.6%). • ANA positivity can be seen in 19.1% of hepatitis B virus infection (HBV) cases, 13.9% of hepatitis C virus infection (HCV) cases, and 23.5% of HCC cases. Only 2.5% of HBV patients, 1.6% of HCV patients, and 4.9% of HCC cases have an ANA titer ≥ 1:320.
Keywords: Antinuclear antibodies; Autoimmune diseases; Autoimmune hepatitis; Liver diseases; Primary biliary cirrhosis.