The significance of cytoplasmic antinuclear antibody patterns in autoimmune liver disease.

We aimed to determine the significance of cytoplasmic antinuclear antibody (ANA) patterns using computer-aided immunofluorescence microscopy in patients with autoimmune liver diseases (AILD). ANA staining pattern was identified by treating cultured human epithelial type 2 (HEp-2) cells with the sera of the patients. Medical records of patients with suspected AILD who had positive cytoplasmic ANA patterns between February 2017 and November 2019 were retrospectively reviewed for clinical, laboratory, and immunological data. Cytoplasmic ANA patterns of AILD and non-AILD groups were compared. Further subgroup analysis of patients with AILD who had reticular or speckled cytoplasmic ANA patterns was conducted. We found that among the 196 patients with positive cytoplasmic ANA patterns, 113 (57.6%) were diagnosed with AILD. The percentage of reticular cytoplasmic pattern was higher in the AILD group than that in the non-AILD group (64.0% vs. 21.9%, p < 0.001). Furthermore, patients with AILD who exhibited a reticular ANA pattern demonstrated a higher positive rate for anti-mitochondrial antibodies (66.7% vs. 2.6%, p < 0.001) than those who exhibited the speckled ANA pattern. Moreover, AILD patients with the reticular ANA pattern displayed a lower positive rate for anti-smooth muscle antibodies (0% vs. 45%, p < 0.001) and nuclear ANA pattern (73.2% vs. 97.5%, p = 0.003) than those with the speckled ANA pattern. Therefore, cytoplasmic ANA patterns could be used to guide AILD characterization in suspected AILD cases, especially as the reticular ANA pattern is strongly associated with AILD. Thus, it is important to check cytoplasmic ANA patterns for AILD evaluation, even when nuclear ANA patterns are negative.