This study aimed to evaluate the differences in the clinical significance of antinuclear antibody (ANA) according to their titers and patterns in the diagnosis of systemic autoimmune diseases (AiD) in pediatric patients. Of the 2442 children who had undergone an ANA test, 473 (19.4%) were positive for ANA, of whom 33 (7.0%) were diagnosed with significant AiD. The positive predictive value (PPV) for significant AiD was considerably high on application of an ANA titer of ≥1:640, and the PPV of a dense fine speckled (DFS) pattern was significantly lower compared with those of speckled and homogenous patterns. The diagnostic value of ANA positivity for AiD is limited, and the clinical significance of the DFS pattern is relatively lower compared with that of other patterns, such as homogenous and speckled patterns, in children. It is necessary to approach the significance of ANA in children individually depending on titers and patterns.
Keywords: antinuclear antibody; autoimmune diseases; children; inflammatory diseases; pattern; titer.