ANTINUCLEAR ANTIBODY (ANA) AS A LABORATORY BIOMARKER FOR THE EARLY DIAGNOSIS OF SYSTEMIC LUPUS ERYTHEMATOSUS

Abstract

Systemic lupus erythematosus (SLE) is an autoimmune disease with heterogeneous manifestations, and its early recognition may be hindered by nonspecific clinical presentations. Antinuclear antibodies (ANA) are part of the laboratory investigation of SLE because of their high frequency of positivity, although their specificity is limited. This study aimed to analyze scientific evidence on the contribution of ANA as an auxiliary laboratory biomarker in the early diagnosis of SLE. An integrative review with a descriptive, qualitative approach was conducted using PubMed/MEDLINE and SciELO, considering articles published between 2022 and 2026. After eligibility criteria were applied, 11 studies were included: seven case reports, one case series, one cross-sectional study with follow-up, and two narrative reviews. Indirect immunofluorescence on HEp-2 cells was the most frequently reported method when the technique was specified, whereas titers and fluorescence patterns were inconsistently reported. ANA testing helped guide the investigation of atypical initial presentations; however, limited specificity, positivity in individuals without SLE, and methodological heterogeneity precluded its use as an isolated diagnostic marker. The findings indicate that ANA is most useful as a screening and diagnostic-work-up guiding tool and should be interpreted together with titer, fluorescence pattern, specific autoantibodies, complement levels, and the clinical context.