Antinuclear antibody staining patterns by indirect immunofluorescence assay observed in patients from a tertiary health center in Latin America

Introduction/Objective

This study aimed to describe the frequency of antinuclear antibody (ANA) staining patterns by indirect immunofluorescence assay observed in patients from a tertiary health center in Latin America.

Materials and methods

This retrospective, descriptive, and observational study evaluated data from all patients undergoing antinuclear antibody indirect immunofluorescence assay from a single-tertiary center (University Hospital Fundación Valle del Lili, Cali-Colombia) in 2020.

Results

One thousand and eight patients met the inclusion criteria. The median patient age was 47 (34–59.2) years, and most were female (769, 75.3%). A positive ANA immunofluorescence assay was observed in approximately two-thirds of patients (664, 65.8%). ANA test results were primarily used to exclude a suspected diagnosis in approximately half of the patients (466, 46.2%). Thirty-seven percent (250/664) of the cohort with ANA-positive titers had a systemic autoimmune rheumatic disease (SARD). The most prevalent SARDs included rheumatoid arthritis (RA) (55, 8.2%) followed by systemic lupus erythematosus (SLE) (37, 5.5%). The vast majority of ANA-positive patients had a reported speckled pattern (anti-cell [AC]-2,4,5; 269; 40.5%) followed by homogenous (AC-1; 266; 40%), nucleolar (AC-8,9,10; 46; 6.9%), and centromere (AC-3; 16; 2.4%). The most frequent patterns observed among SLE patients included homogenous (AC-1) patterns in 17 (45.9%) patients, speckled (AC-2,4,5) nuclear patterns in 11 (29.7%) patients, mixed patterns in 7 (18.9%) patients, and reticular/anti-mitochondrial antibody (AMA, AC-21) cytoplasmic patterns in 2 (5.4%) patients.

Conclusion

This study is the first to describe ANA patterns in a Colombian population. Speckled and homogenous patterns were predominant in patients with SARDs.