Uncommon or rare patterns (occurring in < 1% of ANA-positive patients) have been described and may be divided into 3 groups: cell cycle related (NuMA1, HsEg5, CENP-F, MSA-2, proliferating cell nuclear antigen ) nuclear (multiple nuclear dots, centrosome) and cytoplasmatic (Golgi). The most common reported antinuclear staining patterns include: homogeneous, speckled, centromere, and nucleolar. The associations between ANA and some diseases suggest that they may be useful screening and diagnostic biomarkers and could provide insights into the understanding of disease mechanisms. There are many ANA specificities, and while some antibodies are closely associated with specific diseases, others are non-specific in both patients and healthy individuals. However, ANA are present in various infectious, inflammatory and neoplastic diseases, and healthy individuals. ДЄNA are key biomarkers in the evaluation of rheumatic diseases such as systemic lupus erythematous (SLE), SjГ¶gren syndrome (SS), systemic sclerosis (SSc), mixed connective tissue disease (MCTD), and polymyositis/dermatomyositis. Indirect immunofluorescence (IIF) using HEp-2 cells is the most widely used assay for the detection of ANA.

Other entities of presumed autoimmune origin, like CIU and SNHL, might be associated with these patterns.ДЄntinuclear antibodies (ANA) are a diverse group of autoantibodies that recognize multiple intracellular antigens, classically consisting of nuclear specificities such as deoxyribonucleic acid or small nuclear ribonucleoproteins. More than 50% of patients with anti-MSA had an associated CTD, mainly SS, RA and SLE, and anti-MSA behaved as monospecific antibodies. The most frequent anti-MSA patterns found were NuMA and MSA-2. In a large cohort of ANA determinations, uncommon patterns were found in around 1% of cases. Malignancies were found in 8 patients (50% were papillary thyroid cancer). Chronic idiopathic urticaria (CIU) was associated with the NuMA pattern ( PвЂЉ<вЂЉ.02) and sensorineural hearing loss (SNHL) was associated with the MSA-2 ( PвЂЉ<вЂЉ.001), centrosome ( PвЂЉ<вЂЉ.68) and CENP-F ( PвЂЉ<вЂЉ.38) patterns, previously unreported findings. Undifferentiated connective tissue disease (UCTD) was associated with the centrosome ( PвЂЉ<вЂЉ.001), NuMA ( PвЂЉ<вЂЉ.02) and MSA-2 ( PвЂЉ<вЂЉ.45) patterns. The most frequent systemic autoimmune diseases were SjГ¶gren syndrome (SS) (18.1%), rheumatoid arthritis (RA) (13.8%), and systemic lupus erythematosus (SLE) (11%). The NuMA pattern had the highest ANA titers: mean 320 (range 80вЂ“2560) and behaved as monospecific antibodies. The most frequent patterns were nuclear mitotic apparatus (NuMA) (56%) and MSA-2 (25%). At least one fine reactivity was identified in 19/116 (16.3%) of ANA-positive patients, of which anti-Ro was the most prevalent (18/116, 15.5%). Anti-MSA antibodies were the only ANA positive test in 81% patients.

Of these 592 cases, complete data were available in 329 patients, of whom 116 had an established diagnosis. Of the 113,491 patients tested, 60,501 (53%) were positive for ANA, of which 834 (1.3%) were positive for uncommon/rare patterns of ANA (anti-MSA in 592 cases). Clinical and laboratory data of anti-MSA positive patients were retrospectively collected and analyzed. We aimed to investigate the prevalence and clinical significance of anti-MSA patterns in a Colombian population.Дuring 20, 113,491 consecutive determinations of ANA were studied for the presence of uncommon patterns. The prevalence and clinical significance of uncommon or rare patterns, particularly those directed at the mitotic spindle apparatus (MSA), are not well understood. Antinuclear antibodies (ANA) are key biomarkers in the evaluation of rheumatic diseases.

Spindle apparatus