ANTIBODIES TO MITOTIC APPARATUS: PREVALENCE ANDASSOCIATEDDISEASES

Background: The mitotic spindle apparatus (MSA) is the structure responsible for directing the movement of chromosomes during cell division. The autoantibodies directed to the MSAshow characteristic patterns in the indirect immunofluorescence staining of cells in metaphase. These patterns are slightly different depending on the specificity of the autoantigen. Objectives: The clinical associations of these ANA patterns have not been clearly established. We aim to carry a descriptive study in patients with antibodies directed to the MSA. In this setting, we studiedthe possible association of these patterns with age, sex or clinical manifestations. On the other hand, weaim to establish the prevalence of these patterns in the studied population. Methods: We revised all patients sera with positive anti-nuclear antibodies (ANA) diagnosed by the Clinical Immunology Department of the Hospital Clínico San Carlos, between January 2013 to December 2013. The determination of these patterns was performed by the reference's technique, indirect immunofluorescence on HEp-2 human carcinoma cells with HELIOS autoanalyzer (Aesku, Wendesheilm, Germany) that enable a high output of good quality 2D images. Subsequently,a manual reading was performed with the fluorescence microscope Nikon Eclipse E400. Results: Were studied 1,788 patients with positive ANA, out of 7,280 sera tested representing a 24.56%. Within the group of positive ANA, 78 patients disclosed autoantibodies tothe MSA, with a prevalence of 4.36%. No significant differences were found by sex between the groups formed by the different patterns (p=0.5). The age of the patients showed a great variability, with an overall mean of 60.6±17.6 years.We observed a clear predominance of liver disorders (n=25, 32.0%); thyroid abnormalities (n=9,11.5%), and rheumatic diseases (n=8, 10.0%). Conclusions: The prevalence of autoantibodies to the mitotic spindle apparatus in our series represents the5% of all positive ANAs. Patients with autoantibodies to mitotic apparatus showed a high prevalence of liver abnormalities that deserves further characterization. Disclosure of Interest: None declared DOI: 10.1136/annrheumdis-2014-eular.4956Citation: Annals of the Rheumatic Diseases, volume 73, supplement 2, year 2014, page 816Session: Adaptative immunity (T cells and B cells) in rheumatic diseases (Abstracts accepted for publication )