Journal Article

AB0826 EXPLORING THE POTENTIAL GENDER DIFFERENCE IN MYOSITIS: DISEASE PHENOTYPE AND ANTIBODY PROFILE FROM A SINGLE-CENTER ITALIAN COHORT

D’antonio, A., Chimenti, M. S., Greco, E., Kroegler, B., Modica, S., Conigliaro, P., Triggianese, P., Cela, E., Bergamini, A.

2023

Overview

BackgroundIdiopathic inflammatory myopathies (IMM) include a heterogeneous group of rare autoimmune diseases with a large spectrum of muscular and systemic manifestations, mainly involving skin and lung [1,2]. Myositis specific antibodies (MSA) and myositis associated antibodies (MAA) have been described in IMM patients potentially correlating to disease outcome [3]. As well documented, autoimmune diseases present with a clear gender bias with a greater prevalence among women. To our knowledge, no studies has explored the potential gender difference in IIM patients.ObjectivesThe aim of the study was to explore differences in disease features, clinical outcome, antibody profile, and treatments in IMM patients according to the gender.MethodsIn an observational study, we included patients with a defined IIM diagnosis who were referred to 3rd level Rheumatology Unit “Tor Vergata” University Hospital in Rome (Italy) for the past 5 yrs (to Dec 2022). Inclusion criteria were i. a defined diagnosis of dermatomyositis (DM), polymyositis (PM), and anti-synthetase syndrome (ASS), in accordance with the 2017 EULAR/ACR criteria, ii. age ≥ 18 y.o., iii. availability of medical records and consent to study. Data comprised: disease duration and diagnostic delay, clinical phenotype, treatments, and autoantibodies including anti-nuclear antibodies (ANA), MSAs (anti -MDA5, -NXP2, -SAE, Mi2, -TIF1, anti-tRNA synthetase, -Jo1, -PL7, -EJ), and MAAs (anti-PM/Scl, -Ro52, -Ku, U1RNP).ResultsThe study cohort comprised 31 patients who met the inclusion criteria, with a similar gender distribution [n= 17 (54.8%) females and n=14 (45.2%) males]. The median age at symptoms onset was similar in both groups (59±13.3 vs 58.6±12.6 yrs) while males experienced slightly longer diagnostic delay (10.7±14.4 vs 8.7±9.6 months) and disease duration (30±29 vs 21±20 months) than females (P <0.05 for both). No significant difference in the distribution of IIM occurred between the two groups with a half of patients affecting mostly by DM (F 76.5% vs M 50%). However, both PM (F 6.5% vs M 21.4%) and ASS (F 6.5% vs M 28.6%) were moderately prevalent in males. Skin involvement occurred similarly in both groups while lung disease occurred about twofold in males (57.1%) than females (29.4%). Most patients in the cohort showed ANA titre≥ 1:160, with a comparable rate in females and males (64.7% vs 64.3%), and a positivity for at least one MSA and MAA. A double positivity of MSA occurred in 6.5% of the cohort, all females (MDA5/anti NXP2 and MDA5/EJ). The whole cohort had undergone steroids as 1st line therapy: as steroid-sparing agents, the main difference on treatments occurred for the mycophenolate mofetil which resulted significantly more administered in males (57.14%) than females (6%, P 0.002). Furthermore, among patients with lung involvement (n=13), the need to treat the progression of interstitial lung disease, by using the antifibrotic agent (nintetanib), resulted only in males (15%).ConclusionOur preliminary findings suggest that IMM can present a gender difference in disease outcome by showing a longer diagnostic delay and a higher respiratory involvement in male patients. These data might highlight a possible gender-oriented approach in accordance with a different disease profile and treatment strategies but require further investigations in a larger cohort.References[1]Lundberg, I. E. et al. 2017 European League Against Rheumatism/American College of Rheumatology classification criteria for adult and juvenile idiopathic inflammatory myopathies and their major subgroups. Ann. Rheum. Dis. 76, 1955–1964 (2017).[2]Lilleker, J. B. et al. The EuroMyositis registry: an international collaborative tool to facilitate myositis research. Ann. Rheum. Dis. 77, 30–39 (2018).[3]Halilu, F. & Christopher-Stine, L. Myositis-specific antibodies: Overview and clinical utilization. Rheumatol. Immunol. Res. 3, 1–10 (2022).Acknowledgements:NIL.Disclosure of InterestsNone Declared.

• Publisher: BMJ Publishing Group Ltd and European League Against Rheumatism,Elsevier B.V,Elsevier Limited
• Subject: Antibodies / Autoantibodies / Autoimmune diseases / Dermatomyositis / Diagnosis / Females / Gender / Gender differences / Gender/diversity issues / Inflammation / Inflammatory diseases / Lung diseases / Males / Medical records / Musculoskeletal diseases / Mycophenolate mofetil / Mycophenolic acid / Myositis / Patients / Phenotypes / Polymyositis / Rheumatology / Scientific Abstracts / Steroid hormones / tRNA