AUTOIMMUNE MANIFESTATIONS IN A COHORT OF PATIENTS WITH TYPE 1 DIABETES MELLITUS

Background: Type 1 diabetes mellitus (T1D) is an organ-specific autoimmune disease characterized by the presence of circulating, islet-specific, pancreatic auto-antibodies against glutamic acid decarboxylase (GAD65) and the destruction of insulin-producing pancreatic beta cells. An increased risk of developing other serological manifestations and autoimmune diseases has been described, mainly of the thyroid (20% with antithyroid antibodies) and celiac disease (5%). In addition, it has also been described in association with Addison’s disease, autoimmune polyglandular syndrome, psoriasis and other systemic autoimmune comorbidities diseases such as rheumatoid arthritis (RA), systemic juvenile idiopathic arthritis and Sjogren’s syndrome. It also has been suggested that T1D might has a genetic factor, pathogenic pathways with pleiotropic effects, and cytokines such as interferon type I, among others. Objectives: 1) Study the prevalence of autoimmune comorbidities in patients with T1D. 2) Describe the clinical-immunologic profiles of these patients. Methods: A descriptive, retrospective study of a cohort of patients diagnosed with T1D, according to ADA (American Diabetes Association), follow-up by Endocrinology and Rheumatology Units of a 3rd level hospital from June 1975 to July 2018. Clinical and analytical-immunologic variables were collected. Statistical analysis was was performed with SPSS.25. Results: We included 116 patients from which 55% were women, with a mean age at diagnosis of T1D 18.7 (± 12.3 SD) years. Average age at autoimmune disease diagnosis was 38.8 (± 12.2 SD) years. Average time of evolution between onset of T1D and autoimmune comorbidity was 10.1 (± 10.6 SD) years, except one patient with autoimmune thyroiditis 10 years before T1D. Autoimmune manifestations were showed by 19/116 patients (16.4%), with the following diagnoses: autoimmune hypothyroidism: 10 patients (8.6%); autoimmune polyglandular syndrome: 3 patients (2.6%), RA in 2 patients (1.8%). As well, 1 patient with celiac disease, 1 with cutaneous lupus erythematosus (CLE), 1 with psoriasis and another one with IgG4-related orbital inflammatory disease, (0.9% respectively). Three patients developed articular manifestations (2 rheumatoid polyarthritis and 1 with limited joint mobility or cheiroarthropathy). 4/19 patients (21%) showed cutaneous lesions (2 with vitiligo, 1 CLE and 1 with psoriasis.. Hematological alterations type pernicious anemia in one patient. No visceral involvement was found. Antibodies were detected to be organ-specific: 7/17 antibodies to thyroid peroxidase (TPO) (+) and 3/17 antibodies to thyroglobulin (+) and one with anti-gliadin IgA (+). ANA (+) was detected in four patients (two fine granular pattern, one nucleolar and one homogeneous) with negative specificities and 1 patient RF (+). No Anti-CCP antibodies were detected. Conclusion: 1) 16% of patients with T1D presented autoimmune comorbidity at 10 years after the onset of endocrinopathy. 2) Autoimmune hypothyroidism was the most prevalent autoimmune manifestation (8.6%), followed by autoimmune polyglandular syndrome and RA, similar to other studies. 3) We highlight the unusual finding of IgG4-related orbital inflammation as comorbidity of T1D. 4) The cutaneous lesions (21%) were the most common clinical manifestation in patients with T1D and autoimmunity. We emphasize the absence of visceral involvement. REFERENCES: [1] -Lynne et col, 2018, Associated autoimmune diseases in children and adolescents with T1D, uptodate. [2] -Jiang P et col, 2015, Diabetes Mellitus risk factors in rheumatoid arthritis: a systematic review and meta-analysis. [3] -Kiani AK et col, 2015, Genetic link of type 1 diabetes susceptibility loci with rheumatoid arthritis in Pakistani patients. [4] -Zheng WY et col, 2016Detecting shared pathways linked to rheumatoid arthritis with other autoimmune disease in a in silica analysis. Disclosure of Interests: None declared DOI: 10.1136/annrheumdis-2019-eular.7982Citation: Ann Rheum Dis, volume 78, supplement 2, year 2019, page A998Session: Other orphan diseases (Scientific Abstracts)