6489 Type 1 Diabetes Mellitus And Multiple Sclerosis: A Case Report Showing The Concurrent Association Of Two Autoimmune Diseases

Abstract Disclosure: P.B. Singh: None. B. Sabates: None. A. Sharifzadeh: None. R.F. Rodriguez: None. Introduction: Both Type 1 Diabetes Mellitus (T1DM) and Multiple Sclerosis (MS) represent persistent autoimmune conditions. T1DM is characterized by the presence of specific autoantibodies targeting pancreatic β-cells. In MS, autoreactive cells mediate a demyelinating inflammatory response directed against the central nervous system. Despite differences in demographics and clinical characteristics, their common root in autoimmunity has led researchers to discover commonalities in genetic, environmental and immunological features. Case Presentation We present a case of a 40-year-old female with medical history of T1DM diagnosed at 7 years of age and MS diagnosed at 32 years of age. She presented to the hospital with clinical features of optic neuritis and symptoms of squeezing ribcage pressure consistent with acute MS exacerbation. After confirmatory neuroimaging, high-dose intravenous corticosteroids were initiated, and Endocrinology services were consulted for inpatient glycemic management. As the patient’s diabetes was treated via continuous subcutaneous insulin infusion (CSII), her pump settings were adjusted to maintain euglycemia during hospitalization. This case is reported to highlight and discuss the association between T1DM and MS. Discussion About 4-5% of the general population is affected by autoimmune disorders, among which T1DM and MS comprise a substantial portion. Multiple studies demonstrate the association and shared etiopathogenesis between T1DM and MS. One study revealed that the prevalence of T1DM is five times higher in patients with MS in comparison to the general population. In another prospective cohort study, individuals with T1DM had a three times higher chance of subsequently developing MS. Additionally, first-degree relatives of MS patients had a roughly 40% higher risk of developing T1DM. Women with T1DM had a 20-fold higher risk of having MS than women without the condition, per another study. As T-cell mediated autoimmune disorders, both T1DM and MS are characterized by autoantigen specific T1-helper cell responses, decreased T-cell suppressor activity, and the presence of various autoantibodies, some of which are seen in both diseases. One study showed that autoreactive T cells could target both pancreatic islet and central nervous system autoantigens in patients with MS, patients with T1DM, and relatives of patients with T1DM. Since MS- and T1DM-associated HLA haplotypes differ between populations, HLA class II alleles per se may not alone be responsible for disease susceptibility. It is suggested that variation at other non-HLA class II loci and/or unknown environmental factors might contribute significantly to the co-occurrence of these 2 diseases. In conclusion, individuals who already have one autoimmune condition are more likely to have other autoimmune conditions, with T1DM and MS being associated more often than expected. Presentation: 6/2/2024