Background Autoimmune dysglycemia syndrome is rare entity that can be induced by drugs or associated with rheumatic diseases. This syndrome includes the insulin autoimmune syndrome caused by anti-insulin antibodies; and type B insulin resistance syndrome caused by anti-insulin receptor antibodies. Patients may present with hyperglycemia, hypoglycemia, or both. Clinical case A 41-year-old Peruvian woman; pulmonary tuberculosis at age 14. In 2008 she presented polyarthritis, elevated ESR and CRP, she received methotrexate and deflazacort for 3 months, presenting remission and suspending medication. In 2009, she was admitted to the emergency room with seizures that resolved after intravenous administration of 33% dextrose. She was hospitalized for study, during her stay she presented episodes of fasting hypoglycemia and postprandial hyperglycemia. She reported hyporexia, weight loss, alopecia, and joint pain. On examination: she presented malar and soft palate erythema, mild pretibial edema. Laboratory tests: fasting blood glucose: 52-69mg/dl, albumin 1,6g/L; fasting insulin: 69.3uIU/mL, C-peptide: 3ng/mL; Anti-insulin antibodies: 4,7 (NV < 0,5), proteinuria 4,2 g/24h, ANA 1/2560 mottled pattern. Anti-cardiolipin, Anti-Sm and Anti-DNA (-). Hemoglobin: 10.6, Leukocytes: 3,160, lymphocytes: 1,540, platelets: 166,000. Renal biopsy showed membranous glomerulonephritis. The determination of antibodies against the insulin receptor is not available in Peru. With the diagnosis of autoimmune dysglycemia associated with SLE, she received prednisone 30mg/d, azathioprine 125mg/d, hydroxychloroquine 400mg/d; fractionated normocaloric diet, NPH + crystalline insulin on a correction scale, she was discharged with a progressive decrease in NPH insulin and metformin 850mg bid. Her glucose levels stabilized, control of proteinuria and joint symptoms was achieved with azathioprine, hydroxychloroquine, prednisone 10mg. The patient remained asymptomatic with rheumatological treatment, she suspended metformin and endocrinological follow-up in 2011. In 2013 she presented recurrent episodes of Raynaud's phenomenon and symptoms of proximal muscle weakness, crusted ulcers on the pads of the fingers of both hands, malar rash and exanthema in heliotrope. Laboratory tests: CPK: 8347U/L. Electromyogram: Spontaneous activity with polyphasic short small motor unit potential and early recruitment. Muscle biopsy showed perifascicular atrophy, perivascular and perimysial inflammatory infiltrate with CD4+ T lymphocytes and B lymphocytes. Glucose, insulin, C3, and C4 levels were normal, and anti-insulin antibodies (-). The diagnosis of dermatomyositis was established. She received prednisone 60mg, hydroxychloroquine, methotrexate 10mg, and nifedipine. In August 2020, telemedicine care in endocrinology and rheumatology concluded that there were no episodes of hypoglycemia, glucose: 86 mg/dl, insulin: 12uIU/ml; anti-insulin antibodies (-); CPK levels 136IU/L, C3, C4 normal, no proteinuria and anti ds-DNA (-). Conclusion Autoimmune conditions could cause dysglycemia mainly through different autoantibodies which may cause hyperglycemia and in rare cases hypoglycemia. This case report emphasizes the importance of long-term follow-up in patients with autoimmune conditions including SLE and ADS. Many of these patients are prompt to develope a new autoimmune disease over time. Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m.