Autoimmunity in Type 2 Diabetes: When the Only Effective Therapy Becomes Immunosuppressive

Area of Science:

• Endocrinology
• Immunology
• Rheumatology

Background:

• Type B insulin resistance syndrome is a rare autoimmune disorder characterized by anti-insulin receptor antibodies.
• It leads to severe hyperglycemia, resistance to standard antidiabetic therapies, and often co-occurs with other autoimmune conditions.

Purpose of the Study:

• To report a case of Type B insulin resistance syndrome effectively managed with Rituximab.
• To highlight the diagnostic considerations and treatment outcomes for this rare autoimmune diabetes.

Main Methods:

• A 67-year-old patient with autoimmune hemolytic anemia and severe hyperglycemia unresponsive to insulin therapy was treated with Rituximab.
• Diagnostic workup excluded Type 1 diabetes, and autoimmune pathogenesis was suspected based on clinical presentation and comorbidities.

Main Results:

• The patient showed significant improvement in glycemic control within 2 weeks of Rituximab infusion, with reduced insulin requirements.
• After 3 cycles of Rituximab, the patient achieved normalized HbA1c (6.7%) and discontinued insulin therapy, returning to oral Metformin.
• This outcome supports the efficacy of immunosuppressive therapy in Type B insulin resistance syndrome.

Conclusions:

• Rituximab demonstrated a remarkable response in managing Type B insulin resistance syndrome, supporting its autoimmune etiology.
• Early consideration of this rare condition and prompt initiation of immunosuppressive therapy are crucial for effective treatment.
• Anti-insulin receptor antibodies are implicated in Type B insulin resistance syndrome, predominantly affecting middle-aged women with associated autoimmune diseases.