What are some common autoimmune diseases and their treatments?

Common Autoimmune Diseases and Their Treatments

Autoimmune diseases affect approximately 10% of the global population, with over 75% of affected individuals being women, and include a wide spectrum of organ-specific and systemic disorders characterized by immune system attacks on the body's own tissues. 1, 2

Major Categories of Autoimmune Diseases

Hepatobiliary Autoimmune Diseases

• Autoimmune hepatitis (AIH) manifests as chronic hepatitis with elevated transaminases and IgG levels, requiring immunosuppressive therapy 3
• Primary biliary cholangitis (PBC) occurs as an overlap syndrome in 8-10% of AIH patients 3
• Primary sclerosing cholangitis (PSC) presents as AIH-PSC overlap in 6-11% of Western AIH patients, though it is rare in Eastern populations 3

Endocrine Autoimmune Diseases

• Autoimmune thyroid disease (AITD) is the most common concurrent autoimmune condition, affecting 10-23% of patients with other autoimmune diseases 3, 4
  • Hashimoto's thyroiditis accounts for 10.2-14.1% of concomitant autoimmune diseases 3, 4
  • Graves' disease occurs in 3-6% of patients with autoimmune thyroid disorders 3, 4
• Type 1 diabetes mellitus is associated with type 2 AIH and should be screened for in patients with type 1 diabetes 3, 5
• Primary adrenal insufficiency can occur with type 1 diabetes as part of polyglandular autoimmune syndromes 3

Rheumatologic Autoimmune Diseases

• Systemic lupus erythematosus (SLE) affects 2.2-3% of AIH patients and is associated with higher IgG levels and poorer prognosis when concurrent 3, 6
• Rheumatoid arthritis (RA) develops in 2-4% of AIH patients, more commonly in older individuals 3, 4, 6
• Sjögren syndrome is observed in 2.8-7% of patients with autoimmune conditions 3, 4, 6
• Systemic sclerosis occurs in 0.2% of patients with autoimmune hepatitis and thyroid disorders 3, 4
• Mixed connective tissue disease can coexist with other autoimmune conditions 3
• Polymyositis and dermatomyositis are recognized autoimmune muscle diseases 3

Hematologic Autoimmune Diseases

• Autoimmune hemolytic anemia (AIHA) occurs in 5-7% of chronic lymphocytic leukemia patients and can be associated with other autoimmune conditions 3, 4, 7
• Idiopathic thrombocytopenic purpura (ITP) is less common than AIHA but occurs with various autoimmune diseases 3, 4
• Pure red cell aplasia and autoimmune granulocytopenia are very uncommon 3

Gastrointestinal Autoimmune Diseases

• Celiac disease should be screened for in patients with type 1 diabetes soon after diagnosis 3
• Inflammatory bowel disease (IBD) occurs in 2-11.4% of AIH patients 3
  • Ulcerative colitis is found in 2-8% of AIH patients and 11.4% when annual proctoscopic examination is performed 3, 5
  • Crohn's disease occurs in 1-6% of AIH patients 3, 5
• Autoimmune gastritis can occur with type 1 diabetes 3

Neurologic Autoimmune Diseases

• Multiple sclerosis occurs in 0.17% of AIH patients, higher than the 0.02% general population prevalence 3, 6, 5
• Myasthenia gravis is associated with type 1 diabetes and other autoimmune conditions 3

Dermatologic Autoimmune Diseases

• Vitiligo is associated with type 2 AIH 3
• Leukocytoclastic vasculitis and urticaria occur with type 2 AIH 3, 4
• Alopecia areata is linked to type 2 AIH 3
• Paraneoplastic pemphigus has a proven link with chronic lymphocytic leukemia 3

Other Autoimmune Diseases

• Uveitis can coexist with other autoimmune conditions 3
• Pulmonary fibrosis is rarely associated with AIH 3
• Raynaud's phenomenon can occur with autoimmune diseases 3

Treatment Approaches

Broad-Spectrum Immunosuppression

• Glucocorticoids remain the cornerstone of treatment for AIH and many autoimmune conditions, with 67-83% biochemical response rates 3, 1
• Methotrexate is used for rheumatoid arthritis and other autoimmune diseases, though it requires careful monitoring for hepatotoxicity, bone marrow suppression, and other organ toxicities 8

Targeted Molecular Therapies

• Rituximab (anti-CD20) is highly effective for refractory warm antibody AIHA and B cell-mediated autoimmune diseases 7, 1
• Janus kinase (JAK) inhibitors represent recent advances in molecular-targeted therapy 1
• Monoclonal antibodies targeting specific immune pathways are increasingly used 1

Emerging Cellular Therapies

• CD19-targeted CAR T cell therapies show promise for sustained remission in B cell-mediated autoimmune diseases, representing a potential paradigm shift 9
• Regulatory T cell (Treg) therapies aim for localized immune modulation to minimize generalized immunosuppression 9
• CAR-Treg cells offer tissue-specific or cell type-specific targeting 9

Disease-Specific Considerations

• Autoimmune thyroid disease requires thyroid function monitoring and hormone replacement when indicated 4
• Autoimmune hemolytic anemia in malignancy requires optimizing cancer-directed therapy as controlling the underlying malignancy may resolve the AIHA 7
• AIH-PBC overlap syndrome may respond to glucocorticoid therapy alone despite AMA positivity 3

Clinical Monitoring Recommendations

Screening for additional autoimmune conditions is essential in patients with one autoimmune disease, as 14-44% of AIH cases are associated with other autoimmune diseases. 3, 4

• Extended diagnostic screening should be conducted at diagnosis and at regular intervals during follow-up 4
• First-degree relatives have increased risk and warrant family history evaluation 4
• Patients with type 1 diabetes should be screened for autoimmune thyroid disease and celiac disease soon after diagnosis 3