From the Guidelines
Polyautoimmunity is present in approximately 14-44% of autoimmune hepatitis cases.
Prevalence of Polyautoimmunity
- The prevalence of polyautoimmunity, or the presence of multiple autoimmune diseases, is significant in patients with autoimmune hepatitis (AIH) 1.
- Studies have shown that 14-44% of AIH cases are associated with other autoimmune diseases 1, with autoimmune thyroid disease (AITD) being the most common concurrent autoimmune condition 1.
- Other concurrent autoimmune conditions include rheumatoid arthritis (RA), mixed connective tissue disease, autoimmune hemolytic anemia (AIHA), idiopathic thrombocytopenic purpura, polymyositis, uveitis, Sjögren syndrome, systemic lupus erythematosus (SLE), and ulcerative colitis 1.
- A recent report found that thyroid disorders were the most common concurrent autoimmune disease, accounting for 10.5% of all cases among 3,783 patients with AIH, followed by SLE (2.2%), RA (0.4%), and systemic sclerosis (0.2%) 1.
From the Research
Prevalence of Polyautoimmunity
- The prevalence of polyautoimmunity, defined as the presence of more than one autoimmune disease in a single patient, is estimated to be around 34.4% in patients with autoimmune diseases 2.
- A study analyzing 1,083 patients with autoimmune diseases found that 373 patients (34.4%) had polyautoimmunity, with autoimmune thyroid disease and Sjögren's syndrome being the most frequent diseases encountered 2.
- Another study reported a case of multiple autoimmune syndrome, where a patient had four autoimmune diseases: autoimmune thyroid disease, vitiligo, morphea, and lichen sclerosus, highlighting the increasing prevalence of autoimmune diseases and similar case reports on dermatological polyautoimmunity 3.
Factors Associated with Polyautoimmunity
- Factors significantly associated with polyautoimmunity include female gender and familial autoimmunity 2.
- The coexistence of autoimmune diseases is not uncommon and follows a grouping pattern, with autoimmune thyroid disease, systemic lupus erythematosus, and Sjögren's syndrome being the most hierarchical diseases encountered 2.
Multiple Autoimmune Syndrome
- Multiple autoimmune syndrome (MAS) is defined as the coexistence of three or more autoimmune diseases in a single patient 4, 2, 3, 5.
- A case report highlighted the importance of adequate immunological investigations in conjunction with clinical information for adequate patient management, as patients with MAS are at a higher risk of acquiring infections and tumor development due to prolonged use of immunosuppressants 5.
- Patients with MAS require close surveillance for the development of another autoimmune disease, and a multidisciplinary team approach including an immunologist is necessary for better understanding and management of these disorders 5.