For many patients with autoimmune hepatitis (AIH), the presence of extrahepatic features is well recognised both at the time of presentation and during long-term follow-up. Concomitant ‘autoimmune disorders' have been described in 20-50% of patients with AIH, both in adults and children. Indeed, the presence of these associated phenomena has been incorporated into both the original and revised International AIH group scoring systems as an aid to codifying the diagnosis. In acute index presentations, non-specific joint pains sometimes flitting in nature have been reported in 10-60% of patients, and while joint swelling is uncommon, rheumatoid arthritis and mixed connective tissue disease have been reported in 2-4% of patients with AIH. For a majority of patients, these joint symptoms resolve within days of the introduction of immunosuppressive therapy. Rarer features at index presentation include a maculopapular skin rash and unexplained fever, which are features that tend to resolve quickly with treatment. Interestingly, joint pain and stiffness are also well recognised in the context of steroid withdrawal and cessation in AIH. The occasional co-presentation of AIH with coeliac disease is clinically important (1-6%), since for some patients, there is a risk of immunosuppression malabsorption, thus delaying effective treatment. Similarly, the co-existence of selective IgA deficiency (IgAD) can occur in patients with coeliac disease or in isolation. Selective IgAD as a co-existing extraheaptic feature seems to be more common in paediatric patients with AIH. For these patients, they are at an increased risk of respiratory and sinus infections. Although, typically associated with primary sclerosing cholangitis, the presence of inflammatory bowel disease (IBD; both Crohn's disease and ulcerative colitis) has been described in 2-8% of patients with AIH. Interestingly, for patients with autoimmune sclerosing cholangitis, a distinct pattern of IBD has been recently described. Other conditions have been reported at a lower frequency, including Sjogren's syndrome 1-7%, systemic lupus erythematosus 1-3% and glomerulonephritis 1%. Rarer still and at a frequency of <1% include fibrosing alveolitis, haemolytic anaemia, uveitis, mononeuritis multiplex, polymyositis and multiple sclerosis. In contrast, the reported associations between AIH and thyroiditis 8-23%, diabetes 1-10% and psoriasis 3% are commonly seen and notable in clinical practice.
Regulatory T‐cell conditioning endows activated effector T cells with suppressor function in autoimmune hepatitis/autoimmune sclerosing cholangitis