From the Guidelines
Autoimmune hepatitis diagnosis is primarily based on a combination of clinical features, laboratory tests, and liver biopsy, with the simplified diagnostic criteria of the International Autoimmune Hepatitis Group being a useful tool for establishing the diagnosis 1. The diagnosis of autoimmune hepatitis typically requires elevated liver enzymes (ALT, AST), increased serum IgG levels, and the presence of autoantibodies such as antinuclear antibodies (ANA), anti-smooth muscle antibodies (ASMA), or anti-liver kidney microsomal type 1 antibodies (anti-LKM1).
- Key features of the diagnosis include:
- Elevated liver enzymes (ALT, AST)
- Increased serum IgG levels
- Presence of autoantibodies (ANA, ASMA, anti-LKM1)
- Liver biopsy showing interface hepatitis with lymphoplasmacytic infiltration
- Scoring systems like the revised International Autoimmune Hepatitis Group (IAIHG) score or the simplified criteria can help establish the diagnosis, with a score of 7 or more indicating definite autoimmune hepatitis and a score of 6 indicating probable autoimmune hepatitis 1.
- Other causes of liver disease must be excluded, including viral hepatitis, drug-induced liver injury, alcoholic liver disease, and other autoimmune liver conditions.
- Early diagnosis is crucial as untreated autoimmune hepatitis can progress to cirrhosis, and treatment typically involves corticosteroids (prednisone 30-60 mg daily initially, then tapered) often combined with azathioprine (50-150 mg daily) as a steroid-sparing agent, with response to immunosuppressive therapy supporting the diagnosis 1.
- The presence of high IgG levels is a distinctive feature of autoimmune hepatitis, and the level of immunoglobulins is an important marker in monitoring the response to treatment and the achievement of remission 1.
- A liver biopsy is essential to confirm the diagnosis and provide information on prognosis and management, with the histological features of necroinflammatory activity and severity of autoimmune hepatitis often not in parallel with the biochemical activity of the disease 1.
From the Research
Autoimmune Hepatitis Diagnosis
- Autoimmune hepatitis is characterized by increased serum aminotransferase levels, autoantibodies, hypergammaglobulinemia, and interface hepatitis 2
- The clinical spectrum of autoimmune hepatitis varies from completely asymptomatic to acute-severe or even rarely fulminant hepatic failure, and everybody can be affected irrespective of age, gender, and ethnicity 3
- Diagnosis requires multiple findings and exclusion of similar diseases, and the old revised and the newer simplified diagnostic scores have been established by the International Autoimmune Hepatitis Group (IAIHG) in 1999 and 2008, respectively 3
Diagnostic Criteria
- Autoantibodies detection in patients with suspected autoimmune hepatitis is mandatory, not only for diagnosis but also for classification (AIH-type 1 and AIH-type 2) 3
- Liver biopsy plays an important role in the diagnostic regimen, and the morphological picture of autoimmune hepatitis is characteristic and pathognomic for the disease 4
- The diagnostic criteria of autoimmune hepatitis include the severity of portal inflammation and interface hepatitis, the cell composition of the inflammation, rosette formation of periportal hepatocytes, and the presence and extent of centrilobular and bridging necrosis 4
Diagnostic Challenges
- Diagnosis of autoimmune hepatitis is in most cases challenging for clinicians as there is not a single specific laboratory or histological marker to diagnose or exclude the presence of the disease 3
- Autoimmune serology can be supportive of AIH diagnosis in ≥95% of cases if testing has been performed according to the IAIHG guidelines, but this is not the case under real-life circumstances in routine clinical laboratories 3
- Clinicians should be careful both for the importance of the required testing and how to interpret the results, and they should communicate and discuss with the laboratory personnel to achieve the maximum benefit for the patient 3