Associate Professor, Department of pediatrics, Kashan University of Medical Sciences, Kashan, Iran.
Autoimmune hepatitis is a chronic hepatitis that occurs in children and adults of all ages. Diagnosis is based upon characteristic serologic and histologic findings and the exclusion of other forms of chronic liver disease. Guidelines issued by the AASLD suggest the following diagnostic considerations:
The diagnosis should be made in patients with compatible clinical signs, symptoms, and laboratory abnormalities. Other conditions that can cause chronic hepatitis should be excluded.
In unclear cases a standardized scoring system should be used in the assessment.
In those who are negative for conventional autoantibodies, additional autoantibodies should be sought.
All patients with autoimmune hepatitis and inflammatory bowel disease should undergo cholangiographic studies to exclude primary sclerosing cholangitis.
Scoring systems- A scoring system developed and subsequently revised by the International Autoimmune Hepatitis Group to standardize the diagnosis with using simplified criteria based upon titers of autoantibodies, IgG levels, liver histology, and the exclusion of viral hepatitis.
Autoantibodies: assign one point if the ANA or SMA are 1:40 OR assign two points if the ANA or SMA are ≥1:80 (OR if the LKM ≥1:40 OR if the SLA is positive).
IgG: assign one point if the IgG is > the upper limit of normal OR assign two points if the IgG is >1.10 times the upper limit of normal.
Liver histology: assign one point if the histological features are compatible with autoimmune hepatitis OR two points if the histological features are typical of autoimmune hepatitis.
Absence of viral hepatitis
A probable diagnosis of autoimmune hepatitis is made if the total points are six, while a definite diagnosis is made if the total points are ≥seven.