Aydemir Y, et al. - Among pediatric patients with autoimmune hepatitis, researchers studied the frequency and the traits of IgG4-associated autoimmune hepatitis (defined as patients with more than 10 IgG4-positive plasma cells/HPF). They performed immunostaining for IgG and IgG4 in liver biopsies of 40 pediatric patients with autoimmune hepatitis. A positive association was found between IgG4-positive plasma cell count and degree of portal and lobular inflammation, grade of interface hepatitis and fibrosis. In IgG4-associated autoimmune hepatitis, the time required for normalization of liver transaminases and serum IgG level were significantly shorter. In pediatric and type 2 autoimmune hepatitis patients, IgG4-associated autoimmune hepatitis could be found. Biopsy specimens should be assessed for IgG4-associated autoimmune hepatitis at diagnosis, as steroid response might be improved.