Aims: To explore whether immunoglobulin (Ig)G4-related sclerosing cholangitis (IgG4-SC) contributes to end-stage primary sclerosing cholangitis (PSC) in the United Kingdom.
Methods and results: This study consisted of 41 patients who underwent liver transplantation for advanced PSC. Explanted livers were examined histologically with an emphasis on IgG4-positive plasma cell infiltration. Thirty-nine cases (95%) had minimal or mild infiltration of IgG4-positive plasma cells (≤ 30 cells/high-power field). In contrast, two cases (5%) showed plasma cell IgG4-positivity in more than 100 cells/high-power field. IgG4-positive plasma cells were accumulated preferentially in a (xantho)granulomatous tissue within large bile ducts. Except for the presence of IgG4-positive plasma cells, there was no significant histological difference between IgG4-positive and negative cases. Both showed sclerosing cholangitis with bile duct erosion and xanthogranulomatous reaction more in keeping with PSC than typical IgG4-SC. Clinically, the two patients differed from typical IgG4-related disease, in that both had associated ulcerative colitis, and one of them was younger than expected for IgG4-SC (28 years old).
Conclusions: No classical IgG4-SC could be identified in patients explanted for PSC. The two cases identified with numerous IgG4-positive plasma cells suggest a superimposed immune mechanism of uncertain nature. A prospective study is needed to assess whether such cases will be steroid-sensitive.
© 2011 Blackwell Publishing Limited.