Immunological similarities between primary sclerosing cholangitis and chronic sclerosing sialadenitis - Report of the overlapping of these two autoimmune diseases

Primary sclerosing cholangitis (PSC) is characterized by destructive inflam mation and fibrosis affecting the bile duels. The etiology of PSC is still unknown, although lymphocytic infiltration in the portal areas suggests an immune-mediated destruction of the bile ducts. Patients with one autoimmune disease often suffer from one or more other autoimmune diseases, it is wel l known that there is a close relationship between PSC and inflammatory tro wel disease, particularly ulcerative colitis(UC). However, the pathological findings in UC and other overlap diseases do not resemble those of PSC. In the present study, we report a patient with chronic sclerosing sialadeniti s (Kuttner's tumor) and PSC. It is compared the sclerosing changes in both salivary glands and bile ducts histologically. In addition, the expression pattern of mast cell tryptase, b-FGF, and HLA-DR were examined in both tiss ues immunohistochemically. Histological features of sclerosing change in bo th salivary and bile ducts were quite similar. Marked mast cell infiltratio n and b-FGF expression were seen in the sclerosing areas in both tissues. I n active inflammatory areas of the salivary glands, HLA-DR expression was a lso seen. We hypothesized that similar immune reactions occur in both the s alivary gland and bile ducts and are responsible for the fibrosis that foll ows.