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AUTOIMMUNE CHOLANGITIS

Overlaps between PBC and autoimmune chronic hepatitis are being described increasingly. Sometimes these overlaps are termed mitochondrial antibody- negative PBC. Originally, some of the speculations about the overlaps were based on interpretations of liver biopsies. Tests for serum mitochondrial antibodies (AMA) were crude and nonspecific and made interpretation difficult autoimmune cholangitis. The patients with mitochondrial antibodies were often presented for inclusion in clinical trials or for liver transplantation.

Autoimmune cholangitis is a rare condition. The patient is usually a woman presenting with a slow onset of cholestasis. Biochemical changes are those of cholestasis. No significant biochemical difference is found between AMA-negative and AMA-positive patients classified as having PBC. Appearances on liver biopsy are virtually indistinguishable from PBC. Liver cell rosettes and multinuclear cells are absent, but a heavy infiltrate of plasma cells in the portal zones is a finding common to autoimmune chronic hepatitis and PBC autoimmune cholangitis.

The serum AMA test is negative, although the antinuclear antibody is present in high titer, much higher than in PBC. Serum IgM is lower.

The condition probably differs from the PBC autoimmune hepatitis overlap syndrome. There is only one unexpected feature, such as a low smooth muscle titer in a patient with PBC or abnormal bile duct epithelium in a patient with autoimmune hepatitis. Hepatic histologic features may overlap. It remains uncertain whether autoimmune cholangitis is a separate entity or simply a variant of PBC or autoimmune hepatitis. The genomic associations of AMA-positive.

The prognosis for autoimmune cholangitis is probably the same as for PBC. In a limited follow-up, sequential biopsies at up to 20 years showed progression of fibrosis.

Prednisolone therapy results in decreases in serum transaminase levels and evidence of less inflammatory activity in liver biopsy specimens. Serum gamma glutamyl transferase (GGT) does not reach normal levels, and bile duct damage may increase. Prednisolone has little effect on the bile duct lesions, which are probably irreversible. Prednisolone should only be administered in small doses of 5 to 15 mg daily.

It would be more satisfactory if classification were based on causative factors rather than on serum autoantibodies, which are simply markers. Unfortunately, the causes of PBC, autoimmune cholangitis, and autoimmune hepatitis remain unknown. Autoimmune cholangitis represents an overlap between PBC and autoimmune hepatitis. It closely resembles PBC, but the serum mitochondrial autoantibody is not present.