Do the AMA react with the bile ducts?
In as much as the bile ducts are the main targets of destruction in PBC, the question was asked whether the AMA reacts with the epithelial cell lining of the bile ducts. So, investigators prepared antibodies to PDC-E2. As expected, they found that these antibodies bound to the mitochondria within cells. But, sure enough, recent information suggests that these AMA autoantibodies also bind to PDC-E2 that lies outside the mitochondria yet within the epithelial cells lining the bile ducts. Indeed, these cells are the main targets of destruction in PBC. This accumulation of PDC-E2 within the biliary epithelial cells is observed exclusively in the livers of patients with PBC, and not in normal livers or in livers from patients with any other types of liver disease. Interestingly, it was also observed in the livers of those two to five percent of PBC patients who do not have AMA in their blood (AMA-negative PBC). Furthermore, intense binding of these antibodies to biliary epithelial cells was
