title: Positive antimitochondrial antibody but normal serum alkaline phosphatase levels: Could it be primary biliary cholangitis?
abstract: OBJECTIVE
  Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease, typically diagnosed by elevated cholestatic liver enzymes and a positive antimitochondrial antibody (AMA) test. The clinical significance of AMA positivity in patients with normal cholestatic liver enzymes is uncertain.
  
  
  METHODS
  Charts of patients with normal cholestatic liver enzymes and AMA positivity who underwent liver biopsy between 2012 and 2015 were retrospectively analyzed.
  
  
  RESULTS
  Six AMA-positive patients with normal cholestatic liver enzymes who underwent a liver biopsy were identified. Four (67%) showed florid bile duct lesion compatible with early-stage PBC, whereas the other two showed mild and non-specific histological findings. The patients with histological findings compatible with PBC had higher enzyme-linked immunosorbent assay-determined AMA titers and significantly elevated immunoglobulin M (IgM) level. Patients with non-specific histological findings (33%) had low-titer AMA and a borderline elevated IgM level.
  
  
  CONCLUSIONS
  Antimitochondrial antibody-positive patients with normal cholestatic liver enzymes should be meticulously evaluated for PBC including a liver biopsy, mainly in patients with high-titer seropositivity for AMA and a significantly elevated IgM level. More studies are required to clarify the role of liver biopsy in these patients and further follow-up may elucidate the relationship of these patients to those with more classical forms of PBC.
authors: Liver Disease Center, Sheba Medical Center, Ramat Gan, Israel.|The Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors: Tania
authors: T
authors: Berdichevski
authors: Liver Disease Center, Sheba Medical Center, Ramat Gan, Israel.|The Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors: Oranit
authors: O
authors: Cohen-Ezra
authors: Institute of Pathology, Sheba Medical Center, Ramat Gan, Israel.
authors: Orit
authors: O
authors: Pappo
authors: Liver Disease Center, Sheba Medical Center, Ramat Gan, Israel.|The Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors: Ziv
authors: Z
authors: Ben-Ari
keywords: antimitochondrial antibody; cholestatic liver enzymes; florid bile duct lesion; primary biliary cholangitis