Please use this identifier to cite or link to this item: http://hdl.handle.net/1946/12756
Background: Antimitochondrial antibodies (AMA) are a very sensitive and specific disease marker for primary biliary cirrhosis (PBC). AMAs are present in 95% of patients with PBC. However 5% do not have AMAs and data on these patients is scarce.
Objective: Compare the long term outcome of AMA negative PBC patients with AMA positive patients in terms of disease complications and liver transplant free survival.
Methods: Retrospective chart review of 71 AMA negative PBC patients. Disease presentation, laboratory results, and clinical endpoints were recorded from medical charts. AMA negative patients were matched on year of diagnosis to a control group
of AMA positive patients.
Results: A total of 68/71 (96%) were of female gender with a median age at diagnosis of 55 years (28-82) and a length of follow-up of 7.5 years (1.1-17.0). Five AMA negative patients had features of overlap syndrome. Mayo risk score at presentation
was 3.59 (range 1.58-9.31). Total bilirubin and ALP were 0.7 mg/dL (IQR 0.5-1.3) and 2.66x ULN (1.63-4.61) at presentation, respectively. Eleven patients were cirrhotic, 9 suffered hepatic decompensation, 7 variceal bleeding, 4 were transplanted and 10 died. AMA negative patients had a significantly higher female-to-male ratio than AMA positive patients (P = 0.04) but did not differ in terms of age, IgM, ANA status or length of follow-up (P = NS). AMA negative patients had a shorter complication free survival compared to AMA positive patients (log-rank test: P = 0.0182).
Conclusion: AMA negative patients had a significantly higher proportion of females and a significantly worse prognosis compared to AMA positive patients. The reason for the difference in prognosis is unclear, it may be true difference or reflect a delayed disease detection in AMA negative PBC patients.