Background/Aims First degree relatives (FDR) of patients with primary biliary cholangitis (PBC) frequently
display anti-mitochondrial antibodies (AMA). However, the prevalence of PBC-specific
anti-nuclear antibodies is unknown, nor have FDR been followed up systematically in
order to assess clinical/serological features of PBC over time.
Methods A cohort of 231 FDR of PBC patients was prospectively screened for PBC-specific autoantibodies
(AMA, MIT3, gp210, sp100) and biochemical makers of cholestasis. FDR with features
of PBC were further examined and all participants were followed-up after 2 and 4 years.
All participants completed a comprehensive survey to assess environmental risk-factors
for the development of PBC.
Results At baseline, 5 of 231 (2.2%) FDR were diagnosed with PBC. Sixteen (7%) additional
cases with PBC-specific antibodies were detected without signs of cholestasis. Notably,
in 4 of the 5 identified cases with PBC, the affected family-member was a sister.
The prevalence of disease specific autoantibodies was as follows: AMA: 5% (10/231),
MIT3: 3% (8/231), SP100: 2% (4/231), and gp210: 0%. 80% and 33% of the 231 FDR completed
the 2- and 4-year follow-up, respectively. No additional diagnosis of PBC was identified.
However, 7 additional cases with PBC-specific antibodies were detected. Overall, 28/231
(12%) FDR demonstrated PBC-specific antibodies, with the highest prevalence among
sisters (23%) of PBC patients. No environmental risk factors could be identified.
Conclusions Overall, the prevalence of PBC among FDR was 2%, whereby the prevalence of PBC and
PBC-specific antibodies was particularly increased in sisters of PBC patients. Thus,
screening in this group can be considered.
