Primary Biliary Cirrhosis (PBC) is very closely associated with the presence of antimitochondrial antibodies (AMA); indeed, the presence of these antibodies is virtually disease specific. Despite the major advances made during the last decade in identifying the antigens with which these antibodies react, the reason for the close association remains uncertain. In this review, we examine the clinical correlates of AMA with features of PBC and discuss the possible implications of the association.
CLINICAL CORRELATES
Epidemiology of PBCThere is geographical variation in the prevalence of PBC, being highest in areas such as the north of England and parts of North America but rare in Africa and the Indian subcontinent. 1 Studies from the north of England suggest that the incidence of PBC is increasing. Clustering of cases is well described. 2 PBC may occur in families, and up to 4% of first-degree relatives may have PBC. Where PBC does occur in families, it may be related to maternally inherited factors and tends to present earlier in the second generation. 3
AMA Are Detectable Before the Clinical and Histological Features of PBCOf 29 asymptomatic patients who were found to have AMA in serum (later confirmed to be reactive with E2 components of pyruvate dehydrogenase) but with normal liver tests only two had normal liver histology. 4 A decade later, 76% had developed symptoms of PBC and 83% had cholestatic liver tests. None had progressed to cirrhosis. 5