Table 2 Classic characteristics of autoimmune disease aetiology and the extent to which primary biliary cirrhosis demonstrates those characteristics.

Characteristic	Characteristic seen in PBC?	Comment
Autoreactive immune responses to defined autoantigens	Yes	PDC association is among the strongest seen in any autoimmune disease
Female predisposition	Yes	10 : 1 Female to male ratio although classical disease occurs in men ruling out an obligate female association
HLA association	Yes	Significant associations but with atypical alleles and weaker than in other autoimmune diseases
Induction of disease by sensitisation with autoantigen	Possibly	Observation awaits replication
Response to immunosuppressive therapy	Possibly	Comprehensive trials equivocal. Probably effective in selected individuals with significant inflammatory component
Production of disease by adoptive transfer of autoreactive cells and/or antibody	Possibly	Preliminary data suggestive. As yet unconfirmed
Spontaneous animal model with identical antigen specificity	No	No confirmed spontaneous model
Both children and adults affected	No	Disease in children is anecdotal
Autoantigen distribution matches disease distribution	No	PDC is universal but disease is highly restricted in its distribution

HLA, human leukocyte antigen; PBC, primary biliary cirrhosis; PDC, pyruvate dehydrogenase complex.