Enzyme inhibition assay for pyruvate dehydrogenase complex: Clinical utility for the diagnosis of primary biliary cirrhosis

Table 2 Interpretation of detection of anti-2-OADC by immunoblotting and enzyme inhibition assay

Immunoblotting (IgG/IgM/IgA)	Enzyme inhibition assay	Interpretation	Estimated percentage (%)
Positive	Positive	PBC	72 - 83
Positive	Negative	Non-anti-PDC positive PBC	10 - 25
		Immunoblotting false positive?	10 - 15
Negative	Positive	Enzyme inhibition assay false positive?	Very rare
Negative	Negative	Non-PBC	Very rare

These data are based on our results that the sensitivity of immunoblotting for PBC is almost 100%, and the specificity of enzyme inhibition assay for PBC is nearly 100%, i.e., when the result by immunoblotting is negative, the serum is not from PBC, and when the result of enzyme inhibition assay is positive, the serum should be from the patient with PBC. 2-OADC, 2-oxo-acid dehydrogenase complex; PBC, primary biliary cirrhosis; PDC, pyruvate dehydrogenase complex.