Autoantibody profiling of patients with primary biliary cirrhosis using a multiplexed line-blot assay

To evaluate the autoantibody profile in patients with primary biliary cirrhosis (PBC) using a new multiplexed line-blot assay specifically designed for the diagnosis of autoimmune liver diseases. Sera of 58 consecutive PBC patients and 191 disease controls (144 with autoimmune liver diseases other than PBC, and 67 with non-autoimmune chronic liver diseases) were tested by both the multiplexed line-blot Autoimmune Liver Disease Profile 2 (ALD2) and by IIF on HEp-2 cells and on rat kidney/liver/stomach tissues. ALD2 contains the following PBC-associated antigens: AMA-M2, natively purified from bovine heart; M2-E3, a recombinant fusion protein including the E2 subunits of PDC, BCOADC and OGDC; sp100, PML and gp210 recombinant proteins. With the ALD2 assay, a positive reaction to AMA-M2, M2-E3, sp100, PML and gp210 in PBC patients was observed in 77.6%, 84.5%, 34.5%, 15.1% and 18.9%, respectively, of the PBC sera. The overall sensitivity and specificity for PBC were 98.3% and 93.7%. Using IIF, positivity rates to AMA, and to antinuclear autoantibodies with membranous/rim-like and multiple nuclear dot patterns were 86.2%, 8.6% and 22.4%, respectively. The overall sensitivity and specificity for PBC of the IIF method were 86.2% and 97.9%, respectively. The ALD2 line-blot showed a good diagnostic accuracy for PBC and a higher sensitivity than the IIF method to detect sp100 and gp210 autoantibodies. •The ALD2 showed a good diagnostic accuracy for PBC.•The ALD2 showed a higher sensitivity than the IIF method both for sp100 and gp210.•In general laboratories the ALD2 may be used to confirm IIF results.•In specialized laboratories the ALD2 represent a cost-effective first line technique.