Fig. 1.

Indirect immunofluorescence (IIF) of a human primary biliary cirrhosis (PBC) serum on a conventional clinical laboratory screening substrate, human epidermoid cancer cells (HEp-2), displayed a cytoplasmic staining pattern typical of anti-mitochondrial antibodies (a). Co-localization with a monoclonal antibody 4B6 (anti-GW182) (b) revealed that the some sera also had a cytoplasmic dot staining (CDS) pattern that was masked by the anti-mitochondrial antibodies (AMA) staining but that co-localized (arrows) with GWB, G (glycine) W (tryptophan)-containing bodies (GWBs) (c). Reactivity with GWB was substantiated by addressable laser bead immunoassay (ALBIA) when it was found that these sera had high titres of antibodies to components of GWB (i.e. RAP55, GW182).