Comparison of the Sensitivity of indirect Immunofluorescence and Immunoblot Analysis for the Detection of Autoantibodies in Pemphigus / 대한피부과학회지

ABSTRACT

BACKGROUND: Immunolcgical assays are required for the accurate diagnosis of autoimmune bullous dermatoses including pemphigus vulgaris(PV) and pemphigus foliaceus(PF). In the detection of circulating autoantibodies to pemphigus antigens(desmosomal components), the priority remains controversial between indirect immunofluorescence(IF) and immunoblot(IB) assay. OBJECTIVE: In the present study we compared the sensitivity of indirect IF and that of IB using amplified alkaline phosphatase staining system in the detection of pemphigus autoantibodies. PATIENTS We selected eight patients with serum endpoint titer of 180 in preliminary study. Among these patients three were PV and five were PF. METHODS/RESULTS: The titers of IgG autoantibodies found on indirect IF were confirmed as 1 80 in all patients, whereas the titers examined by IB assay were much higher, 1 640 to 1 2560. In the 3 sera of PV patients, the titers of two cases were 1 1280 and the third case was 1 2560. In 5 cases of PF, one was 1640, two were 1 1280, and two were 12560. CONCLUSION: This result suggests that the immunoblot examination using amplified alkaline phosphatase staining system demonstrates higher sensitivity compared with indirect IF(p=0.0003 by Mann-Whitney U test) in the detection of pemphigus autoantibodies.