Abstract Number: 73

Biochip immunofluorescence microscopy as a newdiagnostic tool for autoimmune blistering skin diseasesin Australia

Y.Z. Chiang, C.Y. Zhao, W. Melbourne,A. Wijayanti, K. Tran, J. Kim, K. Legaspi, N. Ishii, H. Koga

Meeting: 2015 Dermcoll

Session Information

Date: -

Session Title: Poster Presentations

Session Time: -

Introduction: Autoimmune blistering skin diseases are a
group of disorders characterised by autoantibodies targeting
important structural proteins in the skin that mediate
cell-cell or cell-matrix adhesion. Recently, the Biochip
mosaic-based indirect immunofluorescence technique has
been made available in Australia to allow polyvalent immunofluorescence tests and provide antibody profiles in a
single incubation. Our aim is to determine the sensitivity
and specificity of the Biochip technique, using the enzymelinked
immunosorbent assay (ELISA) as the gold standard

Methods: Sera from patients with provisional diagnoses of
autoimmune blistering skin diseases were collected prospectively
and sent to the pathology laboratory for indirect immunofluorescence microscopy using the Biochip method
and to Japan for ELISA. The Biochip mosaic contained 6 test
substrates which included monkey oesophagus, human
salt-split skin, bullous pemphigoid (BP) antigen 180,
desmoglein (Dsg) 1, Dsg 3, and BP230. The results were
compared with each other.

Results: So far, 29 results from 24 patients were included: 9
had pemphigus vulgaris (PV), 2 had pemphigus foliaceus
(PF) and 13 had BP. The Biochip has good diagnostic sensitivities
for PV on cells transfected with Dsg 1 (100%) and
Dsg 3 (90%). The specificities for Dsg 1 and Dsg 3 were 70%
and 50% respectively. In patients with BP, the Biochip also
has a good diagnostic sensitivity (100%) and specificity
(64%) for BP 230. The sensitivity (67%) and specificity
(57%) for BP 180 were lower than that for BP 230. Our
preliminary results showed that the Biochip method has a
high diagnostic accuracy for PV and BP.