Autoimmune blistering diseases (AIBDs) are characterised by autoantibodies against structural components of the skin. Detection of these autoantibodies in tissue or serum is essential to diagnose AIBDs. Traditionally, the diagnosis of AIBDs in Australia relied upon histopathology, indirect immunofluorescence and direct immunofluorescence using monkey oesophagus and salt-split skin. Recently, a newly developed biochip immunofluorescence method, which has reportedly comparable sensitivity and specificity to enzyme-linked immunosorbent assay (ELISA), the gold-standard for AIBD diagnosis, has been available at St George Hospital in Sydney [1].
In the past decade, highly accurate diagnosis of AIBDs in Australia has been difficult. The sera of 47 patients with provisional diagnosis of AIBDs at St George Hospital were sent to Kurume University in Japan for ELISA studies. These included 18 patients with pemphigus vulgaris, 2 with pemphigus foliaceus, 9 with bullous pemphigoid and 18 with other AIBDs. On the same day, 12 pemphigus vulgaris sera were also sent to Westmead Hospital, where 6 patients were misdiagnosed. However, 2 patients' sera, which were tested on the biochip immunofluorescence, showed results matched to the Japanese ELISA results.
We will demonstrate the use of the biochip immunofluorescence at St George Hospital in Sydney to diagnose and differentiate the various types of AIBDs. We will also discuss the advantages and disadvantages of all AIBD diagnostic methods, including traditional indirect and direct immunofluorescence, ELISA and biochip immunofluorescence. In the future, further patients sera will be tested using the newly accessible biochip immunofluorescence, the results of which will be compared to those in ELISAs.