Background
Bullous pemphigoid (BP) is an autoimmune blistering disease associated with autoantibodies against BP180 and/or BP230 antigens. The immunoassays available for serological diagnostics include indirect immunofluorescence (IIF) on monkey esophagus (ME), salt‐split skin (SSS), and enzyme‐linked immunosorbent assay (ELISA) for BP180‐NC16a and BP230. Only a few studies validated innovative BIOCHIP mosaic, but none compared agreement between BIOCHIP substrates with conventional methods separately.
Methods
We evaluated the agreement between BIOCHIP and conventional methods and assessed sensitivity and specificity in BP diagnosis. The study comprised 51 BP patients and 39 controls.
Results
Analysis showed very good agreement between BIOCHIP‐SSS vs classic IIF‐SSS (0.933, P < 0.001) and for BIOCHIP‐BP180‐NC16a vs ELISA‐BP180‐NC16a (0.933, P < 0.001). A good strength of agreement between BIOCHIP‐ME vs classic IIF‐ME was observed (0.694, P < 0.001) similar to BIOCHIP‐BP230 vs ELISA‐BP230 (0.793, P < 0.001). BIOCHIP‐ME sensitivity was 51.0%, whereas IIF‐ME was 76.5%. Epidermal reaction on BIOCHIP‐SSS was found in 94.1% of BP patients and in all patients on IIF‐SSS (sensitivity 100%). BIOCHIP‐BP180‐NC16a sensitivity was lower than in ELISA‐BP180‐NC16a (76.5% vs 82.4%). BP230 sensitivity of both methods was similar (45.1% vs 43.1%). The specificity for all antigens was 100%.
Conclusion
BIOCHIP mosaic is a useful method presenting satisfactory agreement with conventional immunoassays.