The Value of the BIOCHIP Mosaic-based Indirect Immunofluorescence Technique in the Diagnosis of Pemphigus and Bullous Pemphigoid in Turkish Patients.

Autoimmune bullous diseases (ABD) are a rarely seen group of diseases, of which pemphigus and bullous pemphigoid (BP) are the major groups. Diagnosis is generally based on the combination of clinical features, histopathologic and immunofluorescence (IF) findings, and/or enzyme-linked immunosorbent assay (ELISA). Aims of the work were to determine the value of the innovative BIOCHIP mosaic-based indirect IF technique in the diagnosis of pemphigus and BP in Turkish patients. A total of 63 patients (45 pemphigus and 18 BP) in the active phase of the disease alongside 35 healthy controls were included in the study. All sera from patients and controls were tested using the BIOCHIP technique, and the results were compared with direct IF and/or ELISA. The sensitivity and specificity of this new technique were calculated for validity. The sensitivity and specificity of BIOCHIP in the diagnosis of pemphigus was found to be 91.1% and 97.1%, respectively. In detection of anti-Dsg1 and anti-Dsg3 autoantibodies, the correlation between BIOCHIP and ELISA was statistically significant (P<0.01). The sensitivity and specificity of BIOCHIP in the diagnosis of BP was found to be 94.4% and 94.3%, respectively. In detection of anti-BP180 autoantibodies, the correlation between the BIOCHIP and ELISA was statistically significant (P<0.01). The main limitations are the relatively low number of samples and testing with only one dilution. Direct IF was not performed in all patients, and the low rate of DIF positivity also can be a bias in comparison with BIOCHIP. The new BIOCHIP technique is a highly sensitive and specific tool in the diagnosis of pemphigus and BP.