Salivary Samples for the Diagnosis of Pemphigus vulgaris Using the BIOCHIP Approach: a Pilot Study

Pemphigus vulgaris (PV) is a rare autoimmune intraepithelial blistering skin disease characterized by the presence of circulating autoantibodies against desmoglein 3 (DSG3) and desmoglein 1 (DSG1), resulting in loss of the normal epithelial cell-to-cell adhesion, through a process called acantholysis. In recent years, a BIOCHIP-based indirect immunofluorescence technique for the determination of anti-DSG3 and anti-DSG1 autoantibodies has been described. Even though, the use of saliva anti-DSG3 and anti-DSG1 ELISA for the diagnosis of PV has been already reported, there are no studies concerning the utilization of saliva by the BIOCHIP approach. In the present pilot study, ELISA and BIOCHIP were performed, using salivary and serum samples from the same patients to investigate if the detection of anti-desmoglein autoantibodies in salivary samples by BIOCHIP could be used as a test for the diagnosis of PV. There was a strong correlation between ELISA and BIOCHIP results both for anti-DSG3 and anti-DSG1 serum autoantibodies. Autoantibodies to DSG3 were detected in 8 out of 8 salivary samples by ELISA and in 6 out of 8 salivary samples by the BIOCHIP approach. Autoantibodies to DSG1 were negative in all salivary samples using both ELISA and BIOCHIP. There were no positive results in the negative control group. In conclusion, the results of this pilot study indicate lack of correlation between serum and salivary results using both ELISA and BIOCHIP, indicating that saliva may not be the ideal substrate for the laboratory diagnosis of PV using these approaches.