Immunoblot Assay is Still Useful For the Serological Diagnosis of Autoimmune Bullous Dermatosis

The detection of autoantibodies to epidermal or basement membrane zone proteins by immunoblot (IB) is useful for the diagnosis and the classification of autoimmune bullous diseases (AIBD). IB using human skin extracts is actually the reference method but A431 cell line is proposed as easier alternate antigen source. We explored the performances of “A431 IB” in comparison with the reference technique in retrospectively selected patients suffering from well-established bullous pemphigoid (n=42) or pemphigus vulgaris (n=15) and controls (n=80) in order to determine the validity and interest of this simplified IB method. We demonstrated that in our selected population A431 IB performances are comparable to the reference IB. IB remains semi-quantitative and time-consuming but much more economical and informative than commercially available ELISAs. We support the contention that, in 2012, IB, especially A431 IB, is still useful for the serological diagnosis of AIBD.