APPLICATION OF CONFOCAL LASER-SCANNING MICROSCOPY TO DIFFERENTIAL-DIAGNOSIS OF BULLOUS PEMPHIGOID AND EPIDERMOLYSIS-BULLOSA ACQUISITA

We applied confocal laser scanning microscopy to fluorescence overlay antigen mapping (FOAM) for differential diagnosis of bullous pemphigoi d (BP) and epidermolysis bullosa acquisita (EBA). FOAM of tissue-bound IgG and marker basement membrane components (BMCs) including integrin P-Jr, laminin-1, laminin-5 and type IV collagen, showed that tissue-b ound IgG in perilesional skill samples from five patients with BP was localized on the epidermal side of type IV collagen, and colocalized w ith some of the other three BMCs, whereas IgG in a sample from a patie nt with EBA was on the dermal side of all the BMCs. FOAM of binding si tes of autoantibodies in patients' sera and markers including integrin beta 4, laminin-1, type IV collagen and type VII collagen, showed tha t the binding sites of autoantibodies from 16 patients with BP were lo calized on the epidermal side of type IV and type VII collagens, and l ocalized above or codistributed with integrin beta 4 and laminin-l, wh ereas those from five patients with EBA were codistributed with type I V and type VII collagens, and localized on the dermal side of integrin beta 4 and laminin-1. These spatial relationships are compatible with their previously described ultrastructural locations, Thus, this meth od appears to be useful in the differential diagnosis of BP and EBA.