Alkaline phosphatase immuno‐enzymatic technique in the diagnosis of pemphigus vulgaris

Alkaline phosphatase was used in an immuno‐enzymatic procedure to detect tissue‐bound and circulating antibodies in pemphigus vulgaris. Pemphigus antibodies were revealed by a direct method using alkaline phosphatase conjugated goat anti‐human IgG. Cryostat sections were incubated with the specific antiserum, and alkaline phosphatase activity was then revealed histochemically either by Gomori's technique or by the azo dye method. The sections were examined by light microscopy and intercellular staining was demonstrated in the epidermis. The indirect method, in which the patient's serum was incubated with sections of normal skin, gave similar results. Using parallel sections, an immunofluorescent technique was used to demonstrate tissue‐bound and circulating antibodies. The alkaline phosphatase method appeared to be slightly less sensitive than the immunofluorescent method.