Distinct types of IgG and IgA anti‐intercellular autoantibodies from patients with pemphigus and vesiculopustular dermatosis

Summary The pattern of binding of two different types of IgA class pemphigus‐like antibodies was compared with that of the true IgG class pemphigus antibody. The IgG antibodies from pemphigus vulgaris (PV) and pemphigus foliaceus (PF) sera bound to the intercellular spaces in normal human epidermis, whereas only the PV antibody reacted with monolayers of keratinocytes derived from human foreskin. Both IgG and IgA antibodies from a patient with PF were found in the intercellular spaces of the epidermis and only the IgA antibody reacted with the cultured keratinocytes. The IgA antibody from a patient with a vesiculopustular eruption and whose serum contained IgA intercellular space antibody alone, bound to the upper epidermis but not to the monolayers of keratinocytes. These findings indicate that PV but not PF antigens can be expressed by monolayers of cultured human keratinocytes and that there are at least two distinct types of IgA intercellular antibodies.