Heterogeneity of pemphigoid antigens.

The immunologic specificity of bullous pemphigoid (BP) antigens expressed in human skin was studied by reacting the sera of 34 patients with BP with several specimens of normal skin. Most sera with basement membrane zone (BMZ) antibodies reacted to antigens expressed in all specimens of skin examined. A minority of pemphigoid sera reacted to BP antigens expressed in some specimens of skin but not in others. The pattern of cross-reactivity suggests that BP antigens are heterogeneous and that two different groups can be defined serologically. The first is a universal BP antigen(s) which is expressed in all individuals and to which antibodies are formed in most patients with BP. The other group consists of a family of BP antigens whose expression varies from individual to individual. Several immunologically distinct BP antigens can be expressed concurrently in the same specimen of skin. Lastly, the apparent absence of BMZ antibodies in some patients with BP is occasionally the result of antibodies directed to "minor" BP antigens with restricted expression.