Which disease is characterized by autoantibodies against desmoglein causing loss of keratinocyte adhesion?

Which disease is characterized by autoantibodies against desmoglein causing loss of keratinocyte adhesion?

• A. Systemic lupus erythematosus
• B. Pemphigus vulgaris
• C. Rheumatoid arthritis
• D. Multiple sclerosis

Answer: (B)

Desmoglein is a key adhesion molecule in desmosomes that keeps keratinocytes bound to each other. In pemphigus vulgaris, autoantibodies target desmoglein (primarily desmoglein 3, sometimes desmoglein 1), disrupting these bonds. The result is acantholysis, where keratinocytes separate within the epidermis and form fragile, intraepidermal blisters that rupture easily. Clinically, this often presents with flaccid bullae and mucosal involvement, and a positive Nikolsky sign may be observed. The other diseases involve different targets or mechanisms—for example, lupus commonly features antibodies to nuclear components, rheumatoid arthritis involves antibodies like rheumatoid factor or anti-CCP, and multiple sclerosis centers on immune attack against CNS myelin.

Desmoglein is a key adhesion molecule in desmosomes that keeps keratinocytes bound to each other. In pemphigus vulgaris, autoantibodies target desmoglein (primarily desmoglein 3, sometimes desmoglein 1), disrupting these bonds. The result is acantholysis, where keratinocytes separate within the epidermis and form fragile, intraepidermal blisters that rupture easily. Clinically, this often presents with flaccid bullae and mucosal involvement, and a positive Nikolsky sign may be observed.

The other diseases involve different targets or mechanisms—for example, lupus commonly features antibodies to nuclear components, rheumatoid arthritis involves antibodies like rheumatoid factor or anti-CCP, and multiple sclerosis centers on immune attack against CNS myelin.