IgA in dermatitis-herpetiformis skin is dimeric

Area of Science:

• Immunology
• Dermatology
• Gastroenterology

Background:

• Dermatitis herpetiformis (DH) is characterized by IgA deposits in the skin.
• The origin and specific IgA subclass involved in DH pathogenesis remain areas of investigation.

Purpose of the Study:

• To investigate the presence and characteristics of IgA deposits in DH skin lesions.
• To determine the origin of IgA in DH skin by examining J chain and secretory component.

Main Methods:

• Indirect immunofluorescence on skin-biopsy specimens from DH patients.
• Use of specific antisera to detect in-vivo J chain and secretory component in IgA deposits.
• Assessment of IgA's ability to bind purified secretory component.

Main Results:

• Positive J-chain staining was observed in IgA deposits in all DH skin specimens.
• In-vivo secretory component was not detected, but exogenous secretory component bound to IgA deposits.
• Binding of secretory component was coextensive with IgA deposits.

Conclusions:

• The findings suggest that IgA deposited in DH skin originates from plasma cells in the small intestine.
• This supports the hypothesis of a gut-derived immune response in DH pathogenesis.