Immune complexes in pemphigus and bullous pemphigoid

Area of Science:

• Immunodermatology
• Autoimmune Blistering Diseases
• Clinical Immunology

Background:

• Pemphigus vulgaris (PV) and bullous pemphigoid (BP) are autoimmune blistering diseases.
• The in situ formation of immune complexes in these conditions is a subject of ongoing research.

Purpose of the Study:

• To investigate the presence and location of immune complexes in patients with PV and BP.
• To determine if antibodies are part of the precipitated immune complexes or remain in circulation.

Main Methods:

• Polyethylene glycol (PEG) precipitation assay was used to isolate immune complexes from serum and blister fluid specimens.
• Samples were obtained from 28 PV patients and 18 BP patients.
• Detection of anti-intercellular cement substance (ICS) and anti-basement membrane zone (BMZ) antibodies in precipitates and supernatants.

Main Results:

• Elevated immune complexes were found in 11% of PV sera and 30% of PV blister fluids, and 17% of BP sera and 31% of BP blister fluids.
• Anti-ICS antibodies were detected in 70% of precipitated PV blister fluid complexes.
• Anti-BMZ antibodies were found in 57% of precipitated BP blister fluid complexes.

Conclusions:

• The findings support the hypothesis that immune complexes in PV and BP predominantly form in situ.
• Antibodies are integral components of these in situ formed immune complexes, particularly within blister fluid.