A comparative study of expression of Fc receptors in relation to the autoantibody-mediated immune response and neutrophil elastase expression in autoimmune blistering dermatoses

Here we investigated the cutaneous CD32A and CD89 expression in relation to the neutrophil elastase (NE) expression and serum level of anti-desmoglein 1 and 3 (DSG1/DSG3) IgG in pemphigus, anti-BP180/BP230 IgG in bullous pemphigoid (BP), anti-gliadin nonapeptides (npG), tissue (tTG), and epidermal transglutaminases (eTG) IgA in dermatitis herpetiformis (DH).

The examined material consisted of skin/mucosal tissues and sera. In total, 87 patients were studied. Immunohistochemistry on paraffin-embedded sections with quantitative digital morphometry was used to measure the intensity of CD32A/CD89/NE expressions. Levels of anti-DSG1/DSG3 IgG, anti-BP180/BP230 IgG, and anti-npG/tTG/eTG IgA were evaluated with ELISAs.

CD32A was abundantly expressed in cutaneous lesions in pemphigus and BP. We found no statistically significant correlation between the CD32A/CD89 and NE expression intensities in pemphigus, BP, and DH. There was a significant correlation between CD89 expression and anti-npG IgA in DH. Our results revealed a lack of correlation between CD32A expressions and anti-DSG1/DSG3 IgG levels in pemphigus, anti-BP180/BP230 IgG in BP as well as CD89 expression and anti-tTG/eTG IgA in DH.

CD89 seems to be linked with gluten intolerance in DH rather than with proteolytic destruction of dermal-epidermal junction. CD32A appears to play an important role in mediating skin injury in pemphigus and BP, but probably independently from specific autoantibodies.