Circulating immune complexes of IgA type in dermatitis herpetiformis.

There is some evidence that dermatitis herpetiformis may be mediated by circulating immune complexes. This study attempts to define the antibody class of these complexes. All patients studied demonstrated granular deposition of IgA in the papillary dermis on direct immunofluorescence. Serum immune complexes were detected using the qualitative Raji cell immunofluorescent assay, as well as the quantitative immunoradiometric assay. A group of 25 dermatitis herpetiformis patients was found to have higher levels of IgA containing complexes compared to a group of normals (p < .01). Higher levels of IgG containing complexes were also noted in dermatitis herpetiformis patients at a low level of statistical significance (p < .1). The relationship of these complexes to the pathogenesis of dermatitis herpetiformis is yet to be determined.