Background Dermatitis herpetiformis (DH) is a rare gluten-induced skin disorder characterized
predominantly by IgA autoantibodies against endomysium, tissue transglutaminase (TG2/tTG),
epidermal transglutaminase (TG3/eTG) and deamidated gliadin. To date, circulating
autoantibody reactivity has not been systematically described.Objectives Characterization
of serum reactivities in DH.Methods This multicentre international study analysed
sera from 242 patients with DH taken at the time of initial diagnosis. DH-specific
IgA and IgG serum autoantibodies were analysed by indirect immunofluorescence (IF)
on monkey oesophagus, and by enzyme-linked immunosorbent assay (ELISA) based on recombinant
TG2/tTG, TG3/eTG and deamidated gliadin (GAF3X).Results IgA indirect IF microscopy
on monkey oesophagus revealed the highest reactivity (84.3%; specificity 100%) followed
by IgA TG2/tTG ELISA (78.5%, specificity 99.0%), IgA TG3/eTG ELISA (72.7%, specificity
95.0%) and IgA GAF3X ELISA (69.0%, specificity 98.5%).Conclusions Serum IgA and IgG
autoantibodies against endomysium, TG2/tTG, TG3/eTG and deamidated gliadin are highly
prevalent in DH. Indirect IF microscopy on monkey oesophagus (IgA) provides the highest
diagnostic accuracy that can be further enhanced by 4.5% when combined with IgA TG2/tTG
ELISA. Dermatitis herpetiformis is a rare gluten-induced skin disorder characterized
predominantly by IgA autoantibodies against endomysium, tissue transglutaminase, epidermal
transglutaminase and deamidated gliadin. This multicentre international study analysed
sera from patients with dermatitis herpetiformis to characterize circulating autoantibody
reactivity. This study showed that IgA and IgG are highly prevalent in patients and
that indirect immunofluorescence microscopy on monkey oesophagus provides the highest
diagnostic accuracy.
