DEPOSITION OF GRANULAR IGA RELATIVE TO CLINICAL LESIONS IN DERMATITIS-HERPETIFORMIS

Objectives: To compare the deposition of IgA and C3 in the skin of pat ients with active dermatitis herpetiformis relative to the sites of di sease. Design: In the phase 1 study, skin biopsy specimens were obtain ed from erythematous perilesional skin, nonerythematous perilesional s kin, and never-involved skin. In the phase 2 study, specimens from the nonerythematous perilesional and uninvolved skin from the same anatom ic region were sampled. Setting: The Dermatology Clinic al the Univers ity of Utah Health Sciences Center, Salt Lake City. Patients: Patients with known dermatitis herpetiformis: 19 patients in the phase 1 study and 15 patients in the phase 2 study. Suppressive medications were st opped for 48 to 72 hours after biopsy specimens were obtained. All pat ients had active disease at the time that biopsy specimens were taken. Main Outcomes Measure: The intensity of IgA and C3 immunofluorescent staining in 6 sections from each skin biopsy specimen was graded by us ing a semiquantitative scale (0 to 3+) in a blinded fashion by a singl e observer. Results: Deposition of IgA was more intense in noninflamed perilesional skin in 11 of 19 patients compared with that in erytemat ous skin (P<.05). Erythematous skill was negative for IRA in 16% (3/19 ) of the specimens. Noninflamed perilesional skill showed more intense IgA deposition in 18 of 19 specimens compared with that in never-invo lved skin (P<.01); C3 was more intense in erythematous skin (P<.01). I n the phase 2 study, skin from the same anatomic region revealed great er deposition of IgA near lesions in 12 of 15 patients (P<.001). Concl usions: In patients with dermatitis herpetiformis, IgA is not uniforml y distributed throughout the skin, and IgA is present in greater amoun ts near active lesions. The preferred biopsy site For the diagnosis of dermatitis herpetiformis is normal-appearing skin that is adjacent to an active lesion.