Section of Dermatology, Department of Health Sciences, University of Florence, IT-50125 Florence, Italy.
Acta Derm Venereol. 2021 Feb 2;101(2):adv00382. doi: 10.2340/00015555-3742.
Granular deposits of IgA represent the specific cutaneous marker of dermatitis herpetiformis. The prevalence of IgA deposits in the skin of patients with coeliac disease without dermatitis herpetiformis remains unknown. In this prospective case-control study, skin biopsies from newly diagnosed coeliac patients without dermatitis herpetiformis were analysed by direct immunofluorescence. Controls included healthy volunteers and patients with both bowel symptoms and skin eruptions unrelated to coeliac disease. Clinical data and serum level of anti-tissue transglutaminase and anti-epidermal transglutaminase IgA antibodies were collected from patients and controls. Granular deposits of IgA or IgA1 in the skin were found in 29 out of 45 patients with coeliac disease (64.4%), and in none of the included controls (specificity 100%; sensitivity 64.4%). Positive direct immunofluorescence correlated significantly with an increased serum level of anti-epidermal transglutaminase IgA antibodies (p < 0.005). This study shows that granular deposits of IgA represent a low sensitive, but highly specific, cutaneous marker of coeliac disease independent of dermatitis herpetiformis.
IgA 颗粒沉积是疱疹样皮炎的特异性皮肤标志物。尚未明确无疱疹样皮炎的乳糜泻患者皮肤中 IgA 沉积的发生率。在这项前瞻性病例对照研究中，通过直接免疫荧光分析了新诊断为无疱疹样皮炎的乳糜泻患者的皮肤活检。对照组包括健康志愿者和既有肠道症状又有与乳糜泻无关的皮肤疹的患者。从患者和对照组收集了临床数据以及抗组织转谷氨酰胺酶和抗表皮转谷氨酰胺酶 IgA 抗体的血清水平。在 45 例乳糜泻患者中（64.4%）的 29 例中发现了皮肤中的 IgA 或 IgA1 颗粒沉积，而在所有纳入的对照组中均未发现（特异性 100%；敏感性 64.4%）。阳性直接免疫荧光与表皮转谷氨酰胺酶 IgA 抗体的血清水平升高显著相关（p<0.005）。这项研究表明，IgA 颗粒沉积是一种低敏感性但高度特异性的皮肤标志物，可独立于疱疹样皮炎来诊断乳糜泻。
