Samolitis Nancy J, Hull Christopher M, Leiferman Kristin M, Zone John J
Department of Dermatology, University of Utah Health Sciences Center, USA.
J Am Acad Dermatol. 2006 May;54(5 Suppl):S206-9. doi: 10.1016/j.jaad.2005.06.033.
Although the specific IgA autoantibody responsible for the pathogenesis of dermatitis herpetiformis (DH) is unknown, the presence of IgA is considered essential in the pathogenesis of DH. To date, no cases of IgA deficiency have been reported in DH. In contrast, IgA deficiency is found in 2% to 3% of patients with celiac disease, a rate 10 to 15 times higher than the normal population. We report 2 patients with DH who also have partial IgA deficiency. We evaluated the sera of these patients for the presence of IgA autoantibodies to endomysium, tissue transglutaminase, epidermal transglutaminase, and gliadin. Both patients were found to have IgA endomysial and tissue transglutaminase antibodies, and serologic markers for DH. Corresponding IgG autoantibodies were not useful serologic markers of DH in the setting of IgA deficiency, as they often are in celiac disease. We then screened 98 DH sera for total IgA levels and identified 1 additional case with IgA deficiency. In conclusion, DH may develop in patients with partial IgA deficiency, indicating that pathogenically directed IgA antibodies are likely sufficient for cutaneous IgA deposition in this disease.
尽管导致疱疹样皮炎（DH）发病机制的特异性IgA自身抗体尚不清楚，但IgA的存在被认为是DH发病机制中的关键因素。迄今为止，尚未有DH患者伴发IgA缺乏的病例报道。相比之下，2%至3%的乳糜泻患者存在IgA缺乏，这一比例比正常人群高出10至15倍。我们报告了2例同时伴有部分IgA缺乏的DH患者。我们检测了这些患者血清中针对肌内膜、组织转谷氨酰胺酶、表皮转谷氨酰胺酶和麦醇溶蛋白的IgA自身抗体。两名患者均检测到IgA肌内膜抗体和组织转谷氨酰胺酶抗体，以及DH的血清学标志物。在IgA缺乏的情况下，相应的IgG自身抗体并非DH的有效血清学标志物，而在乳糜泻中它们通常是有效的。随后，我们对98份DH血清进行了总IgA水平筛查，又发现了1例IgA缺乏病例。总之，部分IgA缺乏的患者可能会发生DH，这表明针对致病原的IgA抗体可能足以导致该疾病皮肤IgA沉积。
