Differences in Antigen-presenting Cells in Dermatitis Due to Skin Contact and Ingestion of Lacquer Tree

Kim, Ki Joon; Lee, Sun Young; Choi, Kyu Chul; Chung, Byoung Soo

Abstract

Cutaneous hypersensitivity reaction due to Rhus can develop against antigens delivered through the epidermis(allergic contact dermatitis: ACD) or through the blood vessels(systemic contact dermatitis: SCD). Although the role of Langerhans cells(LC) in sensitization and elicitation of ACD(external antigen) has been extensively investigated, there are few studies in cases of SCD(internal antigen). Immunohistochemical differences of Langerhans cells were investigated in cases of two different routes(external antigen vs. internal antigen) of the same antigens. The 7 cases of ACD due to Rhus and the 14 cases of SCD due to ingestion of Rhus were involved in this study. Immunohistochemical staining with anti-CD1a, S-100 protein, HLA-DR, factor XIIIa antibodies were performed. Numbers of CD1a, S-100 protein, and HLA-DR positive cells per linear millimeter of epidermis were counted. The ratio between HLA-DR positive cells and CD1a positive cells(HLA-DR/CD1a) was considered as a possible index of activation of LC. The number of factor XIIIa positive dermal dendritic cells(DDC) per mm2 was evaluated. CD1a positive LC were more significantly numerous in ACD than in SCD(19.6+/-1.95 vs. 9.0+/-0.91 p<0.05). Also, HLA-DR/CD1a in ACD were higher than SCD. Factor XIIIa positive DDC were more numerous in SCD than in ACD(21.6+/-1.57 vs. 16.9+/-2.48), but the differences were not significant statistically. Therefore, the epidermal LC appear to be involved in antigen presentation in ACD (external antigens) as to be well-known. On the other hand, it seems possible that DDC plays some role in immune reactions in SCD (internal antigens).