Streptococcus pyogenes tonsillar infection is well known to trigger and exacerbate psoriasis lesions in both guttate and plaque forms of the disease. Although mucosal and cutaneous tissues are closely involved in psoriasis pathology, the interaction between their specific immune responses has not been deeply explored. This work aims to address and characterize the presence of humoral responses against S. pyogenes in patients with psoriasis and its putative association with cytokine responses detected in vitro in our psoriasis ex vivo model, based on the coculture of cutaneous lymphocyte-associated antigen^+/− T cells with autologous epidermal cells. Patients with psoriasis presented increased IgA response to S. pyogenes when compared with control subjects. In patients with plaque psoriasis, despite being negative for anti-streptolysin O antibody titer, IgA plasma levels against S. pyogenes correlated with cutaneous lymphocyte-associated antigen⁺ T-cell–dependent IL-17F response in vitro. No association is observed for IgG levels in plaque psoriasis. Similar association is observed for IgA anti-S. pyogenes extract and IL-17A in patients with guttate psoriasis. We propose S. pyogenes–specific IgA as a potential new perspective for better understanding the role of S. pyogenes in psoriasis development.

众所周知，化脓性链球菌扁桃体感染可触发并加剧该疾病的肠状和牙菌斑形式的牛皮癣病变。尽管粘膜和皮肤组织与银屑病病理密切相关，但尚未对其特异性免疫反应之间的相互作用进行深入研究。这项工作的目的是基于皮肤淋巴细胞相关抗原的共培养^+/-，针对牛皮癣患者针对化脓性链球菌的体液反应的存在及其在我们的牛皮癣离体模型中体外检测到的细胞因子反应的可能关联进行表征。 T细胞具有自体表皮细胞。牛皮癣患者对化脓性链球菌的IgA反应增强与对照组相比。在斑块状牛皮癣患者中，尽管抗链球菌溶血素O抗体滴度阴性，但针对化脓性链球菌的IgA血浆水平与体外皮肤淋巴细胞相关抗原⁺ T细胞依赖性IL-17F反应相关。在斑块状牛皮癣中未观察到IgG水平的关联。对于患有肠状牛皮癣的患者，IgA抗化脓性链球菌提取物和IL-17A观察到相似的关联。我们建议化脓性链球菌特异性IgA作为更好地了解化脓性链球菌在牛皮癣发展中的作用的潜在新观点。