Merkel cell carcinoma (MCC) is a rare aggressive neuroendocrine cutaneous carcinoma with a high mortality rate. The MCC etiology is not fully understood. Merkel cell-associated polyomavirus (MCPyV) was found in MCC patients, indicating a risk factor for the tumor. Caucasian, elderly, and immunocompromised individuals are more likely to develop this tumor. HLA-G consists of a non-classical class I (Ib) HLA molecule with an immunoregulatory function and was associated with tumor escape in different types of tumors, nonetheless, never been studied in MCC. The purpose of this study was to evaluate the HLA-G expression and also to detect the MCPyV in MCC patients and correlate it with the clinical course of the disease. Forty-five MCC patients were included in a retrospective study. Formalin-fixed paraffin-embedded cutaneous skin biopsies were used by immunohistochemistry and RT-PCR to verify the HLA-G expression and MCPyV infection. HLA-G expression was found in 7 (15.6%), while the presence of MCPyV was detected in 28 (62.2%) of the studied patients. No significant association was found between HLA-G expression and MCPyV infection (p = 0.250). The presence of MCPyV was associated with areas of low sunlight exposure (p = 0.042) and the HLA-G expression with progression to death (p = 0.038). HLA-G expression was detected in MCC patients, as well as the MCPyV presence was confirmed. These markers could represent factors with a possible impact on patient survival; however, further studies with a greater number of patients are needed, to better elucidate the possible role in disease progression.

Merkel 细胞癌 (MCC) 是一种罕见的侵袭性神经内分泌皮肤癌，死亡率很高。MCC 的病因尚不完全清楚。在 MCC 患者中发现了 Merkel 细胞相关多瘤病毒 (MCPyV)，表明该肿瘤存在危险因素。白种人、老年人和免疫功能低下的人更容易患上这种肿瘤。HLA-G 由具有免疫调节功能的非经典 I 类 (Ib) HLA 分子组成，与不同类型肿瘤的肿瘤逃逸有关，但从未在 MCC 中进行过研究。本研究的目的是评估 HLA-G 表达，并检测 MCC 患者的 MCPyV 并将其与疾病的临床过程相关联。45 名 MCC 患者被纳入一项回顾性研究。通过免疫组织化学和 RT-PCR 使用福尔马林固定石蜡包埋的皮肤活检来验证 HLA-G 表达和 MCPyV 感染。在 7 名 (15.6%) 患者中发现 HLA-G 表达，而在 28 名 (62.2%) 研究患者中检测到 MCPyV 的存在。未发现 HLA-G 表达与 MCPyV 感染之间存在显着关联（p  = 0.250）。MCPyV 的存在与低日光照射区域 ( p  = 0.042) 和 HLA-G 表达与进展至死亡相关 ( p  = 0.038)。在 MCC 患者中检测到 HLA-G 表达，并确认存在 MCPyV。这些标志物可能代表可能影响患者生存的因素；然而，需要对更多患者进行进一步研究，以更好地阐明其在疾病进展中的可能作用。