The persistence of residual infection is one of the major factors in failure of the Global Programme to Eliminate Lymphatic Filariasis (GPELF). The present study aims to explore the status of sheath antibody and regulatory T cells (Tregs) known to play key roles in clearance of parasite and patent filarial infection, in individuals with residual infection after MDA. A total of 61 microfilaremic (Mf) individuals were followed up after at least 6 rounds of MDA. Infection status of subjects was assessed through the detection of Mf and circulating filarial antigen (CFA). Antibodies to Mf sheath were determined by immuno-peroxidase assay (IPA). The expression of Tregs was measured by a flow cytometer. IL-10 and IFN-γ were evaluated using the commercially available ELISA kit. The sheath antibody was present in subjects who have cleared both Mf and CFA and absent in individuals who were found to be Mf /CFA positive. Further individuals carrying infection have significantly high levels of Tregs and IL-10. A positive correlation was observed between Tregs, IL-10, and CFA in infected individuals. In contrast, a negative correlation was observed between IFN-γ and IL-10 in both infected and uninfected subjects. Our study reveals that the absence of a sheath antibody and a high level of Tregs and IL-10 are the hallmarks of the persistence of residual filarial infection.

残留感染的持续存在是全球消除淋巴丝虫病计划 (GPELF) 失败的主要因素之一。本研究旨在探讨鞘膜抗体和调节性 T 细胞 (Tregs) 的状态，这些细胞已知在 MDA 后残留感染的个体中，在清除寄生虫和未闭丝虫感染中起关键作用。在至少 6 轮 MDA 后随访了总共 61 名微丝蚴 (Mf) 个体。通过检测 Mf 和循环丝虫抗原 (CFA) 评估受试者的感染状态。通过免疫过氧化物酶测定 (IPA) 测定 Mf 鞘的抗体。通过流式细胞仪测量 Tregs 的表达。IL-10 和 IFN-γ 使用市售的 ELISA 试剂盒进行评估。鞘膜抗体存在于已清除 Mf 和 CFA 的受试者中，而在发现 Mf /CFA 阳性的个体中不存在。其他携带感染者的 Tregs 和 IL-10 水平显着升高。在受感染个体中观察到 Tregs、IL-10 和 CFA 之间存在正相关。相比之下，在受感染和未受感染的受试者中，IFN-γ 和 IL-10 之间均观察到负相关。我们的研究表明，缺乏鞘膜抗体和高水平的 Tregs 和 IL-10 是残留丝虫感染持续存在的标志。在受感染和未受感染的受试者中，IFN-γ 和 IL-10 之间均观察到负相关。我们的研究表明，缺乏鞘膜抗体和高水平的 Tregs 和 IL-10 是残留丝虫感染持续存在的标志。在受感染和未受感染的受试者中，IFN-γ 和 IL-10 之间均观察到负相关。我们的研究表明，缺乏鞘膜抗体和高水平的 Tregs 和 IL-10 是残留丝虫感染持续存在的标志。