Abstract：
Small fiber neuropathy (SFN) is a peripheral nerve condition affecting thin myelinated Aδ and unmyelinated C-fibers, characterized by severe neuropathic pain and other sensory and autonomic symptoms. A variety of medical disorders can cause SFN; however, more than 50% of cases are idiopathic (iSFN). Some investigations suggest an autoimmune etiology, backed by evidence of the efficacy of IVIG and plasma exchange. Several studies suggest that autoantibodies directed against nervous system antigens may play a role in the development of neuropathic pain. For instance, patients with CASPR2 and LGI1 antibodies often complain of pain, and in vitro and in vivo studies support their pathogenicity. Other antibodies have been associated with SFN, including those against TS-HDS, FGFR3, and Plexin-D1, and new potential targets have been proposed. Finally, a few studies reported the onset of SFN after COVID-19 infection and vaccination, investigating the presence of potential antibody targets. Despite these overall findings, the pathogenic role has been demonstrated only for some autoantibodies, and the association with specific clinical phenotypes or response to immunotherapy remains to be clarified. The purpose of this review is to summarise known autoantibody targets involved in neuropathic pain, putative attractive autoantibody targets in iSFN patients, their potential as biomarkers of response to immunotherapy and their role in the development of iSFN.
摘要：
小纤维神经病（SFN）是一种周围神经疾病，影响薄的有髓Aδ和无髓C纤维，以严重的神经性疼痛和其他感觉和自主神经症状为特征。各种医学疾病可以导致SFN;然而，超过50％的病例是特发性（iSFN）。一些调查表明自身免疫性病因，有证据证明IVIG和血浆置换的疗效。一些研究表明，针对神经系统抗原的自身抗体可能在神经性疼痛的发展中起作用。例如,CASPR2和LGI1抗体的患者经常抱怨疼痛，体外和体内研究支持其致病性。其他抗体与SFN相关，包括那些反对TS-HDS的,已经提出了FGFR3和Plexin-D1以及新的潜在靶标。最后,一些研究报告了在COVID-19感染和疫苗接种后SFN的发作，调查潜在抗体靶标的存在。尽管有这些总体发现,只有一些自身抗体才证明了致病作用，与特定临床表型或免疫治疗反应的关联尚待澄清.这篇综述的目的是总结与神经性疼痛有关的已知自身抗体靶标，iSFN患者中推定的有吸引力的自身抗体靶标，它们作为免疫疗法反应的生物标志物的潜力及其在iSFN开发中的作用。
