Vasculitis and Translational Medicine

到目前为止，在脉管炎自然史研究中招募人数仍然很多。所有在NIH临床中心就诊的患者都会接受全面的临床评估，并将样本贡献给不断增长的生物库。在过去的一年里，我们关注了两种较为罕见的脉管炎：药物性脉管炎和大血管脉管炎。 在药物引起的血管炎方面，我们将重点放在左旋咪唑，这是一种抗蠕虫药物，最近被发现与暴露于掺有左旋咪唑的可卡因的人类的药物诱导自身免疫病例有关，以牟利。美国禁毒署估计，美国境内75%的可卡因受到左旋咪唑的污染。我们发现，左旋咪唑通过与中性粒细胞表面的M受体结合来诱导中性粒细胞胞外陷阱(Net)的形成。通过动物模型，我们确定左旋咪唑可以特异性地触发M3受体。与国家药物滥用研究所的同事和旧金山大学的同事合作，我们研究了积极使用被左旋咪唑污染的可卡因的患者队列的血清，以识别针对网络成分的新型自身抗体。我们还研究了左旋咪唑和NETS对血管内皮细胞的影响，发现左旋咪唑诱导的NETs在体外和主动脉肌图模型中对血管内皮细胞有毒性作用。这些数据表明，在左旋咪唑诱导的自身免疫中，Net是自身抗原的来源，有助于血管损伤，到目前为止，胆碱能神经系统和中性粒细胞之间的未知相互作用可能在自身抗体形成和自身免疫性疾病中发挥因果作用。与这项工作相关的摘要已作为口头报告提交给2015年美国风湿病学会年会和2016年欧盟防治风湿病联盟年会。这部作品的手稿目前正在修改中。 在LVV方面，我们继续招募这些罕见疾病的患者。到目前为止，我们已经对60名LVV患者进行了全身PET扫描和血管造影术。我们在正电子发射计算机断层扫描上发现的血管异常提示，在临床上被认为处于疾病缓解期的一部分LVV患者(约50%)中，正在进行亚临床血管炎症。这些发现是耐人寻味的，因为已知有一部分LVV患者在病程后期会发生危及生命的血管并发症，包括主动脉瘤和夹层。我们正在调查我们队列中异常PET扫描的潜在血清学和临床预测因素，并结合相应的血管造影术研究PET扫描结果。临床分析的初步结果已在2016年DC风湿病研究会议上提交，并被接受在2016年美国风湿病学会年会上提交。2015年5月，我们的一组图片和相关文章被接受为《关节炎和风湿病》的封面艺术。体外研究的初步结果表明，在LVV和GT患者中，与PET扫描结果相关的特定免疫细胞群中的新陈代谢发生了变化；此外，在我们队列中的一组LVV患者中，我们继续使用细胞分选技术纯化免疫细胞群。我们计划对不同的细胞群体进行RNA测序实验，并结合放射学和临床结果分析后续发现，作为发现疾病活动的新标记物和潜在的新治疗靶点的一种手段。

Recruitment to date remains strong within the Vasculitis Natural History Study. All patients seen at the NIH Clinical Center receive comprehensive clinical evaluation and contribute samples to a growing biobank. Over the last year, we have focused upon two rarer forms of vasculitis: drug-induced vasculitis and large vessel vasculitis (LVV). In terms of drug-induced vasculitis, we have focused on levamsiole, an anti-helminth drug that has recently been implicated in cases of drug-induced autoimmunity in humans exposed to cocaine adulterated with levamisole for profit. The United States Drug Enforcement Agency estimates that >75% of cocaine within the US has been contaminated with levamisole. We discovered that levamisole induces neutrophil extracellular trap (NET) formation through engagement of muscarinic receptors on the surface of neutrophils. Through animal models we defined that the M3 muscarinic receptor specifically is triggered by levamisole. In collaboration with colleagues from the National Institute of Drug Abuse and colleagues from the University of San Francisco, we studied sera from cohorts of patients actively using cocaine contaminated with levamisole was used to identify novel autoantibodies against NET components. We also studied the effect that levamisole and NETs on vascular endothelial cells and found that levamisole-induced NETs were toxic to endothelial cells in vitro and in aortic myogram models. These data suggest that NETs are a source of autoantigens in levamisole-induced autoimmunity, contribute to vascular damage, and that heretofore uncharacterized interactions between the cholinergic nervous system and neutrophils may play a causal role in autoantibody formation and autoimmune disease. Abstracts related to this work have presented at the 2015 American College of Rheumatology Annual Meeting and the 2016 EULAR League Against Rheumatism Annual meeting as oral presentations. A manuscript of this work is currently under revision. In terms of LVV, we continue to recruit patients with these rare diseases. To date, we have performed whole body PET scans and angiography on 60 patients with LVV. We have discovered vascular abnormalities on PET scans suggestive of ongoing subclinical vascular inflammation in a subset of patients with LVV (approximately 50%) whom clinically were thought to be in disease remission. These findings are intriguing because a subset of patients with LVV are known to develop life-threatening vascular complications including aortic aneurysms and dissections late into the course of disease. We are investigating potential serologic and clinical predictors of abnormal PET scans in our cohort and to study PET scan findings in association with corresponding angiography. Preliminary findings from the clinical analyses have been presented at the 2016 DC Rheumatism Research Conference and were accepted for presentation at the 2016 American College of Rheumatology Annual Meeting. An image from our cohort and accompanying article was accepted as the cover art for Arthritis & Rheumatology May 2015. Preliminary findings from in vitro studies indicate that metabolism is altered in specific immune cell populations in association with PET scan findings in patients with LVV> Additionally, in a subset of patients with LVV in our cohort, we continue to purify immune cell populations using cell sorting techniques. We plan to perform RNA sequencing experiments on the different cell populations and analyze subsequent findings in association with radiographic and clinical outcomes as a means to discover novel markers of disease activity and potentially novel therapeutic targets.