Diagnosis of Crystal-Based Arthropathies via Raman Spectroscopy

描述（由申请方提供）：拟议研究的总体目标是评估使用激光的成本效益器械诊断导致关节炎症的晶体的效率。该研究将制造该设备，从诊所收集样本，并确定该方法与现有临床诊断方法相比的灵敏度。 公共卫生相关性：通过拉曼光谱诊断晶体性关节病由于存在一水尿酸盐（MSU，痛风）或焦磷酸钙（CPPD，假性痛风）晶体，关节会发生极度疼痛的炎症反应。其他晶体，如碱性磷酸钙，钙盐，胱氨酸和黄嘌呤也涉及关节形成条件的创建。仅在美国，痛风的患病率就有5-6百万。虽然有有效的药物治疗来对抗痛风疾病，但次优诊断是痛风管理的障碍。不幸的是，痛风的假阴性率（FNR）为30%，无论诊断是通过滑膜抽吸物的显微镜观察还是通过临床症状[8-13]。假阴性会导致显著的发病率，如关节压痛和肿胀、关节退化、发热、肾损害和疾病扩散至多个关节[1-7]。假阳性的发生率高达20%，导致不适当的长期治疗并延迟实际原因的治疗[9-11]。由于对其他原因的错误调查而损失的财政资源进一步加剧了这一情况[14，15]。滑膜抽吸物的偏振光显微镜分析（PLM）是金标准，然而，它只有在由专家操作员进行时才是可靠的，这些专家操作员大多无法在大多数痛风患者被诊断的社区初级保健环境中进行。因此，医生求助于缺乏可靠性的基于神经网络的诊断[13]。因此，在初级保健环境中明显需要负担得起的、自动化的和便携式的技术，以减少关节间隙中晶体物质的不可接受的高误诊率。较低的误诊率将影响患者的生活质量，因为它可以减少痛苦，减少关节恶化，避免不正确的治疗，从而节省成本。 拉曼分析是一种有前途的替代诊断的晶体物种。在拉曼光谱学中，样品被激光激发，反射的光子保持关于观察区域中化学物质的身份和数量的信息。我们的探索性R21项目的早期结果表明，拉曼光谱可以识别临床相关浓度的滑膜抽吸物中的晶体种类。尽管有这样的前景，有没有数据的灵敏度和特异性的拉曼分析相对于PLM从足够大量的临床样品。临床医生接受拉曼方法的另一个障碍是认为拉曼分析是一种复杂的方法，需要昂贵和庞大的仪器来实现。如果将拉曼分析自动化以在可承受的成本基础上起作用，则该技术在临床实践中的采用将是可能的。我们的初步研究证明了使用低成本的拉曼概念检测晶体物质的可行性，通过使用快速注射器过滤方法将晶体浓缩到亚毫米大小的斑点的方便的样品制备方法使其成为可能。在抽吸样本后15分钟内即可做出诊断。 拟议研究的主要目标是奠定基础工作，将拉曼带到护理点（诊所，家庭办公室，病理单位）作为一个自动化，便携式，实用和负担得起的工具。这一目标将通过集成具有成本效益的拉曼装置并在足够大的临床样本集上对其进行评估来实现。随后的研究将汇集流变学家（亨利福特医院和克拉里安-阿内特卫生系统）与生物医学工程师，继续我们正在进行的合作。第一个目标将是将一个已经工作的成本效益拉曼原型概念转化为一个独立的便携式鲁棒平台（成本效益自动化拉曼设备卡）。这一目标的实现将导致一个强大的设备，将识别晶体的类型在一个自动化的方式。第二个目标是通过评估CARD对临床患者群体的敏感性和特异性来验证和评估CARD。将采集有症状患者的滑膜抽吸物，并进行标准临床诊断。CARD的灵敏度和特异性将与PLM进行比较。还将使用研究级共焦拉曼显微镜对沉积物进行高端拉曼显微分析，以明确证明临床需要拉曼。微离心滑膜样品的X射线微衍射将作为晶体鉴定的金标准。 这项研究的意义在于它有可能改变痛风诊断的临床观点。一个负担得起的，客观和实用的拉曼模式将导致更广泛和有效的滑膜抽吸物的筛选，特别是在社区医疗实践的临床实践。在对具有临床意义的患者人群进行CARD验证之后，这项工作的下一步自然是在多个初级保健场所，医院甚至基于办公室的项目中评估CARD原型。

DESCRIPTION (provided by applicant): The overall goal of the proposed study is to assess the efficiency of diagnosing crystals leading to inflammation of joints using a cost-efficient device which uses laser light. The study will fabricate the device, collect samples from the clinic and determine the sensitivity of the method in comparison to existing clinical diagnostic methods. PUBLIC HEALTH RELEVANCE: Diagnosis of Crystal-Based Arthropathies via Raman Spectroscopy Extremely painful inflammatory reaction occurs at joints due to presence of monosodium urate monohydrate (MSU, gout) or calcium pyrophosphate dehydrate (CPPD, pseudogout) crystals. Other crystals such as basic calcium phosphates, calcium oxalates, cystine and xanthine are also implicated in creation of arthrogenic conditions. The prevalence of gout in the US alone is 5-6 million. While there are effective drug treatments to counter gouty diseases, suboptimal diagnosis is a barrier to management of gout. Unfortunately, false negative rates (FNRs) of gout is 30%, regardless the diagnosis is reached by microscopic observations of synovial aspirates or by clinical symptoms [8-13]. False negatives result in significant morbidity such as tender and swollen joints, joint degradation, fever, renal impairment and spread of the disease to multiple joints [1-7]. False positives happen up to 20% of the time, lead to inappropriate long-term treatment and delay the treatment of the actual cause [9-11]. The financial resources lost due to misdirected investigation of other causes further exacerbate the picture [14, 15]. Polarized light microscopic analysis (PLM) of synovial aspirates is the gold standard, yet, it is reliable only when conducted by expert operators who are mostly unavailable in community based primary care settings where the majority of gout patients are diagnosed. Therefore, physicians resort to symptom-based diagnosis which lacks reliability [13]. Therefore, there is a clear need for affordable, automated and portable technologies at the primary care setting for reducing the unacceptably high misdiagnosis rate of crystal species in joint spaces. A lower misdiagnosis would impact patients' quality of life as it translates to less suffering, less deterioration of joints and avoidance of incorrect treatments, introducing cost savings. Raman analysis is a promising alternative for diagnosis of crystal species. In Raman spectroscopy, the sample is excited by laser and the reflected photons hold information on the identity and the amount of chemical species in the observed region. Earlier results from our exploratory R21 project demonstrated that Raman spectroscopy can identify crystal species in synovial aspirates at clinically relevant concentrations. Despite this promise, there are no data on the sensitivity and specificity of Raman analysis with respect to PLM from a sufficiently large number of clinical samples. Another barrier in terms of Raman method's acceptance amongst the clinicians is the perception of Raman analysis as a complex method that is implemented by expensive and bulky instruments. If Raman analysis were to be automated to function at an affordable cost- basis, the technique's adoption in the clinical practice would be possible. Our preliminary studies demonstrate the feasibility of detecting crystal species using a low-cost Raman concept, made possible by a convenient sample preparation method that concentrates crystals to sub-millimeter sized spots using a quick syringe- filtration approach. The diagnosis is reached within 15 minutes of sample aspiration. The main objective of the proposed study is to lay the foundation work that will bring Raman to the point of care (clinic, home office, pathology units) as an automated, portable, practical and affordable tool. This objective will be attained by integrating a cost-efficient Raman device and assessing it on a sufficiently large clinical sample set. The ensuing studies will bring together rheumatologists (Henry Ford Hospital and Clarian- Arnett Health System) with biomedical engineers to continue our ongoing collaboration. The first aim will be to translate an already working cost effective Raman prototype concept to a stand-alone portable robust platform (Cost-efficient Automated Raman Device-CARD). Accomplishment of this aim will result in a robust device that will identify the types of crystals in an automated fashion. The second aim will validate and evaluate CARD by assessing its sensitivity and specificity over a clinical patient population. Synovial aspirates from symptomatic patients will be collected and also subjected to standard clinical diagnosis. The sensitivity and specificity of CARD will be compared to those of PLM. High-end Raman microscopic analysis of deposits with a research-grade confocal Raman microscope will also be conducted to definitively prove the clinical need for Raman. X-Ray microdiffraction of microcentrifuged synovial samples will serve as the gold standard for crystal identification. The significance of the proposed study is in its potential to shift the clinical opinion on diagnosis of gout. An affordable, objective and practical Raman modality would lead the clinical practice towards screening of synovial aspirates more extensively and effectively, especially in the community medical practice. Following the validation of CARD over a clinically meaningful patient population, a natural next step to this work would be the assessment of CARD prototypes in multiple primary care locations, hospitals and even office-based programs.