How do blood samples compare to CSF samples in the analysis of brain-derived analytes?

Zetterberg教授：由于浓度低且基质复杂，测量血液中的中枢神经系统衍生蛋白存在分析挑战，因此在灵敏度和特异性方面对检测提出了更高的要求。脑脊液生物标志物通常与脑病理学更密切相关，但血液生物标志物正在改善。然而，脑脊液和血浆之间的相关性最常见的保持在0.6到0.9，但不接近1，因为血液水平受到比如肾功能和流体动力学等因素的影响。

Prof Zetterberg: Measuring CNS-derived proteins in blood presents analytical challenges due to low concentrations and complex matrix, so it requires more for the test in terms of sensitivity and specificity. CSF biomarkers often correlate more closely with brain pathology, but blood biomarkers are improving. However, the correlation between CSF and plasma remain most commonly at 0,6 to 0,9, so not close to 1, since the blood levels are affected by e.g. kidney function and fluid dynamics.

一些标志物或疾病显示在脑脊液和血浆水平之间的相关性有意想不到的断裂。例如，GFAP在血液中比脑脊液更准确，原因目前尚不完全清楚，但可能与pH诱导的结构变化有关。此外，外周神经病变和ALS会破坏血液与脑脊液生物标志物之间的相关性，表明独特的疾病特异性机制。随着我们在更大的队列中扩大基于血液的生物标志物的使用，我们必须为意外发现做好准备，并继续完善我们对它们与神经系统疾病关系的理解。

Some markers, or conditions, show unexpected breakage in the correlation between CSF and plasma levels. For example, GFAP is more accurate in blood than CSF, for reasons not fully understood currently, but could possibly be linked to pH-induced structural changes. Also, peripheral neuropathies and ALS can disrupt the correlation between blood and CSF biomarkers, suggesting unique disease-specific mechanisms. As we expand our use of blood-based biomarkers in larger cohorts, we must be prepared for unexpected findings and continue to refine our understanding of their relationship to neurological diseases.

4. 在Medix Biochemica，您会使用哪些分析平台来评估新的备选单抗？

Which assay platforms do you use in Medix Biochemica to evaluate new mAb candidates?

Galli博士：通常，我们会在荧光免疫测定中评估具有一种用铕镧标记的测定成分的候选抗体。从我的演讲中可以明显看出，我们通常在发布前确定动力学。这些数据被添加到产品表中，并受到我们客户的极大赞赏。在某些情况下，如果发现相关，我们也可能使用侧向层析或化学发光法对备选抗体进行测试。

Emilia Galli: Typically, we would evaluate the antibody candidates in fluoroimmunoassay having one of the assay components labelled with Europium lanthanoid. As was evident from my presentation, we most often determine the kinetics before launch. This data is added to the product sheet and has been very appreciated by our customers. In some cases, we may also test candidates using lateral flow or CLIA if found relevant.

5. 还有感兴趣的新兴的标志物吗？

Any emerging markers of interest?

Zetterberg教授：我认为突触标志物真的很有趣，可能是神经退行性病理学的有价值的早期指标。在大多数神经退行性疾病中，突触是第一个受损的。一旦突触丢失，轴突就会丢失，然后最终是神经元细胞损害。从基于血液的生物标志物中，β-突触核蛋白和SNAP-25在反映突触功能障碍方面显示出前景。仍需要进行研究以更好地了解血液中突触标志物与大脑变化之间的关系，这可以通过与神经影像学专家合作来实现。

Prof Zetterberg: I think the synaptic markers are really interesting and could be valuable early indicators of neurodegenerative pathology. In most neurodegenerative diseases, the synapse is the first one to be impaired. And once the synapse is lost, the axon is lost, and then the eventually the neuronal soma. From blood-based biomarkers, beta-synuclein and SNAP-25 show promise in reflecting synaptic dysfunction. There is still research needed to better understand the relationship between synaptic markers in blood and brain changes, and this could be approached by collaborating with neuroimaging experts.

6. 您在Medix Biochemica采取了怎样的可持续性行动？

What kind of sustainability actions do you take in Medix Biochemica?

Galli博士：感谢您提出这个重要的话题。在Medix Biochemica，我们积极关注各种可持续发展举措，包括替代有害化学品或减少包装中的塑料。

Emilia Galli: Thank you for bringing up this important topic. At Medix Biochemica, we are actively keeping our eyes open for various sustainability initiatives, let it be replacing harmful chemicals, or reducing plastics in our packaging.

去年，Medix Biochemica加入了EcoVadis可持续发展评级系统，并在我们的第一次评估中获得了铜牌，得分超过70%的受该系统评级的公司。今年，我们改进了可持续发展行动，表现得更好，得分高于84%的公司，并再次获得铜牌。我们表现最好的领域是环境、劳工与人权以及伦理。

Last year, Medix Biochemica joined the EcoVadis sustainability rating system and earned a Bronze medal on our first assessment, scoring better than over 70% of all companies rated by the system. This year, we improved our sustainability actions and performed even better, scoring better than 84% of all companies and attaining a Bronze medal again. Our top-performing areas were environment, labor & human rights, and ethics.

正如我在演讲中提到的，与单克隆抗体生产相关的是，我们长期以来一直使用无血清培养基在体外生产单克隆抗体，这适用于杂交瘤和重组蛋白。

Related to mAb production, as I mentioned in my presentation, we have a long-standing practice of producing our mAbs in vitro with serum-free medium, which applies to hybridomas as well as recombinants.

7. 与所使用的单克隆抗体相比，检测平台在多大程度上影响检测灵敏度？

To what extent does the test platform influence assay sensitivity compared to the monoclonal antibodies used?

Galli博士：抗体是许多诊断测试的关键。它们仅结合特定靶标提供高特异性，通过检测样品基质中极少量的靶分子提供高灵敏度。然而，单克隆抗体的灵敏度只能在一定程度上得到增强。灵敏度的进一步提高依赖于先进的技术。想要实现最佳结果需要高性能抗体和先进的、超灵敏平台的结合。

Emilia Galli: Antibodies are the backbone of many diagnostic tests. They provide high specificity by binding only to the intended target, and high sensitivity by detecting even smallest amounts of the target molecule in sample matrix. However, the sensitivity of monoclonal antibodies can only be enhanced to a certain extent. Further gains in sensitivity rely on advanced technologies. Achieving optimal results requires a combination of high-performance antibodies and cutting-edge, ultrasensitive platforms.

例如，数字ELISA (或单分子阵列, Simoa) 新方法的灵敏度是标准ELISA的100到1000倍，能够检测极低浓度的生物标志物。此外，将DNA标记抗体与PCR扩增相结合的方法，例如邻位延伸测定 (PEA)，能够对蛋白质进行高灵敏度检测。在PEA中，成对的DNA标记抗体与靶蛋白结合，使它们的DNA标签靠得很近，然后可以通过聚合酶延伸。然后可以通过qPCR对DNA模板进行定量，从而精确检测低丰度蛋白质。

For instance, novel methods like digital ELISA (or single molecule array, Simoa) can be 100 to 1000 times more sensitive than standard ELISA, enabling the detection of very low concentrations of biomarkers. Also, methods combining DNA-tagged antibodies with PCR amplification, such as Proximity Extension Assay (PEA), enable highly sensitive detection of proteins. In PEA, pairs of DNA-tagged antibodies bind to a target protein, bringing their DNA tags close together and then can be extended by polymerase. The DNA template can then be quantified by qPCR, allowing precise detection of low-abundance proteins.

另一种先进的方法是免疫沉淀质谱法 (IP-MS)，它将抗体的精确蛋白质捕获与质谱分析相结合，以对目标分子进行高度特异性和灵敏性的检测。

Another advanced approach is immunoprecipitation mass spectrometry (IP-MS), which pairs precise protein capture by antibodies, with mass spectrometry analysis for highly specific and sensitive detection of target molecules.

8. 在演示的早期，有两张图表显示了A42/A40组合如何成为一个非常好的标记，但也列出了一个A38标记。即使与A42/A40结合使用，A38是否也不被视为可行的标记？如果是这样，为什么不呢？

Early in the presentation there were two graphs showing how A42/A40 combined is a very good marker but there was also an A38 marker listed. Is A38 not viewed as a viable marker even when combined with either A42/A40? If so, why not?

Zetterberg教授：是的，Aβ-38非常有趣，它甚至可以保护淀粉样蛋白级联反应。我认为我们应该更多地研究这种β淀粉样蛋白形式，既作为生物标志物，也可能作为干预目标 (增加其浓度可能会抑制Aβ-42纤维化)。

Prof Zetterberg: Yes, Abeta38 is very interesting and it could even be protective against the amyloid cascade. I think we should work more on this amyloid beta form, both as a biomarker but potentially also a target for intervention (increasing its concentration might inhibit Abeta42 fibrillization).

9. 应该如何看待不同的p217克隆。我猜你展示的数据都不是用Medix Biochemica克隆完成的。每个新克隆都必须在大型临床队列中进行验证，还是与黄金标准的相关性就足够了？

How should one think about different p217 clones. I guess none of the data you showed was done with the Medix Biochemica clone. Would each new clone have to be validated in a large clinical cohort or is correlation to golden standard with a few samples enough?

Zetterberg教授：是的，为了证明等效性，这可能就足够了。为了证明优势，可能需要非常大的样本群 (考虑到当前检测的效果)。

Prof Zetterberg: Yes, to prove equivalence this could be enough. To prove superiority, really large cohorts may be needed (given how well the current assays work).