Jones Charlotte, Dunseath Gareth J, Lemon Jessica, Luzio Stephen D
1 Diabetes Research Unit Cymru, Grove Building, Swansea University, Swansea, UK.
J Diabetes Sci Technol. 2018 Sep;12(5):1024-1028. doi: 10.1177/1932296818763464. Epub 2018 Mar 9.
Microsampling techniques are alternative methods to venous sampling for obtaining blood for measurement of circulating biomarkers, offering the convenience of reduced sample volume and elimination of the need for phlebotomists. Dried blood spot (DBS) microsampling methods have been used for many years while more recently a volumetric absorptive microsampling device (VAMS™) has been introduced. In diabetes mellitus, circulating C-peptide is commonly used as an indicator of endogenous insulin secretion and clinical measurement can aid in diagnosis as well as informing on therapy. This pilot study investigated the effectiveness of microsampling collection of capillary blood for measurement of C-peptide.
Capillary blood was collected into capillary tubes and centrifuged for plasma samples. Simultaneous samples were also collected using both microsampling methods (DBS and VAMS). Blood from both microsamplers was extracted prior to assaying for C-peptide alongside the corresponding plasma samples, using specific immunoassays and results obtained from microsampling compared to the reference plasma concentrations. Stability was determined by collecting duplicate DBS and VAMS and assaying both in a single assay after storing one at -20°C immediately and one at room temperature for 48 hours post-collection.
Good agreement was observed between C-peptide concentrations in plasma and equivalent DBS and VAMS samples ( R = .929 and .9231, DBS and VAMS, respectively), with mean differences of 75.7 and 8.4 pmol/L observed for DBS and VAMS. Small decreases in C-peptide of 11.6% and 0.1% were observed after 48 hours storage for DBS and VAMS, respectively.
C-peptide collected using DBS and VAMS showed good agreement with reference plasma concentrations, suggesting both would be an effective microsampling method for collection and measurement of C-peptide.
微量采样技术是静脉采血的替代方法，用于获取血液以测量循环生物标志物，具有减少样本量的便利性且无需采血技师。干血斑（DBS）微量采样方法已使用多年，而最近引入了一种体积吸收微量采样装置（VAMS™）。在糖尿病中，循环C肽通常用作内源性胰岛素分泌的指标，临床测量有助于诊断并为治疗提供信息。这项初步研究调查了微量采样采集毛细血管血用于测量C肽的有效性。
将毛细血管血收集到毛细管中并离心以获得血浆样本。同时，也使用两种微量采样方法（DBS和VAMS）收集样本。在使用特定免疫测定法测定C肽之前，从两种微量采样器中提取血液，并将微量采样获得的结果与相应的血浆样本进行比较。通过收集重复的DBS和VAMS样本并在采集后立即将其中一个储存在-20°C，另一个在室温下储存48小时后在单次测定中进行测定来确定稳定性。
血浆、等效DBS和VAMS样本中的C肽浓度之间观察到良好的一致性（DBS和VAMS的R分别为0.929和0.9231），DBS和VAMS的平均差异分别为75.7和8.4 pmol/L。DBS和VAMS在储存48小时后，C肽分别有11.6%和0.1%的小幅下降。
使用DBS和VAMS收集的C肽与参考血浆浓度显示出良好的一致性，表明两者都是收集和测量C肽的有效微量采样方法。
