Huey Samantha L, Krisher Jesse T, Morgan David, Mkambula Penjani, Gannon Bryan M, Mbuya Mduduzi N N, Mehta Saurabh
Division of Nutritional Sciences, Cornell University, Ithaca, NY, United States.
Department of Large Scale Food Fortification, The Global Alliance for Improved Nutrition, Geneva, Switzerland.
Curr Res Biotechnol. 2022 May 12;4:253-274. doi: 10.1016/j.crbiot.2022.04.003. eCollection 2022.
We catalog and summarize evidence of the analytical performance of portable quantitative and semi-quantitative devices for the assessment of vitamin A status and vitamin A deficiency (VAD) in various biological samples-including whole blood, plasma, serum, and milk-in addition to VAD determination by functional indicators such as pupillary response.
We searched the literature for published research articles, patents, and information from manufacturers of mobile devices, particularly those appropriate for low-resource settings. The included devices were required to be portable (lightweight and ideally not needing a power outlet) and to measure vitamin A as well as define VAD. Eligible studies compared a portable device to a reference standard of high-performance liquid chromatography for blood and milk, or a Goldmann-Weekers dark adaptometer for eyes/vision. Where available, identified devices were compared with reference methods across several performance criteria. When possible, we compared the device's performance reported in published studies against the stated performance criteria from the manufacturers' websites.
We catalogued 25 portable devices for measuring vitamin A and/or VAD via biological samples. We also identified 18 comparison studies (plus associated reports) assessing nine methods: the iCheck Fluoro, iCheck Carotene, CRAFTi, Tidbit with or without the HYPER filtration system, custom field-friendly immunoassays, and microfluidic assays for blood; the iCheck Fluoro and iCheck Carotene for milk; and the Scotopic Sensitivity Tester-1 for eye function.
The iCheck Fluoro and iCheck Carotene are commercially available for use and are acceptable for measuring vitamin A in blood and milk samples, according to the available validation data. Many of the other identified devices, including other portable fluorometers, photometers, immunoassays, microfluidics-based devices, and dark adaptometers, were proofs of concept and not yet commercially available. Furthermore, none of these other devices included manufacturer-described device performance criteria to compare with descriptions from experimental studies. Several gaps remain, including studies comparing the other portable devices against a reference standard, particularly for functional indicators of vitamin A status/deficiency; available manufacturer-reported device performance criteria against which to compare future results of investigations; and more comprehensive reporting of validation metrics including sensitivity, specificity, precision, and Bland-Altman analysis.
我们整理并总结了便携式定量和半定量设备在评估各种生物样本（包括全血、血浆、血清和乳汁）中维生素A状态及维生素A缺乏（VAD）方面的分析性能证据，此外还包括通过瞳孔反应等功能指标测定VAD的情况。
我们检索了文献，查找已发表的研究文章、专利以及移动设备制造商提供的信息，特别是那些适用于资源匮乏地区的设备。纳入的设备需具备便携性（重量轻且理想情况下无需外接电源），并能测量维生素A以及定义VAD。符合条件的研究将便携式设备与用于血液和乳汁的高效液相色谱参考标准，或用于眼睛/视力的戈德曼-韦克斯暗适应计进行了比较。在可行的情况下，将已识别的设备在多个性能标准方面与参考方法进行了比较。如有可能，我们将已发表研究中报告的设备性能与制造商网站上公布的性能标准进行了比较。
我们整理了25种通过生物样本测量维生素A和/或VAD的便携式设备。我们还识别出18项比较研究（以及相关报告），评估了9种方法：用于血液的iCheck Fluoro、iCheck Carotene、CRAFTi、带或不带HYPER过滤系统的Tidbit、定制的现场友好型免疫测定法和微流控测定法；用于乳汁的iCheck Fluoro和iCheck Carotene；以及用于眼睛功能的暗适应敏感度测试仪-1。
根据现有的验证数据，iCheck Fluoro和iCheck Carotene已可商用，可用于测量血液和乳汁样本中的维生素A。其他许多已识别的设备，包括其他便携式荧光计、光度计、免疫测定法、基于微流控的设备和暗适应计，都只是概念验证，尚未商业化。此外，这些其他设备均未包含制造商描述的设备性能标准，无法与实验研究的描述进行比较。仍存在一些差距，包括将其他便携式设备与参考标准进行比较的研究，特别是针对维生素A状态/缺乏的功能指标；可供比较未来研究结果的制造商报告的设备性能标准；以及对包括灵敏度、特异性、精密度和布兰德-奥特曼分析在内的验证指标进行更全面的报告。
