CYTOMETRIC CD4 COUNTING - A MINIMALIST APPROACH

描述(申请人提供)：1981年底，Gottlieb等人描述了居住在美国的同性恋男子中一种明显新的免疫缺陷综合症。我们现在知道的综合征是艾滋病(获得性免疫缺陷综合征)，认识到逆转录病毒HIV(人类免疫缺陷病毒)是其原因，并将所涉及的细胞亚群描述为CD4阳性(CD4)T细胞。外周血中CD4T细胞的绝对计数很快被确定为艾滋病毒感染患者的一项有价值的预后指标。艾滋病起源于非洲，正是在那里以及世界上其他资源匮乏的地区，艾滋病对公共卫生产生了最大的影响。自20世纪90年代发达国家提供有效的抗逆转录病毒疗法(ART)以来，联合国、各国政府以及盖茨和克林顿基金会等非政府组织一直在寻求为非洲、亚洲、加勒比、东欧和南美洲资源贫乏国家的数百万感染艾滋病毒的成年人和儿童中的至少一些人提供负担得起的治疗。如果有同样负担得起的CD4计数技术，将有助于对这种治疗的最佳规划和监测。流式细胞术被认为是富裕国家进行CD4计数的“黄金标准”，每年要进行数百万次测试，每次测试的费用高达数十美元。在资源匮乏的地区，“负担得起”的CD4细胞计数测试意味着，该测试的成本必须不超过几美元，并且可以在没有支持复杂诊断仪器(如流式细胞仪)的基础设施的地区使用。现在，进行CD4计数所需的测量能力可以整合到更小、更简单、更节能、更便宜的设备中，而不会损失任何准确度和精确度。本项目将确定双参数低分辨率荧光成像细胞仪的最小仪器配置，该仪器使用发光二极管(LED)进行荧光激发，ccd(电荷耦合器件)或cmos(互补金属氧化物半导体)相机芯片(S)用于光检测，适合于使用荧光标记的单抗进行cd4计数，并且只需要最少的样品处理和操作员培训。还将确定带有单一荧光标记的抗体组合是否可以用于在单参数荧光成像或流式细胞仪中准确识别CD4T细胞和其他淋巴细胞亚群。艾滋病(获得性免疫缺陷综合症)影响着全世界数以百万计的成人和儿童，而在世界上资源匮乏的地区，这种疾病对公共卫生的影响最大。各种政府和非政府机构试图为数百万感染艾滋病毒的成人和儿童中的一些人提供负担得起的抗逆转录病毒治疗(ART)。负担得起的CD4计数技术将极大地促进治疗的最佳规划和监测。该项目将尝试使用发光二极管、数码相机和计算机技术来生产一种简单、坚固、极其廉价的自动CD4计数装置，并且只需要最少的样本处理和操作员培训。

DESCRIPTION (provided by applicant): In late 1981, Gottlieb et al described an apparently new immunodeficiency syndrome in homosexual men living in the United States. We now know the syndrome as AIDS (Acquired Immune Deficiency Syndrome), recognize the retrovirus HIV (Human Immunodeficiency Virus) as its cause, and describe the involved cell subset as CD4-positive (CD4+) T cells. The absolute count of CD4+ T cells in peripheral blood was quickly identified as a valuable prognostic measurement in HIV-infected patients. AIDS originated in Africa, and it is there, and in other resource-poor areas of the world, that the disease has had the greatest impact on public health. Since effective antiretroviral therapy (ART) became available in the developed world in the 1990s, the United Nations, various governments, and nongovernmental organizations such as the Gates and Clinton Foundations, have sought to provide affordable treatment to at least some of the millions of HIV-infected adults and children in resource-poor countries in Africa, Asia, the Caribbean, Eastern Europe, and South America. Optimal planning and monitoring of such therapy would be facilitated if equally affordable CD4 counting technology were available. Flow cytometry is recognized as the "gold standard" for CD4 counting in affluent countries, in which several million tests are performed annually at a cost of tens of US dollars each. In resource-poor areas, an "affordable" CD4 counting test means that test must cost no more than a few dollars, and be usable in areas without the infrastructure typically required to support complex diagnostic apparatus such as flow cytometers. The measurement capabilities required to do CD4 counting can now be incorporated into substantially smaller, simpler, more energy- efficient, less expensive devices without any loss of accuracy and precision. This project will determine the minimal instrument configuration for a two-parameter low-resolution fluorescence imaging cytometer using light-emitting diodes (LEDs) for fluorescence excitation and a CCD (charge-coupled device) or CMOS (complementary metal oxide semiconductor) camera chip(s) for photodetection, suitable for CD4 counting using fluorescently labeled monoclonal antibodies, and requiring only minimal sample handling and operator training. It will also be determined whether combinations of antibodies bearing a single fluorescent label can be used to accurately identify CD4+ T cells and other lymphocyte subsets in a single-parameter fluorescence imaging or flow cytometer. AIDS (Acquired Immune Deficiency Syndrome) affects millions of adults and children worldwide, and it is in resource-poor areas of the world that the disease has had the greatest impact on public health. Various government and nongovernmental agencies have sought to provide affordable antiretroviral therapy (ART) to some of the millions of HIV-infected adults and children. Optimal planning and monitoring of therapy would be greatly facilitated by an affordable CD4 counting technology. This project will attempt to produce a simple, rugged, extremely inexpensive automated CD4 counting device using light-emitting diodes and digital camera and computer technology, and requiring only minimal sample handling and operator training.