Simple test to monitor immune status of HIV patients
Researchers have developed a small, simple and affordable device to monitor HIV-infected patients' immune systems in developing countries. This technology could help doctors more readily assess when a patient needs to begin antiretroviral therapy.
The research was published this month (July) in the Journal of Acquired Immune Deficiency Syndromes.
Lead researcher Bill Rodriguez, from Massachusetts General Hospital and Harvard Medical School in the United States, says that to assess how well an HIV-positive person's immune system is functioning, you need to count a component of the immune system, called CD4+ T-cells.
HIV targets these cells and so their numbers in the blood are a good indicator of how likely an HIV-infected patient is to become ill, and thus what level of treatment they need.
The current technology doctors use to count CD4+ T-cells is not readily available in the developing world; laser flow-cytometry machines cost US$30,000–150,000 and require skilled health workers to process samples and analyze data.
The authors write that the microchip device, the size of a business card, will be 'cost-effective' and relatively simple to use.
The device contains a tiny chamber that is filled with a finger prick sample of the patient's blood. A special coating on the inner chamber walls catches the CD4+ T-cells so that when the chamber is flushed through they are left behind and can be counted using an ordinary microscope.
Rodriguez and team have plans for testing the device in Brazil, Uganda and Rwanda. 'We have partners in all three [countries], but are still working… to get official approval,' he says. The next step is to convert the laboratory prototype into a form for mass production.
Peter Mugyenyi, Director of the Joint Clinical Research Centre in Kampala, Uganda, describes the new device as 'exciting provided it is affordable.' 'Africa will in the near future have millions of people on [antiretroviral therapy],' says Mugyenyi. He says at the moment it is not practical to use existing methods to monitor all patients who might need the therapy, because of the complexity of the technology and problems with power shortages.
But Frances Gotch, a professor of immunology from the United Kingdom's Imperial College in London, says developing countries deserve the same equipment as the developed world. 'We need to build up scientific laboratory infrastructure in developing countries,' she says.
简单测试可监视艾滋病感染者的免疫状态
科学家开发出了一种小型、简单且廉价的设备，用于监测发展中国家艾滋病感染者的免疫系统。这种技术可能有助于医生更容易地评估一位艾滋病患者应该何时开始抗逆转录病毒治疗。这项研究发表在了7月出版的《获得性免疫缺陷综合征杂志》上。
美国马萨诸塞总医院和哈佛大学医学院的Bill Rodriguez领导了这项研究，他说为了评估艾滋病感染者免疫系统的功能水平，你需要计算免疫系统的一个组成部分——CD4+ T细胞的数量。
艾滋病病毒攻击这些细胞，因此血液中这些细胞的数量是一个很好的指标，它指示了艾滋病感染者发病的可能性，因此也指示了他们需要什么级别的治疗。
目前医生使用的CD4+ T细胞计数技术在发展中国家并不能轻易获得；激光血球计数仪的价格在3万到15万美元之间，而且需要熟练的技术员处理和分析样本。
本研究开发的这种微芯片设备只有一张名片大小，它“具有性价比”，而且使用相对简单。
这种设备含有一个微腔，患者的指尖血液样本将注入到其中。内腔的一个特殊涂层能捕捉到CD4+ T细胞。因此在冲洗之后，这些细胞将留在那里，可以用普通的显微镜计数。
Rodriguez和他的研究组已经打算在巴西、乌干达和卢旺达测试这种设备。他说：“我们在这三个国家都有合作伙伴，但是还在申请官方批准。”下一步的目标将是把实验室原型设备转化成能大规模生产的形式。
乌干达坎帕拉联合临床研究中心的主任Peter Mugyenyi认为这种新的设备“如果价格能让人负担得起，那么它就是一种令人激动的发明。”
Mugyenyi说：“在不远的将来，非洲将有数以百万人接受[抗逆转录治疗]。”他说目前用现有的技术监视所有可能需要接受治疗的病人是不切实际的，这是由于现有技术很复杂，另外经常断电。
但是英国帝国理工学院的免疫学教授Frances Gotch说，发展中国家与发达国家需要同样的设备。她说：“我们需要在发展中国家建设科学实验室的基础设施。”
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