{"id":13421,"date":"2010-07-01T20:45:06","date_gmt":"2010-07-01T20:45:06","guid":{"rendered":"http:\/\/i-base.info\/htb\/?p=13421"},"modified":"2017-09-20T12:14:21","modified_gmt":"2017-09-20T12:14:21","slug":"13421","status":"publish","type":"post","link":"https:\/\/i-base.info\/htb\/13421","title":{"rendered":"HIV diagnostics pipeline"},"content":{"rendered":"

Polly Clayden<\/strong><\/p>\n

The effectiveness of antiretroviral treatment delivery was traditionally thought to depend\u00a0on the use of sophisticated diagnostic tests.<\/p>\n

Earlier this year, important findings from the Development of AntiRetroviral Therapy\u00a0in Africa (DART) trial, conducted in Zimbabwe and Uganda were published, showing\u00a0impressive survival rates in people receiving routine clinical monitoring alone. This trial\u00a0randomised patients to receive either clinical monitoring or laboratory (hematology, biochemistry and CD4) plus clinical monitoring. At five years, 87% and 90% of patients were\u00a0alive in the clinical and laboratory arms respectively. [1]<\/p>\n

These results were even more impressive as patients in this trial had a median baseline\u00a0CD4 count of 86 cells\/mm3.<\/p>\n

The DART investigators concluded that ART could be delivered safely with good quality\u00a0clinical care, allowing treatment delivery to be decentralised. Despite DART results being\u00a0occasionally misinterpreted to suggest that this argues for no monitoring at all, the investigators also recommended that there is a role for CD4 testing from the second year on ART\u00a0to guide the switch to a second-line regimen\u0096and clearly to start treatment. They added that\u00a0this should encourage accelerated development of simpler, cheaper, point-of-care CD4 tests.<\/p>\n

Furthermore, in an accompanying editorial, Andrew Phillips and Joep van Oosterhout argue that, although the authors suggest that the advantage of measuring viral load on survival\u00a0may have been modest in this cohort, the reduction of transmission of drug-resistant virus,\u00a0which will undermine the effectiveness of antiretroviral therapy over the longer term may be\u00a0another reason to measure it. \u0093Therefore development of cheap robust assays for viral load\u00a0that can easily be used in rural and urban settings is of the highest priority for researchers.\u0094<\/p>\n

There are many arguments for the development of affordable point of point-of-care assays. CD4 measurements are essential for knowing when to initiate ART. CD4 counts\u00a0also guide the use of opportunistic infection prophylaxis.<\/p>\n

Viral load testing is essential to diagnose HIV-infected infants (see next chapter) and to\u00a0monitor virological suppression in pregnant women to reduce the risk of mother to child\u00a0transmission. These tests can be used to monitor adherence early on, and better inform\u00a0decisions about treatment modifications or switches. [3, 4]<\/p>\n

The next edition of the Pipeline Report<\/em> will include a more detailed survey of diagnostics appropriate to low resource settings. Here we look at the qualities required from a point-of-care\u00a0test to be useful and two initiatives that appear to be close to emerging from the pipeline.<\/p>\n

Requirements for point-of-care tests<\/h2>\n

Point-of-care refers to a test that can be conducted in the same facility where a patient\u00a0receives his\/her treatment and other care. In rural areas many patients have to travel vast\u00a0distances to reach testing facilities and then return to get their results. There is considerable loss to follow up from people who do not return for their test results.<\/p>\n

These technologies need to be quick and easy to use and interpret, that work with a\u00a0finger-prick blood sample or other non-venous sample and have a simple read out. They\u00a0need to be appropriate to settings without sophisticated laboratories, where electricity\u00a0and running water cannot be guaranteed. They need to perform in hot, humid or dusty\u00a0environments and have a long shelf life. They need to be used and maintained by health\u00a0workers without advanced technical skills.<\/p>\n

The CD4 initiative point-of-care CD4 test<\/h2>\n

The CD4 Initiative, at Imperial College, was established in 2005. The Initiative came \u00a0about through a substantial activist push from Gregg Gonsalves, and a generous grant\u00a0from the Gates Foundation. [5]<\/p>\n

Led by principal investigator Dr Hans-Georg Batz and project manager Dr Steven\u00a0Reid, their objective is to develop new, low-cost, rapid point-of-care tests to measure\u00a0CD4 counts, which are suitable for use in rural areas of low-income countries.<\/p>\n

The initiative set out to produce tangible results in four years, which is a very ambitious\u00a0timescale to develop this type of product.<\/p>\n

The project began by establishing a set of predetermined specifications:<\/p>\n