For those of you who think that attending a conference is an excuse to ‘skive’, I’ll have you know that I dutifully got up in time to attend the 8 a.m. Medical Research council meeting discussing the PIVOT (protease monotherapy) trial. However, I declined the champagne with the breakfast. As discussed in yesterdays blog, this trial is doing very well and expected to stop recruiting in June/July. The increased number of patients to be recruited in PIVOT is to offset the lower-than-expected failure rate seen in other PI monotherapy studies, such as the Tibotec MONET study of Darunavir monotherapy.
Following this, despite a few technical glitches, there were two excellent presentations by Graeme Moyle and Jonathon Ross. Graeme gave the historical background to how we are were we are with requirements for testing drugs before they are licensed. It was sobering to be reminded of the patients who have died or have been left permanently disabled as a results of treatment with thalidomide, FIAU (a hepatitis B treatment) and more recently the Parexel TGN1412 study which left six patients seriously ill and some needing ITU care following injection of this monocloncal antibody. He described 3 types of adverse drug reaction: type A due to direct pharmacological/dose related effects of the drug (e.g FIAU and liver failure); type B due to patient-based responses (e.g Abacavir hypersensitivity in people who are HLA B5701 +ve); and type C due to increased risk of naturally occuring disease brought on by the drug (e.g. Vioxx and cardiovascular disease). Type C reactions are particularly relevant in HIV with the recent discussion about risk of myocardial infarction and certain ARTs. However, he urged caution in coming to conclusions from cohort studies. Abacavir has been linked to a 70% increased risk of MI in the DAD cohort. In the recently published ACTG 5202 study, a randomised controlled trial, Abacavir has a lower risk for MI than tenofovir and so the MI-risk story is not as clear-cut as people thought.
Jonathan gave an excellant review of new technologies for the diagnosis of STIs. Nuclear acid amplification techniques (NAAT) are well embedded for the diagnosis for gonorrhoea and chlamydia now but although NAAT for gonorrhoea is more sensitive than culture, he reminded us that in populations with a prevalence of only 1%, a positive test has a positive predictive value of only 33%. Microarrays seem to be the new technology to look out for. Using this technology it is possible to test for a large range of STIs in a single test. This could also include tests for gonorhoea-resistance mutations. Trichomonas and genital ulcer multiplex (testing for herpes, syphilis and chancroid) assays are also emerging and thus we are not far from a state where culture for organisms will no longer be our routine tests.
The conference though, is more about presentation of new research with 302 posters to look at! You’ll be impressed to read that I have looked at every one of them and here are a few of my highlights. Several posters look at the success of opening Saturday morning STI clinics. In poster 241 from Colchester they diagnosed more chlamydia than usual which they attribute to people coming as couples and so both partners being tested and treated simultaneously. In poster 254 from St Barts hospital in London, they found a doubling in the diagnosis rate of gonorrhoea and a big increase in chlamydia.
Several posters look at self completed triage and self-directed management for STIs. Up to 40% of patients describing themselves as asymptomatic initially required treatment on the day, so self-triage is still pretty inaccurate. Poster 222 form Kings College Hospital in London asserts that 10% of patients can complete a triage and self-direct management. What they don’t say is whether this management was appropriate!
Trying to get HIV+ women to test their existing children was the subject of several studies. Poster 146 reported that 40% of children under 18 were untested in this situation. One way to overcome this might be to use rapid finger-prick or oral slide tests. In one small study 2/28 children were HIV positive using opportunistic POCT tests at St Marys hospital London.
Finally, two new chronic infections have been described in HIV+ patients. A patient is described with Norovirus-related diarrhoea lasting 18 months in a severly immunocompromised patient at North Manchester (P140). It is also emerging that Hepatitis E can also cause chronic liver disease and possibly cirrhosis, as described in a patient from Truro (P128).
That is just a taster of this, the busiest day of the conference, and proof, if any was needed, that I really am here to work!