Wednesday morning featured a series of oral presentations exploring the interplay of STIs and altered microbiomes might affect PrEP.

Renee Heffron presented research that explored whether bacterial vaginitis decreased the effectiveness of oral PrEP.

In the CAPRISA 004 study which demonstrated the effectiveness of intravaginal tenofovir it was observed that in women that had a vaginal biome consistent with BV there was a significantly decreased effectiveness of vaginal tenofovir gel. It is postulated that anaeobic bacteria may hasten the breakdown of tenofovir. This study explored data from the PARTNERS PrEP study .  It compared baseline vaginal swabs , graded using the nugent scale as to the number of BV related bacteria, with serum tenofovir levels and HIV seroconversion. Reassuringly BV did not seem to affect either Serum levels or PrEP effectInness.

John-Michel Molina presented an interesting IPERGAY sub study. This looked at the controversial area of STI prevention using Doxycycline PEP. Men enrolled in IPERGAY were randomised to be provided with doxycycline PEP or not provided with PEP. Those asked to take the doxycycline PEP were asked to take a stat dose of 200mg between 1 and 3 days after sex. The time to acquisition of an STI (gonorrhoea , chlamydia or syphilis) was compared. In brief , no effect on gono but significantly reduced rates of syphilis and chlamydia. The data presented didn't address the thorny issue of antibiotic resistance. They are still looking at that.

Tuesdayy afternoon provided a session of poster presentations exploring the complicated relationship between ARV treatment , excess weight gain and hepatic steatosis.

In summary ,

Weight gain in an HIV positive male is associated with twice the diabetes risk of the same degree of weight gain in an HIV negative male

Amit Achra from Kirby Institute presented DAD data the relationship between BMI and non AIDS related adverse outcomes. The results suggested that for CV risk both very low BMI (<18) and very high BMI (>30) were associated with an increased risk , and for non AIDS related cancers , risk was significantly associated with very low BMI and very high BMI.

An exercise physiologist from Massachusetts presented a study where overweight HIV positive patients were randomised to either be enrolled in an online weight loss and health coaching program or be in a control arm with minimal weight loss suppport. The results suggested the program was both cheap to run and successful in terms of significant weight loss.

A retrospective  analysis of a study where naive patients were randomised to start either raltegravir, boosted atazanavir or boosted darunavir plus 2 nucs looked at the predictors of excess weight gain. Interestingly they were black race , higher baseline disease severity and use of Raltegravir. There was a lot of discussion about the possible explanation of Raltegravir falling out as a predictor.

Interestingly a study was presented were HIV positive women on NNRTI or PI based regimens were randomised to either stay on th regimen or swap to Raltegravir regimen. They looked a biochemical markers of hepatic steatosis , Chi3L1 and adipokine adiponectin. It was interesting that both these markers droped (suggesting decreased steatosis) in those that switched to Raltegravir.

Finally a study looking at patients swelling from a Efavirenze containing regimen to a Raltegravir regimen appeared to decrease their steatosis as measured by a CAP score, (Controlled Attenuation Parameter , an add on process done with a fibrous scan)

So Raltegravir seemed to lead to weight gain but less hepatic steatosis , a result that seems to pose more questions than it answers.

Hi from Seattle. 

Very interesting plenary this morning at 8.30 presented by Jintanat Ananworanich. She spoke about the potential and possible processes for cure. It was a very good overview. She specifically discussed what can be learned from the way the immune systems of infants and children respond to HIV and how that can inform us in regard to potential for cure. Well worth watching the webcast on the CROI site when it becomes available in a few hours.

 more to come