Study Suggests Potent HAART & Intensification May Prevent Viral Rebound
     Reported by Jules Levin

The full report of the group study is at: This Study Suggests Viral Load Blips Matter

G. Greub presented data (abstract 522) at the 8th Annual retrovirus Conference from the Swiss & Frankfurt Cohort Studies that 2-3 consecutive low level viral rebounds to 200-500 copies/ml increases the risk for viral rebound to higher levels. In abstract 404, B. Ramratnam reports findings suggesting that increasing the potency of HAART with intensification decreases the frequency of intermittent viremia.

This suggests that using a more potent HAART regimen may decrease the risk of viral failure over time. In this study, the investigators intensified HAART with abacavir (n=4) or abacavir+efavirenz (n=1), and found this reduced the incidence of intermittent viremia compared to a group of 5 control patients. This also suggests that using a more potent regimen from the initiation of therapy may prevent viral failure over the course of time on therapy. If a patient is experiencing viral load "blips" or low level rebound, doctor & patient should discuss the best approach to addressing concerns in preventing viral load failure. Potential solutions could be intensification or changing regimen. In addition, adherence problems could be the cause of the blips or low level rebound. In which case, this should be discussed as a separate issue.

Laboratory testing errors or inapprorpriate handling of samples can also cause a random error in reporting of viral load test results. Patients in the study were initially receiving AZT/3TC plus nelfinavir or ritonavir+saquinavir. Both the control group & the patients intensifying had comparable baseline characteristics. Intensification was added after a mean of 34 months and the mean duration of intensification was 14 months.

Prior to intensification there was no statistically significant difference in the median frequency of intermittent viremia (viral load blips or low level rebound) between the control & intensification groups (3.3 per year vs 2.8 per year). When compared to the control group, the intensification patients had a more accelerated decay rate of virus in the latent reservoir (31 months vs 10 months) after intensification. The frequency of intermittent viremia per year decreased in 4/5 patients following intensification (2.4 per year vs 0.8 per year).

The authors concluded that ongoing virus replication during HAART is due in part to inadequate potency of HAART. And, although intensification improves potency & decreases intermittent viremia, HIV replication is still not completely suppressed.