February 19, 2009
In an oral presentation at CROI 2009 in Montreal, Canada, data from the SCOPE study showed a loss of kidney function in people living with HIV, even in those with well controlled HIV levels on potent anti-HIV therapy (HAART). Potent therapy helps to control kidney function, more so than in those with uncontrolled HIV, but some still experience a higher rate of kidney dysfunction. The risk of kidney dysfunction was higher in those with "blips" of viral load, or the occasional rebound in HIV levels that many people can experience.
SCOPE grouped 615 people into four groups and studied outcomes of viral loads below vs. above 1,000: 1) untreated controllers and 2) untreated non-controllers and 3) HAART controllers and 4) HAART non-controllers. Kidney function measurements called glomerular filtration rates, or GFR, were taken throughout. Demographic and other factors were considered, such as age, sex, race, CD4 counts, viral loads, use of potent HIV therapy and presence of co-infections and other conditions.
The average age was 45, men comprised 87% of the volunteers and average CD4 count was 434. All individuals had 10 GFRs taken over their 2.5 years of follow-up.
Results showed that the GFR decline was lowest among untreated controllers (group 1). However, despite their controlled HIV levels and certainly slower decline in kidney function, people on effective therapy (group 3) still experienced loss in GFR. In the successfully treated individuals, occasional blips in viral load were more associated with poorer kidney function beyond age-expected norms.
Loss of kidney function was more associated with viral levels than with CD4 counts. The researchers offered that continued control of HIV levels without the viral blips is key to maintaining good kidney function over time. However, they did not assess the impact of kidney toxic drugs in HIV regimens on these findings. Those without HIV control, not on HIV therapy fared worst among the four groups.