Reducing viral load using antiretroviral therapy can greatly improve renal function in people with HIV and kidney disease, according to a new study published in the February 19 issue of AIDS. These results provide further evidence that uncontrolled HIV replication is a major cause of HIV-associated nephropathy, a form of kidney disease seen in HIV-positive people, notably black men with low CD4 counts.

Robert Kalayjian, MD, of the department of medicine at MetroHealth Medical Center in Cleveland, and his colleagues evaluated data involving 1,776 individuals participating in the AIDS Clinical Trials Group (ACTG) Longitudinal Linked Randomized Trials (ALLRT) study. The average age of the participants was 38 years; 82 percent were male and 30 percent were black. At baseline—when participants first entered the study—4 percent had diabetes, 11 percent had stage 1 (mild) chronic kidney disease (CKD), and 7 percent had stage 2 or greater CKD (moderate to severe).

Kidney function and stage of kidney disease was assessed using patients’ glomerular filtration rates (GFRs), which measure how quickly their kidneys can filter substances like drugs from fluids. A reduction in GFR is synonymous with a reduction in kidney function.

In the cohort as a whole, there was a slight decrease in GFR, over time. This was true in people who began the study with normal kidney function or stage 1 CKD. The opposite was true, however, in people with stage 2 or greater CKD who began treatment with low CD4 counts—they experienced significant GFR improvements upon suppressing their viral loads by at least 1 log or reducing them to less than 400 copies. In fact, 28 percent of people with stage 2 or greater CKD at baseline saw their GFR increase to the normal range after suppressing their viral loads with the use of antiretroviral treatment.

The authors caution that a variety of antiretrovirals were used by the study participants, and that at least two of those antiretrovirals, indinavir (Crixivan) and tenofovir (found in Viread, Truvada and Atripla) have been associated with decreased kidney function, and this may have affected the results to some degree. They point out, however, that the size and design of the study should give people with low CD4 cells and kidney disease confidence that controlling HIV through the use of antiretrovirals can significantly improve kidney function.