the United States have developed a risk score to predict which people living with HIV have the highest risk of developing chronic kidney disease. Published
in the online edition of AIDS, the
risk score is based on the Framingham score used to predict cardiovascular
disease risk. The investigators hope their score will help doctors and the people in their care to
reach decisions about the use of anti-HIV drugs associated with kidney
Kidney disease is
a recognised complication of untreated HIV infection. Certain antiretroviral
drugs have also been associated with an increased risk of kidney disease, especially combinations that
include the drug tenofovir (Viread also in the
combination pills Truvada, Atripla and Eviplera).
Tenofovir is a
potent and well-tolerated drug recommended for first-line antiretroviral
therapy around the world. To better guide the use of tenofovir, investigators
from the US Department of Veterans Affairs sought to develop a scoring tool to
predict the individualised five-year risk of chronic kidney
disease (CKD) in people living with HIV.
The risk score was
based on the records of 21,590 male patients
who started HIV therapy between 1997 and 2010.
disease was defined as estimated glomerular filtration rate (eGFR) below
elevated glucose, elevated systolic blood pressure, hypertension, elevated
triglycerides, proteinuria and a low CD4 cell count were all associated with
the development of chronic kidney disease and included in the risk score.
of follow-up, 7.7% of the men taking tenofovir developed chronic kidney disease compared
to 3.8% of men taking a combination which did not include tenofovir.
tenofovir- and non-tenofovir users there was a relationship between their risk
scores and the development of chronic kidney disease.
For non-users, the
absolute five-year risk increased from less than 1% for men with a zero
risk score to 16% for men with risk scores of nine and above.
relationship between risk score and absolute risk was observed in the men taking
tenofovir. Individuals with a score of zero had a 1.4%
five-year risk, increasing to a 21.4% for men with the highest risk
duration of tenofovir use was associated with a higher five-year rate of
chronic kidney disease (10.9% for those with over one year of use compared to
4.9% for men with less than one year of use). The increased risk
associated with longer duration of tenofovir therapy was found across the range
of risk scores.
used the case of a hypothetical 55-year-old man to illustrate the value of
their model when reaching treatment decisions. The man was described as having a normal CD4
count and glucose, no proteinuria. However, he had high blood pressure,
hypertension and elevated triglycerides. His total risk score was eight. If he was not taking tenofovir, he had an 11% chance of developing chronic
kidney disease over five years; this increased to 19% with tenofovir use.
system allows risk assessment to be quantified, providing physicians and
patients with an estimate of the absolute risk of developing CKD and providing
a more nuanced algorithm for HIV treatment,” comment the authors. “Our CKD risk
score could aid clinicians in designing first-line HIV treatment regimens
optimized for safety as well as efficacy.”