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Dr.Young is assistant clinical professor at University of Colorado and a clinican with Denver Infectious Disease Consultants. Dr. Young is also an expert at The Body's Ask the Expert forums.

Dr. Young, tell me a little bit about what you saw of interest at CROI. I know that you focused on racial/ethnic disparities, and renal and other kinds of toxicities.

Well, this was an interesting CROI meeting for a number of reasons. I think you've heard already from a number of our experts on new drugs, and interesting data on breastfeeding and so on. One of the things that has been a subject of interest of mine for some time -- with several studies presented at CROI this year -- was the issue of racial disparities in a number of aspects of the HIV epidemic. These include issues related to transmission of HIV, access to care, the kinds of medicines that people receive and the spectrum of HIV disease and drug toxicity.

I was particularly interested in a couple of studies that described the changing epidemic of HIV in the United States. There was an interested presentation from Lucy Wilson, from Johns Hopkins, looking at data from this thing called the Multistate HIV Research Network. [The study was called "Rural Versus Urban HIV/AIDS Clinical Outcomes: A Multi-State Perspective"] This is a study that looked at both urban and rural settings in clinics across the United States.

What she showed was that rural patients were much more likely to be black or Hispanic. To me very concerning was the observation that blacks in this country, at least in this cohort of patients, were significantly less likely to be receiving highly active antiretroviral therapies. This suggests to me that there are significant barriers of race and ethnicity, in terms of getting effective medications for HIV.

Did she focus on any particular areas in the United States?

Well, the study, if I recall, was based at five different clinics, scattered primarily in the East and South of the United States, but I don't remember the cities. [Seven sites were included: one in the Northeast, two Western, two in the Midwest and 2 in the South.]

We have to move kind of quickly here. Tell me about other studies on this ethnic disparities in HIV testing and care that interested you?

There was another study from Ellen Wiewel from the New York City Department of Health that characterized the newly diagnosed patients in New York City in 2004. [The study is "Risk Factors for Concurrent Diagnosis of HIV/AIDS in New York City, 2004: The Role of Age, Transmission Risk, and Country of Birth"] Perhaps not surprisingly, about 70 percent of the newly diagnosed HIV-infected persons were male. But 85 percent of those new diagnoses were among persons of color. Specifically, about 50 percent were black; almost 30 percent, Hispanic.

Another area of disparity was that those patients who were newly diagnosed tended to have more advanced disease. Twenty eight percent of patients were diagnosed with an AIDS diagnosis within 31 days of their HIV diagnosis. So, again, we're missing opportunities to intervene earlier in the natural history of the disease. We're missing opportunities to prevent AIDS complications.

That sounds like an awfully lot of people. And what makes it all the more tragic is that New York City has been dealing with HIV from the beginning. You'd think that this city would have gotten further, in terms of prevention and outreach.

I agree with you, and I think that despite 20 years of HIV therapies, and a few more years of knowing about the epidemic, we really have not done a very good job in prevention of HIV in this country or abroad. The fact that there are 3,600 new cases of HIV in New York City alone in 2004 to me speaks to this point. The fact that people are diagnosed with late-stage disease commonly -- this is not just New York City; similar data come from our state, in Colorado. Similar data about the racial disparities of new diagnoses also come from Colorado. In Denver, for example, black women are 25 times more likely to be diagnosed with HIV than white women, black men four times more likely to be diagnosed than white men.

So these racial differences speak a lot to the need to get effective prevention, effective testing strategies into communities at great risk. The fact that these disparities still exist means that we're not doing a good enough job at that.

Anything else at CROI that you saw that interested you?

Again, there were additional studies that actually followed up on this time of diagnosis. There was another study from the Johns Hopkins group that looked at just the CD4 count at the time the person first walks into the clinic. And, again, in this setting, blacks consistently had lower CD4 counts at the first time they walked into the clinic, and they took twice as long to get to the clinic after their HIV-positive test. This speaks to the need to try to figure out ways to improve access to care, to minimize either cultural or medical barriers to accessing care.

An additional study came from Elena Losina from the Massachusetts General Hospital, looking at a large cohort of patients in the National HIV Research Network. [To hear Dr. Losina's summary of her study and questions asked by journalists at a CROI press conference, click here] Again, we're pointing out that nearly half of blacks and Hispanics diagnosed with HIV in this country were diagnosed with CD4 counts less than 200, and a significant proportion of those diagnosed with CD4 counts less than 50. The effect of this was modeled in her presentation, pointing out that these differences in timely diagnosis translates to survival differences, and that blacks diagnosed in this country were projected to live one to two years less than whites, simply on the basis of delayed diagnosis and delayed access to care. I think that that is, again, a significant barrier and problem for our HIV communities as we move forward into the fourth decade of HIV.

Did any of these studies put forward suggestions on how to change the situation?

Very limited ones, although, let me just simply say that these disparities exist and that we need to recognize these. I think that finding strategies that are culturally appropriate and sensitive to the needs of these communities is very important. I work quite closely with the black faith communities of Colorado. Even in our small communities there exist significant barriers, significant mistrust of the medical establishment, significant fear of diagnosis, significant stigma within each community. While these are common themes to HIV communities of all colors, they appear to be significantly affecting communities of color in this country right now.

Lastly, I thought there were a couple of studies -- or several studies -- that address the issue of differential toxicity of drugs, or differences in the natural history of HIV in the African-American community. This is particularly of interest because of known differences in the rates of things like hypertension and kidney disease, differences in the frequency of bone density problems in different ethnic groups. So it was of interest to hear reports from the Johns Hopkins groups, one from Gregory Lucas looking at the Johns Hopkins clinic [To view the abstract for this study, titled: "End Stage Renal Disease Risk in HIV-infected African Americans: 12-fold Higher than Age- and Race-adjusted National Rate and Increasing in the HAART Era," click here], and a second one from Joel Gallant, reporting data from the Gilead clinical trials that looked at the frequency of kidney disease among African-Americans, comparing them to Caucasian Americans. The former study found that the rate of kidney disease among HIV-infected African-Americans was almost 12 times higher than that of the HIV-negative African-American population. So, again, HIV-infected blacks in this country are at significant risk of developing kidney disease.

By contrast, and at least, reassuringly, Dr. Gallant presented data looking at the very detailed prospected studies of tenofovir in Gilead-sponsored clinical trials and pointed out that the rate of new kidney injury in patients who did not have preexisting kidney disease was very, very low, in either the 96 or 144 weeks of the Gilead sponsored studies. This was actually true whether the patient received the tenofovir [TDF, Viread] in the study, or either d4T [stavudine, Zerit] or AZT [zidovudine, Retrovir]. [Gallant's study is titled: "Efficacy and Safety of Tenofovir-containing vs non-Tenofovir-containing Regimens in Black ART-naive Patients." To view the study abstract, click here.

You said the kidney disease was 12 times higher in African-Americans. Do we know why?

The study actually didn't speculate there. The study matched patients on the basis of their age and gender. Presumably the rates of other medical conditions were similar -- although at least in my recollection of the study. So we do know that HIV alone can cause kidney injury, or what's called HIV-associated nephropathy, and that is a component of this HIV-specific difference within the African-American community.

What does this mean in terms of prescribing tenofovir, Truvada or Atripla to African Americans if they are 12 times more likely to have kidney disease?

Well, again, the Gallant analysis suggests that if you don't have preexisting kidney disease, you're unlikely to develop kidney disease over a two or three year period. And that, again, is reassuring. I think that, as we move forward with HIV therapies, we are very fortunate to have a number of treatment choices, and we understand the characteristic side effect profiles of these medications. The overall risk of kidney injury from tenofovir is actually very low, and we, and others, have shown this in both prospective clinical studies, as well as in large cohort studies. But your point is correct insomuch that, if you were an African-American person with significant risk for kidney disease, and -- and this is an important "and" -- there were other treatment options that were equally well tolerated, I think that I would be at least looking at those other alternative to try to prevent kidney disease, in this case. In other words, the idea is to prevent disease before it happens, rather than treat it when it does.

So patients are monitored when they go into the clinic for kidney disease, before they're assigned one regimen or another.

They should be and there are treatment guidelines to discuss just this point. And, yes, patients should receive -- when we initiate patients on therapies, we're really looking at a number of parameters before we prescribe medications and hopefully tailor the medications, both for tolerability, but also to try to prevent or avoid potential toxicities down the road. So patients who have preexisting risk of kidney disease; if they have other options, we generally try to avoid using tenofovir. If they don't have those risk factors, then the use of tenofovir should be safe. And, again, this is the general construct in the way we look at HIV therapies.

Great. Well, thank you very much.

You're very welcome, Bonnie.