February 27, 2007
HIV is colorblind: The virus does not discriminate by race or ethnicity. Despite this simple lesson in virus biology, there are differences in the way that HIV and HIV treatments affect different communities. Understanding these differences can assist in directing prevention and treatment resources to the areas and people who most need them.
Several presentations at the 14th Conference on Retroviruses and Opportunistic Infections described the unequal distribution of the HIV epidemic in the United States. Data continue to show that urban HIV-infected patients disproportionately come from communities of color. For example, in 2006 in my home state of Colorado, newly diagnosed HIV-infected black men and women were 4 and 24 times more likely, respectively, to acquire HIV than their white counterparts.
HIV Diagnosis and Access to Care
Lucy Wilson from the Johns Hopkins University School of Medicine presented data from the multi-state HIV Research Network on differences between 170 rural and 8416 urban HIV-infected individuals at seven high-volume clinics in the United States.1 Five of these clinics were academic and two were community based, with one located in the Northeast, two in the West, two in the Midwest and two in the South. Urban patients were more likely than rural patients to be black (40% versus 22%) or Hispanic (20% versus 11%), although the two populations were similar in age, gender and HIV risk. The rural and urban populations were also equally likely to receive Pneumocystis pneumonia (PCP) or mycobacterium avium complex (MAC) prophylactic treatments. Disturbingly, blacks were 59% less likely than whites to be receiving highly active antiretroviral therapy.
Ellen Wiewel from the New York City Department of Health and Mental Hygiene reviewed the characteristics of 3653 people diagnosed with HIV in New York in 2004.2 She found that 68% of the newly diagnosed persons were male, and a full 85% were persons of color (53.5% black, 28.6% Hispanic, 2.2% Asian/Pacific Islander). Of note, those newly diagnosed frequently had advanced HIV disease: 28% were diagnosed with AIDS at or near (within 31 days) the time of diagnosis.
Another study from Baltimore identified differences in the way that black and white HIV-infected people seek medical care. Jeanne Keruly and colleagues from the Johns Hopkins University School of Medicine described the immune status (i.e., CD4+ cell count) among 3172 persons presenting for initial HIV care at the Johns Hopkins HIV Clinic.3
Overall, patients' first measured CD4+ count declined from 371 cells/mm3 in 1990 to 292 cells/mm3 in 2006. This trend of decreasing CD4+ cell counts was seen in men, women, blacks, whites, heterosexuals and injection drug users; the only risk group that did not have a decrease in the presenting CD4+ cell count was men who have sex with men. Between 2003 and 2006, the time to the first CD4+ cell count measurement after HIV diagnosis was nearly twice as long for blacks as for whites (224 versus 113 days), and blacks had lower mean CD4+ cell counts than whites (289 vs. 317 cells/mm3).
The impact of a late diagnosis and delayed access to care was discussed by Elena Losina from Massachusetts General Hospital.4 She and her colleagues analyzed data regarding racial and ethnic disparities in HIV survival from the U.S.-based National HIV Research Network. In this group, 40% to 50% of blacks and Hispanics were diagnosed with HIV when their CD4+ cell counts were below 200 cells/mm3, and many had very low CD4+ cell counts. In the calculations of the years of life lost (YLL) among HIV-infected persons, the researchers found that blacks were likely to live one to two years less than whites. The years of life lost was found to be greater among persons who had late initiation or premature discontinuation of HIV treatment.
Effect of Race on HIV-Associated Diseases and Antiretroviral Toxicity
Several studies evaluated the effect of race or ethnicity on HIV-associated diseases and the toxicity of antiretroviral therapy. There is considerable interest in these topics. Previous studies have shown that African Americans, and black Africans alike, have lower rates of hypersensitivity to abacavir (ABC, Ziagen) compared with whites. By contrast, it has long been observed that HIV-uninfected blacks experience higher rates of kidney disease than other racial groups. For this reason, there is concern about the potential for an additional risk of HIV-associated kidney disease (or HIV-associated nephropathy) among blacks.
Gregory Lucas and colleagues from Johns Hopkins presented their analysis of the incidence of kidney disease among HIV-infected black patients in two cohorts in Baltimore, Maryland, from 1990 to 2005.5 In this group, 221 of 6255 individuals developed end-stage kidney disease, translating to a rate of 6.2 cases per 1,000 patient-years -- a rate 11.9-fold higher than that for an age-matched, HIV-uninfected black population.
Joel Gallant, also from Johns Hopkins, presented a combined analysis of treatment responses in blacks in Gilead-sponsored clinical trials that utilized tenofovir (TDF, Viread) as compared with either stavudine (d4T, Zerit) or zidovudine (AZT, Retrovir).6 These studies excluded persons who had baseline kidney disease and reassuringly showed very low rates of incident kidney disease during the 96- to 144-week follow-up period.
Only one patient in the thymidine analog control arm discontinued treatment due to acute renal failure. There were also similar changes in calculated kidney function between the tenofovir and thymidine analog groups. This latter assessment should have included the number of patients who experienced abnormal changes in kidney function rather than just the median change -- a point that limits the strength of the conclusion that the treatments studied do not increase the risk of impaired renal function.
The Study to Understand the Natural History of HIV (SUN Study) group presented a cross-sectional description of 562 patients who underwent dual energy x-ray absorptiometry bone mineral density (BMD) screening.7 Overall, abnormal bone mineral density was strikingly common, with osteopenia and osteoporosis identified in 51.7% and 9.8% of individuals. When adjusted for multiple factors, non-white race, older age, a low body mass index, the duration of HIV infection and unemployment were all associated with bone abnormalities.
Overall, these studies painfully emphasize the racial disparities in the U.S. HIV epidemic and highlight significant areas of unmet need. HIV prevention and diagnosis strategies clearly must focus on communities of color, in particular the women in these communities.
The fact that blacks take longer to seek HIV medical care and have lower CD4+ cell counts at the time of diagnosis speaks to issues of stigma, poor access to care and mistrust of the medical establishment. This phenomenon is undoubtedly not isolated to the black American community; it likely affects other racial or ethnic groups as well. Even once in care, minorities are less likely to receive (and take) antiretroviral therapies, and these individuals may have differing patterns of disease and medication toxicity. On both sides of the prescription pad, medical professionals and community groups will need to work together to better understand the reasons for these disparities and identify strategies for overcoming such inequalities.