Rapid progression of HIV subtype C is prevalent in South African women
Among South African women infected with HIV subtype C, disease progression appears to be rapid, with CD4 cell counts dropping to less than 350 cells/mcl within 2 years, according to recent findings.
In the prospective study, researchers evaluated women at high risk of HIV infection in KwaZulu Natal in South Africa between August 2004 and May 2005. The women were followed for up to 4 years and tested monthly (n=245) or once every 3 months (n=594) for acute HIV infection.
Upon confirmation of HIV diagnosis, the women were enrolled in the Acute HIV infection cohort. These patients were seen on a follow-up schedule consisting of an initial phase of visits up to 3 months post infection (acute infection), followed by monthly visits between 3 and 12 months post-infection (early infection), and visits on a quarterly basis (established infection) until the commencement of antiretroviral therapy (ART). At the visits, the women provided samples to be tested for clinical, virologic and immunologic parameters, and viral load and CD4 counts were assessed.
The women were evaluated for rapid disease progression, which was defined as a decrease in CD4 count to less than350 cells /mcl within 2 years of infection onset. The researchers used survival analysis and logistic regression to compare the sequence of clinical and laboratory evaluations. The researchers found that 62 women tested positive for HIV and were identified at median 42 days post-infection (interquartile range 34-59), equaling 282 person-years of follow-up.
In women for whom pre-infection measurements were available, there was a mean decrease in CD4 count by 39.6% at 3 months post-infection and a 46.7% decrease at 6 months. At 1 year post-infection, 31% of women had a decrease in CD4 cells to less than 350 cells/mcl; at 2 years, 44% experienced this decline; and at 3 years, 55% had a reduction in CD4 cells to less than 350 cells/mcl. Declines to less than 500 CD4 cells/mcl occurred in 69% of women at 1 year, 79% at 2 years, and 81% at 3 years.
The researchers determined the following to be independent predictors of rapid progression: CD4 count at 3 months post-infection (HR: 2.07, 95% CI, 1.31-3.28, per 100 cells/mcl decrease; P=.002), set-point viral load (HR: 3.82, 95% CI, 1.51-9.67, P=.012), and coinfection with hepatitis B (HR: 4.54, 95% CI, 1.31-15.69, p=.017). Non-rapid progression was predicted by the presence of any HLAB*1302, B*27, B57, B*5801 or B*8101 alleles (HR: 0.19, 95% CI, 0.05-0.75; P=.016).
According to the researchers, these findings emphasize the need for longer-term antiretroviral therapy (ART), despite the financial obstacles to implementation.
“The rapid progression observed in this cohort provides additional motivation to implement earlier ART initiation,” the researchers wrote. “Although this may present economic and operational challenges, the fact that half of individuals need ART in the first year of HIV infection provides compelling data for continued treatment roll-out.”
Disclosure: The researchers report no relevant disclosures.