HIV disease progression to CD4 count <200 cells/μL and death in Saskatoon,Saskatchewan

OBJECTIVE:

To characterize and identify determinants of HIV disease progression among a predominantly injection drug use (IDU) HIV population in the highly active antiretroviral therapy era.

METHODS:

The present retrospective study was based on 343 HIV patients diagnosed from 2005 to 2010 from two clinics in Saskatoon, Saskatchewan. Disease progression was defined as the time from diagnosis to immunological AIDS (CD4 count <200 cells/μL) and death. Uni- and multivariable Cox proportional hazards models were used.

RESULTS:

Of the 343 patients, 79% had a history of IDU, 77% were hepatitis C virus (HCV) coinfected and 67% were of Aboriginal descent. The one-year and three-year immunological AIDS-free probabilities were 78% and 53%, respectively. The one-year and three-year survival probabilities were 97% and 88%, respectively. Multicollinearity among IDU, HCV and ethnicity was observed and, thus, separate models were built. HCV coinfection (HR 2.9 [95% CI 1.2 to 6.9]) was a significant predictor of progression to immunological AIDS when controlling for baseline CD4 counts, treatment, age at diagnosis and year of diagnosis. For survival, only treatment use was a significant predictor (HR 0.34 [95% CI 0.1 to 0.8]). HCV coinfection was marginally significant (P=0.067).

CONCLUSION:

Baseline CD4 count, HCV coinfection, year of diagnosis and treatment use were significant predictors of disease progression. This highlights the importance of early treatment and the need for targeted interventions for these particularly vulnerable populations to slow disease progression.     

Cellular proviral HIV-DNA decline and viral isolation in naïve subjects with <5000 copies/ml of HIV-RNA and >500 x 10(6)/l CD4 cells treated with highly active antiretroviral therapy

OBJECTIVE: To evaluate the decay rate of cellular proviral HIV-DNA and viral replication in patients receiving highly active antiretroviral therapy (HAART) in the very early phase of infection. METHODS: Thirty-four patients treated with HAART and retrospectively selected for progressive decline of plasma viraemia up to undetectable levels (< 20 copies/ml), were stratified according to CD4+ cell count and plasma viraemia at base line: > 500 x 10(6) cells/l with < 5000 copies/ml (group 1) or with > 5000 copies/ml (group 2), > 5000 copies/ml with 300-500 x 10(6) cells/l (group 3) or with < 300 x 10(6) cells/l (group 4). Plasma HIV-RNA and proviral HIV-DNA were analysed at baseline and after 1, 2, 3, 6, 9 and 12 months of treatment. RESULTS: After 1 year of treatment, a significant decrease of proviral DNA titre was observed in all patients and a decrease > 1 log was achieved in 24 of 29 subjects of the first three groups. The more pronounced decay of HIV-DNA (half-life 28 weeks) up to < 50 HIV-DNA copies/10(6) CD4+ cells was detected in patients of group 1. At the year's endpoint, five patients (four in group 1 and one in group 2) had < 20 HIV-DNA copies. However, HIV strains sensitive to antiretroviral drugs were isolated from peripheral lymphocytes of 16 out of 34 patients. CONCLUSION: In patients with undetectable plasma viraemia after 1 year of HAART, the highest reduction of proviral DNA up to < 50 copies/10(6) CD4+ cells was obtained only in subjects in the early asymptomatic phase of infection. Nevertheless, a replication-competent virus can be detected in all phases of antiretroviral therapy.