Impact of 5 years of maximally successful highly active antiretroviral therapy on CD4 cell count and HIV-1 DNA level

Distinct genetic loci control plasma HIV-RNA and cellular HIV-DNA levels in HIV-1 infection: the ANRS Genome Wide Association 01 study

Previous studies of the HIV-1 disease have shown that HLA and Chemokine receptor genetic variants influence disease progression and early viral load. We performed a Genome Wide Association study in a cohort of 605 HIV-1-infected seroconverters for detection of novel genetic factors that influence plasma HIV-RNA and cellular HIV-DNA levels. Most of the SNPs strongly associated with HIV-RNA levels were localised in the 6p21 major histocompatibility complex (MHC) region and were in the vicinity of class I and III genes. Moreover, protective alleles for four disease-associated SNPs in the MHC locus (rs2395029, rs13199524, rs12198173 and rs3093662) were strikingly over-represented among forty-five Long Term HIV controllers. Furthermore, we show that the HIV-DNA levels (reflecting the HIV reservoir) are associated with the same four SNPs, but also with two additional SNPs on chromosome 17 (rs6503919; intergenic region flanked by the DDX40 and YPEL2 genes) and chromosome 8 (rs2575735; within the Syndecan 2 gene). Our data provide evidence that the MHC controls both HIV replication and HIV reservoir. They also indicate that two additional genomic loci may influence the HIV reservoir.

A more precise HIV integration assay designed to detect small differences finds lower levels of integrated DNA in HAART treated patients

Many studies report the level of total viral DNA in HIV-infected patients, but few studies report the level of integrated DNA. It is important to measure integrated DNA in HIV-infected patients because the information could shed light on the effectiveness of antiretroviral therapy, especially intensified therapy, when viral loads may remain undetectable. In order to develop an integration assay for patient samples, we enhanced the sensitivity of our prior integration assay. To do this, we exploited a technique that we developed, called repetitive sampling, and optimized reaction conditions for rare event detection, rather than large dynamic range. We also designed our primers to match more conserved regions of HIV. The result is a new, sensitive, quantitative assay that allows us to measure integrated DNA in HIV-infected patients. When we applied our integration assay to patient PBMCs, we found that the use of HAART is associated with reduced levels of integrated DNA.

Greater viral rebound and reduced time to resume antiretroviral therapy after therapeutic immunization with the ALVAC-HIV vaccine (vCP1452)

OBJECTIVE

Evaluate immunogenicity and clinical efficacy of two immunization strategies with the ALVAC-HIV-recombinant canarypox vaccine (vCP1452) in treated HIV-infected patients.

DESIGN

Randomized, double-blind, placebo-controlled, phase II study of vCP1452 immunization in chronically HIV-infected patients on therapy with CD4 T-cell count more than 350 cells/microl, CD4 nadir less than 400 cells/microl and pHIV-RNA less than 400 copies/ml. Patients were equally randomized to four injections at weeks 0, 4, 8, 20; three injections at weeks 4, 8, 20; and placebo. The primary endpoint was vaccine immunogenicity at week 24 measured by enzyme-linked immunospot-interferon-gamma against the HIV-gag-reverse transcriptase-nef vaccine sequences. Secondary endpoints included time to treatment resumption and viral quantitation following treatment interruption at week 24. Criteria to resume therapy included CD4 T-cell count decline less than 250 cells/microl or 50% decrease from baseline or pHIV-RNA more than 50,000 copies/ml.

RESULTS

Sixty-five patients enrolled. Changes from baseline in HIV-specific T cells in the four injection arms (+480 spot-forming cells/M-peripheral blood mononuclear cell) were significant compared to placebo (+8; P = 0.014), but not in the three injection arms (+322). The week 36 pHIV-RNA (log10 copies/ml) after treatment interruption was higher in the four (4.71; P = 0.023) and three (4.82; P = 0.009) injection arms compared to placebo (4.40). Percentages of patients reaching treatment resumption criteria by week 48 were 74, 55 and 23% in the three respective arms (P = 0.013). Two independent factors influenced time to therapy resumption: immunization (hazards ratio = 2.7, P = 0.048 for three injections; hazards ratio = 4.1, P = 0.003 for four injections) and CD4 nadir (hazards ratio = 0.4, P = 0.002).

CONCLUSIONS

Significant immunogenicity was induced by vCP1452; however, this strategy was independently associated with a shorter time to resume therapy and higher viral rebound.

Prolonged valproic acid treatment does not reduce the size of latent HIV reservoir

OBJECTIVE

To investigate the impact of prolonged valproic acid treatment on the HIV reservoir in patients on highly active antiretroviral therapy.

DESIGN

In a single-center pilot study, the size of the HIV reservoir of 11 patients receiving valproic acid for seizures for more than 2 years was compared with 13 matched patients. In addition, the outcome of patients receiving valproic acid in the French clinical trials of scheduled treatment interruption was recorded.

METHODS

Total and integrated HIV-1 DNA in, respectively, peripheral blood mononuclear cells and CD4 T cells of the patients were quantified by real-time PCR methods. The frequency of CD4 T cells carrying replication-competent virus was estimated by a quantitative limiting-dilution assay in which virus growth was detected by RT-PCR in culture supernatants of activated CD4 T cells. Clinical charts of the patients included in scheduled treatment interruption trials receiving valproic acid were reviewed.

RESULTS

Total and integrated HIV DNA were logarithmically more abundant than cells carrying replication-competent virus, but there was no significant difference in these three parameters between the two groups of matched patients. Three patients receiving valproic acid were included in scheduled treatment interruption trials. The rebound of viral replication was similar to that of the other patients of the trials.

CONCLUSION

Long-term valproic acid therapy seems to be insufficient to reduce the size of the HIV-1 reservoir.

HIV-1 DNA for the measurement of the HIV reservoir is predictive of disease progression in seroconverters whatever the mode of result expression is

BACKGROUND

HIV-1 DNA levels, reported as copies/10(6) peripheral blood mononuclear cells (PBMC), are very predictive of disease progression in seroconverters, independently of CD4(+)T cell count and HIV-RNA. Previously, HIV-DNA levels have sometimes been reported by other means: copies/10(6) CD4(+)T cells, reflecting the proportion of infected cells; or copies/mL whole blood, reflecting the global blood reservoir size.

OBJECTIVES

We investigated if the predictive value over the natural course of the disease depends on how the results are reported.

STUDY DESIGN

Results reported as HIV-DNA copies/10(6) PBMC were converted to copies/10(6) CD4(+)T cells or to copies/mL whole blood for 422 seroconverters included in the French SEROCO cohort (ANRS).

RESULTS

The three methods for reporting HIV-DNA levels yielded different ranges, but these values were highly correlated. The level of HIV-DNA during the seroconversion period was strongly associated with disease progression in all three reporting methods.

CONCLUSIONS

This reinforces the value of HIV-DNA quantification in physiopathological and therapeutical studies, particularly in an era of research aimed at diminishing the HIV reservoir. Even if blood represents a small part of this reservoir, HIV-DNA in blood is a simple marker that provides an informative picture of the global reservoir and is strongly predictive of disease progression.

Dynamics of total, linear nonintegrated, and integrated HIV-1 DNA in vivo and in vitro

BACKGROUND

In patients infected with human immunodeficiency virus type 1 (HIV-1), HIV-1 DNA persists during highly active antiretroviral treatment, reflecting long-lived cellular reservoirs of HIV-1. Recent studies report an association between HIV-1 DNA levels, disease progression, and treatment outcome. However, HIV-1 DNA exists as distinct molecular forms that are not distinguished by conventional assays.

METHODS

We analyzed HIV-1 RNA levels in plasma, CD4 cell counts, and levels of integrated and nonintegrated HIV-1 DNA in peripheral blood mononuclear cells (PBMCs) from patients with early or chronic infection before and during antiretroviral treatment. We also studied HIV-1 DNA decay in primary CD4 T cells infected in vitro. HIV-1 DNA was analyzed using an assay that is unaffected by the location of HIV-1 integration sites.

RESULTS

HIV-1 RNA levels and total HIV-1 DNA levels decayed rapidly in patients during receipt of suppressive antiretroviral therapy. Ratios of total HIV-1 DNA levels to integrated HIV-1 DNA levels were high before initiation of therapy but diminished during therapy. Levels of linear nonintegrated HIV-1 DNA decayed rapidly in vitro (t (1/2) = 1- 4.8 days).

CONCLUSION

Total HIV-1 DNA decays rapidly with suppression of virus replication in vivo. Clearance of HIV-1 DNA during the first 6 months of therapy reflects a disproportionate loss of nonintegrated HIV-1 DNA genomes, suggesting that levels of total HIV-1 DNA in PBMCs after prolonged virus suppression largely represent integrated HIV-1 genomes.

Differences in proviral DNA load between HIV-1- and HIV-2-infected patients

INTRODUCTION

The lesser pathogenicity of HIV-2 relative to HIV-1 is generally attributed to its slower replication. To compare the amounts of total HIV DNA during human HIV-1 and HIV-2 infection, we developed a quantitative real-time PCR method with a unique external quantification standard based on a single plasmid harboring both the HIV-1 and the HIV-2 LTR.

METHODS

Viral DNA load was compared between 40 HIV-1-infected and 42 HIV-2-infected antiretroviral-naive patients.

RESULTS

The difference between HIV-1 and HIV-2 proviral DNA load was highly significant in patients with CD4 cell counts > 500 cells/microl [HIV-1: n = 14; median, 2.5; interquartile range (IQR), 2.1-2.7; HIV-2: n = 22, median, 1.6; IQR, 1.0-2.0] and in patients with CD4 cell counts between 300 cells/microl and 500 cells/microl (HIV-1: n = 12; median, 2.7; IQR, 2.3-2.8; HIV-2: n = 11; median, 2.0; IQR, 1.0-2.4). Too few HIV-2-infected patients had CD4 cell counts < 300 cells/microl to detect a significant difference but DNA values were again lower in HIV-2-infected patients (HIV-1: n = 14; median, 2.9; IQR, 2.2-3.2; HIV-2: n = 9; median, 2.7; IQR, 2.2-3.3).

CONCLUSIONS

These differences are in line with the natural histories of the two infections and show that HIV-2 infection is a valid model for studying the pathophysiology of HIV infection in general.

Mother-to-child HIV transmission despite antiretroviral therapy in the ANRS French Perinatal Cohort

OBJECTIVE

To identify factors associated with mother-to-child HIV-1 transmission (MTCT) from mothers receiving antenatal antiretroviral therapy.

DESIGN

The French Perinatal Cohort (EPF), a multicenter prospective cohort of HIV-infected pregnant women and their children.

METHODS

Univariate analysis and logistic regression, with child HIV status as dependent variable, were conducted among 5271 mothers who received antiretroviral therapy during pregnancy, delivered between 1997 and 2004 and did not breastfeed.

RESULTS

The MTCT rate was 1.3% [67/5271; 95% confidence interval (CI), 1.0-1.6]. It was as low as 0.4% (5/1338; 95% CI, 0.1-0.9) in term births with maternal HIV-1 RNA level at delivery below 50 copies/ml. MTCT increased with viral load, short duration of antiretroviral therapy, female gender and severe premature delivery: 6.6% before 33 weeks versus 1.2% at 37 weeks or more (P < 0.001). The type of antiretroviral therapy was not associated with transmission. Intrapartum therapy was associated with four-fold lower MTCT (P = 0.04) in case of virological failure (> 10 000 copies/ml). Elective cesarean section tended to be inversely associated with MTCT in the overall population, but not in mothers who delivered at term with viral load < 400 copies/ml [odds ratio (OR), 0.83; 95% CI, 0.29-2.39; P = 0.37]. Among them, only duration of antenatal therapy was associated with transmission (OR by week, 0.94; 95% CI, 0.90-0.99; P = 0.03).

CONCLUSIONS

Low maternal plasma viral load is the key factor for preventing MTCT. Benefits in terms of MTCT reduction may be expected from early antiretroviral prophylaxis. The potential toxicity of prolonged antiretroviral use in pregnancy should be evaluated.

Long-term evolution of CD4 count in patients with a plasma HIV RNA persistently <500 copies/mL during treatment with antiretroviral drugs

BACKGROUND

The increase in CD4 count may reach a plateau after some duration of virological response to highly active antiretroviral therapy (HAART).

METHODS

A total of 1281 HIV-infected patients initiating HAART were enrolled in the AntiPROtease (APROCO) cohort. We investigated determinants of increase in CD4 count using longitudinal mixed models in patients who maintained a plasma HIV RNA <500 HIV-1 RNA copies/mL.

RESULTS

A total of 870 patients had a virological response at month 4. The median follow-up time was 57 months. Mean estimated increases in CD4 count in patients with persistent virological response were 29.9 cells/muL/month before month 4, 6.4 cells/microL/month between months 4 and 36, and 0.7 cells/microL/month (not significantly different from 0) after month 36. Three factors were associated with a significantly positive CD4 count slope after month 36: male gender (+0.9), no history of antiretroviral therapy at baseline (+1.7) and baseline CD4 count <100 cells/microL (+2.6). In patients who maintained a virological response after 5 years of HAART, a CD4 count >500 cells/microL was achieved in 83% of those with a baseline CD4 count >or=200 cells/microL and in 45% of those with a baseline CD4 count <200 cells/microL.

CONCLUSION

The increase in CD4 count reaches a plateau after 3 years of virological response. Even if patients initiating HAART with low CD4 counts still show a CD4 count increase after 3 years, it remains insufficient to overcome immune deficiency in all patients.

CD4+ T-Cell Count Increase in HIV-1-Infected Patients with Suppressed Viral Load Within 1 year after start of antiretroviral therapy

Background

CD4+ T-cell recovery in patients with continuous suppression of plasma HIV-1 viral load (VL) is highly variable. This study aimed to identify predictive factors for long-term CD4+ T-cell increase in treatment-naive patients starting combination antiretroviral therapy (cART).

Methods

Treatment-naive patients in the Swiss HIV Cohort Study reaching two VL measurements <50 copies/ml >3 months apart during the 1st year of cART were included ( n=1,816 patients). We studied CD4+ T-cell dynamics until the end of suppression or up to 5 years, subdivided into three periods: 1st year, years 2–3 and years 4–5 of suppression. Multiple median regression adjusted for repeated CD4+T-cell measurements was used to study the dependence of CD4+ T-cell slopes on clinical covariates and drug classes.

Results

Median CD4+ T-cell increases following VL suppression were 87, 52 and 19 cells/μl per year in the three periods. In the multiple regression model, median CD4+ T-cell increases over all three periods were significantly higher for female gender, lower age, higher VL at cART start, CD4+ T-cell <650 cells/μ l at start of the period and low CD4+ T-cell increase in the previous period. Patients on tenofovir showed significantly lower CD4+T-cell increases compared with stavudine.

Conclusions

In our observational study, long-term CD4+ T-cell increase in drug-naive patients with suppressed VL was higher in regimens without tenofovir. The clinical relevance of these findings must be confirmed in, ideally, clinical trials or large, collaborative cohort projects but could influence treatment of older patients and those starting cART at low CD4+ T-cell levels.

Profile of immunologic recovery in HIV-infected Ugandan adults after antiretroviral therapy

HIV infection is characterized by a decrease in total CD4 cell count, rising viral load, as well as an increase in immune activation levels. Increased activation can lead to an increase in apoptosis and contribute to CD4 depletion. We evaluated the clinical and immunologic responses of 23 HIV-positive Ugandan volunteers following initiation of antiretroviral therapy (ART). All volunteers achieved and maintained complete viral suppression within the first 3 months of therapy (p > 0.05). CD4+ and CD8+ T cell activation also decreased significantly, although it never reached the level of HIV negative Ugandan volunteers. Viral suppression and CD4 cell recovery were also associated with an improved profile in CD8+ T cell functional markers, but had no effect on HIV-specific proliferation. We conclude that ART in a cohort of therapy-naive Ugandans with AIDS partially restores but does not fully reverse the immune dysfunction observed in chronic HIV infection.

Predictors of virological outcome and safety in primary HIV type 1-infected patients initiating quadruple antiretroviral therapy: QUEST GW PROB3005

BACKGROUND

Initiation of antiretroviral therapy during primary human immunodeficiency virus (HIV)-1 infection may confer long-term benefit.

METHODS

After initiation of zidovudine, lamivudine, abacavir, and amprenavir therapy in patients in the QUEST cohort, predictors of virological outcome, virological and immunological changes, and adverse events were evaluated over 48 weeks.

RESULTS

One hundred forty-eight patients started antiretroviral therapy during primary HIV-1 infection with < or =3 bands on Western Blot (median plasma HIV-1 RNA load, 5.4 log copies/mL; median CD4 cell count, 517 cells/mm(3)). By week 48, 36% of patients had stopped treatment or were lost to follow-up. Among the 115 patients receiving follow-up care at week 48 (102 of whom were receiving antiretroviral therapy), the median viral load decrease was -5.4 log copies/mL (interquartile range [IQR], -6.4 to -3.9 log copies/mL), and the median increase in CD4 cell count was 147 cells/mm(3) (IQR, -1 to 283 cells/mm(3)); 84.2% of patients had a viral load < or =50 copies/mL, and 44.7% of patients had a viral load < or =3 copies/mL. The median cell-associated RNA level decreased from 3.4 log copies/million PBMCs (IQR, 2.9-4.1 log copies/million PBMCs) to 0.8 log copies/million PBMCs (IQR, 0.5-1.4 log copies/million PBMCs), and the median cell-associated DNA level decreased from 2.8 log copies/million PBMCs (IQR, 2.4-3.0 log copies/million PBMCs) to 1.6 log copies/million PBMCs (IQR, 1.2-1.9 log copies/million PBMCs); 33.3% of patients had an undetectable RNA level, and 9.5% of patients had an undetectable cell-associated DNA level. The median CD8(+)/CD38(++) T cell count decreased from 459 cells/mm(3) (IQR, 208-974 cells/mm(3)) to 33 cells/mm(3) (IQR, 19-75 cells/mm(3)). Baseline CD8(+)/CD38(++) T cell count and cell-associated DNA level were independent inverse predictors for reaching a viral load < or =3 copies/mL. Eighty-three patients experienced a serious adverse event (median duration of an adverse event, 15 days).Conclusions. Initiation of antiretroviral therapy during primary HIV-1 infection was associated with very significant antiretroviral activity and a decrease in immune activation. Lower baseline CD8(+)/CD38(++) T cell count and cell-associated DNA level were predictive of achieving a viral load < or =3 copies/mL.

Fast and sensitive quantitative detection of HIV DNA in whole blood leucocytes by SYBR green I real-time PCR assay

The aim of this study was the development of a real-time PCR for HIV DNA quantification in whole blood leucocytes providing an alternative assay to those already described, almost based on the gag gene detection. The technique (pbs-rtPCR assay) is more rapid (the whole assay required less than 5h), easy to perform, omitting both PBMC purification step and data normalization to a housekeeping gene, when compared to previously published assays. Our method is able to detect all group M HIV-1 subtypes in the highly conserved primer-binding site (PBS) region and to avoid the interference by retroviral endogenous sequences in HIV DNA quantification. The sensitivity was 100% for 2 copies even in the presence of high amounts of genomic DNA (1 microg). To monitor the HIV DNA level in all possible clinical conditions, the assay has been validated and compared with a previously developed gag-PCR assay on 73 HIV-1 HAART-treated patients with a plasma HIV-1 RNA range from <50 to >500,000 copies/ml. The 50% of the samples with a viremia below the limit of detection (50 copies/ml) was found to contain HIV DNA between 2 and 10 copies/microg DNA. The pbs-rtPCR offers a significant improvement in the percentage of quantitatively detectable sample (99%) compared with the gag-PCR (42%) suggesting caution in the choice of HIV DNA assay.

Twin pregnancy as a risk factor for mother-to-child transmission of HIV-1: trends over 20 years

OBJECTIVE

We investigated whether twin pregnancies were at increased risk of mother-to-child HIV-1 transmission (MTCT), in comparison with singletons.

METHODS

Among HIV-1 infected women enrolled in the French Perinatal HIV Cohort (n = 9262), we studied the association between twin deliveries and MTCT rate according to three time periods (pre-1994, 1994-1996, 1997-2004) and the effect of birth order. The mother was considered to have transmitted if at least one of the twins was infected. Univariate and multivariate analyses of risk factors for MTCT were performed for deliveries in the periods up to 1996.

RESULTS

Overall, 2.1% (192/9262) of all the deliveries were twins. The rate of prematurity was greater in twins than in singletons (54% and 13%, respectively). Up to 1996 the rate of MTCT of HIV-1 was 28.3% (15/53) in twin pregnancies, versus 13.5% (414/3077) in singletons [odds ratio (OR), 2.5; 95% confidence interval (CI), 1.4-4.7; P = 0.002; adjusted OR, 2.3: 95% CI, 1.1-2.3; P = 0.03). In the period from 1997 to 2003, MTCT was low and did not differ between twins (1.0%) and singletons (1.8%; P = 1.0). Overall, the transmission rate for the first-born child was threefold that for the second-born child (14/164, 8.5% versus 4/164, 2.4%; P = 0.008).

CONCLUSION

Twin pregnancies were at increased risk of transmission, but in the era of HAART this risk was reduced for twins, as well as singletons. Management of multiple pregnancies should take into account the risks of premature rupture of the membranes and preterm delivery.

CD4+ Cell Count 6 Years after Commencement of Highly Active Antiretroviral Therapy in Persons with Sustained Virologic Suppression

BACKGROUND

Sustained suppression of the human immunodeficiency virus (HIV) type 1 RNA load with the use of highly active antiretroviral therapy (HAART) results in immunologic improvement, but it is not clear whether the CD4(+) cell count increases to normal levels or whether it reaches a less-than-normal plateau. We characterized the increase in the CD4(+) cell count in patients in clinical practice who maintained sustained viral suppression for up to 6 years.

METHODS

All patients were from the Johns Hopkins HIV Clinical Cohort, a longitudinal observational study of patients receiving primary HIV care in Baltimore, Maryland, who were observed for >1 year while receiving HAART and who had sustained suppression of the HIV RNA load at <400 copies/mL. We analyzed annual change in the CD4(+) cell count for up to 6 years after the start of HAART, stratified by baseline CD4(+) cell counts of < or =200, 201-350, >350 cells/microL, and we assessed the development of clinical events (death and new acquired immunodeficiency syndrome-defining illness) by Kaplan-Meier analysis.

RESULTS

A total of 655 patients were observed for a median of 46 months (range, 13-72 months). The median change from baseline to most recent CD4(+) cell count was +274 cells/microL, with 92% of patients having an increase in CD4(+) cell count. By 6 years, the median CD4(+) cell count was 493 cells/microL among patients with baseline CD4(+) cell counts < or =200 cells/microL, 508 cells/microL among those with baseline CD4(+) cell counts of 201-350 cells/microL, and 829 cells/microL among those with baseline CD4(+) cell counts >350 cells/microL. In addition to baseline CD4(+) cell count, injection drug use and older age were associated with a lesser CD4(+) cell count response, and duration of therapy was associated with a greater CD4(+) cell count response.

CONCLUSION

Only patients with baseline CD4(+) cell counts >350 cells/microL returned to nearly normal CD4(+) cell counts after 6 years of follow-up. Significant increases were observed in all CD4(+) cell count strata during the first year, but there was a lower plateau CD4(+) cell count at lower baseline CD4(+) cell strata. These data suggest that waiting to start HAART at lower CD4(+) cell counts will result in the CD4(+) cell count not returning to normal levels.

Cellular HIV-1 DNA quantitation in patients during simplification therapy with protease inhibitor-sparing regimens

Simplified regimens containing protease-inhibitors (PI)-sparing combinations were used in patients with virological suppression after prolonged highly active antiretroviral therapy. This study evaluated the total HIV-1 DNA quantitation as a predictor of long-term success for PI-sparing simplified therapy. Sixty-two patients were enrolled in a prospective non-randomized cohort. All patients have been receiving a triple-therapy regimen, two nucleoside reverse transcriptase inhibitors (NRTIs) plus one PI, for at least 9 months and were characterized by undetectable plasma HIV-1 RNA levels (<50 cp/ml) for at least 6 months. Patients were changed to a simplified PI-sparing regimen to overcome PI-associated adverse effects. HIV-DNA levels in peripheral blood mononuclear cells (PBMCs) were evaluated at baseline and at the end of follow-up. Patients with proviral DNA levels below the median value (226 copies/10(6) PBMCs) had a significant higher CD4 cell count at nadir (P = 0.003) and at enrolment (P = 0.001) with respect to patients with HIV-DNA levels above the median value. At month 18, 53 out of 62 (85%) patients on simplified regimen showed virological success, 4 (6.4%) patients experienced virological failure and 5 (8%) patients showed viral blip. At logistic regression analysis, HIV-DNA levels below 226 copies/10(6) PBMCs at baseline were associated independently to a reduced risk of virological failure or viral blip during simplified therapy (OR 0.002, 95% CI 0.001-0.46, P = 0.025). The substitution of PI with NRTI or non-NRTIs may represent an effective treatment option. Indeed, treatment failure or viral blip were experienced by 6% and 8% of the patients on simplified therapy, respectively. In addition, sustained suppression of the plasma viral load was significantly correlated with low levels of proviral DNA before treatment simplification.

HIV DNA and dementia in treatment-naïve HIV-1-infected individuals in Bangkok, Thailand

High HIV-1 DNA (HIV DNA) levels in peripheral blood mononuclear cells (PBMC) correlate with HIV-1-associated dementia (HAD) in patients on highly active antiretroviral therapy (HAART). If this relationship also exists among HAART-naïve patients, then HIV DNA may be implicated in the pathogenesis of HAD. In this study, we evaluated the relationship between HIV DNA and cognition in subjects naïve to HAART in a neuro AIDS cohort in Bangkok, Thailand. Subjects with and without HAD were recruited and matched for age, gender, education, and CD4 cell count. PBMC and cellular subsets were analyzed for HIV DNA using real-time PCR. The median log(10) HIV DNA copies per 10(6) PBMC for subjects with HAD (n=15) was 4.27, which was higher than that found in subjects without dementia (ND; n=15), 2.28, p<0.001. This finding was unchanged in a multivariate model adjusting for plasma HIV-1 RNA levels. From a small subset of individuals, in which adequate number of cells were available, more HIV DNA was in monocytes/macrophages from those with HAD compared to those with ND. These results are consistent with a previous report among HAART-experienced subjects, thus further implicating HIV DNA in the pathogenesis of HAD.

Changes in T-cell subpopulations during four years of suppression of HIV-1 replication in patients with advanced disease

We compared the number/percentages of naive and memory CD4+ T-cells, CD38+ CD8+ T-cells, and CD28+ CD4+ and CD28+ CD8+ T-cells in patients with advanced HIV disease (baseline CD4+ count < 100) with those with less advanced (baseline CD4+ cell count > 100) HIV disease during 4 years of suppressive highly active antiretroviral therapy. This prospective, longitudinal study included 30 treatment-naive patients and 32 controls. Advanced HIV-infected patients (n = 13) gained more CD4+ T-cells than less advanced patients (n = 11) at 1 month (median: 60 vs. 36 microL(-1)), 3 months (86 vs. 14), 6 months (111 vs. 23), 12 months (174 vs. 47), 24 months (162 vs. 72) and 48 months (257 vs. 123) (P = 0.15, P < 0.001, P = 0.026, P = 0.021, P = 0.1 and P = 0.06, respectively). Advanced patients gained more naive CD4+ T-cells at 48 months compared to less advanced patients (27.3 vs. 11.4%, P = 0.05). The relative gain in memory CD4+ T-cells was greater in advanced vs. less advanced patients at 1 month (median: 6.4 vs. 1.4%), 3 months (4.3 vs. 2.0), 6 months (6.7 vs. 1.6), 12 months (6.9 vs. 2.4), 24 months (7.5 vs. 3.1) and 48 months (11.3 vs. 6.8) (P = 0.002, P = 0.013, P < 0.001, P = 0.004, P = 0.001 and P = 0.015, respectively). At 48 months, CD38+ CD8+ T-cells and naive CD4+ T-cells reached normal values (9.2%, P = 0.869 vs. controls and 47.5%, P = 0.699, respectively) in less advanced patients, as did CD38+ CD8+ T-cells in advanced patients (4.7%, P = 0.309 vs. controls). The kinetics of naive and memory CD4+ T-cell reconstitution is different in less advanced compared to advanced HIV patients.

Real-time PCR quantification of genital shedding of herpes simplex virus (HSV) and human immunodeficiency virus (HIV) in women coinfected with HSV and HIV

The accuracy and usefulness of laboratory-developed real-time PCR procedures using a Light Cycler instrument (Roche Diagnostics) for detecting and quantifying human immunodeficiency virus type 1 (HIV-1) RNA and DNA as well as herpes simplex virus type 1 (HSV-1)/HSV-2 DNA in cervicovaginal secretions from women coinfected with HIV and HSV were evaluated. For HIV-1, the use of the NEC152 and NEC131 primer set and the NEC-LTR probe in the long terminal repeat gene allowed us to detect accurately the majority of HIV-1 subtypes of group M circulating in sub-Saharan Africa, including subtypes A, B, C, D, and G as well as circulating recombinant forms 02 and 11. The detection threshold of real-time PCR for HIV in cervicovaginal lavage samples was 5 copies per assay for both RNA and DNA; the intra- and interassay coefficients of variation of C(T) values were 1.30% and 0.69% (HIV-1 RNA) and 1.84% and 0.67% (HIV-1 DNA), respectively. Real-time PCR for HSV using primers and probe targeting the HSV DNA polymerase gene allowed both detection and quantification of HSV DNA and also differentiation between HSV-1 and HSV-2 genotypes. The detection threshold of real-time PCR for HSV was 5 copies per assay; the intra- and interassay coefficients of variation of C(T) values were 0.96% and 1.49%, respectively. Both manual and automated silica-based procedures were appropriate for combined extraction of HIV and HSV genomes from female genital secretions. Taken together, these findings indicate that real-time PCR may be used as a unique nucleic acid amplification procedure to detect and quantify HIV and HSV genomes in cervicovaginal secretions and thus to assess at reduced costs the genital shedding of both viruses in women included in intervention studies.

Effect of co-trimoxazole prophylaxis, antiretroviral therapy, and insecticide-treated bednets on the frequency of malaria in HIV-1-infected adults in Uganda: a prospective cohort study

BACKGROUND

HIV-1 and malaria are common infections in Africa, and cause substantial morbidity and mortality. HIV infection has been associated with an increased incidence of malaria, and more severe disease. Our aim was to assess the effect of antiretroviral treatment (ART) on the frequency of clinical malaria in people with HIV, and to measure the additive effects of co-trimoxazole (trimethoprim and sulfamethoxazole) prophylaxis, ART, and insecticide-treated bednets.

METHODS

In 2001, we enrolled 466 HIV-infected individuals aged 18 years or older in Uganda in a prospective cohort study that provided co-trimoxazole prophylaxis to 399 participants after 5 months of no intervention. In 2003, we enrolled 138 survivors from the initial study, and 897 new participants from the same community, to take antiretroviral therapy (ART) in addition to co-trimoxazole prophylaxis. The ART was in most cases a combination of stavudine, lamivudine, and nevirapine or efavirenz. In 2004, we also gave participants insecticide-treated bednets. Households were visited weekly by study staff to record fever, illness, or death in the preceding 7 days. In cases of reported fever in the previous 2 days, we took blood to test for malaria parasites. We compared the frequency of clinical malaria, adjusting for CD4-cell count, age, sex, and season.

FINDINGS

1035 individuals were given co-trimoxazole and ART (median age 38 years, 74% female, and median CD4-cell count 124 cells/microL); 985 of these, plus four new participants, received co-trimoxazole, ART, and bednets. There were 166 cases of clinical malaria in the study. Compared with a baseline malaria incidence of 50.8 episodes per 100 person-years, co-trimoxazole prophylaxis was associated with 9.0 episodes per 100 person-years (adjusted incidence rate ratio [IRR] 0.24, 95% CI 0.15-0.38); ART and co-trimoxazole with 3.5 episodes per 100 person-years (0.08, 0.04-0.17); and co-trimoxazole, ART, and bednets with 2.1 episodes per 100 person-years (0.05, 0.03-0.08). Malaria incidence was significantly lower during ART and co-trimoxazole than during co-trimoxazole alone (IRR 0.36 [95% CI 0.18-0.74], p=0.0056).

INTERPRETATION

A combination of co-trimoxazole, antiretroviral therapy, and insecticide-treated bednets substantially reduced the frequency of malaria in adults with HIV.

The HIV-1 Tat protein enhances megakaryocytic commitment of K562 cells by facilitating CREB transcription factor coactivation by CBP

The human immunodeficiency virus type 1 (HIV-1) Tat protein regulates transcription factor functions and alters cellular gene expression. Because hematopoietic progenitor cell (HPC) differentiation requires activation of lineage-specific transcription factors, Tat may affect hematopoiesis in HIV-1-infected micro-environments. We have monitored the molecular effects of Tat on megakaryocytic differentiation in the HPC line, K562. Flow cytometry analysis of CD61 indicated that phorbol myristate acetate (PMA) (16 nM) stimulated megakaryocytic commitment of K562 cells was increased (3- to 4-fold) following exposure to Tat (1-100 ng/ml). Activation of the megakaryocytic transcription factor cAMP regulatory element binding protein (CREB) and its coactivation by the CREB binding protein (CBP) was subsequently monitored. CREB phosphorylation and DNA binding were measured by Western immunodetection and electrophoretic mobility shift assays (EMSA), respectively. Within 2 hrs after stimulation, Tat increased both CREB phosphorylation and DNA binding by 7- to 10-fold. Transient cotransfection with CREB reporter and CBP expression plasmids demonstrated that Tat treatment increases (3- to 4-fold) both PMA-stimulated and CBP-mediated transcription via the cAMP regulatory element. Histone acetyl transferase (HAT) activity was increased (8- to 10-fold) in Tat-stimulated cells, which suggested increased chromosomal accessibility of transcription factors. Two-hybrid cotransfection assays using reporter plasmid containing the GAL4 DNA-binding domain and expression plasmid coding for the GAL4-CBP fusion protein, showed that Tat increases (2-fold) CBP-mediated coactivation of CREB. Both reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis showed that Tat treatment increases CBP gene expression (7- to 9-fold) and protein levels (5- to 7-fold) within 6-12 hrs after stimulation. Our findings indicated that Tat treatment increases both CREB function and CREB coactivation by CBP, which may facilitate megakaryocytic commitment of K562 cells. Induction of this molecular signaling by HIV-1 Tat protein may have relevance in understanding the HIV-induced hematologic manifestations and possibly in regulation of viral infectivity parameters in progenitor cell reservoirs.

Association between cellular human immunodeficiency virus DNA level and immunological parameters in patients with undetectable plasma viremia level during highly active antiretroviral therapy

The association between human immunodeficiency virus (HIV) DNA load and immunologic parameters was investigated in 163 HIV-infected patients with undetectable plasma viremia during highly active antiretroviral therapy (HAART). Patients with HIV DNA below the 25th percentile (133 copies/10(6) peripheral blood mononuclear cells) had higher pre-HAART (P = 0.001) and current (P = 0.005) CD4 counts and a prolonged duration of treatment (P = 0.001). At adjusted analysis, prolonged duration of treatment was independently associated with lower (P = 0.006) and undetectable (P < 0.001) HIV DNA values.

Virological control during the first 6-18 months after initiating highly active antiretroviral therapy as a predictor for outcome in HIV-infected patients: a Danish, population-based, 6-year follow-up study

BACKGROUND

Our objective was to examine whether virological control during the first 6-18 months after HAART initiation is a predictor for viral suppression, CD4+ cell count increase, and mortality in human immunodeficiency virus (HIV)-infected patients 18-90 months after initiation of highly active antiretroviral therapy (HAART).

METHODS

We conducted a population-based observational cohort study in Denmark. Patients were divided into 3 groups, according to the proportion of time each patient had a detectable HIV RNA load (i.e., > or = 400 copies/mL) during the 6-18 months after HAART initiation: 0% of the time interval (group 1), 1%-99% of the time interval (group 2), and 100% of the time interval (group 3). The proportion of patients with undetectable HIV RNA, CD4+ cell count changes, and mortality were examined by logistic, linear, and Cox regression analyses, respectively. We constructed cumulative mortality curves.

RESULTS

We observed 2046 patients, for a total of 8898 person-years of follow-up that started at 18 months after HAART initiation. Mean CD4+ cell count increase rates during 72 months of follow-up were as follows: group 1, 3.3 x 10(6) cells/L per month (95% confidence interval [CI], 2.9-3.7 x 10(6) cells/L); group 2, 2.9 x 10(6) (95% CI, 2.5-3.3 x 10(6) cells/L); and group 3, 2.6 x 10(6) (95% CI, 2.0-3.3 x 10(6) cells/L). Survival at 72 months were as follows: group 1, 92.7% (95% CI, 90.5%-94.4%); group 2, 85.6% (95% CI, 82.1%-88.5%); and group 3, 76.1% (95% CI, 70.6%-80.7%). At 72 months, 96% of group 1, 83% of group 2, and 57% of group 3 had an HIV RNA load of < 400 copies/mL (P < .01). Treatment interruption before baseline was a predictor of mortality in group 2 (adjusted rate ratio, 2.94; 95% CI, 1.75-4.92]).

CONCLUSIONS

Viral suppression during the first 6-18 months after HAART initiation predicts viral suppression, CD4+ cell count progression, and survival at 72 months.

Residual viraemia in subjects with chronic HIV infection and viral load < 50 copies/ml: the impact of highly active antiretroviral therapy

OBJECTIVE

To determine factors associated with < 2.5 copies/ml plasma HIV RNA in subjects treated with highly active antiretroviral therapy (HAART) and with viraemia < 50 copies/ml.

DESIGN

Cross-sectional analysis of 84 HIV-positive patients taking HAART with plasma HIV RNA < 50 copies/ml for at least 6 months and no history of virological failure.

METHODS

Current HAART therapy was based on a non-nucleoside reverse transcriptase inhibitor (NNRTI) in 66%, a protease inhibitor in 26% and nucleoside reverse transcriptase inhibitors in 7%. Viraemia levels were measured using a modified ultrasensitive Roche Amplicor HIV-1 Monitor test able to quantify plasma HIV RNA to a lower limit of 2.5 copies /ml; proviral DNA was measured with a real-time polymerase chain reaction assay. Analysis of variance and multiple logistic regression analysis were utilized to test for associations between residual replication and other variables.

RESULTS

Residual HIV viraemia > 2.5 copies/ml was found in 50% of subjects; 94% of subjects had detectable proviral DNA (>or= 20 copies/10(6) peripheral blood mononuclear cells) and 21% had archived mutations. Usage of a NNRTI-based HAART was the only independent predictor of viral suppression below the cut-off value of the modified ultrasensitive assay.

CONCLUSIONS

In our population, NNRTI-based HAART seems to have a stronger impact on residual replication than protease inhibitor-based HAART. This finding may be considered in therapeutic decisions such as the choice of initial HAART regimen and the interruption or simplification of treatment.

Structured Treatment Interruptions in Primary HIV-1 Infection

BACKGROUND

Whether structured treatment interruptions (STIs) can induce anti-HIV immune response and control HIV replication following discontinuation of highly active antiretroviral therapy (HAART) in patients with primary HIV infection is controversial.

METHODS

In this multicenter, prospective trial, patients with early symptomatic primary HIV infection were given HAART continuously for 34 weeks. Afterward, patients with plasma viral load (PVL) <50 copies/mL entered the STI phase, which consisted of 3 consecutive periods of 2, 4, and 8 weeks off HAART, each separated by 12 weeks on HAART. HAART was permanently stopped at week 84 and patients were followed up for 24 weeks. The primary endpoint for definition of virologic success was a PVL <50 copies/mL during the 6 months following HAART discontinuation.

RESULTS

Of the 29 patients enrolled, 26 completed the trial. Six months after HAART discontinuation, only 1 patient (3.8%, 95% CI: 0.1% to 19.6%) had PVL <50 copies/mL, whereas 6 of 26 (23.1%, 95% CI: 9.0% to 43.7%) had PVL <1000 copies/mL. Female gender was the only parameter significantly associated with a PVL <1000 copies/mL. No other parameter, either at baseline or before HAART discontinuation, predicted virologic success at week 108. A major protease inhibitor resistance mutation (L90M) developed in 3 patients.

CONCLUSIONS

This trial failed to confirm that a significant proportion of patients with primary HIV infection can maintain suppression of viremia after a sequence of HAART/STIs followed by HAART discontinuation.

HIV Controllers: A Homogeneous Group of HIV-1--Infected Patients with Spontaneous Control of Viral Replication

We identified a total 15 patients who have maintained undetectable plasma HIV RNA loads without antiretroviral treatment for >10 years from cohorts of 1300 and 1551 patients infected with human immunodeficiency virus (HIV). These 15 patients, whom we have referred to as "HIV controllers," are characterized by a low HIV DNA load in peripheral blood mononuclear cells and by a strong HIV-specific immune response.

Decrease of Lewis frequency in HIV-infected patients: possible competition of fucosylated antigens with HIV for binding to DC-SIGN

We explored the impact of human ABO glycosyltransferase and Lewis and secretor fucosyltransferase polymorphisms in HIV infection. We found that, compared with healthy blood donors, HIV-infected patients display a significant decrease in Le(a-b+) phenotype frequencies. We showed that HIV binding on DC-SIGN-transduced Jurkat cells was inhibited by fucosyl bovine serum albumin. Our results suggest a slight protective effect of Lewis b antigen on HIV infection, possibly by the competition of Lewis antigens with HIV for binding to DC-SIGN.

Long-Term CD4+ T-Cell Response to Highly Active Antiretroviral Therapy According to Baseline CD4+ T-Cell Count

Current treatment guidelines for HIV infection recommend a relatively late initiation of highly active antiretroviral therapy (HAART). Nevertheless, there is still a concern that immune recovery may not be as complete once CD4+ T cells have decreased below a certain threshold. This study addressed the long-term response of CD4+ T-cell counts in patients on HAART and analyzed the influence of baseline CD4+ T-cell counts, baseline viral load, and age. An observational analysis of evolution of CD4+ T cells in 861 antiretroviral therapy-naive chronic HIV-1-infected patients who started treatment consisting of at least 3 drugs in or after 1996 was performed. Patients were classified in 4 groups according to baseline CD4+ T cells: <200 cells/mm3, 200-349 cells/mm3, 350-499 cells/mm3, and >or=500 cells/mm3. The main outcome measures were proportion of patients with CD4+ T cells <200/mm3 and >500/mm3 at last determination and rate of CD4+ T-cell recovery. Patients were followed-up for a median of 173 weeks (interquartile range [IQR], 100-234). There were no differences in follow-up between the 4 groups. CD4+ T cells increased in the whole cohort from a median of 214 cells/mm3 (IQR, 90-355) to 499 cells/mm3 (IQR, 312-733) (P<0.001). Compared with the group with a baseline CD4+ T-cell count of >or=500/mm3, the relative risk of having a last determination of CD4+ T-cell counts >200 cells/mm3 was 0.79 (95% CI, 0.75-0.83), 0.92 (95% CI, 0.89-0.96) and 1 for baseline CD4+ T cells <200 cells/mm3, 200-349 cells/mm3, and 350-499 cells/mm3, respectively. The relative risk of having a last determination of CD4+ T-cell counts >500 cells/mm3 was 0.32 (95% CI, 0.27-0.39, P<0.001), 0.69 (95% CI, 0.60-0.79, P<0.001), and 0.94 (95% CI, 0.83-1.06, P=0.38) for baseline CD4+ T-cell counts <200 cells/mm3, 200-349 cells/mm3, and 350-0499 cells/mm3, respectively, compared with a baseline CD4+ T-cell count of >or=500 cells/mm3. The increase in CD4+ T cells from baseline was statistically significant and was maintained for up to 4 years of follow-up. This increase seemed to slow down after approximately 3 years and reached a plateau after 4-5 years of follow-up even in patients who achieved and maintained viral suppression in plasma. Long-term immune recovery is possible regardless of baseline CD4+ T-cell count. However, patients who start therapy with a CD4+ T-cell count <200 cells/mm3 have poorer immunologic outcome as measured by the proportion of patients with CD4+ T cells <200/mm3 or >500/mm3 at last determination. It seems that the immune recovery slows down after approximately 3 years of HAART and reaches a plateau after 4-5 years of HAART.