Delayed central nervous system virus suppression during highly active antiretroviral therapy is associated with HIV encephalopathy,but not with viral drug resistance or poor central nervous system drug penetration

OBJECTIVE: HIV-1 encephalopathy (HIVE) is associated with high levels of viral RNA in the central nervous system (CNS). Highly active antiretroviral therapy (HAART) effectively reduces HIV replication in both plasma and cerebrospinal fluid (CSF). Some individuals, however, exhibit delayed CSF HIV RNA suppression in the presence of rapid plasma responses. We investigated the reasons for this discrepancy. DESIGN: CSF and plasma were collected prospectively in paired samples before and once or several times during HAART in 40 HIV-positive subjects. Ten had HIVE and 30 patients were neurologically asymptomatic or had non-HIVE neurological manifestations. METHODS: The slopes of viral RNA decay during HAART were compared between the compartments. The presence of HIVE was defined by clinical standards and its severity categorized according to the Memorial Sloan Kettering score. CSF and plasma levels of antiretroviral drugs were measured. Viral drug resistance during HAART in CSF and plasma was analysed both genotypically and phenotypically. RESULTS: Slow CSF viral decay and a high degree of compartmental discordance (slopeCSF/slopeplasma) were both significantly correlated with HIVE (P < 0.00002). There was no correlation of a rapid CSF response with Centers for Disease Control and Prevention stage, CD4 cell count, or with the number of antiretroviral compounds and their known CSF penetration. Slow CSF viral decay was associated with neither low levels of antiretroviral drugs in the CSF or plasma, nor with viral drug resistance. CONCLUSIONS: None of the treatment-associated variables, but only the presence of HIVE, was associated with delayed virus elimination during HAART in the CSF. This suggests a distinct pattern of viral replication in the CNS in HIVE.     

Viral dynamics after starting first-line HAART in HIV-1-infected children

BACKGROUND: After starting HAART, the plasma HIV-1 RNA (pVL) declines rapidly to undetectable levels in most treated adults and children. The viral dynamics in children are assumed to differ from those in adults. Therefore viral decay and time to reach a pVL of < 400 copies/ml during the first weeks after starting HAART were studied in a cohort of HIV-1-infected children. METHODS: Viral decay expressed as half-life and time to reach a pVL of < 400 copies/ml in 39 HIV-1-infected children starting HAART were calculated and correlated with age, pretreatment with antiretroviral mono- or duo-therapy, and baseline pVL. RESULTS: Baseline pVL correlated with age (r, -0.41; P = 0.01). Median half-life of the virus was 2.1 days (interquartile range, 1.8-3.0 days). No correlation was found between the half-life of the virus and the baseline pVL at the start of treatment, antiretroviral pretreatment or age. Eight children did not reach a pVL of < 400 copies/ml with the first allocated medication regimen. These children were significantly younger than those in whom HIV was successfully suppressed (P = 0.009). The remaining 31 children reached a pVL of < 400 copies/ml in a median of 8.1 weeks after the start of therapy; time to reach a pVL of < 400 copies/ml was only correlated with baseline pVL. CONCLUSIONS: These results suggest that pVL at baseline correlated with age. HAART was able to suppress pVL below the lower limit of detection in children with a viral decay rate of 2.1 days, similar to adults and irrespective of baseline pVL.     

Relationship of plasma HIV-1 RNA dynamics to baseline factors and virological responses to highly active antiretroviral therapy in adolescents (aged 12-22 years) infected through high-risk behavior

We characterized the viral dynamics of human immunodeficiency virus (HIV) type 1-infected adolescents receiving highly active antiretroviral therapy regimens (lamivudine [3TC]/zidovudine [ZDV]/efavirenz [EFV], 3TC/ZDV/nelfinavir [NFV], or other regimens) and studied the relationship of viral dynamics with baseline factors and virological responses. Viral decay rates for 115 evaluable subjects were estimated from a viral dynamic model. Viral dynamics in HIV-1-infected individuals aged 12-22 years were similar to those of HIV-1-infected adults and infants. Individuals who received 3TC/ZDV/EFV had a more rapid phase 1 viral decay rate than those who received 3TC/ZDV/NFV or other regimens. Phase 1 viral decay rates were positively correlated with baseline RNA levels and week 1 virus load reductions. Our findings indicate that the 3TC/ZDV/EFV regimen may be more potent than 3TC/ZDV/NFV or other regimens and that early viral dynamics or week 1 virus load reduction measurements may be useful in evaluating the potency of antiretroviral regimens.     

Elevated resting energy expenditure among HIV-seropositive persons receiving highly active antiretroviral therapy.

OBJECTIVES: To ascertain the relationships between resting energy expenditure (REE), HIV RNA in plasma, and highly active antiretroviral therapy (HAART). DESIGN: Cross-sectional analysis using data of a large cohort study of nutrition in relation to HIV disease. METHODS: HIV RNA in plasma, REE, fat-free mass (FFM), and medication regimens were assessed at 530 visits among 372 participants in a cohort study of HIV-seropositive men and women. RESULTS: HIV RNA in plasma was directly correlated with REE. After adjustment for FFM, age, CD4 cell count and HAART use, there was an increase in REE of 90 kJ/day per log10 copies/ml increase in HIV RNA [95% confidence interval (CI) 16-164; P = 0.02). HAART use had an independent effect on REE. In patients reporting HAART use, adjusted REE was 339 kJ/day higher than in those not reporting HAART use (95% CI 177-501; P = 0.0001). CONCLUSIONS: Viral load and HAART appear to exert independent effects on REE. Although HAART may decrease metabolic rate by lowering viral burden, it appears to increase metabolic demands through some mechanism(s) independent of its effect on viral burden. This may result in elevated REE despite control of viral replication.     

Long-term decay of the HIV-1 reservoir in HIV-1-infected children treated with highly active antiretroviral therapy

To investigate the decay of the human immunodeficiency virus type 1 (HIV-1) reservoir in children receiving highly active antiretroviral therapy (HAART), we measured HIV-1 DNA in peripheral blood mononuclear cells from 14 children who achieved and maintained suppression of plasma viremia up to 48 months after the initiation of HAART. Levels of intracellular unspliced and multiply spliced HIV-1 RNA were used as markers of residual viral replication. During the first month of HAART, there were significant decays in levels of both plasma HIV-1 RNA and multiply spliced HIV-1 RNA, yet unspliced HIV-1 RNA persisted in most of the children. Greater HIV-1 DNA decay during the first month of HAART correlated with a higher concomitant increase in CD4(+) cell counts (P=.028) and a smaller subsequent HIV-1 DNA decay (P=.0012). Furthermore, HIV-1 DNA decayed faster from 1 to 9 months of HAART (median half-life, 5 months) than during the subsequent follow-up period (median half-life, 30 months). Moreover, after 9 months of HAART, HIV-1 DNA tended to decay more slowly in children with detectable levels of unspliced HIV-1 RNA. These findings suggest that clearance of the viral reservoir in HAART-treated children may be influenced by immune repopulation and residual viral replication and may help in refining long-term treatment strategies.     

Thymic size and lymphocyte restoration in patients with human immunodeficiency virus infection after 48 weeks of zidovudine, lamivudine, and ritonavir therapy

Human immunodeficiency virus (HIV) infection is associated with progressive loss of circulating CD4+ lymphocytes. Treatment with highly active antiretroviral therapy (HAART) has led to increases in CD4+ T lymphocytes of naive (CD45RA+62L+) and memory (CD45R0+RA-) phenotypes. Thymic computerized tomography scans were obtained on 30 individuals with HIV disease to investigate the role of the thymus in cellular restoration after 48 weeks of HAART. Individuals with abundant thymic tissue had higher naive CD4+ T lymphocyte counts at weeks 2-24 after therapy than individuals with minimal thymic tissue. Individuals with abundant thymic tissue had significantly larger increases in naive CD4+ cells during the first 4 weeks of therapy. These individuals were also more likely to experience viral rebound despite comparable initial declines in plasma HIV-1 RNA. These findings suggest that there is a complex relationship among the thymus, viral replication, and lymphocyte restoration after application of HAART in HIV disease.     

Suppression of HIV replication in the resting CD4+ T cell reservoir by autologous CD8+ T cells: implications for the development of therapeutic strategies

CD8+ T cell-mediated antiviral activity against HIV has been described consistently in infected individuals; however, the role of this activity in controlling replication of HIV in the latently infected, resting CD4+ T cell reservoir is unclear. By using an ex vivo system, we show that replication of HIV in this viral reservoir is effectively suppressed in coculture by autologous CD8+ T cells in long-term nonprogressors (LTNPs) and in patients whose viremia was controlled by highly active antiretroviral therapy (HAART), but not in therapy-naive patients who had substantial levels of plasma viremia. This antiviral activity was largely independent of cytotoxic CD8+ T lymphocytes (CTL). When the role of soluble CD8+ T cell-derived factors was examined, we found that CC-chemokines played a major role in inhibition of viral replication in the latent viral reservoir in some LTNPs and patients receiving HAART, but not in chronically infected patients who were not receiving antiretroviral therapy. Potent antiviral activity, independent of CC-chemokines, was found mainly in patients in whom HAART was initiated shortly after the acute phase of HIV infection. These results indicate that CD8(+) T cells provide potent suppressive activity against HIV replication in the latent viral reservoir via direct cellular contact in patients who are naturally LTNPs or in those who are treated with HAART. Furthermore, the profound antiviral activity exerted by non-CC-chemokine soluble factors in infected patients who began HAART early in HIV infection suggests that preservation of this HIV-suppressive mechanism by early initiation of therapy may play an important role in the containment of viral replication in infected patients following interruption of therapy.     

Dynamics of plasma hepatitis B virus levels after highly active antiretroviral therapy in patients with HIV infection

BACKGROUND/AIMS: The optimal strategy to prescribe highly active antiretroviral therapy (HAART) in patients infected with both hepatitis B virus (HBV) and human immunodeficiency virus (HIV) remains unsettled. This study aimed to compare the HBV dynamics between HBeAg-positive and HBeAg-negative coinfected patients treated with lamivudine-containing HAART. METHODS: We retrospectively analyzed the serial changes of plasma HBV DNA levels in 24 HBsAg-positive HIV-infected patients who entered the HAART program. A polymerase chain reaction-based assay, capable of quantifying as few as 400 HBV copies/ml, was used. The median follow-up time was 18 months. RESULTS: HAART containing lamivudine 300 mg/day effectively suppressed plasma HBV-DNA to 10(-3)-10(-5)-fold of the baseline levels, but a multi-phasic decay of HBV DNA was observed. The later phases became flat, as a persistent residual HBV viremia, in eight of the studied 10 HBeAg-positive patients; in contrast, residual HBV viremia was not observed in the 10 HBeAg-negative patients studied (8/10 vs. 0/10, P=0.0007, Fisher's exact test). HAART without lamivudine did not suppress plasma HBV DNA levels in the remaining four patients. CONCLUSIONS: HAART containing lamivudine 300 mg/day effectively suppress HBV replication in HBeAg-negative HIV/HBV-coinfected patients. Nevertheless, residual HBV replication persisted in most HBeAg-positive coinfected patients.     

Evaluation of lymph node virus burden in human immunodeficiency virus-infected patients receiving efavirenz-based protease inhibitor--sparing highly active antiretroviral therapy

Although efavirenz-containing regimens effectively suppress plasma levels of human immunodeficiency virus (HIV) RNA, it is now clear that undetectable plasma viremia may not reflect a lack of viral replication. Because lymphoid tissue is an active site of HIV replication, the lymph node virus burden was analyzed in persons who received highly active antiretroviral therapy (HAART) containing either efavirenz or a protease inhibitor (PI). Testing with in situ hybridization revealed no detectable follicular dendritic cell-associated HIV RNA in either group, and only 2 of 8 persons in the efavirenz group and 1 of 4 in the PI group had detectable RNA in lymph node mononuclear cells (LNMC) when tested by use of nucleic acid sequencebased amplification. Low levels of replication-competent HIV were identified in both groups by use of quantitative coculture assays. There was no evidence of development of resistance to either regimen in virus isolated from LNMC. These data support the use of efavirenz as an alternative to a PI in initial HAART regimens.     

Multiple measures of HIV burden in blood and tissue are correlated with each other but not with clinical parameters in aviremic subjects

OBJECTIVES: To determine the levels of residual HIV DNA and RNA in blood and gut reservoirs in aviremic patients, assess correlations among compartmental measurements of HIV burden, and evaluate association with clinical parameters. DESIGN: Cross-sectional analysis of baseline data only, on 40 patients enrolled in phase II study evaluating efficacy of autologous gene-modified CD4+ and CD8+ T cells. All patients were on stable antiretroviral regimen with undetectable plasma HIV RNA (< 50 copies/ml). METHODS: Measurements repeatedly performed over 8-12 weeks pre-intervention: blood HIV DNA, analysis of rectal mucosa-associated lymphoid tissue for both HIV RNA and HIV DNA, and quantitative co-culture of HIV from CD8-depleted peripheral blood mononuclear cells (PBMC). RESULTS: Quantifiable levels of HIV detected in compartments despite undetectable levels of plasma HIV RNA: HIV co-culture of PBMC (88%), blood HIV DNA (95%), rectal biopsy HIV DNA (95%), rectal biopsy HIV RNA (65%). A significant correlation existed among various measures of HIV burden (HIV co-culture, blood HIV DNA, rectal biopsy HIV RNA and DNA) but not between assays and clinical parameters [duration of highly active antiretroviral therapy (HAART), type of HAART]. All assays had comparable or less variability than in plasma viral load assays; HIV co-culture had the highest coefficient of variability whereas the blood HIV DNA assay had the lowest and was considered the most reliable assay. CONCLUSIONS: The data support safety, feasibility and high compliance of quantifying reservoirs of residual HIV in treated subjects with undetectable plasma HIV RNA. Lack of correlation between levels of HIV in residual reservoirs and duration of HAART suggests treatment-mediated viral suppression alone does not lead to reproducible decay in HIV reservoirs.     

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.     

Kinetics of the T-cell receptor CD4 and CD8 V beta repertoire in HIV-1 vertically infected infants early treated with HAART.

OBJECTIVES: To determine the kinetics and the relationship between the T-cell receptor V beta (TCRBV) complementary determining region 3 length, the CD4 T-cell count and HIV viral load changes in HIV-1 infected infants treated early with highly active antiretroviral therapy (HAART) during 1 year of follow-up. DESIGN: Two HIV-1 vertically infected infants, two HIV-1 vertically exposed uninfected and two healthy controls were analysed by spectratyping. Evaluation of viral load, CD4 naive and memory cell counts and a proliferation test were also carried out. METHODS: Twenty-six families and subfamilies of the TCR on CD4 and CD8 T cells were analyzed by spectratyping. Flow cytometric analysis on peripheral blood mononuclear cells for CD4CD45Ra, CD4CD45Ro, CD8CD38, proliferation tests and plasma viral load measurements were performed at baseline, 1, 6 and after 12 months of therapy. RESULTS: HAART induced a marked reduction of viral load in both HIV-1 infected infants and an increase to normal CD4 T-cell count in the symptomatic infant. At baseline the TCRBV family distribution in the majority of CD8 and a few of the CD4 T cells was highly perturbed, with several TCRBV families showing a monoclonal/oligoclonal distribution. During HAART a normalization of the TCR repertoire in both CD8 and CD4 subsets occurred. TCR repertoire normalization was associated with a good virological and immunological response. CONCLUSION: These results suggest that complete and early virus replication control as a result of early HAART leads to a marked reduction of T-cell oligoclonality and is an essential prerequisite to the development of a polyclonal immune response in HIV-1 infected infants.     

Intensification and stimulation therapy for human immunodeficiency virus type 1 reservoirs in infected persons receiving virally suppressive highly active antiretroviral therapy

Highly active antiretroviral therapy (HAART) has led to significant changes in mortality and morbidity in the human immunodeficiency virus type 1 (HIV-1) epidemic. Nevertheless, because of molecular mechanisms of viral persistence, HAART does not eradicate HIV-1. Didanosine and hydroxyurea were added to the antiretroviral regimens of 3 HIV-1-infected men who were receiving stable HAART and who had HIV-1 RNA levels <50 copies/mL at the initiation of the study protocol, as a novel intensification to attack cryptic viral replication; low-dose OKT3 was then administered, followed by a course of interleukin-2, to stimulate latent provirus. Replication-competent virus was undetectable after treatment, and plasma viral RNA was either undetectable or <5 copies/mL. In trial periods during which no antiretroviral therapy was administered, the patients developed plasma viral rebound. This translational approach combines novel intensification and stimulation therapy to deplete residual HIV-1 reservoirs. Additional experimental approaches must be developed if HIV-1 eradication is to become possible in patients receiving virally suppressive HAART.     

Effects of interleukin-2 plus highly active antiretroviral therapy on HIV-1 replication and proviral DNA (COSMIC trial)

BACKGROUND: The effect of interleukin-2 (IL-2) in combination with antiretroviral therapy on HIV-1 replication and reservoirs was investigated. METHODS: In a prospective, open-label trial, 56 asymptomatic HIV-1-infected subjects (CD4 T cell count > 350 x 10(6) cells/l) were randomized to highly active antiretroviral therapy (HAART: stavudine, lamivudine, nelfinavir, saquinavir) with or without IL-2 (9 megaunits daily for 5 days in 6-weekly intervals for a total of eight cycles). Productive and latent infection were analysed in peripheral blood, and residual virus replication in the lymphoid tissue and in the cerebrospinal fluid. The influence of IL-2 on viral rebound after treatment discontinuation was studied. RESULTS: Virus replication was detected in 21 of 31 on-treatment lymph nodes despite undetectable plasma viraemia. Viral RNA was found in resting as well as in proliferating cells. RNA-negative patients tended towards more rapid proviral DNA elimination. Supplementary IL-2 led to a greater increase in CD4 T cell counts than HAART alone (P < 0.001), resulting in normalization in approximately 90% of IL-2-treated patients compared with approximately 50% HAART-only subjects. IL-2 had no beneficial effect on virus replication and on proviral DNA in peripheral blood. CONCLUSIONS: Viral persistence during HAART is partly a result of continued low-level replication, calling for more active regimens. IL-2 accelerates the normalization of CD4 T cell counts but does not impact on virus production or latency.     

Decay of HIV type 1 DNA and development of drug-resistant mutants in patients with primary HIV type 1 infection receiving highly active antiretroviral therapy.

The present study was aimed at describing the effect of highly active antiretroviral therapy (HAART) in 10 patients with primary HIV infection (PHI). Clearance rates of HIV RNA and HIV DNA in peripheral blood as well as the preexistence and the emergence of drug-resistant strains of HIV were determined over 52 weeks of treatment. The data indicate that HAART is able to induce a suppression of plasma viral load together with a significant decrease, but not a suppression, of peripheral blood mononuclear cell-associated proviral DNA in PHI subjects. Analysis of drug-resistant strains revealed that three PHI patients, showing a complete virologic response, developed mutations in the pol gene, thus suggesting that a persistent residual virus replication exists despite a sustained suppression of plasma viremia.     

Increased human immunodeficiency virus loads in active methamphetamine users are explained by reduced effectiveness of antiretroviral therapy

Abuse of methamphetamine (METH) is a frequent comorbidity among individuals infected with human immunodeficiency virus (HIV) type 1. In cell cultures and animal models, METH accelerates retroviral replication. To determine whether METH increases HIV replication in humans, we evaluated HIV loads in HIV-positive METH users and nonusers. We studied 3 groups: Tox+, active METH use and positive urine toxicology results; METH(+)Tox-, previous METH dependence/abuse and negative urine toxicology results; METH(-)Tox-, no METH dependence/abuse and negative urine toxicology results. Tox+ subjects' plasma virus loads were significantly higher than METH(+)Tox- and METH(-)Tox- subjects'; cerebrospinal fluid virus loads showed a similar but nonsignificant trend. Stratification by use of highly active antiretroviral therapy (HAART) revealed that virus loads were higher only in those Tox+ subjects who reported receiving HAART. In contrast, abstinent former METH abusers (METH(+)Tox-) receiving HAART effectively suppressed viral replication. These data suggest that abstinence programs are a key component of effective treatment of HIV in METH-abusing populations.     

Effect of highly active antiretroviral therapy on viral burden in the lungs of HIV-infected subjects

BACKGROUND: Human immunodeficiency virus (HIV) is readily detectable in the lungs of infected subjects and leads to an accumulation of CD8(+) lymphocytes in the alveolar space. Although highly active antiretroviral therapy (HAART) is effective in reducing viremia, less is known about its effect on tissue compartments. The AIDS Clinical Trials Group Protocol 723 Team evaluated the effect of HAART on lung viral load and cellular constituents. METHODS: Bronchoalveolar lavage (BAL) fluid and blood were collected before initiation of HAART and again at 4 and 24 weeks after initiation of therapy. The BAL cell differential was determined, lymphocyte phenotyping was performed, and acellular BAL fluid, plasma HIV RNA load, and BAL cell and peripheral blood mononuclear cell HIV RNA and DNA loads were measured. RESULTS: HAART induced a rapid decrease in HIV that was detectable in acellular BAL fluid and a slower decrease in the HIV RNA and DNA loads in BAL cells. HAART was associated with a significant decrease in the absolute number and percentage of CD8(+) alveolar lymphocytes. There was a significant correlation between residual BAL cell DNA at 24 weeks and the absolute number of CD4(+) lymphocytes in the alveolar space. CONCLUSION: HAART is associated with a significant decrease in the pulmonary HIV burden and a return of alveolar cellular constituents to normal.