The virological and immunological consequences of structured treatment interruptions in chronic HIV-1 infection.

BACKGROUND: Some individuals with chronic HIV-1 infection have discontinued their drug therapy with consequent plasma virus rebound. In a small number of patients, a delayed or absent rebound in plasma virus load has been noted after drug cessation, apparently associated with prior drug interruptions and autologous boosting of HIV-1 specific immune responses. We hypothesized that cyclic structured treatment interruptions structured treatment interruptions (STI) could augment HIV-1 specific immune responses in chronic HIV-1 infection, which might help to control HIV-1 replication off therapy. METHODS: We initiated an STI pilot study in 10 antiretroviral treatment-naive HIV-1 chronically infected subjects with baseline CD4 T-cell counts > 500 x 10(6) cells/l and plasma viral load > 5000 copies/ml who received highly active antiretroviral therapy (HAART) for 1 year with good response (plasma viral load < 20 copies/ml for at least 32 weeks). Three cycles of HAART interruption were performed. RESULTS: In all of the patients viral load rebounded, but doubling times increased significantly between the first and third stops (P = 0.008), and by the third stop, six out of nine subjects had a virological set-point after a median 12 months off therapy that was lower than baseline before starting HAART (ranging from 0.6 log(10) to 1.3 log(10) lower than baseline) and in four it remained stable below 5000 copies/ml. Those subjects who controlled viral replication developed significantly stronger HIV-1 specific cellular immune responses than subjects lacking spontaneous decline (P < 0.05). During viral rebounds no genotypic or phenotypic changes conferring resistance to reverse trancriptase inhibitors or protease inhibitors was detected, but mean absolute CD4 T-cell counts declined significantly, although never below 450 x 10(6)/l and the mean value at 12 months off therapy was significantly higher than the pre-treatment level (P = 0.004). CONCLUSIONS: Our findings suggest that STI in chronic HIV-1 infection might augment HIV-1-specific cellular immune responses associated with a spontaneous and sustained drop in plasma viral load in some subjects but at the potential cost of lower CD4 T-cell counts.     

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

OBJECTIVES: To evaluate the impact on CD4 cell count and HIV-1 DNA level in peripheral blood mononuclear cells (PBMC) of long-term highly active antiretroviral therapy (HAART) in the setting of maximal success, i.e., constant plasma HIV-1 RNA load suppression. DESIGN: Retrospective analysis of patients selected for a constantly undetectable plasma HIV-1 RNA load since HAART initiation. METHODS: HIV-1 DNA was measured in PBMC using a real-time polymerase chain reaction assay. Loess estimates and regression analysis were used for modelling the variations of the CD4 cell count and HIV DNA level over time. RESULTS: The study included 41 patients chronically infected with HIV-1 who had been taking HAART for a median duration of 60.4 months and had an undetectable plasma HIV RNA load ever since the first 6 months of HAART; 25 were tested for HIV-1 DNA. The mean CD4 cell count increase was high during the first 18 months on therapy (168 x 10 cells/l per year), much lower afterwards (38 x 10 cells/l per year), independently of the baseline CD4 cell count. Most of the patients (73.2%) reached a CD4 cell count constantly > or = 400 x 10/l during follow-up. HIV-1 DNA showed a mean decrease of 0.48 log10 copies/10 PBMC during the first year, of 0.18 log10 copies/10 PBMC per year during the 2nd and 3rd years, but no significant decrease afterwards. CONCLUSIONS: These results question the benefit of very long-term maintenance of HAART in terms of CD4 gain and HIV-1 DNA reduction.     

Raised viral load in patients with viral suppression on highly active antiretroviral therapy: transient increase or treatment failure?

OBJECTIVE: To assess the occurrence of viral load greater than 50 copies/ml in patients on highly active antiretroviral therapy (HAART) having achieved less than 50 copies/ml and the chance of whether a viral load greater than 50 copies/ml would lead to a sustained and increasing viral load. DESIGN: A cohort of 553 patients on HAART with viral loads of less than 50 copies/ml were followed. RESULTS: Over a median of 56 weeks 35% of patients experienced a transient increase and 8% virological failure (two consecutive viral loads of > 400 copies/ml). Transient increases and virological failure were more common in those with greater drug experience, and those with initial raised viral load values of more than 400 copies/ml were more likely to have a sustained increase and become virological failures. CONCLUSION: Transient increases in viral load are common, mainly in the 50-400 copies/ml range, and the majority of subsequent viral load estimations show a return to less than 50 copies/ml. A single raised viral load should lead to adherence support and intensified monitoring. Subsequent treatment decisions can then be based on evidence of true virological rebound and failure.     

Long-term immunological response in HIV-1-infected subjects receiving potent antiretroviral therapy

OBJECTIVE: To determine the long-term T-lymphocyte response to highly active antiretroviral therapy (HAART) and to define predictors of the immunological response. DESIGN: Cohort study, including 135 HIV-1-infected subjects at a city general practice who commenced HAART between 1996 and 1998. METHODS: Collection of plasma HIV-1 RNA, CD4+ and CD8+ T-lymphocyte data at 3-6 monthly time intervals over 2 years. RESULTS: Seventy-three subjects (54%) achieved suppression of plasma HIV-1 RNA to levels below 400 copies/ml during the observation period, 31 individuals (23%) had detectable plasma HIV-1 RNA below 10,000 copies/ml and 31 subjects (23%) had virological failures with viral loads above 10,000 copies/mL. Median CD4+ T lymphocytes increased from 246 to 463 x 10(6) cells/l, showing a median rise of 20 x 10(6) cells/l per month in the first 3 months and 7 x 10(6) cells/l per month thereafter. The proportion of individuals who reached CD4+ cell counts above 500 x 10(6) cells/l increased from 8% at baseline to 54% at 2 years. Treatment-na?ve individuals, subjects with a large reduction of HIV-1 RNA or a large early CD8+ increase had better early CD4+ responses. Long-term CD4+ T-cell increases were inversely correlated with mean plasma HIV-1 RNA levels. Baseline CD4+ T-cell count was the most important determinant of reaching CD4+ cell counts above 500 x 10(6) cells/l. Nineteen per cent of subjects had no further CD4+ T-cell increases in the second year of therapy despite undetectable viral load. CONCLUSIONS: Immune reconstitution is a slow process, showing a large individual variability. The virological response to HAART was the most important determinant of the immunological short- and long-term response.     

Predictors of virological rebound in HIV-1-infected patients initiating a protease inhibitor-containing regimen.

OBJECTIVE: To study the predictors of virological rebound in patients having early virological response to protease inhibitor (PI)-containing regimen. DESIGN AND METHODS: APROCO cohort study prospectively enrolled 1283 HIV-infected patients starting a PI-containing regimen in 1997-1999. Adherence to therapy was measured with self-administered questionnaires after 4 months of therapy (M4). Virological rebound was defined as a viral load (VL) > 500 copies/ml in patients having early virological response, defined as a VL < 500 copies/ml at M4. Predictors of time to virological rebound were studied with multivariate proportional hazards model. RESULTS: During a median follow-up of 20 months, virological rebound was observed in 32% of the 830 patients with early virological response. Virological rebound was more frequent when patients had received previous antiretroviral treatment [adjusted hazards ratio (HR) = 2.4; P < 0.0001], were younger (HR = 1.4 per each 10 years younger; P < 0.0001), had baseline CD4 cell count < 500 x 106/l (HR = 2.3; P < 0.001), had higher baseline VL (HR = 1.4 per each log10 copies/ml higher; P < 0.001), reported low adherence to therapy at M4 (HR = 2.1; P < 0.001) or had stopped PI at M4 (HR = 1.7; P = 0.04). CONCLUSION: Initiation of treatment at a stage of preserved immunity is associated with a more durable virological response under protease inhibitor. Every effort should be made to monitor and strengthen adherence to therapy, even in patients having early virological response.     

Cell-associated HIV-1-DNA quantitation after highly active antiretroviral therapy-treated primary infection in patients with persistently undetectable plasma HIV-1 RNA

OBJECTIVE: To determine the usefulness of cell-associated HIV-1-DNA quantification during the follow-up of highly active antiretroviral therapy (HAART)-treated primary-infected patients with persistently undetectable plasma RNA loads. PATIENTS AND METHODS: In 27 patients given HAART within a median of 24 days after symptomatic primary HIV infection, plasma and peripheral blood mononuclear cell (PBMC) HIV-1 RNA were less than 50 copies/ml and less than 50 copies/10(6) cells after 18 months of treatment. HIV-1 RNA and DNA were quantified every 6 months in PBMC in these 27 patients, 14 of whom accepted excision lymph node biopsy after month 18 for HIV-1-RNA and -DNA quantification in lymph node mononuclear cells (LNMC). RESULTS: The median decreases in plasma HIV-1 RNA, PBMC HIV-1 RNA and DNA over the 18 months of follow-up were 3.6 log (P< 0.005), 1.1 log (P< 0.05), and 1.0 log (P<0.001), respectively. HIV-1 DNA was detected in 92.3% of PBMC samples at baseline and at month 18. In LNMC, 100% of samples were detectable for HIV-1 DNA. CONCLUSION: In this highly selected population of patients with excellent plasma virological response under HAART, HIV-1 DNA showed a progressive decrease but was still detectable in 92.3% of samples at month 18, whereas all LNMC samples tested scored positive for HIV-1 DNA. The utility of proviral HIV-1-DNA monitoring was not clearly demonstrated in this 18-month follow-up of HAART-treated primary-infected patients. However, this finding could be reconsidered when using other therapeutic strategies such as structured treatment interruptions, reinforced treatment or additive immunotherapy.     

Proviral HIV-1 DNA in subjects followed since primary HIV-1 infection who suppress plasma viral load after one year of highly active antiretroviral therapy

OBJECTIVE: An assessment of the impact of one year potent antiretroviral treatment initiated during primary HIV infection on the cell-associated viral burden. DESIGN AND METHODS: Proviral HIV-1 DNA was quantified in serial peripheral blood mononuclear cell (PBMC) samples from 19 patients enrolled in the French prospective PRIMO Cohort for whom plasma HIV RNA was suppressed to undetectable levels after one year of triple therapy; that is, plasma HIV-1 RNA was maintained below 200 copies/ml. Results were compared with those observed in 19 patients with chronic HIV-1 infection presenting the same degree of virus suppression after 12 months of treatment. RESULTS: At study entry, PRIMO subjects presented heterogeneous levels of proviral HIV-1 DNA: 2-3.92 log10 copies/10(6) PBMC and plasma HIV RNA: 2.3-6.5 log10 copies/ml. One year of effective highly active antiretroviral therapy (HAART) resulted in a median diminution of proviral DNA of -0.78 log10/10(6) PBMC in PRIMO subjects. The median decline in chronic-phase patients was -0.32 for those who were pre-treated and -0.52 for those previously naive of treatment. CONCLUSION: The decline in cell-associated HIV DNA observed throughout one year treatment indicated that HAART reduces the proviral HIV-DNA load more effectively when initiated during the primary rather than the chronic phase of HIV infection. These findings therefore tend to lend support to the early initiation of treatment. Nevertheless, heterogeneous baseline values observed for CD4 cell count, plasma HIV RNA and proviral HIV DNA in PRIMO subjects, raise the question of whether treatment should be delayed in some to spare early adverse effects of HAART.     

Does transient HAART during primary HIV-1 infection lower the virological set-point?

OBJECTIVES: To assess the influence of patient characteristics, treatment precocity (how early) and duration of sustained virological response to highly active antiretroviral therapy (HAART) on HIV RNA levels after withdrawal of treatment started during primary infection and to compare HIV RNA levels after HAART withdrawal with levels reached at the same time point during the natural history of infection in the pre-HAART era. DESIGN: HIV RNA was analysed using linear mixed-effects models for 58 patients from the PRIMO cohort (1996-2003) treated during primary infection (with sustained virological responses until HAART interruption) and 116 untreated patients enrolled in the SEROCO cohort within 6 months following infection (1988-1995). Viral loads were estimated in PRIMO patients 36 months after infection (12 months after treatment interruption) and were estimated for the SEROCO patients 36 months after infection, after adjustment for gender and age. RESULTS: HIV RNA levels 12 months after HAART interruption were independently associated with levels at HAART initiation and with the CD4 cell count at HAART interruption, but not with the precocity of HAART or the duration of virological response to HAART. Thirty-six months after infection, mean HIV RNA levels were 3.95 log10 copies/ml 12 months after stopping HAART and 4.11 log10 copies/ml in never-treated patients. CONCLUSION: Viral load 12 months after withdrawal of transient effective HAART started during primary infection is similar to viral load at the same time after infection in never-treated patients, suggesting that early HAART initiation does not lower the virological set-point.     

Factors associated with virological response in HIV-infected patients failing antiretroviral therapy: a prospective cohort study

OBJECTIVES: To assess the antiviral response to optimized therapy following genotypic resistance testing and to identify factors associated with virological response in HIV-1-infected patients failing antiretroviral therapy. METHODS: A prospective cohort study was conducted in 344 HIV-1-infected patients who underwent genotypic resistance testing because of virological failure. Virological response was defined as a plasma HIV RNA level below 200 HIV-1 RNA copies/mL or a drop of plasma viral load from baseline of more than 1 log10. A multivariate logistic regression analysis was performed to identify factors associated with virological response. RESULTS: The median age of the patients was 40 years, with a male to female ratio of 4:1. Fifty-one per cent of patients had received the three major classes of antiretrovirals and the median duration of previous antiretroviral therapy was 4.6 years. At baseline, the median plasma HIV RNA level was 4.4 log10 copies/mL and the median CD4 cell count was 274 cells/microL. At 3 months, 55% of patients (188 of 344) had a virological response, which was sustained at 6 months (53%). Predictors of virological response were exposure to two or fewer protease inhibitors [odds ratio (OR) 1.8; P=0.046], and use in optimized therapy of a new class of antiretrovirals (OR 2.9; P=0.006), of more than two new drugs (OR 3.0; P<0.0001), of abacavir (OR 1.9; P=0.03), or of lopinavir/ritonavir (OR 3.7; P=0.0002). CONCLUSIONS: A high proportion of patients achieved a short-term virological response in this cohort study. Patients with the least experience of protease inhibitor treatment and in whom a new class of antiretroviral, more than two new drugs, abacavir or lopinavir/ritonavir was used in optimized therapy had the best virological outcome.     

Therapeutic immunization with dendritic cells loaded with heat-inactivated autologous HIV-1 in patients with chronic HIV-1 infection

Therapeutic immunization with autologous monocyte-derived dendritic cells (DCs) loaded with heat-inactivated autologous human immunodeficiency virus type 1 (HIV-1) in 12 patients with chronic HIV-1 infection who were receiving highly active antiretroviral therapy (HAART) was feasible, safe, and well tolerated. Virus was obtained during an initial interruption of HAART (hereafter, "stop 1") so that DCs could be pulsed. After immunization and a second interruption of HAART (hereafter, "stop 2"), set-point plasma viral load (PVL; 24 weeks after stop 2) decreased > or =0.5 log(10) copies/mL relative to baseline PVL in 4 of 12 patients. We observed a significant lengthening in mean doubling time of PVL rebound and significant decreases in the area under the curve and the mean peak of PVL rebound after stop 2, compared with those after stop 1. This response was associated with changes in HIV-1-specific CD4(+) lymphoproliferative and CD8(+) T cell responses. These changes were not observed in a group of nonimmunized control patients.     

Gender differences in clinical progression of HIV-1-infected individuals during long-term highly active antiretroviral therapy

OBJECTIVE: To assess gender differences in the long-term clinical, virological and immunological outcomes during highly active antiretroviral therapy (HAART). METHODS: This longitudinal observational multicentre study followed 2460 HIV-infected patients who had begun a protease inhibitor-based regimen for a median period of 43 months. Outcome measures were virological suppression (< 500 copies/ml), confirmed virological rebound after suppression, and death or new AIDS-defining illness (ADI). RESULTS: At baseline, 690 female patients (28.0%) had significantly lower age, higher prevalence of heterosexual contact and lower prevalence of intravenous drug use as risk factors for HIV infection compared with males. Furthermore, females had a lower number of AIDS-defining illnesses, higher CD4 cell counts and lower viral loads.No gender differences were reported in terms of proportion of patients achieving viral suppression or exhibiting rebound after achieving viral suppression. Female patients experienced reduced clinical progression during follow-up compared with males (P = 0.008) by Kaplan-Meier analysis; however this difference was not significant in an adjusted analysis. In a multivariate model, the interaction between gender and risk factor for HIV or viral load showed that female drug users and female patients with a baseline HIV RNA viral load of 10(4)-10(5) copies/ml had a favourable clinical outcome compared with males (P = 0.035 and P = 0.015, respectively). CONCLUSION: No differences were found between genders in terms of virological and immunological outcomes during long-term HAART. Nevertheless, a lower risk of clinical progression was reported among female patients with intermediate baseline viral load than in males.     

Response to highly active antiretroviral therapy varies with age: the UK and Ireland Collaborative HIV Paediatric Study

OBJECTIVE: To evaluate the effect of age, CD4 percentage (CD4%) and plasma HIV-1 RNA on response to highly active antiretroviral therapy (HAART) in previously untreated children. DESIGN: Cohort study. METHODS: We examined the association between age at HAART initiation, and CD4 and HIV-1 RNA response using logistic and Cox regression, adjusting for sex, route of infection and pre-HAART values. RESULTS: CD4% increases of > 10% at 6 months were more likely in younger children [odds ratio (OR), 0.84 per year, P < 0.001] and those with lower pre-HAART CD4% (OR, 0.67 per 5% higher, P < 0.001), but were not related to pre-HAART HIV-1 RNA (P = 0.6). In contrast, HIV-1 RNA suppression < 400 copies/ml at 6 months was more likely in older children (OR, 1.09 per year, P = 0.03), and was unrelated to pre-HAART HIV-1 RNA or CD4% (P > 0.3). CD4% was still increasing during the second year following HAART initiation (60% followed > 24 months). Longer-term increases in CD4% occurred faster, and decreases in HIV-1 RNA occurred more slowly in younger children. The median time to CD4% >/= 30% after initiating HAART with CD4% 相似文献   

Comparative response of African HIV-1-infected individuals to highly active antiretroviral therapy

OBJECTIVE: Few data exist on the virological response to antiretroviral therapy of individuals infected with African HIV-1 subtypes. Our objective was to compare the response, in our clinic, of African HIV-1-infected patients with their British and European contemporaries treated with the same regimes. DESIGN: The St Mary's Hospital HIV database was used to identify drug-naive African and European patients starting a highly active antiretroviral therapy (HAART) regimen. METHODS: HIV-1 subtype was determined by phylogenetic analysis of pol sequences. Kaplan-Meier survival analysis was used to estimate the proportion of patients achieving undetectable viral loads (< 500 copies/ml). The longer-term response to therapy was assessed by changes in CD4 cell counts and viral loads from baseline. RESULTS: A total of 265 patients were classified as 'European' and 97 as 'African', confirmed by sequence. The time to first undetectable viral load was similar for the two groups (P = 0.9). Although there were no statistically significant differences in the CD4 cell count responses (P = 0.11), there was evidence of an increase in viral load after 9 months for the African group, resulting in a widening viral load gap between the two cohorts; the effect of ethnic group was statistically significant (P < 0.001). CONCLUSION: The initial virological and immunological responses of the African and European cohorts to HAART were similar; although the longer-term virological response was poorer in the African cohort, which may be related to adherence. On the basis of these findings, there is no justification for withholding HAART from Africa on virological grounds.