The value of patient-reported adherence to antiretroviral therapy in predicting virologic and immunologic response. California Collaborative Treatment Group.

OBJECTIVE: To correlate self-reported antiretroviral adherence with virologic suppression. DESIGN: Prospective observational study of adherence to therapy nested in a randomized comparative trial of frequent versus infrequent monitoring of plasma HIV RNA. SETTING: Five university-affiliated HIV clinics. PATIENTS: A group of 173 HIV-infected patients with a mean baseline CD4 count of 142 x 10(6) cells/l (range 3-515) of whom 164 and 119 completed adherence questionnaires at 2 and 6 months, respectively. INTERVENTION: Individualized, unrestricted antiretroviral therapy. MEASUREMENTS: Patients were classified into four groups by adherence to therapy in the previous 4 weeks (< 80%, 80-95%, 95-99%, 100%). Plasma HIV RNA levels and CD4 lymphocyte counts were measured bimonthly. RESULTS: Recreational drug or alcohol use was associated with decreased adherence, whereas frequency of HIV RNA monitoring, demographic variables, (age, gender, education, and risk group) and stage of disease had no effect. Greater HIV suppression at 6 months was seen across four categories of increasing adherence (P = 0.009 for linear trend). Patients reporting < 80% adherence at 6 months had a 0.2 log10 copies/ml increase in HIV RNA and a loss of 19 x 10(6) CD4 cells/l compared with a 1.1 log10 copies/ml decrease in HIV RNA and an increase of 72 x 10(6) CD4 cells/l in those reporting 100% adherence (P = 0.02). CONCLUSION: Self-reported poor adherence (< 80%) and drug or alcohol use predicted non-response of HIV RNA at 6 months of antiretroviral therapy.     

Virologic and immunologic values allowing safe deferral of antiretroviral therapy

OBJECTIVE: To determine how long highly active antiretroviral therapy can be deferred in HIV-1 infected persons. DESIGN: Observational cohort study of HIV-1 infected men at four academic centers in the USA. OUTCOME: Progression to clinical AIDS or to CD4 cell counts < 200 x 10(6)/l in the absence of antiretroviral therapy among HIV-1 infected men. RESULTS: No participant with a CD4 cell count between 201 x 10(6) and 350 x 10(6)/l and having < 20 000 copies/ml of HIV RNA progressed to clinical AIDS within 1 year. In men with > 350 x 10(6) CD4 cells/l and < 60 000 copies of HIV RNA/ml there were also no instances of progression to clinical AIDS within 1 year. No participant with < 10 000 copies HIV RNA/ml and between 201 x 10(6) and 350 x 10(6) CD4 cells/l had a decrease in CD4 cells to < 200 x 10(6)/l within 1 year. In men with baseline CD4 cell counts > 350 x 10(6)/l and HIV RNA < 30 000 copies/ml, only 3% had a decrease in CD4 cell count to < 200 x 10(6)/l within 1 year. CONCLUSION: This analysis supports recommendations to defer therapy in HIV-1 infected individuals with CD4 cell counts > 350 x 10(6)/l and HIV RNA < 60 000 copies/ml and in persons with CD4 cell counts between 201 x 10(6) and 350 x 10(6)/l and < 20 000 copies/ml HIV RNA. Up to 79% of persons with > 350 x 10(6) CD4 cells/l and 29% with CD4 cell counts between 201 x 10(6) and 350 x 10(6)/l may, with close monitoring, safely defer therapy.     

Positive outcomes of HAART at 24 months in HIV-infected patients in Cambodia

OBJECTIVES: African and Asian cohort studies have demonstrated the feasibility and efficacy of HAART in resource-poor settings. The long-term virological outcome and clinico-immunological criteria of success remain important questions. We report the outcomes at 24 months of antiretroviral therapy (ART) in patients treated in a Médecins Sans Frontières/Ministry of Health programme in Cambodia. METHODS: Adults who started HAART 24 +/- 2 months ago were included. Plasma HIV-RNA levels were assessed by real-time polymerase chain reaction. Factors associated with virological failure were analysed using logistic regression. RESULTS: Of 416 patients, 59.2% were men; the median age was 33.6 years. At baseline, 95.2% were ART naive, 48.9% were at WHO stage IV, and 41.6% had a body mass index less than 18 kg/m. The median CD4 cell count was 11 cells/microl. A stavudine-lamivudine-efavirenz-containing regimen was initiated predominantly (81.0%). At follow-up (median 23.8 months), 350 (84.1%) were still on HAART, 53 (12.7%) had died, six (1.4%) were transferred, and seven (1.7%) were lost to follow-up. Estimates of survival were 85.5% at 24 months. Of 346 tested patients, 259 (74.1%) had CD4 cell counts greater than 200 cells/microl and 306 (88.4%) had viral loads of less than 400 copies/ml. Factors associated with virological failure at 24 months were non-antiretroviral naive, an insufficient CD4 cell gain of less than 350 cells/microl or a low trough plasma ART concentration. In an intention-to-treat analysis, 73.6% of patients were successfully treated. CONCLUSION: Positive results after 2 years of advanced HIV further demonstrate the efficacy of HAART in the medium term in resource-limited settings.     

Impact of viral hepatitis co-infection on response to antiretroviral therapy and HIV disease progression in the HIV-NAT cohort

OBJECTIVE: To examine the impact of viral hepatitis co-infection on HIV disease outcomes following commencement of combination antiretroviral therapy in a developing country setting. METHODS: HIV RNA suppression, CD4 cell count recovery, and HIV disease progression were examined within a cohort of Thai HIV-infected patients enrolled in eight HIV-NAT randomized controlled trials of antiretroviral therapy (n = 692). Hepatitis B virus (HBV) and hepatitis C virus (HCV) testing was performed on stored serum. RESULTS: Mean age was 32.3 years, 52% were male, 11% had CDC category C HIV disease at baseline, and 22% had received prior antiretroviral therapy. Prevalence of HBV, HCV and HBV/HCV co-infection was 8.7, 7.2 and 0.4%, respectively. Median HIV RNA reductions (log10 copies/ml) were approximately 1.5 for HIV, HIV-HBV, HIV-HCV subgroups from week 4 up to week 48. Mean increases in CD4 cell count were significantly lower among HIV-HBV and HIV-HCV subgroups at week 4 (HIV, 62 x 10(6) cells/l; HIV-HBV, 29 x 10(6) cells/l; HIV-HCV, 33 x 10(6) cells/l), however, by week 48 CD4 cell increases were similar (HIV, 115 x 10(6) cells/l; HIV-HBV, 113 x 10(6) cells/l; HIV-HCV, 97 x 10(6) cells/l). Cox regression analyses showed that HIV-HBV or HIV-HCV co-infection were not associated with a CD4 cell count increase of 100 x 10(6) cells/l over 48 weeks. Estimated progression to AIDS event or death at week 48 was 3.3% (95% confidence interval, 2.0-5.1%) for HIV, 6.7% (2.5-14.6%) for HIV-HBV, and 8.0% (2.2-20.5%) for HIV-HCV subgroups (P > 0.05). CONCLUSIONS: An early delayed CD4 count recovery among HIV/viral hepatitis co-infected patients was not sustained, and was not associated with increased HIV disease progression.     

Ten-year trends in CD4 cell counts at HIV and AIDS diagnosis in a London HIV clinic

OBJECTIVE: To examine temporal trends (1986-1996) in the CD4 cell count at first HIV-1 positive test and initial AIDS diagnosis, and the influence of selected patient characteristics and treatment factors on these trends. DESIGN: A retrospective clinic-based study. SETTING: Three hospital-based clinics in West London. PATIENTS: A group of 5921 adult HIV-1-seropositive persons and 2835 reported patients with AIDS over a 10-year period from 1 January 1986 to 1 October 1996. METHODS: The CD4 cell count at HIV diagnosis (CD4HIV) was defined as the nearest CD4 cell count to within 2 months of HIV diagnosis; and the CD4 cell count at AIDS diagnosis (CD4AIDS) as the last CD4 cell count in the two months prior to the development of AIDS. Simple and multiple linear regression analysis were used to examine the influence of selected covariates on CD4HIV and CD4AIDS. RESULTS: The percentage of patients with an available CD4HIV and CD4AIDS increased from less than 5% in 1987 to 53% and 40%, respectively, in 1990, and 79% and 48%, respectively, in 1996. Patients with a missing CD4HIV or CD4AIDS were younger and less likely to have received antiretroviral therapy or prophylaxis for Pneumocystis carinii pneumonia (PCP). There was no significant change in CD4HIV over a 10-year period (median 334 x 10(6) cells/l), but a lower CD4HIV was associated with older age at presentation and injecting drug use. There was a delay in the onset of clinical AIDS, with a fall in the median CD4AIDS value from 99 x 10(6) cells/l prior to 1987, to 58 x 10(6) cells/l in 1990, 68 x 10(6) cells/l in 1994 and 60 x 10(6) cells/l in 1996; this decline in onset was seen for PCP as well as for cytomegalovirus and atypical mycobacterial infections. At all time periods, a lower CD4AIDS was associated with combined use of antiretroviral therapy and PCP prophylaxis. After adjustment for use of antiretroviral therapy and PCP prophylaxis prior to AIDS diagnosis, year of diagnosis was no longer associated with CD4AIDS. There was a significant trend towards an improved survival following AIDS diagnosis from 20.1 months prior to 1988, to 20.3 months (1989-1990), 21.0 months (1991-1992) and 22.1 (1993-1994) (P < 0.0005). CONCLUSIONS: The observed decline in CD4AIDS value was related to the introduction of antiretroviral therapy in 1988, and PCP prophylaxis in 1989. Temporal changes in the CD4 cell count at HIV and AIDS diagnosis among different demographic groups can provide insights into the changing natural history of the HIV epidemic and access to medical care. We recommend monitoring of the CD4 cell count at new HIV and AIDS diagnosis and at initiation of antiretroviral therapy as additional measures in national HIV/AIDS surveillance.     

Prognostic value of plasma HIV RNA among highly active antiretroviral therapy users

BACKGROUND: The study objective was to compare the prognostic value of plasma HIV RNA and CD4 cell count at baseline and as time-updated variables in highly active antiretroviral therapy (HAART) users for two outcomes: development of AIDS and change in CD4 cell count. METHODS: The study population comprised 387 men enrolled in the Multicenter AIDS Cohort Study who were AIDS-free and initiated HAART between 1996 and 2001. Follow-up until AIDS diagnosis (n=36, 9%) or the last AIDS-free visit was included. To determine the predictive value of combining HIV RNA and CD4 cell count, regression tree methods using recursive partitioning at pre-specified cut points for both variables were used. RESULTS: Low CD4 cell count was a strong predictor of AIDS among HAART users. However, HIV RNA showed strong prognostic value for AIDS development among those with CD4 cell counts > 250 x 10(6) cells/l, in whom an HIV RNA level > 1000 copies/ml carried a 4.6-fold greater risk of developing AIDS. HIV RNA < 5000 copies/ml was also predictive of subsequent increase in CD4 cell count with significantly higher increases among those with initial CD4 counts > 300 x 10(6) cells/l. CONCLUSION: Although, in HAART users, CD4 cell count was the primordial prognostic marker, an HIV RNA > 1000 copies/ml attained after HAART initiation was a strong predictor of the rate of subsequent CD4 cell count increase and of developing AIDS in patients whose CD4 cell counts were > 250 x 10(6) cells/l.     

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.     

Plasma cytomegalovirus DNA, pp65 antigenaemia and a low CD4 cell count remain risk factors for cytomegalovirus disease in patients receiving highly active antiretroviral therapy

OBJECTIVE: To study the natural history and the current risk factors for cytomegalovirus (CMV) disease in the context of highly active antiretroviral therapy (HAART). SETTING: Prospective multicentre cohort in 15 university hospitals in France. METHODS: A group of 198 patients with CD4 cell count < 100 x 10(6) cells/l (or < 200 x 10(6) cells/l under HAART for at least 2 months), no previous CMV disease and CMV-positive serology were followed every 4 months clinically and for virological testing including HIV RNA and CMV blood markers (culture, pp65 antigenaemia, plasma CMV DNA and CMV late mRNA by the polymerase chain reaction). RESULTS: At inclusion, median CD4 was 77 x 10(6) cells/l (0-308) and 85% of the patients received protease inhibitors. The percentage of patients receiving HAART reached 99% at 12 months. After a follow-up of 23.6 months, the incidence of CMV disease was 3.2/100 patient-years [95% confidence interval (CI) 1.3-5.0]. In univariate Cox models, all the CMV markers, a CD4 cell count remaining < 75 x 10(6) cells/l and an HIV viral load > 100,000 copies/ml were predictive for CMV disease. The hazard ratios for CMV disease were 11 for blood culture; 14 and 70 for pp65 antigenaemia of > or = 1 and > or = 100 nuclei/200,000 cells, respectively; 35 for plasma CMV DNA; 6 for CMV mRNA; 29 for CD4 < 75 x 10(6) cells/l; and 12 for HIV RNA > 100,000 copies/ml. In a stepwise multivariate analysis, only three covariates were independently associated with the occurrence of a disease: plasma CMV DNA, pp65 antigenaemia > or = 100 nuclei/200,000 cells and a CD4 count < 75 x 10(6) cells/l. CONCLUSION: CMV blood markers and CD4 count < 75 x 10(6) cells/l remain risk factors for CMV disease in patients receiving HAART. Analysis of plasma CMV DNA by the polymerase chain reaction is a reproducible and standardized tool that could be used as a decision marker for initiating CMV pre-emptive therapy.     

HIV disease progression in a patient cohort treated via a clinical research network in a resource limited setting

OBJECTIVE: To examine HIV disease progression in a cohort of adult patients treated with antiretroviral therapy (ART) via a clinical research network in Thailand. DESIGN, SETTING, PARTICIPANTS AND INTERVENTION: A cohort of 417 patients enrolled in a series of randomized ART trials, between 1996 and December 2002. MAIN OUTCOME MEASURES: Progression to combined endpoint of AIDS defining illness or death according to baseline characteristics, ART used, immunological and virological responses to initial 6 months of ART. RESULTS: During 1677 person years of follow-up, 29 of 417 patients progressed; tuberculosis was the most common event defining progression (14 of 29 events). The rates of progression to combined endpoint or death alone were 1.7 [95% confidence interval (CI), 1.1-2.4] and 0.7 (95% CI, 0.3-1.3) per 10 person years respectively. Compared to patients with baseline CD4 cell counts > or =350 x 10/l, the adjusted hazard ratio (HR) for progression was 3.67 (95% CI, 1.31-10.27) for patients with <200 x 10 cells/l. Responses to 6 months of therapy were the strongest predictors of disease progression; compared to patients with undetectable viral load at 6 months, HR for progression was 4.95 (95% CI, 2.14-11.46) for viral load >4 log10. Compared to patients with a 6-month CD4 cell count > or =350 x 10/l, HR for progression was 5.22 (95% CI, 1.90-14.37) for patients with <200 x 10 cells/l. CONCLUSIONS: HIV-infected patients in Thailand who had access to ART, appropriate care, CD4 cell and viral load monitoring facilities via a clinical research network had progression rates comparable to those in developed countries. In this setting, ART initiation could generally be delayed until the CD4 cell count approaches 200 x 10/l.     

CD4 cell-monitored treatment interruption in patients with a CD4 cell count > 500 x 106 cells/l

BACKGROUND: Little is known about CD4 cell count changes in patients with high CD4 cell counts who interrupt antiretroviral therapy, especially in those with a nadir of 250-350 x 10 cells/l. METHODS: Data derived from 139 patients from seven prospective cohorts who had > 12 months highly active antiretroviral therapy (HAART), CD4 cell count nadir of > 250 x 10 cells/l and at pre-interruption of > 500 x 10 cells/l. Endpoint was time to CD4 cell count < 350 x 10 cells/l or reinitiation of treatment. RESULTS: At interruption, the median CD4 cell count was 800 x 10 cells/l, median viral load was 1.7 log10 copies/ml. At the time of analysis, 63 (45.3%) had resumed therapy or experienced < 350 x 10 cells/l CD4 cells over a median interruption of 75 weeks. Of these, 33 (52.4%) experienced a decline to < 350 x 10 cells/l and 30 (47.6%) restarted therapy before their CD4 cell count had fallen below this level. In 43 patients with CD4 cell nadir of 251-350 x 10 cells/l, median time to therapy resumption or CD4 cell count < 350 x 10 cells/l was 61 weeks. Higher CD4 cell count nadir, longer duration of viral load suppression on therapy, and higher viral load level at interruption were independently associated with longer time to restart therapy. The risk of clinical events was 5 per 1000 person-years of follow-up. CONCLUSIONS: Patients who started therapy with CD4 cell count of 250-350 x 10 cells/l and who later interrupted therapy appear able to remain off therapy with a CD4 cell count > 350 x 10 cells/l for a substantial period of time.     

CD4+ cell-count-guided treatment interruptions in chronic HIV-infected patients with good response to highly active antiretroviral therapy

OBJECTIVE: To evaluate the safety of treatment interruption guided by CD4+ cell count in HIV-infected patients followed up prospectively. METHODS: Patients on highly active antiretroviral therapy with CD4+ cell counts > 500 x 10(6) cells/l discontinued therapy with instructions to start therapy again before their CD4+ count dropped below 200 x 10(6) cells/l. Any patients who resumed therapy would be eligible to interrupt treatment again once their CD4+ cell count increased above 500 x 10(6) cells/l. RESULTS: Data on 71 HIV infected patients is reported. Their median nadir CD4+ cell count before antiretroviral treatment was 352 x 10(6) cells/l [interquartile range (IQR), 294-445 x 10(6) cells/l]. The median CD4+ cell count at the time of first interruption was 790 x 10(6) cells/l (IQR, 657-1041 x 10(6) cells/l). The median follow-up after starting the first treatment interruption was 28.3 months (IQR, 21.4-37.0 months). During the follow-up 49 patients restarted therapy and 22 patients remain off therapy; 24 patients have interrupted therapy twice, nine patients have interrupted therapy three times and six patients four times. No AIDS-defining illnesses occurred during the follow-up. The median duration of the first interruption was 15 months (IQR, 6-26 months). The overall reduction of time on therapy was 71.1%. The duration of the first interruption and the reduction of time on therapy were related to nadir CD4+ cell count. The patients who resumed HAART rapidly regained CD4+ cells and achieved viral suppression. CONCLUSION: If carefully monitored, treatment interruptions guided by CD4+ cell count in patients with an initially high CD4+ cell counts are clinically safe, decrease exposure to the drugs and do not reduce the efficacy of therapy when this is re-started.     

Discordant response to antiretroviral therapy: HIV isolation,genotypic mutations,T-cell proliferation and cytokine production

OBJECTIVE: To study virologic and immunologic factors associated with discordant treatment response in HIV-infected patients receiving highly active antiretroviral therapy (HAART). DESIGN: Study participants included a total of 27 patients: (a) 10 discordant patients (mean CD4+ cell count, 396.1 x 10 cells/l; mean HIV-RNA, 5.4 log copies/ml); (b) seven responder patients (mean CD4+ cell count, 997.5 x 10 cells/l); and (c) 10 failing patients (mean CD4+ cell count 66.5 x 10 cells/l; mean HIV-RNA, 5.4 log copies/ml).(10) (10)METHODS: The HIV-1 isolation rate and biological phenotype, drug resistance genotypic mutations of HIV-1 strains, recall and HIV-1-specific antigen lymphocyte proliferation (LP), and interleukin (IL)-15 production were studied. RESULTS: Virus isolation was obtained in 30% of discordant patients, and in 100% of failing patients. A higher replication constant was reported in discordant patients. No difference in the number of drug resistance mutations and biological phenotypes of HIV-1 was found in discordant patients with respect to failing patients. Discordant patients developed positive LP responses to and HIV-1 p24. LP in response to, HIV-1 p24 and gp160 was positive in responder patients. No significant LP was found in failing patients. Increased levels of IL-15 after stimulation with lipopolysaccaride (LPS) and were found in both discordant patients and responder patients. Conversely, a strong reduction of IL-15 levels was observed in failing patients. CONCLUSION: The present results suggest that decreased virus isolation rate, restoration of both lymphocyte proliferation and IL-15 production are factors involved in the discordant antiretroviral therapy response of HIV-infected patients.     

Mean CD4 cell count changes in patients failing a first-line antiretroviral therapy in resource-limited settings

ABSTRACT: BACKGROUND: Changes in CD4 cell counts are poorly documented in individuals with low or moderate-level viremia while on antiretroviral treatment (ART) in resource-limited settings. We assessed the impact of on-going HIV-RNA replication on CD4 cell count slopes in patients treated with a first-line combination ART. METHOD: Naive patients on a first-line ART regimen with at least two measures of HIV-RNA available after ART initiation were included in the study. The relationships between mean CD4 cell count change and HIV-RNA at 6 and 12 months after ART initiation (M6 and M12) were assessed by linear mixed models adjusted for gender, age, clinical stage and year of starting ART. RESULTS: 3,338 patients were included (14 cohorts, 64% female) and the group had the following characteristics: a median follow-up time of 1.6 years, a median age of 34 years, and a median CD4 cell count at ART initiation of 107 cells/uL. All patients with suppressed HIV-RNA at M12 had a continuous increase in CD4 cell count up to 18 months after treatment initiation. By contrast, any degree of HIV-RNA replication both at M6 and M12 was associated with a flat or a decreasing CD4 cell count slope. Multivariable analysis using HIV-RNA thresholds of 10,000 and 5,000 copies confirmed the significant effect of HIV-RNA on CD4 cell counts both at M6 and M12. CONCLUSION: In routinely monitored patients on an NNRTI-based first-line ART, on-going low-level HIV-RNA replication was associated with a poor immune outcome in patients who had detectable levels of the virus after one year of ART.     

Determinants of sustainable CD4 lymphocyte count increases in response to antiretroviral therapy

OBJECTIVE: HIV-induced CD4 lymphocyte depletion is partially reversed by antiretroviral therapy but it is unclear if the degree to which the CD4 count rises depends on viral suppression (if so, the extent of viral suppression required to achieve a maximal CD4 count rise), whether the rise is sustainable and whether it occurs in patients with CD4 count <10 x 10(6) cells/l. We aimed to address these issues. METHODS: We studied CD4 count and plasma HIV RNA values every 4 weeks for 72 weeks in 154 patients starting indinavir-containing regimens. RESULTS: Mean baseline HIV RNA and CD4 count were 4.8 log10 copies/ml and 180 x 10(6) cells/l, respectively. Overall, there was a mean increase in CD4 count of 143 x 10(6) cells/l by 72 weeks. The adjusted mean increase (adjusted for initial viral load, CD4 count and age) was strongly related to the mean viral suppression over the follow-up period (P < 0.0001). Importantly, there was a highly significant difference (P = 0.0004) in the rise in CD4 count between those with 2-3 log suppression (161 x 10(6) cells/l) and those with > 3 log suppression (314 x 10(6) cells/l; mean 3.6 log suppression in this group), suggesting that with even greater suppression the rise in CD4 lymphocytes may be still larger. We also studied whether CD4 counts were still rising after 72 weeks in patients with sustained suppression of at least 3 log in viral load. There was a significant (P = 0.004; paired t-test) rise in count of 43 x 10(6) cells/l between weeks 64 and 72 in these patients, suggesting that regeneration continues at least up to 72 weeks after therapy, provided virus replication continues to be suppressed. Patients with initial CD4 counts < 10 x 10(6) cells/l experienced no smaller rises than those at higher levels, even after adjustment for other factors. CONCLUSION: These results strongly support a direct causal relationship between HIV replication and CD4 lymphocyte count depletion. The rise in those with > 3 log suppression provides the best available indicator of the potential for natural CD4 regeneration in HIV-infected patients. However, since still greater CD4 count rises may be seen with more suppressive regimens, it may not be possible to study the intrinsic CD4 regenerative capacity until such regimens are available.     

Continued CD4 cell count increases in HIV-infected adults experiencing 4 years of viral suppression on antiretroviral therapy

OBJECTIVE: To determine the extent to which HIV-infected patients, including those with advanced immunodeficiency, can reverse peripheral CD4 T-cell depletion while maintaining long-term viral suppression on highly active antiretroviral therapy. DESIGN: Cohort study. PARTICIPANTS: Four-hundred and twenty-three HIV-infected patients who initiated HAART prior to 1998 and achieved a viral load 1000 copies/ml. MAIN OUTCOME MEASURE: CD4 count changes. RESULTS: Among patients who maintained plasma HIV RNA levels /= 350 x 10(6)/l, respectively (all gains were significantly greater than zero; P < 0.05). Among those with a pre-therapy CD4 count of < 50 x 10(6)/l, 88% achieved a CD4 cell count of >/= 200 x 10(6)/l and 59% achieved a count of >/= 350 x 10(6)/l by year 4. Factors associated with increased CD4 cell count gains from month 3 to year 4 included lower pre-therapy CD4 cell count, younger age, female sex, and infrequent low-level viremia (versus sustained undetectable viremia). CONCLUSIONS: Most patients who achieve and maintain viral suppression on HAART continue to experience CD4 T-cell gains through 4 years of therapy. The immune system's capacity for CD4 T lymphocyte restoration is not limited by low pre-therapy CD4 counts.     

A randomised, open-label comparison of three highly active antiretroviral therapy regimens including two nucleoside analogues and indinavir for previously untreated HIV-1 infection: the OzCombo1 study

BACKGROUND: Highly active antiretroviral therapy (HAART) including two nucleoside analogues and a potent protease inhibitor is standard of care initial therapy for HIV-infected adults. The best-tolerated and most potent initial HAART regimen is unknown and was investigated in this study. METHODS: One hundred and nine HIV-infected adults with no prior antiretroviral therapy, and CD4 lymphocyte counts < 500 x 10(6) cells/l or plasma HIV RNA > 30,000 copies/ml were randomized to zidovudine-lamivudine-indinavir (ZDV-3TC-IDV), stavudine-lamivudine-indinavir (d4T-3TC-IDV) or stavudine-didanosine-indinavir (d4T-ddI-IDV) for 52 weeks. The primary endpoints were plasma HIV RNA and drug-related adverse events. Other assessments were overall safety, adherence and adverse events, CD4 lymphocyte counts, cutaneous delayed type hypersensitivity (DTH) responses and quality of life (Euroqol). RESULTS: Only 58% patients had HIV RNA < 50 copies/ml plasma at 12 months, with no significant difference between the three regimes (P = 0.34). Drug-related adverse events sufficiently severe to warrant drug discontinuation were less common (P = 0.06) in patients receiving d4T-3TC-IDV (18%) than in those receiving ZDV-3TC-IDV (34%) or d4T-ddI-IDV (41%). The percentages of patients who remained on their assigned therapy with plasma HIV RNA < 50 copies/ml at 52 weeks were 60% with d4T-3TC-IDV, 53% with ZDV-3TC-IDV and 35% with d4T-ddI-IDV. Virological failure at 52 weeks was more likely in those whose adherence was estimated to be < 100% in the first 4 weeks of therapy (P = 0.02), but not in those who developed grade 3 or 4 drug-related adverse events. At 52 weeks, the mean CD4 lymphocyte count increase was 200 x 10(6) cells/l with only 7% of patients having counts lower than at baseline; DTH responses improved but remained clinically impaired in most patients. Quality of life improved significantly in all groups. CONCLUSIONS: Initial HAART regimens including IDV failed to suppress plasma HIV RNA to < 50 copies/ml in > 40% patients after only 12 months of therapy although there was significant overall improvement immunologically and in quality of life. The type of dual nucleoside combination used was less important in predicting virological failure than was imperfect adherence early in therapy. Consideration should be given to modifying a HAART regimen relatively early in non-adherent patients.