Diagnostic accuracy of CD4 cell count increase for virologic response after initiating highly active antiretroviral therapy

OBJECTIVE: To derive and internally validate a clinical prediction rule for virologic response based on CD4 cell count increase after initiation of HAART in a resource-limited setting. DESIGN AND METHODS: A retrospective cohort study at two HIV care clinics in Gaborone, Botswana. The participants were previously treatment-naive HIV-1-infected individuals initiating HAART. The main outcome measure was a plasma HIV-1 RNA level (viral load) < or = 400 copies/ml (i.e. undetectable) 6 months after initiating HAART. RESULTS: The ability of CD4 cell count increase to predict an undetectable viral load was significantly better in those with baseline CD4 cell counts < or = 100 cells/microl [area under the ROC curve (AUC), 0.78; 95% confidence interval (CI), 0.67-0.89; versus AUC, 0.60; 95% CI, 0.48-0.71; P = 0.018]. The sensitivity, specificity, and positive and negative predictive values of a CD4 cell count increase of > or = 50 cells/microl for an undetectable viral load in those with baseline CD4 cell counts < or = 100 cells/microl were 93.1, 61.3, 92.5 and 63.3%, respectively. Alternatively, these values were 47.8, 87.1, 95.0 and 24.5%, respectively, if a increase in CD4 cell count of > or = 150 cells/microl was used. CONCLUSIONS: CD4 cell count increase after initiating HAART has only moderate discriminative ability in identifying patients with an undetectable viral load, and the predictive ability is higher [corrected] in patients with lower baseline CD4 cell counts. Although HIV treatment programs in resource-constrained settings could consider the use of CD4 cell count increases to triage viral load testing, more accurate approaches to monitoring virologic failure are urgently needed.     

Disease progression in patients with virological suppression in response to HAART is associated with the degree of immunological response

OBJECTIVE: To determine if immunological response is associated with disease progression in patients with virological suppression after initiating HAART. DESIGN: A cohort study of 1084 treatment-naive participants in the British Columbia HIV/AIDS Drug Treatment Program who had achieved viral loads < 500 copies/ml at 3-9 months after initiating triple-drug therapy. METHODS: Cox proportional hazards was used to model the association with disease progression of baseline variables, change in CD4 cell counts and CD4 cell count strata at 6 months. Logistic regression analysis was used to examine associations with two definitions of poor immunological response. RESULTS: Patients were followed for a median of 51.4 months. In univariate analyses, increases in CD4 cell counts of < 25 cells/microl and absolute CD4 cell counts of < 200 cells/microl were associated with an increased risk of death or new AIDS events. Two mulitivariate models, one including baseline CD4 cell count and change in CD4 cell count from baseline and the other including only absolute CD4 cell counts at 6 months, were found to predict disease progression in this setting. Increases in CD4 cell count of < 25 cells/microl were associated with increasing age and inversely associated with low baseline CD4 cell counts, high baseline viral loads and good adherence to therapy. CD4 cell counts of < 200 cells/microl at 6 months were associated with low baseline CD4 cell counts and having AIDS at baseline. CONCLUSION: Patients with virological suppression are still at risk for HIV disease progression if adequate immunological responses are not achieved.     

Immunological and virological responses to highly active antiretroviral therapy in a non-clinical trial setting in a developing Caribbean country

OBJECTIVE: Few data exist on the efficacy of antiretroviral therapy in individuals infected with HIV in the Caribbean. We evaluated the virological and immunological responses of HIV-infected adults starting highly active antiretroviral therapy (HAART). DESIGN: This was a prospective observational cohort study. METHODS: A total of 158 antiretroviral-naive patients who initiated HAART between January 2002 and March 2003, and completed at least 6 months of treatment and follow up, were included in the analysis. The response to therapy was assessed by changes in CD4 cell counts and viral loads from baseline. The mean increase in CD4 cell count, the rate of virological success (a viral load of <50 HIV-1 RNA copies/mL) and the rate of immunological success (an increase in CD4 cell count of > or =50 cells/microL over the baseline value) after commencing HAART were measured. RESULTS: In total, 82% of patients (123 of 150) achieved viral loads of <50 copies/mL after 6 months of therapy. Viral success rate after 6 months of HAART was similar irrespective of gender, pre-HAART CD4 cell count and pre-HAART viral load. However, patients older than 40 years were significantly more likely to achieve virological success than those younger than 40 years. At 6 months after starting HAART, 79.5% of patients were estimated to have achieved immunological success and 17.9% had an increase in CD4 cell count of > or =200 cells/microL over the baseline value. The median increase in CD4 cell count for the 156 patients who had CD4 cell counts at baseline and at 6 months of therapy was 122 cells/microL. CONCLUSION: In this cohort of antiretroviral-naive HIV-infected adults, there was a high rate of virological and immunological success after 6 months of HAART, irrespective of the pre-HAART viral load and CD4 cell count.     

Hydroxychloroquine, hydroxyurea and didanosine as initial therapy for HIV-infected patients with low viral load: safety, efficacy and resistance profile after 144 weeks

OBJECTIVES: To evaluate the long-term safety and efficacy of the combination of hydroxychloroquine, hydroxyurea and didanosine. METHODS: We recruited antiretroviral-naive patients with viral loads less than 100 000 HIV-1 RNA copies/mL and CD4 counts greater than 150 cells/microL. All patients received hydroxychloroquine (200 mg), hydroxyurea (500 mg) and didanosine (125-200 mg) twice daily. Clinical and laboratory safety assessments and measurements of viral load and CD4 count were made at regular intervals, and genotypic resistance testing was performed on samples with detectable viral load at 48, 96 and 144 weeks. RESULTS: Fourteen of the 17 patients who commenced therapy remained on treatment at 144 weeks. Treatment was well tolerated but caused neutropenia, usually mild and transient, in 12 patients (71%). Mean viral load was reduced by 1.6 log(10) copies/mL below baseline (P<0.001), eight patients (47%) had undetectable viral load (<400 copies/mL), and two patients (12%) had detectable viral load but no detectable resistance mutations at week 144. Four patients (24%) had detectable viral load together with major resistance mutations (three with both 74 V and 184 V, and one with both 62 V and 65R) at week 144, but still had viral load suppression below baseline. Mean CD4 count was increased by 106 cells/microL above baseline (P=0.07) at week 144. CONCLUSIONS: This novel and well-tolerated combination controls viral replication during long-term follow up, with development of few resistance mutations. With careful monitoring it may be a useful strategy for delaying highly active antiretroviral therapy (HAART) and associated toxicity in selected patients with low initial viral loads.     

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.     

The impact of highly active antiretroviral therapy (HAART) on visceral leishmaniasis in Spanish patients who are co-infected with HIV

Clinicians in Madrid have been observing and treating HIV-positive patients with visceral leishmaniasis (VL) for over a decade. As their records cover some of the co-infection cases that occurred before and after highly active antiretroviral therapy (HAART) was introduced into Spain, retrospective analysis of the records has allowed some of the effects of HAART on local VL to be determined. Encouragingly, HAART appears to have decreased the annual incidence of VL among local AIDS cases, from 4.81 cases/100 to just 0.8 case/100 (P <0.0005), a first episode of VL now appearing only when there is obvious HAART failure. Unfortunately, it does not seem to be very good at preventing VL relapses; within 24 months of antileishmanial treatment, 70% of patients who were receiving HAART had such relapses. The mean time between antileishmanial treatment and VL relapse was, however, longer when HAART was used than when it was not (20 v. 13 months). In those receiving HAART, relapses of the VL often occurred despite increasing CD4+ cell counts and undetectable HIV loads, indicating that successful treatment of the viral infection is insufficient to prevent the relapse of the leishmaniasis. These results are in general agreement with other observations made in Spain. VL relapses are possible and even frequent in HIV-positives who have no more than 200 CD4+ cells/microl, but secondary prophylaxis to prevent VL relapses may be safely suspended if a CD4+ count of >200 cells/microl can be maintained using HAART. VL also seems to hamper the immunological recovery of the HIV-positive, although HAART appears to have little effect on the clinical manifestations of VL.     

Excessive early mortality in the first year of treatment in HIV type 1-infected patients initiating antiretroviral therapy in resource-limited settings

The response to treatment and risk factors for early mortality following initiation of combination antiretrovirals(ARVs) in a cohort of African patients are described in a retrospective cohort design. Medical history, laboratory parameters, and mortality data were reviewed for patients initiating ARVs in 12 clinical centers in Mozambique, Tanzania, and Malawi. Among 3456 HIV-1-infected patients who received ARVs for more than 6 months, at baseline 72% had WHO clinical stages 3/4, 7% had a viral load 400 copies/ml, and 38% had a CD4 cell count >200/microl. One year later, 78% had undetectable virus loads and 79% had CD4 cell counts >200 cells/mm3. In the first year of HAART 260 deaths occurred (97 per 1000 person/years) with mortality peaking in the first 3 months. The highest mortality was observed in patients with low BMI, low hemoglobin levels, and CD4 values <200 cells/microl at baseline. Mortality rates following initiation of HAART are higher in patients in resource-limited areas, particularly in the first 90 days following treatment initiation.HAART initiated at higher CD4 cell count levels, especially among malnourished and/or anemic patients, will carry significant public health impact.     

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.     

Retrospective analysis of suspending HAART in selected patients with controlled HIV replication

We sought to determine the consequences of stopping highly active antiretroviral therapy (HAART) in a group of 41 HIV-infected individuals with undetectable HIV viral loads and CD4+ counts greater than 500 cells per microliter for 6 months or more. Clinical and laboratory parameters were monitored, as was the time to HAART reinitiation. Three months after HAART interruption, the median CD4+ count declined by 162 cells per microliter and HIV viral load increased by 24,000 copies per milliliter. Over the next year, CD4+ counts continued to decrease by an average of 11 cells per microliter per 3-month intervals. In contrast, HIV viral loads remained stable over the same period. Five of 7 patients (71%) with elevated cholesterol levels and 6 of 13 patients (46%) with elevated triglyceride levels had these values normalize after stopping HAART. After a median of 21 months follow-up, 26 of 41 patients (63%) have restarted HAART. Patients with Centers for Disease Control (CDC) HIV/AIDS C classification were more likely to restart HAART than those with A or B classification (p = 0.008). Reasons for HAART restart included clinical events in 8 patients. Fifteen patients restarted HAART for immunologic reasons: CD4+ count less than 300 cells per microliter (n = 7); HIV viral load greater than 55,000 copies per milliliter (n = 3); or both (n = 5). Three patients restarted HAART because of personal preference. Within 4 months, all 26 patients who restarted HAART achieved HIV viral loads less than 50 copies per milliliter. Although patients were able to rapidly achieve nondetectable HIV viral loads after restarting HAART, the inability to foresee clinical events among 8 patients (20%) is disconcerting. We advise caution before HAART interruption, particularly for those patients with a preceding history of significant HIV-related complications.     

Successful discontinuation of fluconazole as secondary prophylaxis for cryptococcosis in AIDS patients responding to highly active antiretroviral therapy

Seven AIDS patients with disseminated cryptococcosis who had had immune reconstitution following highly active antiretroviral therapy (HAART) had discontinued their secondary antifungal prophylaxis to prevent relapse of Cryptococcus neoformans infection. The median CD4+ count was 236 cells/ micro L (range, 117-404 cells/ micro L; mean, 247 cells/ micro L) and the plasma viral loads were undetectable in five patients at discontinuation of antifungal prophylaxis. No relapse of cryptococcosis was detected in these patients after a median observation duration of nine months (range, 5.5-4.1 months, mean, 14.6 months) following discontinuation. Our data and review of the literature suggest that discontinuation of fluconazole prophylaxis is safe in patients with reconstitution of immunity following#10; initiation of HAART.     

Improved outcomes with earlier initiation of highly active antiretroviral therapy among human immunodeficiency virus-infected patients who achieve durable virologic suppression: longer follow-up of an observational cohort study

On the basis of studies with relatively short follow-up, treatment guidelines currently recommend that highly active antiretroviral therapy (HAART) be initiated in asymptomatic human immunodeficiency virus-infected patients when the CD4+ lymphocyte count is < or =200 cells/mm3. We assessed the development of a new opportunistic infection or death among 1173 patients initiating HAART. Durable virologic suppression was defined as having more undetectable (<400 copies/mL) than detectable virus loads after the initiation of therapy. The median durations of therapy and follow-up were 29 and 36 months, respectively. Among patients who achieved durable virologic suppression, those with baseline CD4+ lymphocyte counts of <200 cells/mm3 tended to progress faster than those with baseline CD4+ lymphocyte counts of 201-350 cells/mm3 (P=.09) and progressed faster than those with baseline CD4+ lymphocyte counts of >350 cells/mm3 (P=.01). Among those with durable virologic suppression, there was no difference in disease progression between those with baseline CD4+ lymphocyte counts of 201-350 cells/mm3 and those with durable virologic suppression with baseline CD4+ lymphocyte counts of >350 cells/mm3 (P=.40). Initiating HAART with a CD4+ lymphocyte count of <200 cells/mm3 was associated with a higher risk of disease progression, even with durable virologic suppression. HAART should be initiated at CD4+ lymphocyte counts of >200 cells/mm3.     

Immunophenotype of HIV+ patients during CD4 cell-monitored treatment interruption: role of the IL-7/IL-7 receptor system

OBJECTIVE: To investigate immunological changes during CD4-guided therapy interruption in HIV(+) patients who suspended HAART. PATIENTS: Seventeen patients aged > 18 years, who had received HAART for at least 12 months, and had a pre-interruption CD4+ cell count > 500 cells/microl, interrupted treatment. Median nadir CD4(+) cell count was 288 cells/microl. HIV plasma viral load at discontinuation was < 50 or > 50 copies/ml. Criteria for restarting treatment were: a CD4(+) T-lymphocyte count < 350 cells/microl on two separate occasions, a clinical manifestation of AIDS, and the patient's desire to resume HAART. Eleven patients were still off therapy after 12 months (group A); according to the first criterion, six patients restarted therapy within 12 months (group B). METHODS: Haematological, viro-immunological, cytofluorimetic and molecular assays were performed at baseline and every 2 months following standard methods. Statistical analysis was performed under Stata 7.0. RESULTS: In the first 2 months of treatment interruption, a significant increase in viral load and CD8(+) lymphocyte activation occurred. Then such parameters decreased and remained stable. In all patients, a decrease in CD4(+) lymphocytes took place as well, that affected in a similar manner naive, central memory, effector memory and terminally differentiated cells. Group B always presented lower amounts of CD4(+) effector memory lymphocytes. The expression of CD127 was always higher in group A. CONCLUSIONS: The loss of CD4(+) lymphocytes upon viral rebound is equal among naive and memory subsets. Patients with higher expression of CD127, who are likely to exert a better capacity to utilize endogenous interleukin-7 by T cells, could remain off therapy for longer periods.     

Maintaining antiretroviral therapy reduces the risk of AIDS-defining events in patients with uncontrolled viral replication and profound immunodeficiency.

BACKGROUND: The benefits of continuing antiretroviral therapy are questionable in human immunodeficiency virus (HIV) type 1-infected patients with profound immunodeficiency and multiple treatment failure due to viral resistance. METHODS: From the French Hospital Database on HIV, we selected 12,765 patients with a CD4(+) cell count <200 cells/mm(3) who received a combination antiretroviral therapy (cART) during 2000-2005. Three groups of patients were defined: patients who interrupted cART at least once, patients who had at least 2 consecutive detectable viral loads (VLs) while receiving cART, and patients who had undetectable VL during treatment with cART. Incidence rates and risks of new acquired immunodeficiency syndrome-defining events (ADEs) were assessed among the 3 groups of patients, overall and after CD4(+) cell count stratification (<50 and 50-200 cells/mm(3)). RESULTS: The estimated incidence rates +/- standard deviation of ADEs were 18.5+/-1.9, 14.5+/-0.7, and 4.9+/-0.5, respectively, for patients who interrupted cART, patients who had detectable VL during treatment with cART, and patients who had undetectable VL during treatment with cART. These differences were observed in both CD4(+) cell count strata. Overall, after adjustment, risks of a new ADE in patients who had detectable VL and in patients who had undetectable VL while receiving cART were 22% and 62% lower, respectively, than in patients who stopped cART. Among patients with CD4(+) cell count <50 cells/mm(3), the risk of a new ADE was 22% lower in patients who continued to receive a failing cART regimen than in patients who stopped treatment with cART. Likewise, among patients with a CD4(+) cell count of 50-200 cells/mm(3), the risk was 34% lower in patients who continued to receive a failing cART regimen than in those who stopped taking cART. CONCLUSIONS: Even when effective virological control is no longer achievable, cART still reduces the risk of ADEs in profoundly immunodeficient HIV-infected patients.     

Effect of prolonged discontinuation of successful antiretroviral therapy on CD4+ T cell decline in human immunodeficiency virus-infected patients: implications for intermittent therapeutic strategies

This study evaluates the change in CD4(+) T cell counts among patients who achieved complete viral suppression and subsequently discontinued highly active antiretroviral therapy (HAART). We included 72 human immunodeficiency virus (HIV)-1-infected patients with plasma HIV RNA loads of <500 copies/mL for at least 3 months who then discontinued therapy for at least 12 weeks. The median CD4(+) T decay while off HAART was 16 cells/mm(3)/month (interquartile range, -6 to -34 cells/month). The mean follow-up after therapy ended was 45 weeks. The slope of the CD4(+) T cell decay was inversely correlated with the increase of CD4(+) T cells while receiving HAART, baseline virus load, CD4(+) T cell count at the time therapy was discontinued, age, and duration HIV RNA levels were undetectable. In a multiple regression analysis model, the increase of CD4(+) T cells while receiving therapy and age were independently associated with the rate of CD4(+) T cell loss.     

Utility of repeat genotypic resistance testing and clinical response in patients with three class resistance and virologic treatment failure

We sought to determine the utility of repeat genotypic resistance testing (GRT) and the clinical response in HIV-1-infected patients with known resistance to three of the major classes of antiretroviral drugs. The HIV-1 genetic sequences for 20 patients who had high-level 3 class resistance demonstrated on a prior GRT (3C-GRT 1) measured during the period from November 1, 2000 through July 1, 2004 were retrospectively evaluated. At the time of 3C-GRT 1, the median CD4 count and HIV-1 RNA viral load were 168 cells/mm(3) and 4.5 log copies per milliliter, respectively. The median time to the second GRT (3C-GRT 2) was 17 months. At that time, the median CD4 count and VL were 140 cells/mm(3) and 4.9 log copies per milliliter (p = 0.8 and p = 0.12, respectively). On 3C-GRT 2, all patients retained essentially identical mutations, with the exception of the loss of the M184V mutation in 6 patients. After 3C-GRT 2, all patients continued on protease inhibitor-containing highly active antiretroviral therapy (HAART) regimens. At 24 weeks after 3C-GRT 2, there was no significant change in CD4 count or HIV-1 RNA viral load (p = 0.68 and p = 0.30, respectively). Repeat GRT in patients with documented high-level 3 class resistance does not provide new or clinically useful information. Under continued antiretroviral selective pressure, the viral genetic sequences in this patient population remained stable. In addition, continuing HAART regimens containing protease inhibitors appeared to forestall further immunological and virologic deterioration in patients with multiple resistance mutations. Providers should focus on obtaining access to combinations of novel agents for patients with 3 class resistance rather than repeated GRT.     

高效抗逆转录病毒治疗12个月后艾滋病患者的免疫重建观察

目的探讨高效抗逆转录病毒治疗（HAART）对AIDS患者的疗效及毒副作用。方法45例未经治疗的AIDS病人按基线CD4^＋T细胞计数分为两组,予12个月HAART,分别在基线及治疗1、3、6、9、12个月末随访血浆病毒载量（VL）、T细胞亚群和临床症状。结果抗病毒治疗12个月后45例病人血浆VL平均下降2．8lg拷贝／ml;CD4^＋细胞平均增长187个／μl,其中记忆表型增长119个／μl,纯真表型增长68个／μl,CD4^＋CD28^＋细胞比例显著升高;CD8^＋T激活亚群比例显著降低。基线CD4^＋T细胞计数〉100个／μl的14例病人治疗12个月后有10例血浆VL〈50拷贝／ml,而〈100个／μl的31例病人治疗后仅有11例血浆VL〈50拷贝／ml（P〈0．05）。出现血浆波动的病例数在两组也有统计学差异（分别为2例和14例,P〈0．05）。CD4^＋T细胞计数呈双相增长过程,其增量与血浆VL减少量呈显著正相关。常见的药物副作用有消化道反应、外周神经炎、肝功能损害等。结论HAART方案对AIDS病人有较好的疗效,能够实现免疫重建,但也存在较多毒副作用。     

Response to highly active antiretroviral therapy among severely immuno-compromised HIV-infected patients in Cambodia

BACKGROUND: HAART efficacy was evaluated in a real-life setting in Phnom Penh (Médecins Sans Frontières programme) among severely immuno-compromised patients. METHODS: Factors associated with mortality and immune reconstitution were identified using Cox proportional hazards and logistic regression models, respectively. RESULTS: From July 2001 to April 2005, 1735 patients initiated HAART, with median CD4 cell count of 20 (inter-quartile range, 6-78) cells/microl. Mortality at 2 years increased as the CD4 cell count at HAART initiation decreased, (4.4, 4.5, 7.5 and 24.7% in patients with CD4 cell count > 100, 51-100, 21-50 and < or = 20 cells/microl, respectively; P < 10). Cotrimoxazole and fluconazole prophylaxis were protective against mortality as long as CD4 cell counts remained < or = 200 and < or = 100 cells/microl, respectively. The proportion of patients with successful immune reconstitution (CD4 cell gain > 100 cells/microl at 6 months) was 46.3%; it was lower in patients with previous ART exposure [odds ratio (OR), 0.16; 95% confidence interval (CI), 0.05-0.45] and patients developing a new opportunistic infection/immune reconstitution infection syndromes (OR, 0.71; 95% CI, 0.52-0.98). Similar efficacy was found between the stavudine-lamivudine-nevirapine fixed dose combination and the combination stavudine-lamivudine-efavirenz in terms of mortality and successful immune reconstitution. No surrogate markers for CD4 cell change could be identified among total lymphocyte count, haemoglobin, weight and body mass index. CONCLUSION: Although CD4 cell count-stratified mortality rates were similar to those observed in industrialized countries for patients with CD4 cell count > 50 cells/microl, patients with CD4 cell count < or = 20 cells/microl posed a real challenge to clinicians. Widespread voluntary HIV testing and counselling should be encouraged to allow HAART initiation before the development of severe immuno-suppression.     

Immunological, virological and clinical response to highly active antiretroviral therapy treatment regimens in a complete clinic population. Royal Free Centre for HIV Medicine

BACKGROUND: Highly active antiretroviral therapy (HAART) is now widely used in clinical practice and gives rise to a range of immunological, virological and clinical responses. OBJECTIVES: To describe the immunological, virological and clinical response to HAART and to examine the frequency of modification of the HAART regimen among patients from a single treatment centre. METHODS: Kaplan-Meier estimation and incidence rates were used to describe responses to HAART (a protease inhibitor or non-nucleoside drug in addition to at least two nucleoside analogues) among 421 patients from the Royal Free Hospital in London. RESULTS: The median CD4 cell count at starting HAART was 186 x 10(6) cells/l [interquartile range (IQR) 76-310] and viral load was 5.13 log10 copies/ml (IQR 4.66-5.56). At 6 months after starting HAART, 51.1% of patients were estimated to have experienced a 100 x 10(6) cells/l increase in CD4 cell count; the median time for viral load to fall below 400 copies/ml was 3.7 months (95% confidence interval 3.2-4.4). At 6 months after the first viral load was < 400 copies/ml, 16.4% of patients were estimated to have failed on the basis of a single viral load > 400 copies/ml and 12.4% were estimated to have failed if the more stringent definition of two viral loads above the limit of detection was used. Compared with the pre-HAART era, the incidence of death among patients on HAART was one sixth of that level; new AIDS-defining illnesses was one seventh; and hospital admissions was one fifth. In total, 141 patients (33.5%) stopped at least one of the antiretroviral agents included as part of their HAART regimen; the occurrence of side effects was the most common reason (n = 63; 44.7%). CONCLUSION: A good response occurred to an initial HAART regimen. There was a high rate of virological relapse, which varied considerably according to the definition of failure used. Even so, the rates of clinical progression and hospital admissions observed to date were low. Further follow-up of these patients is required to determine their long-term immunological, virological and clinical outcome.