The EuroSIDA study: 25 years of scientific achievements

The EuroSIDA study was initiated in 1994 and follows adult people living with HIV (PLHIV) in 100 collaborating clinics across 35 countries covering all European regions, Israel and Argentina. The study aims to study the long-term virological, immunological and clinical outcomes of PLHIV and to monitor temporal changes and regional differences in outcomes across Europe. Annually collected data include basic demographic characteristics, information on AIDS- and non-AIDS-related clinical events, and details about antiretroviral therapy (ART), hepatitis C treatment and other medications, in addition to a range of laboratory values. The summer 2016 data set held data from a total of 23 071 individuals contributing 174 481 person-years of follow-up, while EuroSIDA's unique plasma repository held over 160 000 samples. Over the past 25 years, close to 300 articles have been published in peer-reviewed journals (h-index 52), covering a range of scientific focus areas, including monitoring of clinical and virological outcomes, ART uptake, efficacy and adverse events, the influence of hepatitis virus coinfection, variation in the quality of HIV care and management across settings and regions, and biomarker research. Recognizing that there remain unresolved issues in the clinical care and management of PLHIV in Europe, EuroSIDA was one of the cohorts to found The International Cohort Consortium of Infectious Disease (RESPOND) cohort consortium on infectious diseases in 2017. In celebration of the EuroSIDA study's 25th anniversary, this article aims to summarize key scientific findings and outline current and future scientific focus areas.

Improvement of BMD after Switching from Lopinavir/R Plus Two Nucleos(T)ide Reverse Transcriptase Inhibitors to Lopinavir/R Plus Lamivudine: OLE-LIP Substudy

OBJECTIVE

To compare 48-week changes in bone mineral density (BMD) and body fat distribution between patients continuing lopinavir/ritonavir and two NRTIs and those switching to lopinavir/ritonavir and lamivudine.

METHODS

Substudy of a randomized, open-label, multicenter OLE study was carried out. Adult HIV-infected patients with <50 copies/mL for ≥6 months were randomized (1:1) to continue lopinavir/ritonavir and two NRTIs or switching to lopinavir/ritonavir and lamivudine. Dual-energy X-ray absorptiometry (DXA) was performed at baseline and after 48 weeks to measure bone composition and body fat distribution in both the groups.

RESULTS

Forty-one patients (dual-therapy, n = 23; triple-therapy, n = 18) of 239, who received at least one dose of study medication, completed the study: median age, 42 years, 71% male, 73% Caucasian. At week 48, total BMD increased by 1.04% (95% CI, 0.06 to 2.01%) among patients switching to dual-therapy, whereas no significant changes occurred in patients maintaining triple-therapy. Dual-therapy and older age were independently associated with total BMD increase. Among patients discontinuing tenofovir-DF, a significant increase was seen in total BMD (1.43; 95% CI, -0.04 to 2.91) and total hip (1.33%; 95% CI, 0.44 to 2.22%). A non-statistically significant decrease in femoral and spinal BMD was observed in patients who discontinued abacavir and in those continuing triple-therapy. Regarding fat distribution, no significant changes were seen in both the treatment groups.

DISCUSSION

BMD increased following switching to lopinavir/ritonavir plus lamivudine in HIV-infected patients on suppressive triple-therapy with lopinavir/ritonavir and two NRTIs including tenofovir-DF.

Auditing HIV Testing Rates across Europe: Results from the HIDES 2 Study

European guidelines recommend the routine offer of an HIV test in patients with a number of AIDS-defining and non-AIDS conditions believed to share an association with HIV; so called indicator conditions (IC). Adherence with this guidance across Europe is not known. We audited HIV testing behaviour in patients accessing care for a number of ICs. Participating centres reviewed the case notes of either 100 patients or of all consecutive patients in one year, presenting for each of the following ICs: tuberculosis, non-Hodgkins lymphoma, anal and cervical cancer, hepatitis B and C and oesophageal candidiasis. Observed HIV-positive rates were applied by region and IC to estimate the number of HIV diagnoses potentially missed. Outcomes examined were: HIV test rate (% of total patients with IC), HIV test accepted (% of tests performed/% of tests offered) and new HIV diagnosis rate (%). There were 49 audits from 23 centres, representing 7037 patients. The median test rate across audits was 72% (IQR 32–97), lowest in Northern Europe (median 44%, IQR 22–68%) and highest in Eastern Europe (median 99%, IQR 86–100). Uptake of testing was close to 100% in all regions. The median HIV+ rate was 0.9% (IQR 0.0–4.9), with 29 audits (60.4%) having an HIV+ rate >0.1%. After adjustment, there were no differences between regions of Europe in the proportion with >0.1% testing positive (global p = 0.14). A total of 113 patients tested HIV+. Applying the observed rates of testing HIV+ within individual ICs and regions to all persons presenting with an IC suggested that 105 diagnoses were potentially missed. Testing rates in well-established HIV ICs remained low across Europe, despite high prevalence rates, reflecting missed opportunities for earlier HIV diagnosis and care. Significant numbers may have had an opportunity for HIV diagnosis if all persons included in IC audits had been tested.

A comparison of estimated glomerular filtration rates using Cockcroft-Gault and the Chronic Kidney Disease Epidemiology Collaboration estimating equations in HIV infection

OBJECTIVES

The aim of this study was to determine whether the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI)- or Cockcroft-Gault (CG)-based estimated glomerular filtration rates (eGFRs) performs better in the cohort setting for predicting moderate/advanced chronic kidney disease (CKD) or end-stage renal disease (ESRD).

METHODS

A total of 9521 persons in the EuroSIDA study contributed 133 873 eGFRs. Poisson regression was used to model the incidence of moderate and advanced CKD (confirmed eGFR < 60 and < 30 mL/min/1.73 m(2) , respectively) or ESRD (fatal/nonfatal) using CG and CKD-EPI eGFRs.

RESULTS

Of 133 873 eGFR values, the ratio of CG to CKD-EPI was ≥ 1.1 in 22 092 (16.5%) and the difference between them (CG minus CKD-EPI) was ≥ 10 mL/min/1.73 m(2) in 20 867 (15.6%). Differences between CKD-EPI and CG were much greater when CG was not standardized for body surface area (BSA). A total of 403 persons developed moderate CKD using CG [incidence 8.9/1000 person-years of follow-up (PYFU); 95% confidence interval (CI) 8.0-9.8] and 364 using CKD-EPI (incidence 7.3/1000 PYFU; 95% CI 6.5-8.0). CG-derived eGFRs were equal to CKD-EPI-derived eGFRs at predicting ESRD (n = 36) and death (n = 565), as measured by the Akaike information criterion. CG-based moderate and advanced CKDs were associated with ESRD [adjusted incidence rate ratio (aIRR) 7.17; 95% CI 2.65-19.36 and aIRR 23.46; 95% CI 8.54-64.48, respectively], as were CKD-EPI-based moderate and advanced CKDs (aIRR 12.41; 95% CI 4.74-32.51 and aIRR 12.44; 95% CI 4.83-32.03, respectively).

CONCLUSIONS

Differences between eGFRs using CG adjusted for BSA or CKD-EPI were modest. In the absence of a gold standard, the two formulae predicted clinical outcomes with equal precision and can be used to estimate GFR in HIV-positive persons.

Late presentation of HIV infection: a consensus definition

OBJECTIVES

Across Europe, almost a third of individuals infected with HIV do not enter health care until late in the course of their infection. Surveillance to identify the extent to which late presentation occurs remains inadequate across Europe and is further complicated by the lack of a common clinical definition of late presentation. The objective of this article is to present a consensus definition of late presentation of HIV infection.

METHODS

Over the past year, two initiatives have moved towards a harmonized definition. In spring 2009, they joined efforts to identify a common definition of what is meant by a 'late-presenting' patient.

RESULTS

Two definitions were agreed upon, as follows. Late presentation: persons presenting for care with a CD4 count below 350 cells/μL or presenting with an AIDS-defining event, regardless of the CD4 cell count. Presentation with advanced HIV disease: persons presenting for care with a CD4 count below 200 cells/μL or presenting with an AIDS-defining event, regardless of the CD4 cell count.

CONCLUSION

The European Late Presenter Consensus working group believe it would be beneficial if all national health agencies, institutions, and researchers were able to implement this definition (either on its own or alongside their own preferred definition) when reporting surveillance or research data relating to late presentation of HIV infection.

A comparison of the long-term durability of nevirapine, efavirenz and lopinavir in routine clinical practice in Europe: a EuroSIDA study

OBJECTIVES

The durability of combination antiretroviral therapy (cART) regimens can be measured as time to discontinuation because of toxicity or treatment failure, development of clinical disease or serious long-term adverse events. The aim of this analysis was to compare the durability of nevirapine, efavirenz and lopinavir regimens based on these measures.

METHODS

Patients starting a nevirapine, efavirenz or lopinavir-based cART regimen for the first time after 1 January 2000 were included in the analysis. Follow-up started ≥ 3 months after initiation of treatment if viral load was <500 HIV-1 RNA copies/mL. Durability was measured as discontinuation rate or development/worsening of clinical markers.

RESULTS

A total of 603 patients (21%) started nevirapine-based cART, 1465 (51%) efavirenz, and 818 (28%) lopinavir. After adjustment there was no significant difference in the risk of discontinuation for any reason between the groups on nevirapine and efavirenz (P=0.43) or lopinavir (P=0.13). Compared with the nevirapine group, those on efavirenz had a 48% (P=0.0002) and those on lopinavir a 63% (P<0.0001) lower risk of discontinuation because of treatment failure and a 31% (P=0.01) and 66% (P<.0001) higher risk, respectively, of discontinuation because of toxicities or patient/physician choice. There were no significant differences in the incidence of non-AIDS-related events, worsening anaemia, severe weight loss, increased aspartate aminotransferase (AST)/alanine aminotransferase (ALT) levels or increased total cholesterol. Compared with patients on nevirapine, those on lopinavir had an 80% higher incidence of high-density lipoprotein (HDL) cholesterol decreasing below 0.9 mmol/L (P=0.003), but there was no significant difference in this variable between those on nevirapine and those on efavirenz (P=0.39).

CONCLUSIONS

The long-term durability of nevirapine-based cART, based on risk of all-cause discontinuation and development of long-term adverse events, was comparable to that of efavirenz or lopinavir, in patients in routine clinical practice across Europe who initially tolerated and virologically responded to their regimen.

Normalisation of CD4 counts in patients with HIV-1 infection and maximum virological suppression who are taking combination antiretroviral therapy: an observational cohort study

BACKGROUND

Combination antiretroviral therapy (cART) has been shown to reduce mortality and morbidity in patients with HIV. As viral replication falls, the CD4 count increases, but whether the CD4 count returns to the level seen in HIV-negative people is unknown. We aimed to assess whether the CD4 count for patients with maximum virological suppression (viral load <50 copies per mL) continues to increase with long-term cART to reach levels seen in HIV-negative populations.

METHODS

We compared increases in CD4 counts in 1835 antiretroviral-naive patients who started cART from EuroSIDA, a pan-European observational cohort study. Rate of increase in CD4 count (per year) occurring between pairs of consecutive viral loads below 50 copies per mL was estimated using generalised linear models, accounting for multiple measurements for individual patients.

FINDINGS

The median CD4 count at starting cART was 204 cells per microL (IQR 85-330). The greatest mean yearly increase in CD4 count of 100 cells per microL was seen in the year after starting cART. Significant, but lower, yearly increases in CD4 count, around 50 cells per microL, were seen even at 5 years after starting cART in patients whose current CD4 count was less than 500 cells per microL. The only groups without significant increases in CD4 count were those where cART had been taken for more than 5 years with a current CD4 count of more than 500 cells per microL, (current mean CD4 count 774 cells per microL; 95% CI 764-783). Patients starting cART with low CD4 counts (<200 cells per microL) had significant rises in CD4 counts even after 5 years of cART.

INTERPRETATION

Normalisation of CD4 counts in HIV-infected patients for all infected individuals might be achievable if viral suppression with cART can be maintained for a sufficiently long period of time.

Effects of nandrolone decanoate compared with placebo or testosterone on HIV-associated wasting

Objectives Current research is unclear about the most effective pharmacological agents for managing the loss of weight and fat-free mass common in HIV/AIDS. The aim of this study was to compare nandrolone decanoate with placebo and testosterone. Methods The study was a multicentre randomized double-blind placebo-controlled trial. Three hundred and three adult HIV-positive male patients with a weight loss of 5-15% in the last 12 months, or a body mass index of 17-19 kg/m(2), or a body cell mass/height ratio lower than 13.5 kg/m, were randomly assigned to receive nandrolone decanoate (150 mg), testosterone (250 mg) or placebo intramuscularly every 2 weeks for 12 weeks. Fat-free mass, weight, immune markers and perception of treatment were the main outcome measures. Results Treatment with nandrolone resulted in significantly greater increases in fat-free mass [mean increase 1.34 kg; 95% confidence interval (CI) 0.60; 2.08 kg] and in weight (mean increase 1.48 kg; 95% CI 0.82; 2.14 kg) compared with placebo. The mean increase in weight with nandrolone of 1.00 kg (95% CI 0.27; 1.74 kg) when compared with testosterone was significant, although the difference in fat free mass did not reach significance (mean increase 0.69 kg; 95% CI-0.13; 1.51 kg). Patient perception of benefit was significantly greater in the nandrolone group when compared with both the placebo and the testosterone groups. Conclusions Treatment with nandrolone decanoate increased body weight when compared with placebo and testosterone. Nandrolone decanoate treatment resulted in greater increases in fat-free mass than placebo and demonstrated a trend for a significant increase when compared with testosterone.

Thymidine Analogue Mutation Profiles: Factors Associated with Acquiring Specific Profiles and their Impact on the Virological Response to Therapy

Background

Studies have suggested that HIV-1 may develop thymidine analogue mutations (TAMs) by one of two distinct pathways – the TAM1 pathway (including mutations 41L, 210W and 215Y) or the TAM2 pathway (including mutations 67N, 70R and 219E/Q) – under the pressure of a not fully suppressive thymidine-analogue-containing regimen.

Methods

Frozen plasma samples stored in the EuroSIDA repository were selected and sent to two central laboratories for genotypic analysis. We considered 733 patients with at least one genotypic test showing ≥1 TAMs (the first of these tests in chronological order was used). TAM1 and TAM2 genotypic profiles were defined in accordance with previous literature. Statistical modelling involved logistic regression and linear regression analysis for censored data.

Results

The observed frequencies of patterns classifiable as TAM1 or TAM2 profiles were markedly higher than the probabilities of falling into these classifications by chance alone. The chance of detecting a TAM2 profile increased by 25% per additional year of exposure to zidovudine. We found that mutations 67N and 184V were not associated with a particular TAM profile. In the presence of TAM2 profiles, the adjusted mean difference in the 6-month viral reduction was 0.96 log10 copies/ml (95% confidence interval: 0.20; 1.73) higher in patients who started stavudine-containing regimens instead of zidovudine-containing regimens.

Conclusions

This study provides evidence that the suggested TAM clustering is a real phenomenon and that it may be driven by which thymidine analogue the patients has used. In patients with TAM2-resistant viruses, stavudine appears to retain greater viral activity than zidovudine.

Quality of Life in Patients Treated with First-Line Antiretroviral Therapy Containing Nevirapine And/Or Efavirenz

Objective

To assess whether differences in safety profiles between nevirapine (NVP) and efavirenz (EFV), as observed in the 2NN study, translated into differences in ‘health related quality of life’ (HRQoL).

Design

A sub-study of the 2NN study, with antiretro-viral-naive patients randomly allocated to NVP (once or twice daily), EFV or NVP+EFV, in addition to stavudine and lamivudine.

Methods

Comparing differences in changes of HRQoL over 48 weeks as measured with the Medical Outcomes Study HIV Health Survey (MOS-HIV) questionnaire, using analysis of variance.

Results

The 2NN study enrolled 1216 patients. No validated questionnaires were available for 244 patients, and 55 patients had no HRQoL data at all, leaving 917 patients eligible for this sub-study. A total of 471 (51%) had HRQoL measurements both at baseline and week 48. The majority (69%) of patients without HRQoL measurements did, however, complete the study. The change in the physical health score (PHS) was 3.9 for NVP, 3.4 for EFV and 2.4 for NVP+EFV ( P=0.712). For the mental health score (MHS) these values were 6.1, 7.0 and 3.9, respectively ( P=0.098). A baseline plasma HIV-1 RNA concentration (pVL) ≥100 000 copies/ml and a decline in pVL (per log10) were independently associated with an increase of PHS. An increase of MHS was only associated with pVL decline. Patients experiencing an adverse event during follow-up had a comparable change in PHS but a significantly smaller change in MHS, compared with those without an adverse event.

Conclusions

First-line ART containing NVP and/or EFV leads to an improvement in HRQoL. The gain in HRQoL was similar for NVP and EFV, but slightly lower for the combination of these drugs.

HIV Lipodystrophy Case Definition using Artificial Neural Network Modelling

Objective

A case definition of HIV lipodystrophy has recently been developed from a combination of clinical, metabolic and imaging/body composition variables using logistic regression methods. We aimed to evaluate whether artificial neural networks could improve the diagnostic accuracy.

Methods

The database of the case-control Lipodystrophy Case Definition Study was split into 504 subjects (265 with and 239 without lipodystrophy) used for training and 284 independent subjects (152 with and 132 without lipodystrophy) used for validation. Back-propagation neural networks with one or two middle layers were trained and validated. Results were compared against logistic regression models using the same information.

Results

Neural networks using clinical variables only (41 items) achieved consistently superior performance than logistic regression in terms of specificity, overall accuracy and area under the ROC curve. Their average sensitivity and specificity were 72.4 and 71.2%, as compared with 73.0 and 62.9% for logistic regression, respectively (area under the ROC curve, 0.784 vs 0.748). The discriminating performance of the neural networks was largely unaffected when built excluding 13 parameters that patients may not have readily available. The average sensitivity and specificity of the neural networks remained the same when metabolic variables were also considered (total 60 items) without a clear advantage against logistic regression (overall accuracy 71.8%). The performance of networks considering also body composition variables was similar to that of logistic regression (overall accuracy 78.5% for both).

Conclusions

Neural networks may offer a means to improve the discriminating performance for HIV lipodystrophy, when only clinical data are available and a rapid approximate diagnostic decision is needed. In this context, information on metabolic parameters is apparently not helpful in improving the diagnosis of HIV lipodystrophy, unless imaging and body composition studies are also obtained.

Avanti 3: A Randomized, Double-Blind Trial to Compare the Efficacy and Safety of Lamivudine plus Zidovudine versus Lamivudine plus Zidovudine plus Nelfinavir in HIV-1-Infected Antiretroviral-Naive Patients

The objective of our randomized, multicentre, double-blind, placebo-controlled study was to investigate the safety, tolerability, and antiretroviral and immunological effect of double and triple combination therapy regimens. A total of 105 antiretroviral therapy-naive patients were randomized to receive either zidovudine (300 mg twice per day) plus lamivudine (150 mg twice per day) plus nelfinavir placebo (three times per day) ( n=52), or zidovudine/lamivudine (dose as before) plus nelfinavir (750 mg three times per day) ( n=53) for 28 weeks. After this time, patients were allowed to switch to open-label zidovudine/lamivudine/nelfinavir. The overall log10 reduction from baseline in plasma HIV-1 RNA was significantly greater in the zidovudine/lamivudine/nelfinavir group than the zidovudine/lamivudine group ( P=0.001; median treatment difference, –1.01 log10 copies/ml; 95% confidence interval –1.23 to –0.79), as measured by the average area under the curve minus baseline over 28weeks. Increases from baseline in CD4 cell counts were statistically significantly greater in the zidovudine/lamivudine/nelfinavir group (101.5 cells/ml) than the zidovudine/lamivudine group (47.0 cells/ml; P=0.027) at week 28.

Of note, the addition of nelfinavir from weeks 28–52 led to an increase in the proportion of subjects with plasma HIV-1 RNA <400 copies/ml from 17% (9/52 patients on zidovudine/lamivudine) to 50% (13/26 patients who switched to zidovudine/lamivudine/nelfinavir). Incidence of drug-related adverse events was similar in the two groups, except for nausea (more common in zidovudine/lamivudine group; 40 versus 17%) and diarrhoea (more common in zidovudine/lamivudine/nelfinavir group; 45 versus 14%). In conclusion, our study confirms the efficacy of triple combination therapy with two nucleoside analogues and a protease inhibitor compared with double-nucleoside therapy. Interestingly, the addition of nelfinavir to zidovudine/lamivudine, even after 6 months of double nucleoside therapy, led to a substantial virological benefit that was sustained over 24weeks in a subset of patients.

The use of and response to second-line protease inhibitor regimens: results from the EuroSIDA study

OBJECTIVE

To describe the use of second line protease-inhibitor (PI) regimens across Europe and to determine factors associated with virological and immunological response.

DESIGN

Analysis of data from 984 patients with a median follow-up of 21 months enrolled in EuroSIDA. Patients started their second PI-containing regimen at least 16 weeks after starting the first PI-containing regimen and with viral load > 1000 copies/ml.

METHODS

Virological response was defined as a viral load < 500 copies/ml and immunological response as an increase of 50 x 10(6)/l or more in CD4 lymphocyte count.

RESULTS

The median CD4 cell count at starting the second PI was 171 x 10(6) cells/l; viral load was 4.45 log copies/ml. As a second PI regimen, 45% were using a dual PI, while of those on one PI, indinavir (42%) and nelfinavir (34%) were most common. In multivariate Cox models, a higher viral load at starting the second PI [relative hazard (RH), 0.67 per 1 log higher; 95% confidence interval (CI), 0.58-0.77; P < 0.0001) and a lower CD4 cell count (RH, 1.15 per 50% higher; 95% CI, 1.06-1.26; P = 0.0014) were associated with a reduced probability of virological response. Those who had achieved viral suppression on the first PI-regimen were more likely to respond to the second (RH, 1.65; 95% CI, 1.30-2.10; P < 0.0001) as were those who added one or two new nucleosides to their second PI.

CONCLUSIONS

Patients who initiate a second PI regimen at lower viral load, higher CD4 cell count or who added new nucleosides tended to be more likely to achieve a viral load < 500 copies/ml. The roles of cross-resistance and adherence in response to second-line regimens needs further investigation.

AVANTI 1: randomized, double-blind trial to evaluate the efficacy and safety of zidovudine plus lamivudine versus zidovudine plus lamivudine plus loviride in HIV-infected antiretroviral-naive patients. AVANTI Study Group

The objective of this randomized double-blind, placebo-controlled trial was to investigate the effect of combination antiretroviral therapy on plasma HIV-1 RNA as measured by HIV RNA PCR and to assess the safety and tolerability of such regimens. The trial was carried out in seven European countries, Australia and Canada and involved antiretroviral-naive patients (n = 106) with CD4 counts between 150-300 cells/mm3 (CDC group A) and 150-500 cells/mm3 (CDC group B/C). Patients were randomly assigned to zidovudine (200 mg three times daily) plus lamivudine (300 mg twice daily) or to zidovudine plus lamivudine plus loviride (100 mg three times daily) for 52 weeks. The main outcome measures were degree and duration of reduction of plasma HIV-1 RNA as measured by RNA PCR and the development of drug-related toxicities sufficiently severe to warrant dose modification, interruption or permanent discontinuation. A mild, though statistically significant difference in favour of zidovudine plus lamivudine plus loviride for log10 plasma HIV-1 RNA (P = 0.022), as compared to zidovudine plus lamivudine, was observed using area-under-the-curve minus baseline (AUCMB). An increase in CD4 cell count in the zidovudine plus lamivudine plus loviride group was observed with a median improvement of 124 cells/mm3 at week 52 compared with 70 cells/mm3 in the zidovudine plus lamivudine group (P = 0.06). Both treatment regimens were well tolerated.

A comparison of exposure groups in the EuroSIDA study: starting highly active antiretroviral therapy (HAART), response to HAART, and survival

BACKGROUND

Concerns have been raised that intravenous drug users may be less likely to start highly active antiretroviral therapy (HAART) and that adherence to therapy may be poor among this group of patients. Given the decreased mortality and incidence of AIDS-defining illnesses among patients with HIV who start HAART, this may lead to a poorer prognosis among intravenous drug users.

PURPOSE

To compare homosexual men, intravenous drug users, and heterosexuals in EuroSIDA, a prospective European cohort of 7331 patients with HIV in terms of starting a HAART treatment regimen, immunologic and virologic response to therapy, and survival.

METHODS

6645 patients were included in this analysis. Logistic regression and Cox proportional hazards models were used to investigate the factors associated with use of HAART regimens and survival following recruitment to the EuroSIDA study.

RESULTS

In a multivariate logistic regression model, intravenous drug users were significantly less likely to be receiving HAART at recruitment to EuroSIDA (odds ratio [OR], 0.48; 95% confidence interval [CI], 0.37-0.62; p<.0001) when compared with homosexual men. Similarly, during follow-up, intravenous drug users were at a 27% reduced risk of starting HAART, after adjustment for other factors related to starting HAART (relative hazard [RH], 0.73; 95% CI, 0.64-0.82; p<.0001). There were no differences between heterosexual and homosexual patients, and similar results were found within regions of Europe (South, Central and Northern). Among those patients who started HAART, there were no significant differences between exposure groups in CD4 lymphocyte count response to HAART or virologic response to HAART. After adjustment for factors related to survival, intravenous drug users were at a small, but nonsignificant increased risk of death compared with homosexuals (RH 1.16; 95% CI, 0.99-1.38; p = .074).

CONCLUSIONS

Intravenous drug users were significantly less likely to start HAART, but among those who did, response to therapy was similar to that of other exposure groups. There were no differences in risk of death. If intravenous drug users continue to use HAART less commonly than other exposure groups, it may result in a poorer prognosis, a different spectrum of AIDS-defining illnesses, and differential long-term clinical needs.

Coming therapies: amprenavir

Amprenavir is a new peptidomimetic inhibitor of the HIV protease enzyme. Amprenavir has a twice daily dosing schedule and can be administered with or without food making it a convenient dosing regimen among the protease inhibitors (PIs). It is currently being investigated in combination with various nucleoside reverse transcriptase inhibitors (NRTIs) and initial results are promising. Amprenavir may also be useful for salvage therapy in patients failing PI-containing regimens as little cross-resistance has been observed so far with nelfinavir, indinavir or saquinavir. However, amprenavir resistant strains show cross-resistance with ritonavir. Clinical evidence indicates amprenavir is generally well tolerated. However, there is little information to date regarding the ability of amprenavir to cause lipodystrophy or other disturbances of lipid metabolism.

High incidence of herpes zoster in patients with AIDS soon after therapy with protease inhibitors

A high incidence of herpes zoster was noticed among patients with AIDS, shortly after addition of a protease inhibitor to their baseline treatment with nucleoside analogue reverse-transcriptase inhibitors. Within a median follow-up of 64 weeks (range, 34-103 weeks), 14 patients (7%) had a first episode or a recurrence of herpes zoster (6.2 episodes per 100 patient-years). No episodes of zoster were diagnosed before week 4. Twelve episodes (86%) occurred between weeks 4 and 16. The risk of zoster was independent of age, sex, type of protease inhibitor, and CD4+ lymphocyte count and viral load at baseline and month 1. A CD8+ lymphocyte proportion at baseline of > 66% (hazard ratio [HR], 10.6; 95% confidence interval [CI], 3.4-33.1) and an increase in CD8+ lymphocyte proportion at month 1 of > 5% (HR, 32; 95% CI, 8.1-126.4) were independently associated with the risk of herpes zoster. These data might be clinically useful for determining transient prophylaxis for those patients at high risk.

Antiretroviral therapy for HIV infection. A knowledge-based approach to drug selection and use

In the absence of evidence that eradication of HIV from an infected individual is feasible, the established goal of antiretroviral therapy is to reduce viral load to as low as possible for as long as possible. Achieving this with the currently available antiretroviral agents involves appropriate selection of components of combination regimens to obtain an optimal antiviral response. In addition, consideration of a plan for a salvage or second-line regimen is required if initial therapy fails to achieve an optimal response or should loss of virological control occur despite effective initial therapy. Such a planned approach, based on consideration of the likely modes of therapeutic failure (viral resistance, cellular resistance, toxicity) could be called rational sequencing. Choice of therapy should never involve compromise in terms of activity. However, the choice of drug should also be guided by tolerability profiles and considerations of coverage of the widest range of infected cells, compartmental penetration, pharmacokinetic interactions and, importantly, the ability of an agent or combination to limit future therapeutic options through selection of cross-resistant virus. Available clinical end-point data clearly indicate that combination therapy is superior to monotherapy, with clinical and surrogate marker data supporting the use of triple drug (or double protease inhibitor) combinations over double nucleoside analogue combinations. Thus, 3-drug therapy should represent current standard practice in a nontrials setting. Treatment should be considered as early as practical, and may be best guided by measurement of viral load, with a range of other markers having potential utility in individualising treatment decisions. Therapeutic failure may be defined clinically, immunologically or, ideally, virologically, and should prompt substitution of at least 2, and preferably all, components of the treatment regimen. Drug intolerance may also be best managed by rational substitution.

Avanti 1: Randomized, Double-Blind Trial to Evaluate the Efficacy and Safety of Zidovudine plus Lamivudine versus Zidovudine plus Lamivudine plus Loviride in HIV-Infected Antiretroviral-Naive Patients

The objective of this randomized double-blind, placebo-controlled trial was to investigate the effect of combination antiretroviral therapy on plasma HIV-1 RNA as measured by HIV RNA PCR and to assess the safety and tolerability of such regimens. The trial was carried out in seven European countries, Australia and Canada and involved antiretroviral-naive patients ( n=106) with CD4 counts between 150–300 cells/mm3 (CDC group A) and 150–500 cells/mm3 (CDC group B/C). Patients were randomly assigned to zidovudine (200 mg three times daily) plus lamivudine (300 mg twice daily) or to zidovudine plus lamivudine plus loviride (100 mg three times daily) for 52 weeks. The main outcome measures were degree and duration of reduction of plasma HIV-1 RNA as measured by RNA PCR and the development of drug-related toxicities sufficiently severe to warrant dose modification, interruption or permanent discontinuation. A mild, though statistically significant difference in favour of zidovudine plus lamivudine plus loviride for log10 plasma HIV-1 RNA ( P=0.022), as compared to zidovudine plus lamivudine, was observed using area-under-the-curve minus baseline (AUCMB). An increase in CD4 cell count in the zidovudine plus lamivudine plus loviride group was observed with a median improvement of 124 cells/mm3 at week 52 compared with 70 cells/mm3 in the zidovudine plus lamivudine group ( P=0.06). Both treatment regimens were well tolerated.

Meta-analysis of five randomized controlled trials comparing continuation of zidovudine versus switching to didanosine in HIV-infected individuals

A meta-analysis of the original data from 2411 patients in the ACTG 116A, ACTG116B/117, ACTG175, BMS010 and CTN002 trials was conducted to improve the estimate of the effect of switching from zidovudine to didanosine on rates of clinical progression, to better quantify the rates of neurological events (including AIDS dementia and peripheral neuropathy) and to examine the effects of switching from zidovudine to didanosine among women and racial subgroups. In total, 1012 patients received zidovudine therapy, 557 received high-dose didanosine and 842 received didanosine. The median duration of follow-up was 15 months. Ninety-one percent of patients were male, 78% were white, mean age was 36.5 years. The median CD4 count was 195 cells/mm3 (range: 0-762) and the median duration of prior zidovudine therapy was 14 months (range: 0.1-94). There were 336 deaths and 686 new AIDS-defining illnesses (ADIs) or deaths. After stratification by study and adjusting for baseline CD4 count and presence of an AIDS diagnosis prior to baseline, the relative risks of death associated with switching from zidovudine to high-dose didanosine or to didanosine were 0.94 (P = 0.64) and 0.77 (P = 0.07), respectively. The relative risks of a new ADI or death associated with switching from zidovudine to high-dose didanosine and didanosine were 0.78 (P = 0.01) and 0.66 (P = 0.0001), respectively. There were 21 documented cases of AIDS dementia complex (ADC) during the entire follow-up period. The rates per 100 person years of follow-up were 0.70, 0.65 and 0.41 for the zidovudine, high-dose didanosine and didanosine arms, respectively. There were no significant differences in risks of ADC between treatment arms (zidovudine versus high-dose didanosine: P = 0.30, zidovudine versus didanosine: P = 0.97, didanosine versus high-dose didanosine: P = 0.41). Our data confirm a clinical benefit and CD4 increase associated with a switch from zidovudine to didanosine therapy. No statistical differences were detected between doses of didanosine with respect to survival or progression to a new ADI or death. Furthermore, there was no statistical difference in the frequency of ADC between treatment arms.

Regional differences in use of antiretroviral agents and primary prophylaxis in 3122 European HIV-infected patients. EuroSIDA Study Group

Little is known about how widely HIV-related drugs are used outside controlled clinical trials. We therefore assessed factors associated with use of antiretroviral (ARV) therapy and primary prophylactic regimens to prevent HIV-associated opportunistic infections. Baseline data from a prospective study from May to August 1994, on 3122 consecutive HIV infected patients with a CD4 count <500 cells/microl, followed in 37 centers from 16 European countries, were analyzed. Two thousand and twenty patients (65%) were receiving at least 1 ARV drug at the time of the study. ARV therapy was more frequently used among patients from southern and central Europe as compared with patients from northern Europe, especially among patients with CD4 counts >200 cells/microl (73%, 57%, and 42%, respectively, p < 0.0001). Of patients on ARV therapy, 34% received open-label combination therapy. This proportion was higher in central Europe compared with other regions (27%, 50%, and 31% for southern, central, and northern Europe, respectively, p < 0.0001). Primary prophylaxis against Pneumocystis carinii pneumonia (PCP) was used by 85% of patients with a CD4 count <200 cells/microl, without marked regional differences. In patients without esophageal candidiasis or other invasive fungal infections, antifungal drugs were far less frequently used in patients from southern and central Europe compared with patients from northern Europe (10%, 10%, and 25%, respectively, p < 0.0001). Only 5% of patients with a CD4 count <100 cells/microl received rifabutine as primary prophylaxis against nontuberculous mycobacterioses. ARV and antifungal therapies are used differently in different parts of Europe, whereas primary PCP prophylaxis is uniformly administered to most at-risk patients. U.S. recommendations on the use of antimycobacterial prophylaxis have not been implemented in Europe.