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Objective. —To describe the rate of development of immunodeficiency in human immunodeficiency virus (HIV) infection and to relate this to the risk of death. Design. —Inception cohort followed up for up to 12 years from HIV seroconversion until January 1, 1992. Setting. —A regional hemophilia center based in a major teaching hospital. Patients. —All 111 patients with hemophilia who seroconverted to HIV-1 between 1979 and 1985 were registered at the center. Patients have been closely followed up clinically and immunologically. Outcome Measures. —Development of immunodeficiency, defined by a CD4 lymphocyte count falling beneath 0.20 and 0.05 ×109/L, and death. Results. —Kaplan-Meier estimates suggest that almost half (46%; 95% confidence interval [CI], 26% to 66%) of patients alive 12 years after seroconversion will have a CD4 lymphocyte count that has remained above 0.05 ×109/L. Thirty-five percent (95% CI, 22% to 48%) remain above 0.20 ×109/L. Thirty-seven patients died of HIV-related causes, and there was a 52% probability (95% CI, 35% to 69%) of HIV-related mortality by 12 years from seroconversion. Mortality risk was closely associated with severe immunodeficiency. There was only a 15% chance (95% CI, 6% to 25%) of HIV-related death occurring before a CD4 count of below 0.05 × 109/L had been reached. There was an average of one HIV-related death per 96.7 patient-years of observation before the CD4 count had fallen below 0.05 ×109/L, as compared with one death per 2.5 patient-years of observation after the CD4 count had fallen below this level (P Conclusions. —In patients with HIV infection who are closely followed up, the risk of death is low before the CD4 lymphocyte count has fallen to 0.05 × 109/L, a count many patients remain above up to 12 years after seroconversion. (JAMA. 1992;268:2662-2666)

To the Editor. —In their study of female-to-male transmission of HIV, Padian et al1draw attention to the considerable methodological difficulties in the design of partner studies, in particular the biases that may lead to overestimation of the risk of transmission and their careful attempts to overcome them. As they discuss, their estimate is lower than many other studies.1,2In addition to the issues raised by Padian et al, we suggest that another explanation for the differences could be a methodological problem in their own study that produces a bias toward zero in the estimated transmission rate. The study recruited both men and women infected with HIV and tested the serostatus of their heterosexual partners. For concordantly infected couples, the direction of transmission was ascertained by identifying a "well-established" source of risk for one partner. Overall, 379 couples were reported, 62 of whom were concordantly infected—an "either direction" heterosexual

To the Editor. —Halsey et al 1 reported an association between cigarette smoking and the risk of HIV-1 infection in Haitian women that remained after adjustment for "all known risk factors." The authors suggest two alternative explanations for their results: First, that there is a "hidden" or "unrecognized" confounder that has not been accounted for and, second, that there is a biologic effect of cigarette smoking on the risk of HIV transmission. We would like to suggest a third possibility, namely, that the association is not due to an unknown confounder, but rather the inability to properly measure a well-known confounder—frequency of unprotected sexual intercourse with an HIV-infected man or men. The dichotomous variable "≥3 lifetime sexual partners" that was used in the study is only a poor proxy measure of this true confounder and thus considerably underestimates its association with risk of HIV infection. 2-4 The underestimation of the

112 haemophilic patients infected with HIV were followed up with clinical and laboratory assessment between 1 December 1979 and 30 November 1988. Sixty-six (59%) of the patients developed HIV-related clinical symptoms and 22 (20%) developed AIDS. Twenty (18%) of the patients developed p24 antigenaemia. Amongst the 59 patients whose date of seroconversion could be estimated the calculated 8-year cumulative incidence of AIDS was 40% (symptoms 73%). For the whole cohort of 112 patients, the median slope of linear regression of the absolute T4 lymphocyte count was steeper for those with AIDS (-0.113 x 10(9)/l per year) than for those without AIDS (-0.054 x 10(9)/l per year) (P less than 0.02). While 15 cases of AIDS developed during 58 patient-years of follow up after falling below a T4 lymphocyte count of 0.2 x 10(9)/l, only two cases occurred during 450 patient-years before reaching this count. Thus the decline of the T4 lymphocyte count to 0.2 x 10(9)/l may be an appropriate additional end-point for the assessment of new treatments for asymptomatic patients infected with HIV.

Serial CD4 lymphocyte counts were recorded in 112 anti-HIV-positive haemophiliacs who were followed for up to 8 years after seroconversion. The patients remained at low risk of developing AIDS until their CD4 lymphocyte count fell to 0.25 X 10(9)/l. From this point, the risk increased as their count approached zero. Using this result and on the assumption (which is evaluated) that the underlying trend over time in CD4 lymphocyte counts is linear, the predicted rate of progression to AIDS was calculated for the cohort. It was estimated that 73% (95% confidence limits 60-86%) of the cohort will develop AIDS within 15 years of HIV-seropositivity. During 8 years of follow-up, this cohort had shown similar rates of progression to AIDS to other cohorts--haemophilic and otherwise--suggesting that this estimate may well have general applicability. The method described could be used to plan the provision of health-care resources for groups of anti-HIV-positive patients as it allows the number of new cases of AIDS to be predicted year by year, even when the patients' dates of seroconversion are unknown.

SummaryBackgroundCombination antiretroviral therapy has substantially increased life-expectancy in people living with HIV, but the effects of chronic infection on health-related quality of life (HRQoL) are unclear. We aimed to compare HRQoL in people with HIV and the general population.MethodsWe merged two UK cross-sectional surveys: the ASTRA study, which recruited participants aged 18 years or older with HIV from eight outpatient clinics in the UK between Feb 1, 2011, and Dec 31, 2012; and the Health Survey for England (HSE) 2011, which measures health and health-related behaviours in individuals living in a random sample of private households in England. The ASTRA study has data for 3258 people (response rate 64%) and HSE for 8503 people aged 18 years or older (response rate 66%). HRQoL was assessed with the Euroqol 5D questionnaire 3 level (EQ-5D-3L) instrument that measures health on five domains, each with three levels. The responses are scored on a scale where a value of 1 represents perfect health and a value of 0 represents death, known as the utility score. We used multivariable models to compare utility scores between the HIV and general population samples with adjustment for several sociodemographic factors.Findings3151 (97%) of 3258 of participants in ASTRA and 7424 (87%) of 8503 participants in HSE had complete EQ-5D-3L data. The EQ-5D-3L utility score was lower for people with HIV compared with that in the general population (marginal effect in utility score adjusted for age, and sex/sexuality −0·11; 95% CI −0·13 to −0·10; p0·05).InterpretationPeople living with HIV have significantly lower HRQoL than do the general population, despite most HIV positive individuals in this study being virologically and immunologically stable. Although this difference could in part be due to factors other than HIV, this study provides additional evidence of the loss of health that can be avoided through prevention of further HIV infections.FundingUK National Institute for Health Research.

Fetal movements in the uterus are a natural part of development and are known to play an important role in normal musculoskeletal development. However, very little is known about the biomechanical stimuli that arise during movements in utero, despite these stimuli being crucial to normal bone and joint formation. Therefore, the objective of this study was to create a series of computational steps by which the forces generated during a kick in utero could be predicted from clinically observed fetal movements using novel cine-MRI data of three fetuses, aged 20–22 weeks. A custom tracking software was designed to characterize the movements of joints in utero, and average uterus deflection of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$6.95 \pm 0.41$$\end{document}6.95±0.41 mm due to kicking was calculated. These observed displacements provided boundary conditions for a finite element model of the uterine environment, predicting an average reaction force of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$0.52 \pm 0.15$$\end{document}0.52±0.15 N generated by a kick against the uterine wall. Finally, these data were applied as inputs for a musculoskeletal model of a fetal kick, resulting in predicted maximum forces in the muscles surrounding the hip joint of approximately 8 N, while higher maximum forces of approximately 21 N were predicted for the muscles surrounding the knee joint. This study provides a novel insight into the closed mechanical environment of the uterus, with an innovative method allowing elucidation of the biomechanical interaction of the developing fetus with its surroundings.

Contains fulltext : 154578.pdf (Publisher’s version ) (Open Access) BACKGROUND: Mathematical models are widely used to simulate the effects of interventions to control HIV and to project future epidemiological trends and resource needs. We aimed to validate past model projections against data from a large household survey done in South Africa in 2012. METHODS: We compared ten model projections of HIV prevalence, HIV incidence, and antiretroviral therapy (ART) coverage for South Africa with estimates from national household survey data from 2012. Model projections for 2012 were made before the publication of the 2012 household survey. We compared adult (age 15-49 years) HIV prevalence in 2012, the change in prevalence between 2008 and 2012, and prevalence, incidence, and ART coverage by sex and by age groups between model projections and the 2012 household survey. FINDINGS: All models projected lower prevalence estimates for 2012 than the survey estimate (18.8%), with eight models' central projections being below the survey 95% CI (17.5-20.3). Eight models projected that HIV prevalence would remain unchanged (n=5) or decline (n=3) between 2008 and 2012, whereas prevalence estimates from the household surveys increased from 16.9% in 2008 to 18.8% in 2012 (difference 1.9, 95% CI -0.1 to 3.9). Model projections accurately predicted the 1.6 percentage point prevalence decline (95% CI -0.3 to 3.5) in young adults aged 15-24 years, and the 2.2 percentage point (0.5 to 3.9) increase in those aged 50 years and older. Models accurately represented the number of adults on ART in 2012; six of ten models were within the survey 95% CI of 1.54-2.12 million. However, the differential ART coverage between women and men was not fully captured; all model projections of the sex ratio of women to men on ART were lower than the survey estimate of 2.22 (95% CI 1.73-2.71). INTERPRETATION: Projections for overall declines in HIV epidemics during the ART era might have been optimistic. Future treatment and HIV prevention needs might be greater than previously forecasted. Additional data about service provision for HIV care could help inform more accurate projections. FUNDING: Bill & Melinda Gates Foundation.

The importance of variable time of entry for analysis of survival following variceal bleeding has recently been disputed. In a study of 194 cirrhotic patients with bleeding esophageal varices in whom 2-day mortality was 3%, statistically significant differences in both survival and rebleeding rates were obtained by shifting the starting point for analysis of survival by 2 weeks following admission to hospital or by 5 days for the analysis of rebleeding. In addition, the curve of hazard function for death or for failure to control bleeding following admission clearly showed that any change in entry time in a study of variceal bleeding would introduce bias and alter survival or rebleeding rates. Thus, the starting point for analysis following variceal hemorrhage is an important confounding variable when calculating both survival and rebleeding. It should always be taken into account, particularly in clinical trials, which are often performed in centers where patients are referred from other hospitals at different times following bleeding.

Some studies have suggested that lean hypertensive men may be at greater risk of major ischaemic heart disease (IHD) events than obese hypertensive men. The issue was examined on data from the British Regional Heart Study for 7735 middle-aged men followed up for an average of 7·5 years; during this time 443 men experienced a major IHD event. Hypertension was defined as systolic blood pressure of 160 mm Hg or above, diastolic blood pressure of 95 mm Hg or above, or receiving treatment for hypertension. For both hypertensive and normotensive men the rate of major IHD events, standardised for age and cigarette smoking, rose with increasing body mass index (BMI). The relative odds associated with a 5 kg/m 2 difference in BMI (ie, a 15 kg difference in weight in men of average height [1·73 m]) were 1·30 (p=0·02) and 1·43 (p=0·0004) for hypertensive and normotensive men, respectively. A review of eleven prospective studies, including the British Regional Heart Study, presented in standard form for comparative purposes, suggests that lean hypertensive men are not at higher risk of major IHD events than overweight/obese hypertensive men. There seems to be no justification for the suggestion that a policy of weight reduction to lower blood pressure might be inappropriate.

Methods of determining the required number of disease cases for estimation of relative odds in prospective studies are evaluated, with examples from coronary heart disease. Data from a British prospective study of coronary heart disease are used in simulation exercises to assess the reliability of estimation formulae for both continuous and categorical risk factors. For continuous risk factors, a univariate formula based on estimation of the standardized relative odds (Whittemore A. S. JAMA 1981; 76: 27-32 [1]), gives reliable estimation of the required number of disease cases, provided the risk factor has a near normal distribution. An extension of the formula to adjustment for other risk factors, was less satisfactory, perhaps because of departures from multivariate normality. For categorical risk factors, an adaption of a univariate method for case control studies (Smith PG, Day NE. Int J Epidemiol 1984; 13: 356-365 [2]), gives reliable estimates of the number of cases required. However, this depends on approximate prior knowledge of the relative odds. In general, prospective studies of coronary heart disease risk factors should aim for at least 400 cases to enable sufficient accuracy of estimation.

We compared two procedures for the emergency treatment of bleeding esophageal varices in patients who did not respond to blood transfusion and vasoactive drugs. We randomly assigned 101 patients with cirrhosis of the liver and bleeding esophageal varices to undergo either emergency sclerotherapy (n = 50) or staple transection of the esophagus (n = 51). Four patients assigned to sclerotherapy and 12 assigned to staple transection did not actually undergo those procedures, but all analyses were made on an intention-to-treat basis. Total mortality did not differ significantly between the two groups; the relative risk of death for staple transection as compared with sclerotherapy was 0.88 (95 percent confidence interval, 0.51 to 1.54). Mortality at six weeks was 44 percent among those assigned to sclerotherapy and 35 percent among those assigned to staple transection. Complication rates were similar for the two groups. An interval of five days without bleeding was achieved in 88 percent of those assigned to staple transection and in 62 percent of those assigned to sclerotherapy after a single injection (P less than 0.01) and 82 percent after three injections. In only 2 of the 11 patients who received a third sclerotherapy injection was bleeding controlled for more than five days, and 9 died. We conclude that staple transection of the esophagus is as safe as sclerotherapy for the emergency treatment of bleeding esophageal varices and that it is more effective than a single sclerotherapy procedure. We currently recommend surgery after two injection treatments have failed.

The role of mutations in protease (PR) and reverse-transcriptase (RT) of human immunodeficiency virus (HIV) in predicting virologic failure was assessed in 248 antiretroviral-naive HIV-positive patients who began a PR inhibitor-containing antiretroviral regimen. Genotypic testing was performed on plasma samples stored before the start of therapy. Twenty-seven patients (10.9%) had mutations in the RT, 5 (2%) carried primary mutations in the PR, and 131 (52.8%) showed only secondary PR mutations. Virologic failure at week 24 occurred in 62 (25.0%) of 248 patients. There was a statistically significant correlation between virologic failure and the number of PR mutations (P= .04, chi(2) test). Mutations at codons 10 and 36 of PR (present in 39.3% and 40.0% of patients in whom treatment failed, respectively) were identified by stepwise logistic regression as the strongest predictors of virologic failure (odds ratio, 2.20; 95% confidence interval, 1.30-3.75; P= .004). If confirmed in independent studies, this result may justify the increased use of HIV genotyping in drug-naive patients requiring antiretroviral therapy.

The impact of highly active antiretroviral therapy (HAART) among human immunodeficiency virus (HIV)-infected patients on the incidences of mycobacterial infections has not been studied in detail. We assessed incidences of mycobacterial diseases among HIV- infected patients following the introduction of HAART, using data from the EuroSIDA study, a European, multicenter observational cohort of more than 7,000 patients. Overall incidences of Mycobacterium tuberculosis (TB) and Mycobacterium avium complex (MAC) were 0.8 and 1.4 cases/100 person-years of follow-up (PYF), decreasing from 1.8 (TB) and 3.5 cases/100 PYF (MAC) before September 1995 to 0.3 and 0.2 cases/100 PYF after March 1997. After adjustment for changes in CD4 cell count and use of antiretroviral treatment in Cox proportional hazards models, the risk of MAC decreased with increasing calendar time (hazard ratio per calendar year; HR = 0.58 [95% confidence intervals: 0.45–0.74], whereas this was not the case for TB; 0.95 [0.74–1.22]). In conclusi...

OBJECTIVES: To determine whether rate of development of AIDS is affected by category of exposure to HIV and whether the more rapid development found in older subjects persists for each exposure category. DESIGN: Longitudinal study of people with known date of seroconversion to HIV. SETTING: 16 HIV treatment centres throughout Italy. SUBJECTS: 1199 people infected with HIV through use of injected drugs, homosexual sex, or heterosexual sex. MAIN OUTCOME MEASURES: AIDS as defined by 1987 definition of Centers for Disease Control (including and excluding neoplasms) and by 1993 European definition. RESULTS: 225 subjects (18.8%) progressed to AIDS (Centers for Disease Control 1987 definition) during median follow up of 5.8 years. Univariate analyses showed more rapid progression to AIDS for older subjects compared with younger subjects and for homosexual men compared with other exposure categories. The age effect was of similar size in each exposure category and in men and women. In a bivariate model with age and exposure categories simultaneously included as covariates, differences by exposure category disappeared for use of injected drugs and heterosexual sex compared with homosexual sex (relative hazards 1.02 (95% confidence interval 0.71 to 1.45) and 1.07 (0.70 to 1.64) respectively), while the age effect remained (relative hazard 1.55 (1.32 to 1.83) for 10 year increase in age). Analyses using the other definitions for AIDS did not appreciably change these results. CONCLUSIONS: There was no evidence of differences in rate of development of AIDS by exposure category, while there was a strong tendency for more rapid development in older subjects for all three groups. This supports the view that external cofactors do not play major role in AIDS pathogenesis but that age is of fundamental importance.

The interrelationships between the CD4 lymphocyte count, plasma viral load [human immunodeficiency virus (HIV) RNA], beta-2-microglobulin (beta2-M) and immunoglobulin A (IgA) and the mortality risk was explored in 234 HIV-infected individuals (median CD4 count 230 cells/mm3, range 1-1,247). Product-moment correlation analysis was used to study the association between beta2-M, IgA and HIV RNA. A proportional hazards Cox model was used to estimate the relative hazard (RH) of death. Both beta2-M (r = 0.49, p < 0.0001) and IgA (r = 0.42, p < 0.0001) were positively correlated with HIV RNA. High beta2-M levels were associated with an increased risk of death in both univariate Cox analysis and after adjustment for HIV RNA, CD4 lymphocyte count and age [RH = 1.16 per 100 nmol/l higher beta2-M, 95% confidence interval (CI) 1.05-1.27]. Raised IgA levels were associated with shorter survival in individuals with a CD4 count above 50 cells/mm3 in univariate analysis as well as after adjusting for age and CD4 lymphocyte count (RH = 1.19 per 10 micromol/l higher IgA, 95% CI 1.01-1.39). However, this association was no longer significant after further adjusting for HIV RNA. In conclusion, beta2-M levels provided additional prognostic information for survival to the information obtained by CD4 count and HIV RNA levels, whereas serum IgA only was a weak prognostic marker in this fairly progressed cohort.

It has consistently been reported that older AIDS patients have a shortened survival compared with younger patients. The aim of the present study was to investigate whether this difference in survival is caused by differences in the pattern of the complicating diseases. Information on patient follow-up after the AIDS diagnosis was obtained by retrospective case note review. The 6,546 patients were followed from the time of AIDS diagnosis as part of the multicentre AIDS in Europe study, which examined AIDS cases diagnosed at 52 centres in 17 European countries between 1979 and 1989. Occurrence of AIDS-defining events and demographic variables were recorded for all patients, and CD4 lymphocyte count at the time of AIDS diagnosis for approximately half the patients. After adjusting for imbalances in other variables, personsor = 50 years of age had a significantly higher risk of contracting AIDS wasting syndrome, AIDS dementia complex and oesophageal candidiasis after the initial AIDS diagnosis, compared with age group 30-39 years [relative risk (RR) 95% confidence interval (CI)], 3.23 (2.70-3.75 CI); 2.48 (2.16-2.80 CI); 1.55 (1.26-1.83 CI), respectively]. Shortened survival after the time of AIDS diagnosis was associated with older age. After adjusting for pattern of complicating diseases, the age effect remained unchanged. Older age predisposes to AIDS-related wasting syndrome, AIDS dementia complex and oesophageal candidiasis. Independent of these differences, older age is significantly associated with shortened survival, suggesting that factors such as severity of complicating diseases or the capability of handling serious infections, rather than disease pattern, are responsible for the shortened survival.

To evaluate survival according to use of different nucleoside drugs in a routine clinical setting, we studied a large group of zidovudine-treated patients seen in clinics across Europe. A total of 3128 subjects was recruited to the observational, prospective EuroSIDA study in May 1994. These were consecutive patients (up to a predefined limit) seen at outpatient clinics in 37 centers from 16 European countries and followed at 6-month intervals by use of standardized forms completed by clinicians at the respective centers. This report concerns 2367 subjects who began antiretroviral therapy with a regime that included zidovudine either before study entry or during the course of follow-up. Cox proportional hazards models were fitted, with use of other antiretroviral drugs, CD4 count, and date of development of AIDS fitted as time-dependent covariates. Survival times from start of therapy were left truncated at study entry to avoid survival bias. In addition to zidovudine, antiretroviral drugs used included didanosine (ddI) (n = 1119; median 1.6 years after starting zidovudine), dideoxycytidine (ddC) (n = 592; median 1.9 years after starting zidovudine), stavudine (d4T) (n = 241; median 2.9 years after starting zidovudine) and lamivudine (3TC) (n = 33 ; median 2.7 years after starting zidovudine). Of the 2367 patients, 613 died during follow-up. Overall, risk of death was reduced in those zidovudine-treated patients who began at least one other nucleoside analogue drug with or after taking zidovudine (relative hazard [RH], 0.61; 95% confidence interval [CI], 0.51-0.72, adjusting for CD4 count, development of AIDS, and age). Fitting each drug separately, there was a larger association with reduced mortality for starting 3TC (RH, 0.41; 95% CI, 0.28-0.62) than for starting ddl (RH, 0.79; 95% CI, 0.67-0.93), ddC (RH, 0.74; 95% CI, 0.59-0.92) or d4T (RH, 0.67; 95% CI, 0.49-0.91). These results suggest that the beneficial effect of nucleoside combination therapy identified in controlled trials can be seen in routine clinical practice.

Objectives: To evaluate the association between time since initiation of pre-AIDS antiretroviral therapy [mainly with zidovudine (ZDV)] and AIDS-free survival in a cohort of HIV seroconverters, and to assess possible differences in this association and in the use of antiretroviral therapy by HIV exposure group.Design: Observational study of HIV-infected individuals, both those treated with antiretroviral therapy and those untreated, enrolled in an ongoing prospective cohort (median follow-up, 5.3 years).Setting: Sixteen HIV outpatient clinics throughout Italy.Patients: A total of 1078 individuals infected with HIV through injecting drug use or home-/heterosexual activity, and with accurately estimated dates of seroconversion.Main outcome measures and methods: Kaplan-Meier estimates of the probability of receiving antiretroviral therapy before AIDS. Crude and adjusted relative hazards of AIDS and of death from AIDS using Cox regression models.Results: The cumulative incidence of beginning pre-AIDS antiretroviral therapy within 7 years of seroconversion was 49.2%. Injecting drug users (IDU) were less likely to undergo antiretroviral treatment before AIDS than homosexual men and heterosexual contacts. The adjusted relative hazard of developing AIDS for patients treated with ZDV (relative hazard adjusted for occurrence of acute HIV disease, pre-AIDS HIV-related diseases, CD4 count, and use of prophylaxis for Pneumocystis carinii pneumonia) was 0.57 within the first year of starting zidovudine and 0.92 after 1 year of therapy. Stratifying by HIV exposure category, the adjusted relative hazards of AIDS for individuals who started ZDV less and more than 1 year before AIDS were 0.74 and 0.99 among IDU, 0.31 and 0.89 among homosexual men, and 0.69 and 0.72 among heterosexuals, respectively. Similar results were obtained when using death from AIDS as an endpoint.Conclusions: IDU began pre-AIDS antiretroviral therapy significantly later than homosexual men and heterosexuals, even after adjusting for CD4 count. Results from this non-randomized study confirm that antiretroviral treatment has only a short-term clinical benefit. There was a stronger association between antiretroviral treatment and lower risk of AIDS in homosexual men than in IDU.

ObjectivesTo investigate the ability of several HIV-1 drug-resistance interpretation systems, as well as the number of pre-specified combinations of abacavir-related mutations, to predict virological response to abacavir-containing regimens in antiretroviral therapy-experienced, abacavir-naive patients starting an abacavir-containing regimen in the EuroSIDA cohort.Patients and methodsA total of 100 HIV-infected patients with viral load (VL) >500 copies/ml who had a plasma sample available at the time of starting abacavir (baseline) were included. Resistance to abacavir was interpreted by using eight different commonly used systems that consisted of rules-based algorithms or tables of mutations. Correlation between baseline abacavir-resistance mutations and month 6 virological response was performed on this population using a multivariable linear regression model accounting for censored data.ResultsThe baseline VL was 4.36 log10RNA copies/ml [interquartile range (IQR): 3.65–4.99 log10RNA copies/ml] and the median CD4 cell count was 210 cells/μl (IQR: 67–305 cells/μl). Our patients were pre-exposed to a median of seven antiretrovirals (2–12) before starting abacavir therapy. The median (range) number of abacavir mutations (according to the International AIDS Society-USA) detected at baseline was 3.5 (0–8). Overall, the Kaplan–Meier estimate of the median month 6 VL decline was 0.86 log10RNA copies/ml [95% confidence intervals (95% CI): 0.45–1.24]. The VL in those patients ( n=31) who intensified treatment by adding only abacavir decreased by a median 0.20 log10RNA copies/ml (95% CI: -0.18; +0.94). The proportion of patients who harboured viruses fully resistant to abacavir among the eight genotypic resistance interpretation algorithms ranged from 12% [Agence Nationale de Recherches sur le SIDA (ANRS)] to 79% [Stanford HIV RT and PR Sequence Database (HIVdb)]. Some interpretation systems showed statistically significant associations between the predicted resistance status and the virological response while others showed no consistent association. The number of active drugs in the regimen was associated with greater virological suppression (additional month 6 VL reduction per additional sensitive drug=0.51, 95% CI: 0.15–0.88, P=0.006); baseline VL was also weakly associated (additional month 6 VL reduction per log10higher=0.30, 95% CI: -0.02; +0.62, P=0.06). In contrast, the number of drugs previously received was associated with diminished viral reduction (additional month 6 VL reduction per additional drug=-0.14, 95% CI: -0.28; 0.00, P=0.05).ConclusionsOur results revealed a high degree of variability among several genotypic resistance interpretation algorithms currently in use for abacavir. Therefore, the interpretation of genotypic resistance for predicting response to regimens containing abacavir remains a major challenge.

ObjectivesTo compare two analytic approaches to assess the virological effect of HAART according to the intention-to-treat (ITT) principle.MaterialData from 2318 patients enrolled in 10 randomised clinical trials (RCTs) and from 3091 patients followed in an observation cohort (EuroSIDA) starting their first HAART regimen.MethodsTwo classifications of defining virological response 48 weeks after starting the therapy to be evaluated were compared: 1) only patients remaining on the therapy and having a plasma viral load (pVL) below a given cut-off level at week 48 were classified as responders (ITT/s=f); and 2) patients with a pVL below a given cut-off at week 48 whether they remained on initial assigned therapy or switched therapy were responders (ITT/s incl). In both analyses, patients with missing data at week 48 were classified as failures (i.e., non-responders).ResultsAccording to ITT/s=f, 22–70% of the patients starting a HAART regimen in a RCT experienced a virological response at week 48. Only two RCTs had complete follow-up data ( n=424): between 29 and 62% achieved a virological response at week 48 in the six treatment arms evaluated in the studies according to ITT/s=f, and 41–72% according to ITT/s incl. Among those who discontinued the therapy to be evaluated in these two trials, 13–45% (cohort: 39–74%) subsequently experienced a virological response at week 48. The subsequent response rates were associated with the reason for discontinuation (toxicity versus confirmed virological failure: 63 vs 33%), varied largely across regimens and were not associated with the discontinuation rate.ConclusionsDiscontinuation of follow-up at switch from the therapy to be evaluated remains common in anti-retroviral treatment trials, but leads to an imprecise and incomplete assessment of the intrinsic effect of a given regimen. Complete follow-up of all patients should be encouraged strongly as this will allow for several complementary analytic approaches and a focus on optimal treatment strategies rather than specific regimens.

Macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, and RANTES production were measured by ELISA in whole blood that had been stimulated for 4.5 h with phytohemagglutinin. The blood was from 90 healthy human immunodeficiency virus (HIV)-negative controls and from 245 HIV-infected subjects who were followed for < or = 4.5 years. HIV-infected persons without AIDS had increased levels of MIP-1alpha, MIP-1beta, and RANTES (P < .01) compared with levels in controls. Subjects with AIDS, compared with controls, had decreased production levels of MIP-1beta (P < .0001) and similar levels of MIP-1alpha and RANTES. A high level of MIP-1beta production was associated with a decreased risk of progressing to AIDS or death, as determined by univariate analysis (P < .01) and adjusted for CD4 cell count and age (P = .07, P = .06, respectively). The findings suggest that the production level of beta-chemokine changes during HIV infection and that a high level of beta-chemokine production in peripheral blood lymphocytes may be associated with less rapid disease progression in HIV infection.

The clinical presentation of HIV-1 related diseases could have changed after the introduction of highly active antiretroviral treatment (HAART). We aimed to assess changes over time in the incidence of ADIs overall and within CD4 lymphocyte count strata, the relationship with treatment and degree of immunodeficiency at diagnosis of ADIs.We did a prospective observational multicentre study of over 7300 patients in 52 European HIV-1 outpatient clinics. Incidence rates per 100 patient-years of observation were calculated.In total, we recorded 1667 new ADIs; the incidence of ADIs declined from 30.7 per 100 patient-years of observation during 1994 (95% CI 28.0-33.4) to 2.5 per 100 patient-years of observation during 1998 (95% CI 2.0-3.0, p0.0001, test for trend). Median CD4 lymphocyte count at diagnosis of a new ADI increased from 28 cells/microL to 125 cells/microL between 1994 and 1998 (p0.0001), yet a steep decline in the rate of ADIs was seen after stratification by latest CD4 lymphocyte count within each year (or = 50, 51-200, and200 cells/microL). Patients on HAART had a lower rate of ADIs than patients not on this treatment within each CD4 lymphocyte count strata. The proportion of ADIs attributable to cytomegalovirus retinitis and Mycobacterium avium complex declined over time (p=0.0058 and 0.0022, respectively), whereas the proportion of diagnoses attributable to non-Hodgkin lymphoma has increased (p0.0001). In 1994, less than 4% of ADIs were non-Hodgkin lymphoma, in 1998 the proportion was almost 16%. This condition has become one of the most common ADIs in patients on HAART.Our findings lend support to the idea that treatment regimens can lower the incidence of ADIs. The immediate risk of an ADI for a given CD4 lymphocyte count has declined over time and is lower among patients on HAART. Long-term follow-up of patients on combination treatment is essential to monitor the incidence of new and emerging diagnoses.

The aim of this review is to summarise the evidence on the population-level effect of antiretroviral therapy (ART) in preventing HIV infections, and to discuss potential implications in the European context of recommending starting ART when the CD4 count is above 350 cells/mm3. The ability of ART to reduce the risk of HIV transmission has been reported in observational studies and in a randomised controlled trial (HPTN 052), in which ART initiation reduced HIV transmission by 96% within serodiscordant couples. As yet, there is no direct evidence for such an effect among men having sex with men or people who inject drugs. HPTN 052 led international organisations to develop recommendations with a higher CD4 threshold for ART initiation. However, there remains a lack of strong evidence of clinical benefit for HIV-positive individuals starting ART with CD4 count above 350 cells/mm3. The main goal of ART provision should be to increase ART coverage for all those in need, based on the current guidelines, and the offer of ART to those who wish to reduce infectivity; increased HIV testing is therefore a key requirement. Other proven prevention means such as condom use and harm reduction for people who inject drugs remain critical.

Summary Background The introduction of combination antiretroviral therapy and protease inhibitors has led to reports of falling mortality rates among people infected with HIV-1. We examined the change in these mortality rates of HIV-1-infected patients across Europe during 1994-98, and assessed the extent to which changes can be explained by the use of new therapeutic regimens. Methods We analysed data from EuroSIDA, which is a prospective, observational, European, multicentre cohort of 4270 HIV-1-infected patients. We compared death rates in each 6 month period from September, 1994, to March, 1998. Findings By March, 1998, 1215 patients had died. The mortality rate from March to September, 1995, was 23·3 deaths per 100 person-years of follow-up (95% Cl 20·6–26·0), and fell to 4·1 per 100 person-years of follow-up (2·3–5·9) between September, 1997, and March, 1998. From March to September, 1997, the death rate was 65·4 per 100 person-years of follow-up for those on no treatment, 7·5 per 100 person-years of follow-up for patients on dual therapy, and 3·4 per 100 person-years of follow-up for patients on triple-combination therapy. Compared with patients who were followed up from September, 1994, to March, 1995, patients seen between September, 1997, and March, 1998, had a relative hazard of death of 0·16 (0·08–0·32), which rose to 0·90 (0·50–1·64) after adjustment for treatment. Interpretation Death rates across Europe among patients infected with HIV-1 have been falling since September, 1995, and at the begining of 1998 were less than a fifth of their previous level. A large proportion of the reduction in mortality could be explained by new treatments or combinations of treatments.

BackgroundIn recent years, several new drugs from the protease inhibitor (PI) class designed to treat HIV infection have become available and the use of ritonavir-boosting has increased in popularity. These changes might be expected to affect the prevalence and patterns of protease resistance in the population of patients who experience treatment failure.MethodsThe UK HIV Drug Resistance Database aims to capture the results of all genotypic resistance tests conducted nationally. Tests on antiretroviral therapy-experienced patients were identified through linkage with the UK Collaborative HIV Cohort Study, from which detailed clinical information on these patients, including a full antiretroviral therapy history, was obtained.ResultsAnalyses were on the basis of 8,553 genotypic resistance tests carried out between 1998 and 2005, during which time the overall prevalence of protease resistance halved from 35% to 16%. Substantial declines were observed regardless of whether the patient had been exposed to unboosted PIs and/or boosted PIs. The frequency of protease resistance among patients who had received boosted PIs fell sharply until 2002 with a weaker trend thereafter, falling to 12% in 2005. Individual mutations L33F, M46I/L, V82A/F/T/S/L and I84V became relatively more frequent over the period of study.ConclusionsThe decline in protease resistance was partly due to increasing use of ritonavir-boosting. Nonetheless, the prevalence of resistance was higher than suggested by clinical trials, indicating that prolonged exposure to a boosted PI could ultimately select for major protease mutations.

Objective The benefit of transient combination antiretroviral treatment (CART) during acute HIV infection is uncertain. We used the seroconverter database CASCADE to provide a historical comparison for the Quest trial, in which 79 subjects with acute HIV infection received CART for an average of 2.6 years, and 17.7% (95% confidence interval [CI]: 10.9–27.6) fulfilled the primary endpoint of VL≤1,000 copies/ml 24 weeks after CART discontinuation. Methods We estimated the prevalence of VL ≤1,000 copies/ml three years after seroconversion and prior to any ART among 385 sexually infected subjects in CASCADE who seroconverted between 1988 and 1996. We conducted a pre-specified comparison with the recently published Quest results, and considered potential biases. Results and discussion The prevalence of VL ≤1,000 copies/ml at year three in CASCADE was 10.1% (95% CI: 7.5–13.5) (absolute difference compared to 17.7% in Quest: 7.6%; 95% CI: -0.1–17.8; P=0.053). In CASCADE, VL≤1,000 copies/ml was less common among homosexual and heterosexual men compared with women (8.5%, 7.3% and 17.6% respectively) and in subjects with symptomatic infection compared with those without (6.2% and 12.6%, respectively). As Quest had a much greater proportion of symptomatic subjects than CASCADE, any true difference in VL might be underestimated. Therefore this comparison suggests that transient CART in acute infection might result in a modest increase in the probability of low VL subsequently. However, several factors mitigate this conclusion. First, this historical comparison might be subject to other unmeasured confounders. Second, a comparison of median VL at the same time point was not significant (4.02 copies/ml and 4.20 copies/ml in Quest and CASCADE, respectively; P=0.55). Finally, additional analysis suggested that the observed difference in low VL at year three would be consistent with an immediate effect of CART only - a delay of usual VL decline without additional benefit. Conclusions A small but significant proportion of seroconverters have low VL without ART. Transient CART in acute infection might increase the probability of low VL after treatment discontinuation, but such an effect is likely to be modest, and might represent a delay of natural history rather than a long-term therapeutic benefit.

BACKGROUND: With the aging of the population living with HIV, the absolute risk of cardiovascular disease (CVD) is increasing. There is a need to further facilitate the identification of persons at elevated risk in routine practice.METHODS AND RESULTS: Prospective information was collected on 32,663 HIV-positive persons from 20 countries in Europe and Australia, who were free of CVD at entry into the Data-collection on Adverse Effects of Anti-HIV Drugs (D:A:D) study. Cox regression models (full and reduced) were developed that predict the risk of a global CVD endpoint. The predictive performance of the D:A:D models were compared with a recent CVD prediction model from the Framingham study, which was assessed recalibrated to the D:A:D dataset. A total of 1010 CVD events occurred during 186,364.5 person-years. The full D:A:D CVD prediction model included age, gender, systolic blood pressure, smoking status, family history of CVD, diabetes, total cholesterol, high-density lipoprotein, CD4 lymphocyte count, cumulative exposure to protease- and nucleoside reverse transcriptase-inhibitors, and current use of abacavir. A reduced model omitted antiretroviral therapies. The D:A:D models statistically significantly predicted risk more accurately than the recalibrated Framingham model (Harrell's c-statistic of 0.791, 0.783 and 0.766 for the D:A:D full, D:A:D reduced, and Framingham models respectively; p CONCLUSIONS: An updated, easily recalibrated, global CVD-risk equation tailored to HIV-positive persons was developed using routinely collected CVD risk parameters and incorporating markers on immune function (CD4 lymphocyte count), and exposure to antiretroviral therapies. The estimated CVD risk can be used to quantify risk and to guide preventive care.

In most European countries, HIV drug resistance testing has become a routine clinical tool. However, its practical implementation in a clinical context is demanding. The European HIV Drug Resistance Panel was established to make recommendations to clinicians and virologists on this topic and to propose quality control measures. The panel recommends resistance testing for the following indications: i) drug-naive patients with acute or recent infection; ii) therapy failure, including suboptimal treatment response, when treatment change is considered; iii) pregnant HIV-1-infected women and paediatric patients with detectable viral load when treatment initiation or change is considered; and iv) genotype source patient when post-exposure prophylaxis is considered. In addition, for drug-naive patients with chronic infection in whom treatment is to be started, the panel suggests that resistance testing should be strongly considered and recommends testing the earliest sample for drug resistance if suspicion of resistance is high or prevalence of resistance in this population exceeds 10%. The panel does not favour genotyping over phenotype, however it is anticipated that genotyping will be used more often because of its greater accessibility, lower cost and faster turnaround time. For the interpretation of resistance data, clinically validated systems should be used to the greatest extent possible. It is mandatory that laboratories performing HIV resistance tests take regular part in quality assurance programs. Similarly, it is necessary that HIV clinicians and virologists take part in continuous education and meet regularly to discuss problematic clinical cases. Indeed, resistance test results should be used in the context of all other clinically relevant information for predicting therapy response. The panel also encourages the timely collection of epidemiological information to estimate the impact of transmission of resistant HIV and the prevalence of HIV-1 non-B subtypes in the different European countries. ispartof: Antiviral therapy vol:9 issue:6 pages:829-848 ispartof: location:England status: published

Objective To examine whether the level of primary resistance to HIV drugs is increasing in the United Kingdom. Design Multicentre observational study. Setting All virology laboratories in the United Kingdom carrying out tests for HIV resistance as part of routine clinical care. Participants 2357 people infected with HIV who were tested for resistance before receiving antiretroviral therapy. Main outcome measure Prevalence of drug resistance on basis of the Stanford genotypic interpretation system. Results Over the study period (February 1996 to May 2003), 335 (14.2%, 95% confidence interval 12.8% to 15.7%) samples had mutations that conferred resistance to one or more antiretroviral drugs (9.3% high level resistance, 5.9% medium level resistance). The prevalence of primary resistance has increased markedly over time, although patterns are specific to drug class; the largest increase was for non-nucleoside reverse transcriptase inhibitors. In 2002-3, the prevalence of resistance to any antiretroviral drug to nucleoside or nucleotide reverse transcriptase inhibitors, to non-nucleoside reverse transcriptase inhibitors, or to protease inhibitors was 19.2% (15.7% to 23.2%), 12.4% (9.5% to 15.9%), 8.1% (5.8% to 11.1%), and 6.6% (4.4% to 9.3%), respectively. The risk of primary resistance was only weakly related to most demographic and clinical factors, including ethnicity and viral subtype. Conclusions The United Kingdom has one of the highest reported rates of primary resistance to HIV drugs worldwide. Prevalence seems still to be increasing and is high in all demographic subgroups.

Meta-analysis is a statistical procedure that integrates the results of several independent studies considered to be “combinable.”1 Well conducted meta-analyses allow a more objective appraisal of the evidence than traditional narrative reviews, provide a more precise estimate of a treatment effect, and may explain heterogeneity between the results of individual studies.2 Ill conducted meta-analyses, on the other hand, may be biased owing to exclusion of relevant studies or inclusion of inadequate studies.3 Misleading analyses can generally be avoided if a few basic principles are observed. In this article we discuss these principles, along with the practical steps in performing meta-analysis. Meta-analysis should be viewed as an observational study of the evidence. The steps involved are similar to any other research undertaking: formulation of the problem to be addressed, collection and analysis of the data, and reporting of the results. Researchers should write in advance a detailed research protocol that clearly states the objectives, the hypotheses to be tested, the subgroups of interest, and the proposed methods and criteria for identifying and selecting relevant studies and extracting and analysing information. As with criteria for including and excluding patients in clinical studies, eligibility criteria have to be defined for the data to be included. Criteria relate to the quality of trials and to the combinability of treatments, patients, outcomes, and lengths of follow up. Quality and design features of a study can influence the results.4 5 Ideally, researchers should consider including only controlled trials with proper randomisation of patients that report on all initially included patients according to the intention to treat principle and with an objective, preferably blinded, outcome assessment.6 Assessing the quality of a study …

Objective: To investigate the clinical implications of impaired levels of the natural immunity mediated by natural killer (NK) cells and lymphokine activated killer (LAK) cells during infection with HIV-1.Design: Data used were from 172 individuals with an estimated measure of NK cell activity and 146 with an estimated measure of LAK cell activity. Patients had active HIV infection at the time of enrolment in the study and have been follow-up prospectively for a median of 3.0 years.Methods: The lytic activity of NK cells and LAK cells, the CD4 T lymphocyte count, and the concentration of CD16/CD56 NK cells were measured at enrolment. HIV RNA in plasma was measured retrospectively. Survival analysis was performed considering three main endpoints: CD4 cell counts below 100 x 10(6) cells/l, clinical AIDS, and death.Results: In unadjusted analysis and after adjustment for age, CD4 T lymphocyte count and plasma HIV RNA at enrolment, low LAK cell activity was significantly associated with higher risk of progression to a CD4 T lymphocyte count < 100 x 106 cells/l (crude P = 0.001; adjusted P = 0.04) and to death (crude P = 0.0002; adjusted P = 0.02). Patients with low NK cell responsiveness to interferon-alpha tended to be at higher risk of death (crude P = 0.04; adjusted P = 0.13) whereas unstimulated NK cell activity and the concentration of NK cells were of no prognostic value for patients in this cohort.Conclusions: The present study suggests that low LAK cell activity and low NK cell responsiveness to interferon-alpha may be important in the pathogenesis of HIV infection. (C) 1999 Lippincott Williams & Wilkins.

BackgroundStudies 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.MethodsFrozen 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.ResultsThe 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 log10copies/ml (95% confidence interval: 0.20; 1.73) higher in patients who started stavudine-containing regimens instead of zidovudine-containing regimens.ConclusionsThis 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.

Objectives To compare the development rate of new AIDS-defining diseases between 566 women and 1988 men with AIDS who were infected with HIV via the same routes (mainly by sharing drug injecting equipment and heterosexual sex). Design Information on patient follow-up after AIDS diagnosis was obtained by retrospectively reviewing case notes. Methods The 2554 men and women were followed from the time of AIDS diagnosis as part of the multicentre AIDS in Europe study, which examined AIDS cases diagnosed at 52 centres in 17 European countries between 1979 and 1989. Incidence of AIDS-defining diseases and demographic variables were recorded for all patients and CD4 lymphocyte count at the time of AIDS diagnosis for approximately half the patients. Results Only toxoplasmosis and herpes simplex virus ulceration showed statistically significant differences in occurrence rate between women and men [relative risks (RR), 1.51 and 3.44; 95% confidence interval (CI), 1.51 1.09-2.08 and 3.44 1.92-6.23, respectively] which remained after adjusting for imbalances in other variables. For both diseases, the additional absolute rate in women was approximately three per 100 person-years at risk. Survival after AIDS diagnosis was also similar between the two sexes (RR, 0.96; 95% CI, 0.86-1.08). Conclusion There appears to be little difference between women and men in the clinical course of AIDS.