Combining hippocampal volume metrics to better understand Alzheimer's disease progression in at-risk individuals.

To date nearly all clinical trials of Alzheimer's disease (AD) therapies have failed. These failures are, at least in part, attributable to poor endpoint choice and to inadequate recruitment criteria. Recently, focus has shifted to targeting at-risk populations in the preclinical stages of AD thus improved predictive markers for identifying individuals likely to progress to AD are crucial to help inform the sample of individuals to be recruited into clinical trials. We focus on hippocampal volume (HV) and assess the added benefit of combining HV and rate of hippocampal atrophy over time in relation to disease progression. Following the cross-validation of previously published estimates of the predictive value of HV, we consider a series of combinations of HV metrics and show that a combination of HV and rate of hippocampal atrophy characterises disease progression better than either measure individually. Furthermore, we demonstrate that the risk of disease progression associated with HV metrics does not differ significantly between clinical states. HV and rate of hippocampal atrophy should therefore be used in tandem when describing AD progression in at-risk individuals. Analyses also suggest that the effects of HV metrics are constant across the continuum of the early stages of the disease.

Delayed linkage to care in one-third of HIV-positive individuals in the Netherlands.

OBJECTIVES: To determine time to linkage to HIV care following diagnosis and to identify risk factors for delayed linkage. METHODS: Patients newly diagnosed with HIV at sexually transmitted infections (STI) clinics in the Netherlands were followed until linkage to care. Data were collected at the time of diagnosis and at first consultation in care, including demographics, behavioural information, CD4+ counts and HIV viral load (VL) measurements. Delayed linkage to care was defined as >4 weeks between HIV diagnosis and first consultation. RESULTS: 310 participants were included; the majority (90%) being men who have sex with men (MSM). For 259 participants (84%), a date of first consultation in care was known; median time to linkage was 9 days (range 0-435). Overall, 95 (31%) of the participants were not linked within 4 weeks of diagnosis; among them, 44 were linked late, and 51 were not linked at all by the end of study follow-up. Being young (<25 years), having non-Western ethnicity or lacking health insurance were independently associated with delayed linkage to care as well as being referred to care indirectly. Baseline CD4+ count, VL, perceived social support and stigma at diagnosis were not associated with delayed linkage. Risk behaviour and CD4+ counts declined between diagnosis and linkage to care. CONCLUSIONS: Although most newly diagnosed patients with HIV were linked to care within 4 weeks, delay was observed for one-third, with over half of them not yet linked at the end of follow-up. Vulnerable subpopulations (young, uninsured, ethnic minority) were at risk for delayed linkage. Testing those at risk is not sufficient, timely linkage to care needs to be better assured as well.

Risk of non-AIDS-defining events among HIV-infected patients not yet on antiretroviral therapy.

OBJECTIVES: Certain non-AIDS-related diseases have been associated with immunodeficiency and HIV RNA levels in HIV-infected patients on combination antiretroviral therapy (cART). We aimed to investigate these associations in patients not yet on cART, when potential antiretroviral-drug-related effects are absent and variation in RNA levels is greater. METHODS: Associations between, on the one hand, time-updated CD4 counts and plasma HIV RNA and, on the other hand, a composite non-AIDS-related endpoint, including major cardiovascular diseases, liver fibrosis/cirrhosis, and non-AIDS-related malignancies, were studied with multivariate Poisson regression models in 12 800 patients diagnosed with HIV infection from 1998 onwards while not yet treated with cART. RESULTS: During 18 646 person-years of follow-up, 203 non-AIDS-related events occurred. Compared with a CD4 count ≥ 500 cells/µL, adjusted relative risks (RRs) for the composite endpoint were 4.71 [95% confidence interval (CI) 2.98-7.45] for a CD4 count < 200 cells/µL, 2.06 (95% CI 1.38-3.06) for a CD4 count of 200-349 cells/µL, and 1.19 (95% CI 0.82-1.74) for a CD4 count of 350-499 cells/µL. There was no evidence for an independent association with HIV RNA. Other important covariates were age [RR 1.40 (95% CI 1.31-1.49) per 5 years older], hepatitis B virus coinfection [RR 5.66 (95% CI 3.87-8.28)] and hepatitis C virus coinfection [RR 9.26 (95% CI 6.04-14.2)]. CONCLUSIONS: In persons not yet receiving cART, a more severe degree of immunodeficiency rather than higher HIV RNA levels appears to be associated with an increased risk of our composite non-AIDS-related endpoint. Larger studies are needed to address these associations for individual non-AIDS-related events.

High incidence of intermittent care in HIV-1-infected patients in Curaçao before and after starting cART.

Retention in care is one of the major challenges to scaling up and maximizing the effectiveness of combination antiretroviral therapy (cART). High attrition rates have been reported in the Caribbean region, varying from 6% to 23%. We studied the incidence of and risk factors for intermittent care in a cohort of adult HIV-1-positive patients, who entered into care in Curaçao between January 2005 and July 2009. A total of 214 therapy-naïve HIV-1-infected patients aged 15 years or older, entered HIV care between January 2005 and July 2009. Intermittent care was defined as at least one period of 365 days or longer in which there was no HIV care contact in Curaçao. Cox regression models were used to identify characteristics associated with time to intermittent care. In all, 203 (95%) patients could be classified as having intermittent or continuous care. The incidence of intermittent care before starting cART was 25.4 per 100 person years observation (PYO), whilst it was 6.1 per 100 PYO after starting cART. Being born outside Curaçao was associated with intermittent care before and after starting cART. Time from diagnosis to entry into care was an independent predictor for intermittent care before starting cART. Younger age was independently associated with intermittent care after starting cART. Half of the patients returned to care after intermitting care. Upon returning to care, median CD4 count was 264 cells/mm(3) (IQR, 189-401) for those who intermitted care before starting cART, and 146 cells/mm(3) (IQR, 73-436) in those who intermitted care after starting cART. In conclusion, the incidence of intermitting care is high in Curaçao, especially before starting cART, and intermitting care before starting cART is an independent predictor for starting cART late.

Temporary antiretroviral treatment during primary HIV-1 infection has a positive impact on health-related quality of life: data from the Primo-SHM cohort study.

OBJECTIVES: The aim of the study was to compare health-related quality of life (HRQL) over 96 weeks in patients receiving no treatment or 24 or 60 weeks of combination antiretroviral therapy (cART) during primary HIV-1 infection (PHI). METHODS: A multicentre prospective cohort study of PHI patients, with an embedded randomized trial, was carried out. HRQL was assessed with the Medical Outcomes Study Health Survey for HIV (MOS-HIV) and a symptom checklist administered at weeks 0, 8, 24, 36, 48, 60, 72, 84 and 96. Mixed linear models were used for the analysis of differences in HRQL among the three groups. RESULTS: A total of 112 patients were included in the study: 28 received no treatment, 45 received 24 weeks of cART and 39 received 60 weeks of cART. Over 96 weeks of follow-up, the groups receiving 24 and 60 weeks of cART had better cognitive functioning than the no-treatment group (P = 0.005). Patients receiving 60 weeks of cART had less pain (P = 0.004), better role functioning (P = 0.001), better physical functioning (P = 0.02) and a better physical health summary score (P = 0.006) than the groups receiving no treatment or 24 weeks of cART. Mental health was better in patients receiving 24 weeks of cART than in patients in the no-treatment group or the group receiving 60 weeks of cART (P = 0.02). At week 8, patients in the groups receiving 24 and 60 weeks of cART reported more nausea (P = 0.002), diarrhoea (P < 0.001), abdominal pain (P = 0.02), stomach pain (P = 0.049) and dizziness (P = 0.01) than those in the no-treatment group. These differences had disappeared by week 24. CONCLUSIONS: Temporary cART during PHI had a significant positive impact on patients' HRQL as compared with no treatment, despite the initial, short-term occurrence of more physical symptoms, probably related to drug toxicity.

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.

Hydrogels of collagen-inspired telechelic triblock copolymers for the sustained release of proteins.

We studied the release of entrapped protein from transient gels made of thermosensitive, collagen-inspired ABA triblock copolymers with tailorable properties and with mid blocks of two different lengths (~37 kDa and ~73 kDa). These polymers were produced as heterologous proteins in recombinant yeast. By varying polymer length and concentration, the elastic properties of the hydrogels as well as their mesh size, swelling and erosion could be tuned. Whereas the volume of the investigated dense networks decreased in time as a result of temperature- and polymer concentration-dependent surface erosion, the release of entrapped protein was governed by a combination of gel erosion and protein diffusion. The prevalence of one or the other was strongly dependent on polymer concentration. Most importantly, the encapsulated protein was quantitatively released, which demonstrates that these hydrogels offer great potential as drug delivery systems.

Baseline lipid levels rather than the presence of reported body shape changes determine the degree of improvement in lipid levels after switching to atazanavir.

PURPOSE: To study factors influencing lipid changes after switching to atazanavir (ATV) and the effectiveness of ATV in maintaining virus suppression. METHODS: Retrospective cohort study in patients with viral suppression, comparing patients switching to ATV with those continuing combination antiretroviral therapy (cART). Outcome measures were 48-week total (TC), high-density (HDL) and low-density lipoprotein (LDL) cholesterol, and triglycerides (TG) changes, stratified for dyslipidemia and lipodystrophy and virological failure (time to first of two consecutive detectable HIV RNA). RESULTS: 225 patients switched to ATV (193 [85.8%] RTV boosted), and 3120 continued cART. In patients with baseline TC >6.2 mmol/L, those switching had greater mean (95% CI) TC decreases compared to those continuing cART (-1.26 [-1.63 to -0.89] and -0.54 [-0.64 to -0.44] mmol/L, p = .002). Likewise greater TG changes were observed in patients with high (>2.3 mmol/L) baseline TG (-1.44 [-2.05 to -0.83] and -0.54 [-0.70 to -0.38] mmol/L, p = .002). Effects were seen irrespective of presence of lipodystrophy. Patients switching to ATV had virological failure more often (17/224 [7.8%]) than those continuing cART (73/3100 [2.4%], p < .0001). CONCLUSIONS: Patients with virological suppression, including those with lipodystrophy, may benefit from switching to ATV with lipid profile improvement, especially if baseline lipid levels are high. This should be balanced against a possible higher virological failure risk.

Steady-state nevirapine plasma concentrations are influenced by pregnancy.

OBJECTIVES: Optimal plasma concentrations of antiretroviral drugs are required during pregnancy to treat maternal HIV infection and prevent mother-to-child transmission. We investigated the effect of pregnancy on nevirapine (NVP) plasma concentrations. METHODS: We included all HIV-1-infected women for whom NVP plasma concentrations were available as part of routine patient care at two university hospitals. Plasma NVP concentrations were compared for pregnant (n=45) and non-pregnant (n=152) women. Univariate and multivariate linear regression analyses were used to identify and adjust for other confounding factors associated with NVP plasma concentrations. For pregnant women who had a plasma NVP concentration available both during and outside pregnancy, a paired analysis was performed. RESULTS: Steady-state NVP plasma concentrations were lower in pregnant women: 5.2 mg/L (interquartile range 3.9-6.8) vs. 5.8 mg/L (4.3-7.7) (P=0.08). After adjusting for confounders, both pregnancy (regression coefficient=-0.90 mg/L, P=0.046) and African descent (regression coefficient=+1.13 mg/L, P=0.005) influenced NVP concentrations significantly. The paired analysis showed mean concentrations of 4.8 mg/L during pregnancy and 5.8 mg/L outside pregnancy (paired t-test, P=0.073). CONCLUSIONS: Pregnancy has a moderate but significant lowering effect on NVP plasma concentrations. Being of African descent compensates for the lowering effect of pregnancy on NVP concentrations.

Therapeutic drug monitoring of the HIV protease inhibitor atazanavir in clinical practice.

BACKGROUND: Therapeutic drug monitoring (TDM) is being applied for a number of antiretroviral agents. Little is known about the use of TDM for atazanavir. METHODS: This is a retrospective cohort analysis on the use of TDM of atazanavir at three clinical sites in The Netherlands. Patients were divided into three groups: (i) all patients with evaluable data of plasma atazanavir concentrations and its relationship with hyperbilirubinaemia; (ii) patients who started atazanavir without documented evidence of protease inhibitor (PI) mutations; (iii) patients who started atazanavir with documented evidence of PI mutations. The genotypic inhibitory quotient (GIQ) was calculated by dividing the mean atazanavir plasma trough concentration by the number of PI mutations. RESULTS: A total of 108 patients were included; 70 (65.8%) were using atazanavir/ritonavir (300/100 mg once daily). No significant relationship was observed between atazanavir plasma trough concentration and antiviral response in patients starting atazanavir without PI mutations (group 2; n = 82). In contrast, a significant relationship was observed between atazanavir GIQ and treatment response in patients starting atazanavir while having PI mutations (group 3; n = 26). The cut-off value for GIQ most predictive of virological failure was 0.23 mg/L/mutation: patients (n = 8) with a GIQ equal to or below this value had 50% virological failure whereas patients (n = 18) with a GIQ above 0.23 mg/L/mutation had only 11% virological failure (chi(2): P = 0.030). Atazanavir plasma trough concentrations were significantly related with the occurrence of increased total bilirubin concentrations. CONCLUSIONS: TDM of atazanavir might be beneficial for patients with documented PI resistance or patients with hyperbilirubinaemia.

Gender difference in HIV-1 RNA viral loads.

OBJECTIVES: To test and characterize the dependence of viral load on gender in different countries and racial groups as a function of CD4 T-cell count. METHODS: Plasma viral load data were analysed for > 30,000 HIV-infected patients attending clinics in the USA [HIV Insight (Cerner Corporation, Vienna, VA, USA) and Plum Data Mining LLC (East Meadow, NY, USA) databases] and the Netherlands (Athena database; HIV Monitoring Foundation, Amsterdam, Netherlands). Log-normal regression models were used to test for an effect of gender on viral load while adjusting for covariates and allowing the effect to depend on CD4 T-cell count. Sensitivity analyses were performed to test the robustness of conclusions to assumptions regarding viral loads below the lower limit of quantification (LLOQ). RESULTS: After adjusting for covariates, women had (nonsignificantly) lower viral loads than men (HIV Insight: -0.053 log(10) HIV-1 RNA copies/mL, P = 0.202; Athena: -0.005 log(10) copies/mL, P = 0.667; Plum: -0.072 log(10) copies/mL, P = 0.273). However, further investigation revealed that the gender effect depended on CD4 T-cell count. Women had consistently higher viral loads than men when CD4 T-cell counts were at most 50 cells/microL, and consistently lower viral loads than men when CD4 T-cell counts were greater than 350 cells/microL. These effects were remarkably consistent when estimated independently for the racial groups with sufficient data available in the HIV Insight and Plum databases. CONCLUSIONS: The consistent relationship between gender-related differences in viral load and CD4 T-cell count demonstrated here explains the diverse findings previously published.

Differential CD4 T-cell response in HIV-1-infected patients using protease inhibitor-based or nevirapine-based highly active antiretroviral therapy.

OBJECTIVES: To study the dynamics of CD4 T-lymphocyte counts (CD4 counts) after the initiation of either protease inhibitor (PI)-based or nevirapine (NVP)-based first-line highly active antiretroviral therapy (HAART). DESIGN AND METHODS: A retrospective cohort study of 1029 HIV-infected antiretroviral therapy-naive patients initiating either PI-based or NVP-based HAART was carried out. Patients were censored as soon as they experienced virological failure, or changed their original antiretroviral regimen for any reason. RESULTS: In total, 920 and 109 patients initiated PI- and NVP-based HAART, respectively. The patients in the PI group more often had AIDS (15 vs. 6% in the NVP group), had a lower median baseline CD4 count (234 vs. 250 cells/microL in the NVP group) and had higher median baseline plasma HIV-1 RNA levels (pVL) (5.0 vs. 4.7 log10 HIV-1 RNA copies/mL in the NVP group). After 96 weeks of follow-up, the mean increase from baseline in CD4 count, adjusted for baseline CD4 count, age, gender and baseline pVL, was 310 cells/microL in the PI group and 212 cells/microL in the NVP group (P=0.003). This difference was mainly attributable to the patients in the NVP group initiating HAART with a baseline CD4 count below 200 cells/microL. There were no differences between the PI and NVP groups with respect to the change in the number of CD4 cells as a proportion of the total number of lymphocytes. CONCLUSION: Patients successfully treated with NVP-based HAART have a smaller increase in absolute CD4 cells compared with those treated with PI-based HAART.

Prognostic importance of initial response in HIV-1 infected patients starting potent antiretroviral therapy: analysis of prospective studies.

BACKGROUND: We examined whether the initial virological and immunological response to highly active antiretroviral treatment (HAART) is prognostic in patients with HIV-1 who start HAART. METHODS: We analysed 13 cohort studies from Europe and North America including 9323 adult treatment-naive patients who were starting HAART with a combination of at least three drugs. We modelled clinical progression from month 6 after starting HAART, taking into account CD4 count and HIV-1 RNA measured at baseline and 6 months. FINDINGS: During 13408 years of follow-up 152 patients died and 874 developed AIDS or died. Compared with patients who had a 6-month CD4 count of fewer than 25 cells/microL, adjusted hazard ratios for AIDS or death were 0.55 (95%CI 0.32-0.96) for 25-49 cells/microL, 0.62 (0.40-0.96) for 50-99 cells/microL, 0.42 (0.28-0.64) for 100-199 cells/microL, 0.25 (0.16-0.38) for 200-349 cells/microL, and 0.18 (0.11-0.29) for 350 or more cells/microL at 6 months. Compared with patients who had a 6-month HIV-1 RNA of 100000 copies/mL or greater, adjusted hazard ratios for AIDS or death were 0.59 (0.41-0.86) for 10000-99999 copies/mL, 0.42 (0.29-0.61) for 500-9999 copies/mL, and 0.29 (0.21-0.39) for 6-month HIV-1 RNA of 500 copies/mL or fewer. Baseline CD4 and HIV-1 RNA were not associated with progression after controlling for 6-month concentrations. The probability of progression at 3 years ranged from 2.4% in the patients in the lowest-risk stratum to 83% in patients in the highest-risk stratum. INTERPRETATION: At 6 months after starting HAART, the current CD4 cell count and viral load, but not values at baseline, are strongly associated with subsequent disease progression. Our findings should inform guidelines on when to modify HAART.

A Bayesian approach to parameter estimation in HIV dynamical models.

In the context of a mathematical model describing HIV infection, we discuss a Bayesian modelling approach to a non-linear random effects estimation problem. The model and the data exhibit a number of features that make the use of an ordinary non-linear mixed effects model intractable: (i) the data are from two compartments fitted simultaneously against the implicit numerical solution of a system of ordinary differential equations; (ii) data from one compartment are subject to censoring; (iii) random effects for one variable are assumed to be from a beta distribution. We show how the Bayesian framework can be exploited by incorporating prior knowledge on some of the parameters, and by combining the posterior distributions of the parameters to obtain estimates of quantities of interest that follow from the postulated model.

Surrogate markers for disease progression in treated HIV infection.

OBJECTIVE: To characterize the relationships among highly active antiretroviral therapy (HAART), HIV-1 RNA levels, immune system markers, and clinical outcome in a cohort of HIV-1-infected homosexual men. PATIENTS: A total of 123 men enrolled in the Amsterdam cohort study of HIV-1 infection and AIDS with a documented seroconversion for HIV-1 antibodies and known date of seroconversion were included in this study. METHODS: CD4 + /CD8 + T-cell counts and HIV-1 RNA levels in plasma were measured approximately every 6 months. Dates of starting and stopping antiretroviral therapy were also recorded. The relationship between HIV-1 RNA in plasma, CD4 + /CD8 + T-cell counts and HAART and their influence on clinical outcome were examined using a graphical chain modeling approach. Generalized estimating equations were used to examine correlations among the three disease markers. Hazards models with time-dependent covariates were used to examine the influence of HAART and the disease markers on progression to AIDS. RESULTS: HAART was significantly associated with reduced disease progression (relative hazard [RH] of AIDS, 0.20;, 95% confidence interval [CI], 0.05-0.85). The most recent HIV-1 RNA measurement and CD4 + T-cell count are independently associated with disease progression (adjusted RH for HIV-1 RNA 1.8 per log 10 increase; 95% CI, 1.2-2.6, p =.002; adjusted RH for CD4 + 0.48 per 100 x 10(6)/L increase; 95% CI, 0.40-0.58; p <.001). Depending on these measurements, HAART was no longer significantly associated with AIDS (adjusted RH, 0.81; 95% CI, 0.18-3.6; p =.78). CONCLUSIONS: HIV-1 RNA levels in plasma and CD4 + T-cell counts are currently considered as effective surrogate markers for the effect of HAART on disease progression in this cohort.

The role of antigenic stimulation and cytotoxic T cell activity in regulating the long-term immunopathogenesis of HIV: mechanisms and clinical implications.

This paper develops a predictive mathematical model of cell infection, host immune response and viral replication that reproduces observed long-term trends in human immunodeficiency virus (HIV) pathogenesis. Cell activation induced by repeated exposure to many different antigens is proposed as the principal mechanism of providing target cells for HIV infection and, hence, of CD4+ T cell depletion, with regulation of the overall T cell pool size causing concomitant CD8 pool increases. The model correctly predicts the cross-patient variability in disease progression, the rate of which is found to depend on the efficacy of anti-HIV cytotoxic T lymphocyte responses, overall viral pathogenicity and random effects. The model also predicts a variety of responses to anti-viral therapy, including episodic residual viral replication and discordant responses and we find that such effects can be suppressed by increasing the potency of treatment.

Limited patient adherence to highly active antiretroviral therapy for HIV-1 infection in an observational cohort study.

BACKGROUND: Adherence to highly active antiretroviral therapy (HAART) for human immunodeficiency syndrome type 1 (HIV-1) infection is essential to sustain viral suppression and prevent drug resistance. We investigated adherence to HAART among patients in a clinical cohort study. METHODS: Patients receiving HAART had their plasma concentrations of protease inhibitors or nevirapine measured and completed a questionnaire on adherence. We determined the percentage of patients who reported taking all antiretroviral medication on time and according to dietary instructions in the past week. Drug exposure was compared between patients reporting deviation from their regimen and fully adherent patients. Among patients who received HAART for at least 24 weeks, we assessed the association between adherence and virologic outcome. RESULTS: A total of 224 of 261 eligible patients completed a questionnaire. Forty-seven percent reported taking all antiretroviral medication on time and according to dietary instructions. Patients who reported deviation from their regimen showed lower drug exposure compared with fully adherent patients (median concentration ratio, 0.81 vs 1.07; P =.001). Among those receiving HAART for at least 24 weeks, patients reporting deviation from their regimen were less likely to have plasma HIV-1 RNA levels below 500 copies/mL (adjusted odds ratio, 4.0; 95% confidence interval, 1.4-11.6) compared with fully adherent patients. CONCLUSIONS: Only half of the patients took all antiretroviral medication in accordance with time and dietary instructions in the preceding week. Deviation from the antiretroviral regimen was associated with decreased drug exposure and a decreased likelihood of having suppressed plasma HIV-1 RNA loads. Patient adherence should remain a prime concern in the management of HIV-1 infection.

[HIV-1 therapy in the Netherlands; virological and immunological response to antiretroviral therapy]. / Behandeling van HIV-1 in Nederland: virologische en immunologische respons op antiretrovirale therapie.

OBJECTIVE: To evaluate the effect of treatment of HIV-1 infection with combination therapy consisting of since 1996 in the Netherlands available protease and reverse transcriptase inhibitors. DESIGN: Prospective cohort study. METHODS: In an observational clinical cohort of HIV-1-infected individuals, the short-term successful treatment end point of antiviral therapy including at least one antiretroviral drug licensed in the Netherlands since July 1, 1996 (protease inhibitors and reverse transcriptase inhibitors), was HIV-1 RNA plasma levels < or = 500 copies/ml (virological success). Cox proportional hazard models were used to identify prognostic markers for therapy success. The study included 2,148 infected individuals with a median follow-up of 135 weeks of treatment; 1,049 had been pre-treated with antiretroviral drugs before starting their new regimen and 1,099 were treatment naive. RESULTS: Plasma HIV-1 RNA levels < or = 500 copies/ml at 24 weeks of treatment were seen in 61% of all patients. The chance of therapy success for naive patients was twice that for pre-treated patients (relative risk: 1.8; p < or = 0.001). Following the first 24 weeks, the chance of virological success was higher in the naive group (78% versus 63%; p < or = 0.001), and the number of naive patients failing therapy after initial success was smaller compared to pre-treated patients (22% versus 45%; p < or = 0.001). In the naive group, the CD4+ T-cell number increased from 239 to 440 (x 10(6) cells/l) in case of success, and decreased from 150 to 320 in case of treatment failure. HIV-1 related morbidity declined from 0.26 to 0.05 and mortality dropped from 0.07 to 0.03 per person-year of follow-up. Regimens were changed at least once in 76% of patients. Toxicity and therapy failure were the main reasons for regimen changes in naive and pre-treated patients, respectively. CONCLUSION: A combination of antiretroviral drugs, including at least one of the drugs licensed since 1996, led to a drop in HIV-1 plasma concentrations. Morbidity and mortality also decreased. The chance of a better immunological and virological response to the new drug regimens was greatest in therapy-naive patients.

Secreted production of a custom-designed, highly hydrophilic gelatin in Pichia pastoris.

A custom-designed, highly hydrophilic gelatin was produced in Pichia pastoris. Secreted production levels in single-copy transformants were in the range 3-6 g/l of clarified broth and purification to near homogeneity could be accomplished by differential ammonium sulfate precipitation. Despite the fact that gelatins are highly susceptible to proteolysis because of their unfolded structure, the recombinant protein was shown to be fully intact by SDS-PAGE, N-terminal sequencing, gel filtration chromatography and mass spectrometry. Owing to its highly hydrophilic nature, the migration of the synthetic gelatin in SDS-PAGE was severely delayed. Esterification of the carboxylic amino acid side chains resulted in normal migration. The high polarity of the synthetic gelatin also accounts for its negligible surface activity in water at concentrations up to 5% (w/v), as determined by tensiometry. Circular dichroism spectrometry showed that the non-hydroxylated gelatin did not form triple helices at 4 degrees C. The spectrum was even more representative of the random coil conformation than the spectrum of natural non-hydroxylated gelatins.

OKT3 and IL-2 treatment for purging of the latent HIV-1 reservoir in vivo results in selective long-lasting CD4+ T cell depletion.

Activation of resting T cells has been proposed to purge the reservoir of HIV-1-infected resting CD4+ T cells. We therefore treated three HIV-1-infected patients on antiretroviral therapy with OKT3, a CD3 monoclonal antibody, and recombinant human IL-2. Here we report the profound and partially long-lasting host responses induced by the OKT3 and IL-2 treatment. OKT3/IL-2 induced a strong but transient release of plasma cytokines and chemokines. The percentage CD4+ and CD8+ cells in the blood expressing the activation marker CD38 transiently increased to almost 100%, and in lymph nodes we "observed" a 10-fold increase in the number of dividing Ki67+ cells and increased numbers of apoptotic cells. Following OKT3/IL-2 treatment, a long-lasting depletion of CD4+ cells in the peripheral blood and lymph nodes occurred, suggesting the physical deletion of these cells. Increases in CD4+T cell numbers during the two year followup period were due mainly to increased memory cell numbers. CD8+ cells were also depleted in the blood, but less severely in lymph nodes, and returned to baseline levels within several weeks.