Transmitted drug resistant HIV-1 and association with virologic and CD4 cell count response to combination antiretroviral therapy in the EuroSIDA Study.

OBJECTIVES: To investigate prevalence of transmitted drug-resistant human immunodeficiency virus (TDR) and factors associated with TDR and to compare virological and CD4 count response to combination antiretroviral therapy. METHODS: In this study, 525 mostly chronically infected EuroSIDA patients were included who had genotypic resistance tests performed on plasma samples collected while antiretroviral therapy naive. TDR was defined as at least one resistance mutation from a list proposed for genotypic TDR surveillance. Multivariable logistic regression was used to analyze factors associated with detection of TDR, with virological (viral load<500 copies/mL) and CD4 count response (>or=50% increase) to combination antiretroviral therapy at months 6-12. RESULTS: The overall prevalence of TDR was 11.4%, which was stable over 1996-2004. There were no significant differences in virological suppression (those resistant to at least one drug prescribed versus susceptible), adjusted odds ratio: 0.68 (95% confidence interval: 0.27 to 1.71; P=0.408) or CD4 count response, adjusted odds ratio: 1.65 (95% confidence interval: 0.73 to 3.73; P=0.231). CONCLUSIONS: Prevalence of TDR in antiretroviral-naive patients was found to be in line with other European studies. No significant differences were found in virological and CD4 count response after initiation of first-line combination antiretroviral therapy between resistant and susceptible patients, possibly due to the small number of patients with resistance and consequently low power.

Introducing a first AIDS vaccine in Switzerland: a Policy Delphi analysis.

This preliminary exploration was limited by a number of factors. The format of the study has necessarily induced some form of selection bias of the panelists, because of the complexity of some questions, and the time required to complete the questionnaires. Several issues have not been addressed. One example could be the response to HIV infection occurring in a vaccinee. The study also did not address the difficulties related to the licensing of the vaccine. Indeed, the proposed scenario assumed that the vaccine had been registered as a starting point for the analysis. Finally, it has not been possible to conduct a sensitivity analysis, in order to evaluate how the responses would have been modified if some important characteristics of the vaccine had been modified.Very diverse evaluations were given in response to questions related with attitudes and perception of AIDS and AIDS vaccine. The possibility that vaccine availability or usage can be associated with an increased frequency in risky behaviors was spontaneously mentioned by half of the panelists. The estimation of the proportion of persons at highest risk who would choose to use this vaccine also indicated a high degree of uncertainty. This study offers important lessons. According to a broad and diverse panel of individuals, an incompletely effective AIDS vaccine would result in an additional level of complexity for the AIDS prevention strategy, rather than a simplification. The use of such a vaccine would have to be coupled with counselling. This implies a sustained emphasis on the recommendations which have been central to the STOP AIDS campaigns until now. In addition, consensual issues, as well as other issues more likely to be controversial have been identified. This should greatly help focusing the work of any committee designated to develop and implement a vaccination policy if an AIDS vaccine became available. Finally, our experience with the Policy Delphi indicates that this mode of structured communication could be usefully applied to other public health issues presenting a high visibility as well as a complex relationship with public perception.

Histoplasma capsulatum var. duboisii infection in a patient with AIDS: rapid diagnosis using polymerase chain reaction-sequencing.

We describe an original case of disseminated infection with Histoplasma capsulatum (Hc) var. duboisii in an African patient with AIDS who migrated to Switzerland. The diagnosis of histoplasmosis was suggested using direct examination of tissues and confirmed in 24 h with a panfungal polymerase chain reaction assay. The variety duboisii of Hc was established using DNA sequencing of the polymorphic genomic region OLE. Molecular tools allow diagnosis of histoplasmosis in 24 h, which is drastically shorter than culture procedures.

Long-term expansion of transplantable human fetal liver hematopoietic stem cells

Hematopoietic stem cells (HSCs), with their dual ability for self-renewal and multilineage differentiation, constitute an essential component of hematopoietic transplantations. Human fetal liver (FL) represents a promising alternative HSC source, and we previously reported simple culture conditions allowing long-term expansion of FL hematopoietic progenitors. In the present study, we used the nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mouse xenotransplantation assay to confirm that human FL is rich in NOD/SCID-repopulating cells (SRCs) and to show that these culture conditions repeatedly maintained short- and long-term SRCs from various FL samples for at least 28 days. Quantitative limited dilution analysis in NOD/SCID mice demonstrated for the first time that a 10- to over a 100-fold net expansion of FL SRCs could be achieved after 28 days of culture. The efficiency of this culture system may lead to an increase in the use of FL as a source of HSCs for transplantation in adult patients, as previously demonstrated with umbilical cord blood under different culture conditions.

Humoral Response to the Influenza A H1N1/09 Monovalent AS03-Adjuvanted Vaccine in Immunocompromised Patients.

Background. Few data are available regarding the immunogenicity and safety of the pandemic influenza vaccine in immunocompromised patients. We evaluated the humoral response to the influenza A H1N1/09 vaccine in solid-organ transplant (SOT) recipients, in patients with human immunodeficiency virus (HIV) infection, and in healthy individuals. Methods. Patients scheduled to receive the pandemic influenza vaccine were invited to participate. All participants received the influenza A H1N1/09 AS03-adjuvanted vaccine containing 3.75 μg of hemagglutinin. SOT recipients and HIV-infected patients received 2 doses at 3-week intervals, whereas control subjects received 1 dose. Blood samples were taken at day 0, day 21, and day 49 after vaccination. Antibody responses were measured with the hemagglutination inhibition assay (HIA) and a microneutralization assay. Results. Twenty-nine SOT recipients, 30 HIV-infected patients, and 30 healthy individuals were included in the study. Seroconversion measured by HIA was observed in 15 (52%) of 29 SOT recipients both at day 21 and day 49; in 23 (77%) of 30 at day 21 and 26 (87%) of 30 at day 49 in HIV-infected patients, and in 20 (67%) of 30 at day 21 and in 23 (77%) of 30 at day 49 in control subjects (P = .12 at day 21 and P = .009 at day 49, between groups). Geometric means of antibody titers were not significantly different between groups at day 21 or at day 49. Conclusions. Influenza A H1N1/09 vaccine elicited a similar antibody response in HIV-infected individuals and in control subjects, whereas SOT recipients had an overall lower response. A second dose of the vaccine only moderately improved vaccine immunogenicity in HIV-infected patients.

Variations of CYP3A activity induced by antiretroviral treatment in HIV-1 infected patients.

OBJECTIVE: To measure the in vivo variations of CYP3A activity induced by anti-HIV drugs in human immunodeficiency virus (HIV)1-positive patients. METHODS: A low oral dose of midazolam (MID) (0.075 mg) was given to the patients and the 30-min total 1-OH midazolam (1-OHMID)/MID ratio was determined. Patients were phenotyped either before the introduction of antiretroviral treatments (control group, 90 patients) or after a variable period of antiretroviral treatment (56 patients). Twenty-one subjects underwent multiple phenotyping tests (before and during the course of the treatment). RESULTS: The median MID ratio was 3.51 in the control group (range 0.20-14.6). It was 5-fold higher in the group with efavirenz (28 patients; median, range: 16.0, 3.81-367; P < 0.0001), 13-fold lower with nelfinavir (18 patients; 0.27, 0.06-36.3; P < 0.0001), 17-fold lower with efavirenz + ritonavir (three patients; 0.21, 0.05-0.47; P = 0.006), 50-fold lower with ritonavir (four patients; 0.07, 0.06-0.17; P = 0.0007), and 7-fold lower with nevirapine + (ritonavir or nelfinavir or grapefruit juice) (three patients; 0.48, 0.03-1.83; P = 0.03). CYP3A activity was lower in the efavirenz + ritonavir group (P = 0.01) and in the ritonavir group (P = 0.04) than in the nelfinavir group, although already strongly inhibited in the latter. CONCLUSION: The low-dose MID phenotyping test was successfully used to measure the in vivo variations of CYP3A activity induced by antiretroviral drugs. Efavirenz strongly induces CYP3A activity, while ritonavir almost completely inhibits it. Nelfinavir strongly decreases CYP3A activity, but to a lesser extent than ritonavir. The inhibition of CYP3A by ritonavir or nelfinavir offsets the inductive effects of efavirenz or nevirapine administered concomitantly. Finally, no induction of CYP3A activity was noticeable after long-term administration of ritonavir at low dosages (200 mg/day b.i.d.) or of nelfinavir at standard dosages (2,500 mg/day b.i.d.).

Long term global evaluation of a national AIDS prevention strategy: the case of Switzerland.

OBJECTIVES: The Swiss Aids prevention strategy has been subject to a continuous process of evaluation for the past 12 years. This paper describes the conceptual approach, methodology, results obtained and contribution to policy-making of that evaluation.¦DESIGN: The evaluation is on-going, global with respect to all components of the strategy, and utilization-focused. Each successive phase of the evaluation has included 10-20 studies centred either on aspects of process, of outcome or of environmental context. Findings are synthesized at the end of each phase. METHODS: Both quantitative and qualitative methods are used. Studies generally have one of three functions within the overall evaluation: assessment of trends through surveys or other types of repeated studies; evaluation of specific areas through a series of studies from different viewpoints; in-depth investigation or rapid assessment through one-off studies. Various methods of triangulation are used to validate findings. RESULTS: The evaluation has allowed for: the observation of behavioural change in different populations; the availability of scientific data in controversial fields such as drug-use policy; an understanding of the diversity of public appropriation of prevention messages. Recommendations are regularly formulated and have been used by policy-makers and field workers for strategy development. CONCLUSIONS: The global approach adopted corresponds well to the evaluation requirements of an integrated long-term prevention strategy. Cost is low relative to the extent of information provided. Such an evaluation cannot however address the question of causal relationship between the strategy and observed changes. The evaluation has contributed to the development of a culture of evaluation in Swiss AIDS prevention more generally.

MACROPHAGES FROM CROHN'S DISEASE PATIENTS EXHIBIT DEFICIENT REPAIR FUNCTIONS

AbstractBackground: Mucosal healing is becoming a major goal in the treatment of Crohn's disease. It has been previously reported that myeloid cells induce mucosal healing in a mouse model of acute colitis. The aim in this study is to investigate the pro-repair function of myeloid cells in healthy donors (HD) and Crohn's disease patients (CD).Methods: Peripheral blood mononuclear cells (PBMC) from HD and CD patients were isolated from blood samples and tested either directly or after differentiation ex-vivo into macrophages (Μφ). Intestinal macrophages (IMACs) were isolated from the bowel mucosa of patients undergoing intestinal surgical resections. Through an in vitro wound healing assay the repairing ability of these various human myeloid cells and the mechanisms responsible of wound healing were evaluated.Results: PBMC and myeloid CD14+ cells from HD and CD were not able to repair at any tested cell concentration. Μφ from HD and ulcerative colitis (UC) patients were able to induce wound healing and this capacity was partially mediated by Hepatocyte Growth Factor (HGF). Remarkably, CD Μφ were unable to promote wound healing and produced lower levels of HGF as compared to Μφ from HD or UC patients. In particular, Μφ from CD in active phase (ACD) exhibited the weakest repair function, but this defect was rescued if rh- GM-CSF was added during the differentiation of PBMCs. Interestingly, IMACs from HD promoted wound healing and produced HGF.Conclusion: We demonstrated that CD Μφ, unlike HD or UC Μφ, were defective in promoting wound healing, in particular if coming from an ACD. This deficient pro-repair function was related to a lower production of HGF. IMACs from HD colonic mucosa induced wound healing, confirming the results obtained with Μφ. Our results are in keeping with the current theory of CD as an innate immunodeficiency. In this context, Μφ may be responsible for the mucosal repair defects observed in CD patients and for the subsequent chronic activation of the adaptive immune response.

Hyperlactatemia and antiretroviral therapy: the Swiss HIV Cohort Study.

The prevalence, clinical presentation, and risk factors for hyperlactatemia among patients receiving antiretroviral therapy was determined during a 1-month period for patients in the Swiss HIV Cohort Study. Overall, 73 (8.3%) of 880 patients presented an increase in serum lactate of >1.1 times the upper normal limit (UNL). For 9 patients (1%), lactate elevation was moderate or severe (>2.2 times the UNL). Patients who presented with hyperlactatemia were more likely to be receiving stavudine with or without didanosine (odds ratio, 2.7; 95% confidence interval, 1.5-4.8), as compared with patients who received zidovudine-based regimens. The risk increased with increasing time receiving stavudine with or without didanosine. The association between hyperlactatemia and stavudine with or without didanosine was not biased by these medications being more recently available and, therefore, being given preferentially to patients who had prolonged use of nucleoside analog reverse-transcriptase inhibitors. Hyperlactatemia was associated with lipoatrophy, hyperlipidemia, and hyperglycemia. Age, sex, or stage of infection with human immunodeficiency virus were not predictive of hyperlactatemia. Determination of lactate levels may prove useful in the screening for mitochondrial toxicity.

Counteraction of HLA-C-mediated immune control of HIV-1 by Nef.

A host genetic variant (-35C/T) correlates with increased human leukocyte antigen C (HLA-C) expression and improved control of HIV-1. HLA-C-mediated immunity may be particularly protective because HIV-1 is unable to remove HLA-C from the cell surface, whereas it can avoid HLA-A- and HLA-B-mediated immunity by Nef-mediated down-modulation. However, some individuals with the protective -35CC genotype exhibit high viral loads. Here, we investigated whether the ability of HIV-1 to replicate efficiently in the "protective" high-HLA-C-expression host environment correlates with specific functional properties of Nef. We found that high set point viral loads (sVLs) were not associated with the emergence of Nef variants that had acquired the ability to down-modulate HLA-C or were more effective in removing HLA-A and HLA-B from the cell surface. However, in individuals with the protective -35CC genotype we found a significant association between sVLs and the efficiency of Nef-mediated enhancement of virion infectivity and modulation of CD4, CD28, and the major histocompatibility complex class II (MHC-II)-associated invariant chain (Ii), while this was not observed in subjects with the -35TT genotype. Since the latter Nef functions all influence the stimulation of CD4(+) T helper cells by antigen-presenting cells, they may cooperate to affect both the activation status of infected T cells and the generation of an antiviral cytotoxic T-lymphocyte (CTL) response. In comparison, different levels of viremia in individuals with the common -35TT genotype were not associated with differences in Nef function but with differences in HLA-C mRNA expression levels. Thus, while high HLA-C expression may generally facilitate control of HIV-1, Nef may counteract HLA-C-mediated immune control in some individuals indirectly, by manipulating T-cell function and MHC-II antigen presentation.

The role of migration and domestic transmission in the spread of HIV-1 non-B subtypes in Switzerland.

BACKGROUND: By analyzing human immunodeficiency virus type 1 (HIV-1) pol sequences from the Swiss HIV Cohort Study (SHCS), we explored whether the prevalence of non-B subtypes reflects domestic transmission or migration patterns. METHODS: Swiss non-B sequences and sequences collected abroad were pooled to construct maximum likelihood trees, which were analyzed for Swiss-specific subepidemics, (subtrees including ≥80% Swiss sequences, bootstrap >70%; macroscale analysis) or evidence for domestic transmission (sequence pairs with genetic distance <1.5%, bootstrap ≥98%; microscale analysis). RESULTS: Of 8287 SHCS participants, 1732 (21%) were infected with non-B subtypes, of which A (n = 328), C (n = 272), CRF01_AE (n = 258), and CRF02_AG (n = 285) were studied further. The macroscale analysis revealed that 21% (A), 16% (C), 24% (CRF01_AE), and 28% (CRF02_AG) belonged to Swiss-specific subepidemics. The microscale analysis identified 26 possible transmission pairs: 3 (12%) including only homosexual Swiss men of white ethnicity; 3 (12%) including homosexual white men from Switzerland and partners from foreign countries; and 10 (38%) involving heterosexual white Swiss men and females of different nationality and predominantly nonwhite ethnicity. CONCLUSIONS: Of all non-B infections diagnosed in Switzerland, <25% could be prevented by domestic interventions. Awareness should be raised among immigrants and Swiss individuals with partners from high prevalence countries to contain the spread of non-B subtypes.

Antiretroviral drug toxicity in relation to pharmacokinetics, metabolic profile and pharmacogenetics.

Introduction: Besides therapeutic effectiveness, drug tolerability is a key issue for treatments that must be taken indefinitely. Given the high prevalence of toxicity in HIV therapy, the factors implicated in drug-induced morbidities should be identified in order to improve the safety, tolerability and adherence to the treatments. Current approaches have focused almost exclusively on parent drug concentrations; whereas recent evidence suggests that drug metabolites resulting from complex genetic and environmental influences can also contribute to treatment outcome. Pharmacogenetic variations have shown to play a relevant role in the variability observed in antiretroviral drug exposure, clinical response and sometimes toxicity. The integration of pharmacokinetic, pharmacogenetic and metabolic determinants will more probably address current therapeutic needs in patients. Areas covered: This review offers a concise description of three classes of antiretroviral drugs. The review looks at the metabolic profile of these drugs and gives a comprehensive summary of the existing literature on the influence of pharmacogenetics on their pharmacokinetics and metabolic pathways, and the associated drug or metabolite toxicity. Expert opinion: Due to the high prevalence of toxicity and the related risk of low adherence to the treatments, association of kinetic, genetic and metabolic markers predictive of therapeutic or toxicity outcomes could represent a more complete approach for optimizing antiretroviral therapy.

Long-term safety and effectiveness of ritonavir, nelfinavir, and lopinavir/ritonavir in antiretroviral-experienced HIV-infected children.

AIM: To evaluate the long-term safety and effectiveness of ritonavir, nelfinavir, and lopinavir/ritonavir in antiretroviral-experienced, initially protease inhibitor (PI)-naive, human immunodeficiency virus (HIV)-1-infected children. METHODS: HIV-1-infected children enrolled in the Swiss Mother and Child HIV Cohort Study were eligible for this observational cohort study if they received at least 1 PI of interest between March 1996 and October 2003: ritonavir, nelfinavir, or lopinavir/ritonavir. Data regarding demographics, clinical disease and antiretroviral treatment history, HIV-1 RNA copies/mL, CD4 T-cell counts [absolute (cells/microL) and percentages (%)], adverse events, clinical laboratory values, reasons for discontinuation of PIs, and concomitant medications were extracted from the database for PI-naive (first-line) and PI-experienced (second- or higher-line) PI use. RESULTS: The total duration of ritonavir, nelfinavir, and lopinavir/ritonavir use for 133 HIV-1-infected children was 163.8, 235.0, and 46.1 patient-years, respectively. In an on-treatment analysis, first-line therapy with any of the PIs significantly reduced HIV-1 concentrations and increased CD4 T-cell counts and percentages from baseline throughout the 288-week study (P <or= 0.05) for ritonavir and nelfinavir and throughout 84 weeks of use for lopinavir/ritonavir, which was introduced into treatment more recently. All PIs investigated were most effective in PI-naive children. Thirteen PI-associated toxicities occurred requiring treatment changes or interruptions (neurologic symptoms, n = 2; pancreatitis, n = 1; allergic reactions, n = 4; visual symptoms, n = 3; and hyperlipidemia, n = 3). CONCLUSIONS: Long-term PI-based therapy seems to be safe and to result in durable virologic and immunologic effectiveness in HIV-1-infected antiretroviral-experienced children.