Chronic hepatitis C in HIV-infected patients: low eligibility and applicability of therapy with pegylated interferon-alpha plus ribavirin.
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Biomedical subjects
Publications and source records attributed to Hansjakob Furrer.
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OBJECTIVES: The human immunodeficiency virus protease inhibitor nelfinavir is substrate of polyspecific drug transporters encoded by ABCB1 (P-glycoprotein), ABCC1 (MRP1) and ABCC2 (MRP2), and an inhibitor of BCRP, encoded by ABCG2. Genetic polymorphism in these genes may be associated with changes in transport function. METHODS: A comprehensive evaluation of single nucleotide polymorphisms (39 SNPs in ABCB1, 7 in ABCC1, 27 in ABCC2, and 16 in ABCG2), and inferred haplotypes was done to assess possible associations of genetic variants with cellular exposure of nelfinavir in vivo. Analysis used peripheral mononuclear cells from individuals receiving nelfinavir (n=28). Key results were re-examined in a larger sample size (n=129) contributing data on plasma drug levels. RESULTS AND CONCLUSIONS: There was no significant association between cellular nelfinavir area under the curve (AUC) and SNPs or haplotypes at ABCC1, ABCC2, ABCG2. There was an association with cellular exposure for two loci in strong linkage disequilibrium: ABCB1 3435C>T; AUCTT>AUCCT>AUCCC (ratio 2.1, 1.4, 1, Ptrend=0.01), and intron 26 +80T>C; AUCCC> AUCCT > AUCTT (ratio 2.4, 1.3, 1, Ptrend=0.006). Haplotypic analysis using tagging SNPs did not improve the single SNP association values.
BACKGROUND: Efavirenz (EFV) and nevirapine (NVP) are metabolized by cytochrome P450 2B6 (CYP2B6). Allele 516 G>T (Gln172His) is associated with diminished activity of this isoenzyme, and may lead to differences in drug exposure. METHODS: We evaluated this allele as a pharmacogenetic marker of EFV and NVP pharmacokinetics and EFV toxicity in 167 participants receiving EFV and 59 receiving NVP recruited within the genetics project of the Swiss HIV Cohort Study. Drug concentrations were measured in plasma and in peripheral blood mononuclear cells (PBMCs) from the same sample. Neuropsychological toxicity of EFV (sleep disorders, mood disorders, fatigue) was assessed using a standardized questionnaire. RESULTS AND CONCLUSIONS: CYP2B6 516TT was associated with greater plasma and intracellular exposure to EFV, and greater plasma exposure to NVP. Intracellular drug concentration, and CYP2B6 genotype were predictors of EFV neuropsychological toxicity. CYP2B6 genotyping may be useful to complement an individualization strategy based on plasma drug determinations to increase the safety and tolerability of EFV.
Since the introduction of effective antiretroviral therapy (ART), HIV-infected individuals are travelling more frequently and international travel has become much safer. Specific concerns include the safety of ART during travel, drug adherence and interaction considerations, and effects of immunosuppression. This review describes potentially important infections, vaccine effectiveness, safety and special approaches for their use, and HIV-related issues regarding predeparture counselling. With advanced immunosuppression (CD4+ T-cell count < 200/microl or < 14%), the immunogenicity of several vaccines is reduced, complications could occur after live attenuated vaccines and certain infections acquired during travel may be more frequent or severe. Challenges include the best options for malaria chemoprophylaxis, standby treatment and medical follow-up of the increasing number of HIV-infected long-term travellers.
BACKGROUND: Body fat changes are common in patients with HIV. For patients on protease inhibitor (PI)-based highly active antiretroviral therapy (HAART), these changes have been associated with increasing exposure to therapy in general and to stavudine in particular. Our objective is to show whether such associations are more or less likely for patients on non-nucleoside reverse transcriptase inhibitor (NNRTI)-based HAART. METHODS: We included all antiretroviral-naive patients in the Swiss HIV Cohort Study starting HAART after April 2000 who had had body weight, CD4 cell count and plasma HIV RNA measured between 6 months before and 3 months after starting HAART, and at least one assessment of body fat changes after starting HAART. At visits scheduled every 6 months, fat loss or fat gain is reported by agreement between patient and physician. We estimate the association between reported body fat changes and both time on therapy and time on stavudine, using conditional logistical regression. RESULTS: Body fat changes were reported for 85 (9%) out of 925 patients at their first assessment; a further 165 had only one assessment. Of the remaining 675 patients, body fat changes were reported for 156 patients at a rate of 13.2 changes per 100 patient-years. Body fat changes are more likely with increasing age [odds ratio (OR) 1.18 (1.00-1.38) per 10 years], with increasing BMI [OR 1.06 (1.01-1.11)] and in those with a lower baseline CD4 cell count [OR 0.91 (0.83-1.01) per 100 cells/microl]. There is only weak evidence that body fat changes are more likely with increasing time on HAART [OR 1.16 (0.93-1.46)]. After adjusting for time on HAART, fat loss is more likely with increasing stavudine use [OR 1.70 (1.34-2.15)]. There is no evidence of an association between reported fat changes and time on NNRTI therapy relative to PI therapy in those patients who used either one therapy or the other [OR 0.98 (0.56-1.63)]. CONCLUSION: Fat loss is more likely to be reported with increasing exposure to stavudine. We find no evidence of major differences between PI and NNRTI therapy in the risk of reported body fat changes.
BACKGROUND: Blood lipid abnormalities in patients on highly active antiretroviral therapy (HAART) have been associated with exposure to protease inhibitors (PIs), particularly ritonavir. First therapy with a non-nucleoside reverse transcriptase inhibitor (NNRTI) leads to relatively favourable lipid profiles. We report on medium-term lipid profiles (up to 5 years) for antiretroviral-naive patients starting NNRTI- and PI-based HAART in the Swiss HIV Cohort Study. METHODS: Since April 2000, blood samples taken at visits scheduled every 6 months have been analysed for cholesterol and triglyceride concentrations. For 1065 antiretroviral-naive patients starting HAART after April 2000, we estimated changes in concentration over time using multivariate linear regression with adjustment for baseline covariates, use of lipid-lowering drugs and whether the sample was taken in a fasting state. RESULTS: Non-high density lipoprotein (HDL) cholesterol levels increase with increasing exposure to either PI- or NNRTI-based therapy, HDL cholesterol levels increase and triglyceride levels decrease with increasing exposure to NNRTI-based therapy, whereas triglyceride levels increase with increasing exposure to PI-based therapy. Between NNRTI-based therapies, there is a slight difference in triglyceride levels, which tend to increase with increasing exposure to efavirenz and to decrease with increasing exposure to nevirapine. Of the three common PI-based therapies, nelfinavir appears to have a relatively favourable lipid profile, with little change with increasing exposure. Of the other two PI therapies, lopinavir with ritonavir has a more favourable profile than indinavir with ritonavir, with smaller increases in both non-HDL cholesterol and triglycerides and an increase in HDL cholesterol. Increasing exposure to abacavir is associated with a decrease in the level of triglycerides. CONCLUSION: In general, NNRTI-based therapy is associated with a more favourable lipid profile than PI-based therapy, but different PI-based therapies are associated with very different lipid profiles. Nelfinavir appears to have a relatively favourable lipid profile. Of the two boosted PI therapies, lopinavir appears to have a more favourable lipid profile than indinavir.
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OBJECTIVES: To assess the long-term safety of discontinuation of secondary anti-Pneumocystis prophylaxis in HIV-infected adults treated with antiretroviral combination therapy and who have a sustained increase in CD4 cell counts. DESIGN: Prospective observational multicentre study. PATIENTS AND METHODS: The incidence of P. jirovecii pneumonia after discontinuation of secondary prophylaxis was studied in 78 HIV-infected patients on antiretroviral combination therapy after they experienced a sustained increase in CD4 cell counts to at least 200 x 10(6) cells/l and 14% of total lymphocytes measured twice at least 12 weeks apart. RESULTS: Secondary prophylaxis was discontinued at a median CD4 cell count of 380 x 10(6) cells/l. The median follow-up period after discontinuation of secondary prophylaxis was 40.2 months, yielding a total of 235 person-years of follow-up. No cases of recurrent P. jirovecii pneumonia occurred during this period. The incidence was thus 0 per 100 person-years with a 95% upper of confidence limit of 1.3 cases per 100 patient-years. CONCLUSIONS: Discontinuation of secondary prophylaxis against P. jirovecii pneumonia is safe even in the long term in patients who have a sustained immunologic response on antiretroviral combination therapy.
OBJECTIVE: Pancreatic disorders in HIV-positive patients are frequent. CFTR and SPINK-1 mutations have been reported to increase the risk of pancreatitis, but no data are available in HIV-positive patients. This study will evaluate the frequency of CFTR mutations and SPINK-1 polymorphisms in HIV-positive patients with clinical pancreatitis or asymptomatic elevation of serum pancreatic enzymes. METHOD: Cases (patients with hyperamylasemia) were identified during a toxicity study conducted in August 1999 among 1152 participants of the Swiss HIV Cohort Study. We designed a case-control study in which each case was matched one to one to an HIV-infected control according to sex, age, CD4 cell count, viraemia and medication use. CFTR mutations and SPINK-1 polymorphisms were studied using polymerase chain reaction techniques. RESULTS: Fifty-one HIV-positive patients with hyperamylasemia were detected among 1152 participants in the toxicity study (4.4%). There were 13 carriers of CFTR and SPINK-1 mutations (12.7%). Amylase levels were 316 +/- 130 U/l for the group with mutations, and 135 +/- 18 U/l for non-carriers (P = 0.79). However, among patients with hyperamylasemia, those with CFTR or SPINK-1 mutations had 648 +/- 216 U/l amylase levels compared with 232 +/- 28 U/l for those without (P = 0.025). Ten patients had acute pancreatitis, four of whom had CFTR mutations or SPINK-1 polymorphisms (40%) compared with seven of the control patients (14%) (P = 0.01). CONCLUSION: CFTR mutations and SPINK-1 polymorphisms are frequent among HIV-positive patients suffering from acute pancreatitis. These mutations may increase the susceptibility to pancreatitis when exposed to environmental risk factors.
We analyzed the humoral immune response in 46 patients following structured treatment interruption (STI) to investigate the general potential of therapeutic vaccination in chronic HIV-1 infection. Evoked antibody titer increases to glycoprotein 120 (gp120) and p24 were low during 4 short-term STIs and only reached significance during a fifth long-term interruption. Although induction of binding antibodies to viral antigens was not associated with potent suppression of viremia, we observed that individuals with a rapid and high response to p24, and to a lesser extent also to gp120, lowered their viral set points significantly. Of note, the increase of the anti-p24 response correlated with specific CD4 T helper frequency to this antigen. Despite induction of binding antibody responses, which correlated with improved viral control, the increase in neutralizing activity was marginal and did not lead to this enhanced viral suppression. However, a subgroup of patients who potently suppressed viremia independently of STI had significantly higher pre-existing neutralization titers, suggesting a role of humoral immunity in conferring potent protection. In summary, measuring the kinetics of antibody responses provided a marker to validate the responsiveness and capacities of the immune system of HIV-1-infected individuals and reflected the patients' ability to decrease viral set points.
OBJECTIVES: To explore the association between a stable partnership and clinical outcome in HIV infected patients receiving highly active antiretroviral therapy (HAART). DESIGN: Prospective cohort study of adults with HIV (Swiss HIV cohort study). SETTING: Seven outpatient clinics throughout Switzerland. PARTICIPANTS: The 3736 patients in the cohort who started HAART before 2002 (median age 36 years, 29% female, median follow up 3.6 years). MAIN OUTCOME MEASURES: Time to AIDS or death (primary endpoint), death alone, increases in CD4 cell count of at least 50 and 100 above baseline, optimal viral suppression (a viral load below 400 copies/ml), and viral rebound. RESULTS: During follow up 2985 (80%) participants reported a stable partnership on at least one occasion. When starting HAART, 52% (545/1042) of participants reported a stable partnership; after five years of follow up 46% (190/412) of participants reported a stable partnership. In an analysis stratified by previous antiretroviral therapy and clinical stage when starting HAART (US Centers for Disease Control and Prevention group A, B, or C), the adjusted hazard ratio for progression to AIDS or death was 0.79 (95% confidence interval 0.63 to 0.98) for participants with a stable partnership compared with those without. Adjusted hazards ratios for other endpoints were 0.59 (0.44 to 0.79) for progression to death, 1.15 (1.06 to 1.24) for an increase in CD4 cells of 100 counts/microl or more, and 1.06 (0.98 to 1.14) for optimal viral suppression. CONCLUSIONS: A stable partnership is associated with a slower rate of progression to AIDS or death in HIV infected patients receiving HAART.
According to official Swiss data an increasing number of HIV-positive migrants reside in Switzerland. The present study examined epidemiologic, clinical, and migration-specific characteristics of HIV-infected migrants at the HIV clinic of the University Hospital of Berne, which is one of the centers of the national, prospective Swiss HIV cohort study. Data were collected by chart review. Among the 1331 patients the proportion of northwestern European patients decreased from 88% before 1989 to 67% in the late 1990s while the number of patients from sub-Saharan Africa and Southeast Asia increased from 3 (1.6%) to 47 (14%) and from 2 (1%) to 17 (5%), respectively. Sub-Saharan Africans and Southeast Asians were more likely to be younger, female, and infected heterosexually. At first clinical visit the various patient groups did not differ in CD4 counts or HIV RNA levels. Sub-Saharan African patients were more likely to be anemic. A majority of HIV-positive migrants were most likely infected prior to arrival in Switzerland. Sub-Saharan Africans and Southeast Asians were often diagnosed to be HIV-positive after showing suggestive symptoms of infection, while European patients were more often diagnosed in a screening setting. Thirteen patients with indication for antiretroviral therapy were forced to leave Switzerland because they were denied asylum. In response to the increasing migrant population attending the HIV clinic, further qualitative and quantitative research is required to improve understanding of this vulnerable population group and to promote their knowledge of the disease and its prevention.
OBJECTIVE: Information about the virological response to sequential highly active antiretroviral therapy (HAART) for HIV infection is limited. The virological response to four consecutive therapies was evaluated in the Swiss HIV Cohort. DESIGN: Retrospective analysis in an observational cohort. METHODS: 1140 individuals receiving uninterrupted HAART for 4.8 +/- 0.6 years were included. The virological response was classified as success (<400 copies/ml), low-level (LF: 400-5000 copies/ml) or high-level failure (HF: >5000 copies/ml). Potential determinants of the virological response, including patient demographics, treatment history and virological response to previous HAART regimens were analysed using survival and logistic regression analyses. RESULTS: 40.1% failed virologically on the first (22.0% LF; 18.1% HF), 35.1% on the second (14.2% LF; 20.9% HF), 34.2% on the third (9.9% LF; 24.3% HF) and 32.7% on the fourth HAART regimen (9% LF; 23.7% HF). Nucleoside pre-treatment (OR: 2.34; 95% CI: 1.67-3.29) and low baseline CD4 T-cell count (OR: 0.79/100 cells rise; 95% CI: 0.72-0.88) increased the risk of HF on the first HAART. Virological failure on HAART with HIV-1 RNA levels exceeding 1000 copies/ml predicted a poor virological response to subsequent HAART regimens. A switch from a protease inhibitor- to a non-nucleoside reverse transcriptase inhibitor-containing regimen significantly reduced the risk of HF. Multiple switches of HAART did not affect the recovery of CD4 T lymphocytes. CONCLUSION: Multiple sequential HAART regimens do not per se reduce the likelihood of long-term virological suppression and immunological recovery. However, early virological failure increases significantly the risk of subsequent unfavourable virological responses. The choice of a potent initial antiretroviral drug regimen is therefore critical.
Transmission of drug-resistant variants is influenced by several factors, including the prevalence of drug resistance in the population of HIV-1-infected patients, HIV-1 RNA levels and transmission by recently infected patients. In order to evaluate the impact of these factors on the transmission of drug-resistant variants, we have defined the population of potential transmitters and compared their resistance profiles to those of newly infected patients. Sequencing of pol gene was performed in 220 recently infected patients and in 373 chronically infected patients with HIV-1 RNA >1000 copies/ml. Minimal and maximal drug-resistance profiles of potential transmitters were estimated by weighting resistance profiles of chronically infected patients with estimates of the Swiss HIV-1-infected population, the prevalence of exposure to antiviral drugs and the proportion of infections attributed to primary HIV infections. The drug-resistance prevalence in recently infected patients was 10.5% (one class drug resistance: 9.1%; two classes: 1.4%; three classes: 0%). Phylogenetic analysis revealed significant clustering for 30% of recent infections. The drug-resistance prevalence in chronically infected patients was 72.4% (one class: 29%; two classes: 27.6%; three classes: 15.8%). After adjustment, the risk of transmission relative to wild-type was reduced both for one class drug resistance (minimal and maximal estimates: odds ratio: 0.39, P<0.001; and odds ratio: 0.55, P=0.011, respectively), and for two to three class drug resistance (odds ratios: 0.05 and 0.07, respectively, P<0.001). Neither sexual behaviour nor HIV-1 RNA levels explained the low transmission of drug-resistant variants. These data suggest that drug-resistant variants and in particular multidrug-resistant variants have a substantially reduced transmission capacity.
BACKGROUND: Scheduled treatment interruptions are being evaluated in an effort to decrease costs and side effects of highly active antiretroviral therapy (HAART). A schedule of 1 week on and 1 week off therapy offers the promise of 50% less drug exposure with continuously undetectable HIV RNA concentration. METHODS: In the Staccato study 600 patients on successful HAART were to be randomized to either continued therapy, CD4-guided therapy, or one week on, one week off therapy. A scheduled preliminary analysis evaluated effectiveness in the 1-week-on-1-week-off arm. RESULTS: Of 36 evaluable patients, 19 (53%) had two successive HIV RNA concentrations > 500 copies/ml at the end of the week off therapy, and were classified as virological failure. Most of those who failed took didanosine, stavudine, saquinavir, and ritonavir (11 patients). In these patients, there was no evidence of mutations suggestive of drug resistance, and plasma saquinavir levels were within the expected range. Two of three patients failing on triple nucleotides had drug resistance mutations, but nonetheless responded to reintroduction of triple nucleotide therapy. One of two patients taking nevirapine, and one of eight taking efavirenz, also failed. Both had resistance mutations at the time of failure, but not at baseline. CONCLUSIONS: The 1-week-on-1-week-off schedule, as tested in the Staccato study, showed an unacceptably high failure rate and was therefore terminated.
OBJECTIVE: To examine the proportion of migrants from Sub-Saharan Africa entering the Swiss HIV Cohort Study (SHCS) and to compare these participants with participants from Northwestern Europe for access to antiretroviral therapy, progression to AIDS and survival. DESIGN: Prospective national cohort study of HIV-1-infected adults from seven HIV centres in Switzerland. METHODS: Trends in the proportion of participants from Sub-Saharan Africa were followed in 11 872 HIV-infected adults entering the SHCS from 1984 to 2001. Survival methods were used to compare uptake of antiretroviral therapy, survival and progression to AIDS in the 2684 participants from Sub-Saharan Africa and Northwest Europe enrolled from 1997-2001. RESULTS: There was a steady increase in the proportion of Sub-Saharan African participants over time, reaching 11.9% in 1997-2001. These participants were more likely to be younger, female, to have been infected by heterosexual intercourse and had lower CD4 cell counts at presentation. There were no differences between Sub-Saharan Africans and Northwest Europeans in uptake of triple antiretroviral therapy, progression to AIDS or survival up to 48 months after starting treatment. Tuberculosis was the most frequent AIDS-defining event in Sub-Saharan African patients. CONCLUSIONS: There is no evidence that access to potent antiretroviral therapy is influenced by geographic origin of participants. The prognosis of Sub-Saharan African patients on triple therapy is equivalent to that of Northwest European patients. Future research should address wider issues about access to specialist health services for HIV-infected people from Sub-Saharan Africa.
BACKGROUND: Highly active antiretroviral therapy (HAART) for human immunodeficiency virus (HIV)-1 infection allows recovery of CD4 T lymphocytes. Few studies have explored the long-term T-lymphocyte responses to HAART. METHODS: Plasma HIV-1 RNA levels and CD4 and CD8 T-lymphocyte counts were longitudinally analyzed over 4 years in 2235 participants of the Swiss HIV Cohort, commencing HAART between 1996 and 1997. The CD4 T-lymphocyte count increase, the percentage of individuals with a CD4 T-lymphocyte count of 500/microL or greater and less than 200/microL, and the determinants of CD4 T-lymphocyte recovery were evaluated in individuals treated with continuous (CONT; n = 985) and discontinuous (DISCONT; n = 1250) HAART. RESULTS: At 4 years, 69.5% of subjects (CONT, 84.5%; DISCONT, 53.6%; P<.001) showed HIV-1 RNA levels below 400 copies/mL, while the median CD4 T-lymphocyte count increased from 190/microL to 423/microL (CONT, 486/microL; DISCONT, 343/microL; P<.001). Of the 2235 participants, 38.8% (CONT, 47.7%; DISCONT, 29.4%; P<.001) reached a CD4 T-lymphocyte count of 500/microL or greater, but in 15.6%, CD4 T-lymphocyte count remained below 200/microL (CONT, 5.9%; DISCONT, 25.9%; P<.001). Larger increases in CD4 T-lymphocyte count were associated with higher baseline HIV-1 RNA, a larger percentage of undetectable HIV-1 RNA levels, lower baseline CD8 T-lymphocyte count, and younger age. Individuals reaching a CD4 T-lymphocyte count of 500/microL or greater at 4 years were characterized by higher nadir and baseline CD4 T-lymphocyte counts and a more sustained reduction of HIV-1 RNA levels. CONCLUSIONS: At 4 years, only 39% of individuals treated with HAART reached a CD4 T-lymphocyte count of 500/microL or greater, and 16% with CD4 T-lymphocyte counts less than 200/microL remained susceptible to opportunistic infections. Treatment interruptions, a poor virologic response, and older age were the major factors negatively affecting the recovery of CD4 T lymphocytes.
Sexual contact is the major mode of HIV transmission. Increased sexual risk taking has been described in HIV-infected individuals receiving potent antiretroviral therapy. A new questionnaire on sexual behavior was introduced into the Swiss HIV Cohort Study on April 1, 2000. We evaluated sexual behavior in all individuals who completed the questionnaire for the first time within 1 year after its introduction. Our primary hypothesis was that self-reported unsafe sexual behavior would be more prevalent among individuals with optimal viral suppression. On April 1, 2000, 4948 individuals were registered in the study, and 4723 (95%) completed the questionnaire. Of these individuals, 12% reported unsafe sex, 78% received antiretroviral therapy, and 25% had optimal viral suppression (HIV RNA level always <50 copies/mL during the preceding 12 months). During the preceding 6 months, 55% of individuals had stable and 19% had occasional partners, and 6% had both types of partners. Sexual intercourse was reported by 82% of individuals with stable and 87% of individuals with occasional partners, and of those reporting sexual intercourse in each group, 76% and 86%, respectively, said that they always used condoms. After adjustment for covariates, reported unsafe sex was not associated with optimal viral suppression (odds ratio, 1.04; 95% confidence interval, 0.81-1.33) or antiretroviral therapy (odds ratio, 0.83; 95% confidence interval, 0.65-1.07), but it was associated with gender, age, ethnicity, HIV transmission group, HIV status of partner, having occasional partners, and living alone. There is no evidence that self-reported unsafe sexual behavior is more prevalent among HIV-infected individuals with optimal viral suppression. However, unsafe sex is associated with other factors.