Immunogenicity, Safety, and Efficacy of a Standalone Universal Influenza Vaccine, FLU-v, in Healthy Adults: A Randomized Clinical Trial.

Background: FLU-v is a broad-spectrum influenza vaccine that induces antibodies and cell-mediated immunity. Objective: To compare the safety, immunogenicity, and exploratory efficacy of different formulations and dosing regimens of FLU-v versus placebo. Design: Randomized, double-blind, placebo-controlled, single-center phase 2b clinical trial. (ClinicalTrials.gov: NCT02962908; EudraCT: 2015-001932-38). Setting: The Netherlands. Participants: 175 healthy adults aged 18 to 60 years. Intervention: 0.5-mL subcutaneous injection of 500 µg of adjuvanted (1 dose) or nonadjuvanted (2 doses) FLU-v (A-FLU-v or NA-FLU-v) or adjuvanted or nonadjuvanted placebo (A-placebo or NA-placebo) (2:2:1:1 ratio). Measurements: Vaccine-specific cellular responses at days 0, 42, and 180 were assessed via flow cytometry and enzyme-linked immunosorbent assay. Solicited information on adverse events (AEs) was collected for 21 days after vaccination. Unsolicited information on AEs was collected throughout the study. Results: The AEs with the highest incidence were mild to moderate injection site reactions. The difference between A-FLU-v and A-placebo in the median fold increase in secreted interferon-γ (IFN-γ) was 38.2-fold (95% CI, 4.7- to 69.7-fold; P = 0.001) at day 42 and 25.0-fold (CI, 5.7- to 50.9-fold; P < 0.001) at day 180. The differences between A-FLU-v and A-placebo in median fold increase at day 42 were 4.5-fold (CI, 2.3- to 9.8-fold; P < 0.001) for IFN-γ-producing CD4+ T cells, 4.9-fold (CI, 1.3- to 40.0-fold; P < 0.001) for tumor necrosis factor-α (TNF-α), 7.0-fold (CI, 3.5- to 18.0-fold; P < 0.001) for interleukin-2 (IL-2), and 1.7-fold (CI, 0.1- to 4.0-fold; P = 0.004) for CD107a. At day 180, differences were 2.1-fold (CI, 0.0- to 6.0-fold; P = 0.030) for IFN-γ and 5.7-fold (CI, 2.0- to 15.0-fold; P < 0.001) for IL-2, with no difference for TNF-α or CD107a. No differences were seen between NA-FLU-v and NA-placebo. Limitation: The study was not powered to evaluate vaccine efficacy against influenza infection. Conclusion: Adjuvanted FLU-v is immunogenic and merits phase 3 development to explore efficacy. Primary Funding Source: SEEK and the European Commission Directorate-General for Research and Innovation, European Member States within the UNISEC (Universal Influenza Vaccines Secured) project.

Declining Hepatitis C Virus (HCV) Incidence in Dutch Human Immunodeficiency Virus-Positive Men Who Have Sex With Men After Unrestricted Access to HCV Therapy.

Background: Direct-acting antivirals (DAAa) cure hepatitis C virus (HCV) infections in 95% of infected patients. Modeling studies predict that universal HCV treatment will lead to a decrease in the incidence of new infections but real-life data are lacking. The incidence of HCV among Dutch human immunodeficiency virus (HIV)-positive men who have sex with men (MSM) has been high for >10 years. In 2015 DAAs became available to all Dutch HCV patients and resulted in a rapid treatment uptake in HIV-positive MSM. We assessed whether this uptake was followed by a decrease in the incidence of HCV infections. Methods: Two prospective studies of treatment for acute HCV infection enrolled patients in 17 Dutch HIV centers, having 76% of the total HIV-positive MSM population in care in the Netherlands. Patients were recruited in 2014 and 2016, the years before and after unrestricted DAA availability. We compared the HCV incidence in both years. Results: The incidence of acute HCV infection decreased from 93 infections during 8290 person-years of follow-up (PYFU) in 2014 (11.2/1000 PYFU; 95% confidence interval [CI], 9.1-13.7) to 49 during 8961 PYFU in 2016 (5.5/1000 PYFU; 4.1-7.2). The incidence rate ratio of 2016 compared with 2014 was 0.49 (95% CI, .35-.69). Simultaneously, a significant increase in the percentage positive syphilis (+2.2%) and gonorrhea (+2.8%) tests in HIV-positive MSM was observed at sexual health clinics across the Netherlands and contradicts a decrease in risk behavior as an alternative explanation. Conclusions: Unrestricted DAA availability in the Netherlands was followed by a 51% decrease in acute HCV infections among HIV-positive MSM.

Fast and accurate prediction of positive and negative urine cultures by flow cytometry.

BACKGROUND: Urinary tract infection (UTI) is a widespread infectious disease in humans. Urine culture, a huge workload in the microbiology laboratory, is still the standard diagnostic test for UTI, but most of the cultures are negative. A reliable screening method could reduce unnecessary cultures and quicken reporting of negative results. METHODS: We evaluated the usefulness of a flow cytometry (FC) screening method in the prediction of positive urine culture to reduce the number of urine cultures. The urine specimens sent to the laboratory for culture were tested with the flow cytometer Accuri C6. FC bacterial counts were compared to standard urine culture results to assess the best cut-off values. RESULTS: Two hundred nine urine samples were included, of which 79 (37.8 %) were culture positive. On comparing the culture and the FC data in the ROC curve, the FC bacterial counts of ≥10(6) bacteria/mL provided a reliable screening for bacteriuria with a sensitivity and specificity of 99 and 58 %, respectively. All negative FC results (<10(6) bacteria/mL) showed a negative predictive value of 99 % with a negative likelihood ratio of 0.02. The FC bacterial counts of ≥10(8)/mL showed a positive predictive value of 99 % with a positive likelihood ratio of 60.9. CONCLUSIONS: Counting bacteria in human urine samples by the FC is a fast, accurate and cost-effective screening method for bacteriuria. Our results showed that FC is able to rule out UTI, which can lead to a substantial reduction (36 %) of urine cultures. It also demonstrated that this method predicts positive cultures accurately.

Follow-up of Contacts of Middle East Respiratory Syndrome Coronavirus-Infected Returning Travelers, the Netherlands, 2014.

Notification of 2 imported cases of infection with Middle East respiratory syndrome coronavirus in the Netherlands triggered comprehensive monitoring of contacts. Observed low rates of virus transmission and the psychological effect of contact monitoring indicate that thoughtful assessment of close contacts is prudent and must be guided by clinical and epidemiologic risk factors.

Chronic Hyponatremia: The Role of Reset Osmostat in Patients with Suspected SIAD.

Background: Hyponatremia is common, particularly among the elderly. Reset osmostat (RO) serves as an alternative diagnosis to the syndrome of inappropriate antidiuresis (SIAD). There is limited information available regarding the prevalence of RO in outpatient clinics and hospital wards. The water-diluting test is considered the gold standard for the diagnosis of RO. The recent identification of copeptin provides an additional diagnostic marker alongside the utilization of fractional uric acid excretion. Methods: This single-center, prospective, observational study involved eight patients undergoing a water-diluting test over a study period of 2 years. Results: Reset osmostat was diagnosed in 50% of cases, while SIAD was confirmed in one patient. The tests were inconclusive for the remaining three patients. Conclusions: Our findings suggest that reset osmostat, despite its rarity, is a plausible diagnosis in chronic hyponatremia. The relevance of copeptin could not be confirmed in this study. Moreover, fractional uric acid excretion might be as effective as the water-diluting test in diagnosing reset osmostat.

Dolutegravir/Lamivudine Is Noninferior to Continuing Dolutegravir- and Non-Dolutegravir-Based Triple-Drug Antiretroviral Therapy in Virologically Suppressed People With Human Immunodeficiency Virus: DUALING Prospective Nationwide Matched Cohort Study.

Background: Confirming the efficacy of dolutegravir/lamivudine in clinical practice solidifies recommendations on its use. Methods: Prospective cohort study (DUALING) in 24 human immunodeficiency virus (HIV) treatment centers in the Netherlands. HIV RNA-suppressed cases were on triple-drug antiretroviral regimens without prior virological failure or resistance and started dolutegravir/lamivudine. Cases were 1:2 matched to controls on triple-drug antiretroviral regimens by the use of dolutegravir-based regimens, age, sex, transmission route, CD4+ T-cell nadir, and HIV RNA zenith. The primary endpoint was the treatment failure rate in cases versus controls at 1 year by intention-to-treat and on-treatment analyses with 5% noninferiority margin. Results: The 2040 participants were 680 cases and 1380 controls. Treatment failure in the 390 dolutegravir-based cases versus controls occurred in 8.72% and 12.50% (difference: -3.78% [95% confidence interval {CI}, -7.49% to .08%]) by intention-to-treat and 1.39% and 0.80% (difference: 0.59% [95% CI, -.80% to 1.98%]) by on-treatment analyses. The treatment failure risk in 290 non-dolutegravir-based cases was also noninferior to controls. Antiretroviral regimen modifications unrelated to virological failure explained the higher treatment failure rate by intention-to-treat. A shorter time on triple-drug antiretroviral therapy and being of non-Western origin was associated with treatment failure. Treatment failure, defined as 2 consecutive HIV RNA >50 copies/mL, occurred in 4 cases and 5 controls but without genotypic resistance detected. Viral blips occured comparable in cases and controls but cases gained more weight, especially when tenofovir-based regimens were discontinued. Conclusions: In routine care, dolutegravir/lamivudine was noninferior to continuing triple-drug antiretroviral regimens after 1 year, supporting the use of dolutegravir/lamivudine in clinical practice. Clinical Trials Registration: NCT04707326.

Lower plasma calcium associated with COVID-19, but not with disease severity: a two-centre retrospective cohort study.

BACKGROUND: Previous studies indicate hypocalcaemia as a potential diagnostic and prognostic marker of corona-virus disease 2019 (COVID-19). Our aim was to investigate these relations in more detail in a large test cohort and an independent validation cohort. METHODS: We retrospectively included 2792 COVID-19 suspected patients that presented to the emergency department (ED) of two hospitals. Plasma calcium and ionized plasma calcium levels were compared between COVID-19 positive and negative patients, and between severe and non-severe COVID-19 patients using univariate and multivariate analyses in the first hospital (N = 1363). Severe COVID-19 was defined as intensive care unit (ICU) admission or death within 28 d after admission. The results were validated by repeating the same analyses in the second hospital (N = 1429). RESULTS: A total of 693 (24.8%) of the enrolled patients were COVID-19 positive, of whom 238 (34.3%) had severe COVID-19. In both hospitals, COVID-19 positive patients had lower plasma calcium levels than COVID-19 negative patients, regardless of correction for albumin, in univariate and multivariate analysis (Δ0.06-0.13 mmol/L, p < .001). Ionized plasma calcium concentrations, with and without correction for pH, were also lower in COVID-19 positive patients in multivariate analyses (Δ0.02-0.05 mmol/L, N = 567, p < .001). However, we did not find a significant association between COVID-19 disease severity and plasma calcium in multivariate analyses. CONCLUSIONS: Plasma calcium concentrations were lower in COVID-19 positive than COVID-19 negative patients but we found no association with disease severity in multivariate analyses. Further understanding of plasma calcium perturbation may facilitate the development of new preventive and therapeutic modalities for the current pandemic.

Recovery of viremic control after superinfection with pathogenic HIV type 1 in a long-term elite controller of HIV type 1 infection.

A human immunodeficiency virus type 1 (HIV-1)-infected elite controller (defined as an untreated HIV-1-infected person with a plasma HIV-1 RNA level <50 copies/mL for at least 12 months) who experienced a viremic episode after superinfection regained natural viremic control, although the viral loads in the patient's 2 partners, infected with the same viral strain, were continuously approximately 30-fold higher. Thus, host mechanisms seem to be able to repeatedly control HIV-1 replication, halting disease progression.

Flow cytometric analysis of viable bacteria in urine samples of febrile patients at the emergency department.

BACKGROUND: Fast and reliable diagnostics are important in febrile patients admitted to the emergency department. Current urine diagnostics are fast but moderately reliable or reliable but time consuming. Flow cytometry (FC) is a new promising technique in the diagnostics of complicated urinary tract infections by counting bacteria in urine samples. The aim of this study is to improve the FC method by counting only viable bacteria. METHODS: Urine was obtained from 135 consecutive febrile patients at the emergency department. According to protocol regular diagnostic urine tests were performed. In addition, FC counting of viable and non-viable bacteria was executed after staining with thiazole orange and propidium iodide. All test results were compared to the results of urine culture (≥ 105 colony forming units/mL). RESULTS: At a cut-off value of 2.01 × 105 viable bacteria/mL the sensitivity was 100% and specificity was 78.4% (AUC-value 0.955 on ROC-curve). Spearman correlation test exhibited a higher correlation for flow cytometric counting of only viable bacteria than counting of all bacteria (0.59 vs. 0.37). Using ROC-curves, the AUC-values for FC counting of all bacteria, only viable bacteria and Gram staining were respectively 0.935, 0.955, and 0.968 (P > 0.05). CONCLUSION: FC counting of only viable bacteria can predict quickly and reliably positive and negative urine cultures in febrile patients admitted to the emergency department. It can help to improve the speed and accuracy of the diagnostic procedure at the emergency department. © 2017 Clinical Cytometry Society.

Accurate and fast urinalysis in febrile patients by flow cytometry.

BACKGROUND: The urine culture is worldwide accepted as the gold standard in diagnosing urinary tract infections, but is time consuming and costly, other methods are fast but moderately reliable. We investigated whether counting the number of bacteria by flow cytometry could be a fast and accurate method to analyze urine samples in febrile patients at the emergency department (ED). METHODS: Urine samples were obtained from 140 febrile patients at the ED. Urinalysis was performed according to standard procedures. Flow cytometric analysis for bacteria was performed with the Accuri C6 flow cytometer. Diagnostic values were determined at various cut-off points by using urine culture as the gold standard. RESULTS: The highest diagnostic accuracy of urinalysis of bacteria was obtained with flow cytometric analysis (AUC of 0.96). The best cut-off value for bacteria counted by flow cytometry based on the ROC-curve was 3.72 × 106 bacteria/mL, this resulted in a sensitivity of 94.7% and a specificity of 88.2%. CONCLUSIONS: Counting bacteria by flow cytometry has the highest diagnostic accuracy and is superior to other methods in urinalysis in febrile patients in the ED when using urine culture as the gold standard.

Effectiveness and cost-effectiveness of a nurse-delivered intervention to improve adherence to treatment for HIV: a pragmatic, multicentre, open-label, randomised clinical trial.

BACKGROUND: No high-quality trials have provided evidence of effectiveness and cost-effectiveness of HIV treatment adherence intervention strategies. We therefore examined the effectiveness and cost-effectiveness of the Adherence Improving self-Management Strategy (AIMS) compared with treatment as usual. METHODS: We did a pragmatic, multicentre, open-label, randomised controlled trial in seven HIV clinics at academic and non-academic hospitals in the Netherlands. Eligible participants were patients with HIV who were either treatment experienced (ie, with ≥9 months on combination antiretroviral therapy [ART] and at risk of viral rebound) or treatment-naive patients initiating their first combination ART regimen. We randomly assigned participants (1:1) to either AIMS or treatment as usual (ie, containing a range of common adherence intervention strategies) using a computer-generated randomisation table. Randomisation was stratified by treatment experience (experienced vs naive) and included block randomisation at nurse level with randomly ordered blocks of size four, six, and eight. 21 HIV nurses from the participating clinics received three training sessions of 6 h each (18 h in total) on AIMS and a 1·5 h booster training session at the clinic (two to three nurses per session) after each nurse had seen two to three patients. AIMS was delivered by nurses during routine clinic visits. We did mixed-effects, intent-to-treat analyses to examine treatment effects on the primary outcome of log10 viral load collected at months 5, 10, and 15. The viral load results were exponentiated (with base 10) for easier interpretation. Using cohort data from 7347 Dutch patients with HIV to calculate the natural course of illness, we developed a lifetime Markov model to estimate the primary economic outcome of lifetime societal costs per quality-adjusted life-years (QALYs) gained. This trial is registered at ClinicalTrials.gov (number NCT01429142). FINDINGS: We recruited participants between Sept 1, 2011, and April 2, 2013; the last patient completed the study on June 16, 2014. The intent-to-treat sample comprised 221 patients; 109 assigned to AIMS and 112 to treatment as usual. Across the three timepoints (months 5, 10, and 15), log viral load was 1·26 times higher (95% CI 1·04-1·52) in the treatment-as-usual group (estimated marginal mean 44·5 copies per mL [95% CI 35·5-55·9]) than in the AIMS group (estimated marginal mean 35·4 copies per mL [29·9-42·0]). Additionally, AIMS was cost-effective (ie, dominant: cheaper and more effective) since it reduced lifetime societal costs by €592 per patient and increased QALYs by 0·034 per patient. INTERPRETATION: Findings from preparatory studies have shown that AIMS is acceptable, feasible to deliver in routine care, and has reproducible effects on medication adherence. In this study, AIMS reduced viral load, increased QALYs, and saved resources. Implementation of AIMS in routine clinical HIV care is therefore recommended. FUNDING: Netherlands Organisation for Health Research and Development.

Tumor necrosis factor-alpha genetic predisposing factors can influence clinical severity in nephropathia epidemica.

Severe human infection with Hantavirus is characterized by high fever, cold chills, thrombocytopenia, arterial hypotension, acute renal failure, and/or adult respiratory distress syndrome (ARDS)-like pulmonary involvement, but the clinical course varies greatly between individuals. We investigated whether genetically determined differences in tumor necrosis factor (TNF)-alpha production can influence the severity of Hantavirus disease. We studied a TNF-alpha single-nucleotide promoter polymorphism (SNP) at position -238 (a guanine [G]-to-adenine [A] transition) and ex vivo TNF-alpha production in a recall study of 36 Belgian patients who had a serologically proven form of Puumala virus-induced Hantavirus infection with the kidney as main target organ. In our study, the highest creatinine levels were found in patients with the lowest ex vivo TNF-alpha production. Creatinine levels correlated inversely with TNF-alpha production (R = -0.35, p < 0.05). The number of thrombocytes was significantly lower in patients with the GA-238 genotype (low TNF-alpha producers) compared with patients with the GG-238 genotype. In our study, genetically determined low production of TNF-alpha was associated with some parameters indicating a more severe clinical course of Puumala Hantavirus infection in humans, possibly by impaired activation of TNF-alpha-dependent antiviral mechanisms, which could in turn result in decreased clearance of Hantavirus.

[Unexplained anaemia in men: be aware of hypogonadism]. / Onverklaarde anemie bij mannen: denk aan hypogonadisme.

Unexplained anaemia is not uncommon. We present two male patients suffering from longstanding mild anaemia, for which no cause could be found. We performed an extensive analysis, but there were no signs of malignant disease, chronic inflammation, renal failure, hypothyroidism, myelodysplastic syndrome, haemolysis or nutritional deficiencies. However, both patients had symptoms of hypogonadism, confirmed by biochemical testing. The 56-year-old man known with metabolic syndrome turned out to have secondary hypogonadism without a pituitary tumour and the 75-year-old man had primary hypogonadism. After exclusion of prostate carcinoma, testosterone substitution therapy was started in both patients, which improved their haematocrits and sexual and general well-being substantially. Testosterone exerts anabolic effects in multiple organ systems; in bone marrow it potentiates the stimulatory effect of erythropoietin on erythropoiesis. Primary hypogonadism frequently occurs in elderly patients, while secondary hypogonadism is frequently seen in middle-aged men with type 2 diabetes mellitus and obesity.

Time-measured phylogenies of gag, pol and env sequence data reveal the direction and time interval of HIV-1 transmission.

OBJECTIVE: To investigate whether time-measured phylogenetic analysis of longitudinal viral sequences can establish the direction and timing of HIV-1 transmission in an epidemiologically linked transmission cluster of three homosexual men. DESIGN: An HIV-1-infected homosexual man (patient 1) and his long-term HIV-negative partner (patient 2) engaged in a triangular relationship with an additional partner (patient 3). On the basis of phylogenetic analysis of gag sequences, patient 3 was previously identified as the source for superinfection of patient 1 but the source of HIV-1 infection of patient 2, who seroconverted during the triangular relationship, remained unclear. Here, we set out to analyze newly obtained gag, pol and env sequences from all three patients to fully elucidate the transmission history in this epidemiologically linked cluster. METHODS: Bayesian Markov Chain Monte Carlo (MCMC) phylogenetic analyses incorporating a relaxed clock model and a flexible Bayesian skyride tree prior were applied to the longitudinally obtained gag, pol and env sequences from all three patients. RESULTS: Our time-measured evolutionary reconstructions convincingly supported transmission of HIV-1 from the new partner patient 3 to both patients 1 and 2. In addition, estimates of viral divergence times assisted in narrowing down the transmission intervals delineated by seroconversion estimates. CONCLUSION: Our analysis implies that Bayesian MCMC phylogenetic reconstruction incorporating temporal information can indeed reveal the direction of multiple HIV-1 transmission events in an epidemiologically linked cluster and provide more detail on the timing of transmission.

[Evaluation of diagnosis and therapy of Staphylococcus aureus bacteraemia: recommended minimum treatment duration of 2 weeks not always met]. / Evaluatie van de diagnostiek en behandeling van bacteriëmie door Staphylococcus aureus. Minimale behandelduur van 2 weken vaak niet gehaald.

OBJECTIVE: Bacteraemia caused by Staphylococcus aureus (SA bacteraemia) can run a relatively mild course, but can also be complicated by focal infections in bones, joints, soft tissue and the heart. The Infectious Disease Society of America (IDSA) advises a transoesophageal echocardiogram (TOE) be taken in each case of SA bacteraemia in order to rule out endocarditis, in addition to sampling blood for culture 2-3 days after the start of treatment. Both the IDSA and the Dutch Stichting Werkgroep Antibiotica Beleid (SWAB - Foundation for Antibiotic Policy Work Groups) recommend that patients with SA bacteraemia be treated intravenously for at least 14 days; longer if a complicated course is expected. We investigated whether SA bacteraemia was diagnosed and treated according to current guidelines. DESIGN: Retrospective cohort study METHOD: A case series of consecutive patients ≥ 18 years of age with SA bacteraemia was identified using the electronic microbiology registration system. RESULTS: A total of 93 patients were identified. Median follow-up duration was ≥ 3 months. Of the 81 patients who had survived one week after admission to the hospital, 41(60%) did not undergo TOE. Blood cultures on day 3 were performed in only 6 (6%) patients. Of the 79 (85%) patients who had survived the first two weeks of infection, 26 (33%) had been treated with intravenous antibiotics for less than 14 days. Recurrent SA bacteraemia occurred in 4 patients. CONCLUSION: In the majority of patients with SA bacteraemia, diagnostic work-up and duration of therapy did not comply with ISDA and SWAB guidelines.

[Chronic norovirus infection in an immunocompromised patient]. / Chronische norovirusinfectie bij een immuungecompromitteerde patiënt.

A 68-year-old man, immunocompromised due to non-Hodgkin lymphoma and chemotherapy, was admitted for a community-acquired norovirus infection. He developed chronic intermittent diarrhoea and cachexia. A video-capsule examination showed severe mucosal atrophy in the jejunum. The patient died eight months after the initial norovirus infection. Eight of the nine stool examinations were positive for the norovirus during this entire period. Excretion of norovirus is known to persist after the symptoms have been resolved. However, there is only one previously reported case of excretion over such a long period. Recognising a chronic norovirus infection in immunocompromised patients is vital as then complications such as mucosal atrophy with malabsorption and cachexia can be diagnosed and supportive therapy can be started. Furthermore, recognising a chronic norovirus infection is essential for preventing norovirus outbreaks. Infected patients should always be isolated, regardless of their symptoms and faecal viral load.

Abacavir/lamivudine/zidovudine maintenance after standard induction in antiretroviral therapy-naïve patients: FREE randomized trial interim results.

Maintenance with a triple nucleoside reverse transcriptase Inhibitor (NRTI) regimen after successful induction with a dual NRTI/protease inhibitor (PI) combination may be advantageous, because of low pill burden, favorable lipids, and less drug interactions. This strategy to become free of PI-related problems without losing viral efficacy has not been formally tested. We performed a randomized, open-label, multicenter, 96-week comparative study in antiretroviral therapy (ART)-naïve patients with CD4 50 copies per milliliter). Two hundred seven patients had similar baseline (BL) characteristics: median CD4 180 cells/mm(3), median VL 5.19 log(10) copies per milliliter. One hundred twenty subjects (58%) met randomization criteria. Baseline VL differed significantly between dropouts and randomized subjects (median 5.41 versus 5.06 log(10) copies per milliliter, p = 0.017), as did CD4 cells (median 160 and 200 cells/mm(3), p = 0.044). Sixty-one subjects received TZV and 59 subjects continued NRTIs/PI. At week 48, 2 patients in the TZV group and 5 in the PI group did not have a sustained virologic suppression (log rank test; p = 0.379). CD4 counts increased significantly in both arms. In ART-naïve patients, TZV maintenance had similar antiviral efficacy compared to continued standard ART at 48 weeks after baseline. Patients on successful standard ART can be safely switched to a NRTI-only regimen, at least for the tested time period.

Interpatient variability in the pharmacokinetics of the HIV non-nucleoside reverse transcriptase inhibitor efavirenz: the effect of gender, race, and CYP2B6 polymorphism.

AIMS: To characterize the demographic and pharmacogenetic factors that influence interpatient variability in the plasma concentrations of the HIV non-nucleoside reverse transcriptase inhibitor efavirenz. METHODS: Data from all samples analyzed for efavirenz in our TDM service in 2002 and 2003 were reviewed. Information on gender, age, body weight, height, race, hormonal contraceptive use (in a subset of patients), and time between sampling and last intake was recorded. PCR-restriction fragment length polymorphism analysis was performed to detect the cytochrome P450 2B6 (CYP2B6) C1459T variant (present in CYP2B6*6 and CYP2B6*7) which is associated with low CYP2B6 activity. RESULTS: A total of 255 patients were included in this analysis. The median plasma efavirenz concentration was 2.50 (interquartile range: 1.85-3.55) mg l(-1). Eight patients (3.1%) were considered to have a subtherapeutic plasma concentration (<1.0 mg l(-1)) and 48 (18.9%) a toxic efavirenz concentration (>4.0 mg l(-1)). Gender, time after last intake, and race were the only factors that were significantly related to plasma efavirenz concentration in a multivariate analysis. No influence was observed for body weight, hormonal contraceptive use, and the presence of the CYP2B6 C1459T polymorphism. CONCLUSIONS: Gender and race are important factors in determining interpatient variability in plasma efavirenz concentrations which were unaffected by the presence of the CYP2B6 C1459T polymorphism. Physicians should be particularly alert for signs of efavirenz-induced toxicity in females and non-Caucasian patients.

Natural controlled HIV infection: preserved HIV-specific immunity despite undetectable replication competent virus.

Long-term non-progressive HIV infection, characterized by low but detectable viral load and stable CD4 counts in the absence of antiviral therapy, is observed in about 5% of HIV-infected patients. Here we identified four therapy naïve individuals who are strongly seropositive for HIV-1 but who lack evidence of detectable HIV p24 antigen, plasma RNA, and proviral DNA in routine diagnostic testing. With an ultrasensitive PCR, we established that frequencies of pol proviral DNA sequences were as low as 0.2-0.5 copies/10(6) PBMC. HIV could not be isolated using up to 30x10(6) patient PBMC. One individual was heterozygous for CCR5 Delta32, but CCR5 expression on CD4+ T cells was normal to high in all four individuals. In vitro R5 and X4 HIV-1 susceptibility of CD8-depleted PBMC of all study subjects was significantly lower than the susceptibility of CD8-depleted PBMC of healthy blood donors. All individuals expressed protective HLA-B*58s alleles and showed evidence of HIV-specific cellular immunity either by staining with HLA-B*57 tetramers folded with an HIV RT or gag peptide or after stimulation with HIV-1 p24 gag, RT, or nef peptides in ELIspot analysis. HIV-specific CD4+ T helper cells were demonstrated by proliferation of CD4+ T cells and intracellular staining for IL-2 and IFNgamma after stimulation with an HIV-gag peptide pool. Sera of all individuals showed antibody-mediated neutralization of both R5 and X4 HIV-1 variants. These data implicate that very low-level antigen exposure is sufficient for sustained HIV-specific immunity and suggest the possibility of a multi-factorial control of HIV infection.