Ensuring quality control in a COVID-19 clinical trial during the pandemic: The experience of the Inserm C20-15 DisCoVeRy study

SETTING

Health measures taken during the pandemic deeply modified the clinical research practices. At the same time, the demand for the results of the COVID-19 trials was urgent. Thus, the objective of this article is to share Inserm's experience in ensuring quality control in clinical trials in this challenging context.

OBJECTIVES

DisCoVeRy is a phase III randomized study that aimed at evaluating the safety and efficacy of 4 therapeutic strategies in hospitalized COVID-19 adult patients. Between March, 22nd 2020 and January, 20th 2021, 1309 patients were included. In order to guarantee the best quality of data, the Sponsor had to adapt to the current sanitary measures and to their impact on clinical research activity, notably by adapting Monitoring Plan objectives, involving the research departments of the participating hospitals and a network of clinical research assistants (CRAs).

RESULTS

Overall, 97 CRAs were involved and performed 909 monitoring visits. The monitoring of 100% of critical data for all patients included in the analysis was achieved, and despite of the pandemic context, a conform consent was recovered for more than 99% of patients. Results of the study were published in May and September 2021.

DISCUSSION/CONCLUSION

The main monitoring objective was met thanks to the mobilization of considerable personnel resources, within a very tight time frame and external hurdles. There is a need for further reflection to adapt the lessons learned from this experience to the context of routine practice and to improve the response of French academic research during a future epidemic.

Management of pharmacovigilance during the COVID-19 pandemic crisis by the safety department of an academic sponsor: Lessons learnt and challenges from the EU DisCoVeRy clinical trial

The current COVID-19 pandemic was an exceptional health situation, including for drug use. As there was no known effective drug for COVID-19 at the beginning of the pandemic, different drug candidates were proposed. In this article, we present the challenges for an academic Safety Department to manage the global safety of a European trial during the pandemic. The National Institute for Health and Medical Research (Inserm) conducted a European multicenter, open-label, randomized, controlled trial involving three repurposed and one-in development drugs (lopinavir/ritonavir, IFN-β1a, hydroxychloroquine, and remdesivir) in adults hospitalized with COVID-19. From 25 March 2020 to 29 May 2020, the Inserm Safety Department had to manage 585 Serious Adverse Events (SAEs) initial notification and 396 follow-up reports. The Inserm Safety Department's staff was mobilized to manage these SAEs and to report Expedited safety reports to the competent authorities within the legal timeframes. More than 500 queries were sent to the investigators due to a lack of or incoherent information on SAE forms. At the same time, the investigators were overwhelmed by the management of patients suffering from COVID-19 infection. These particular conditions of missing data and lack of accurate description of adverse events made evaluation of the SAEs very difficult, particularly the assessment of the causal role of each investigational medicinal product. In parallel, working difficulties were accentuated by the national lockdown, frequent IT tool dysfunctions, delayed implementation of monitoring and the absence of automatic alerts for SAE form modification. Although COVID-19 is a confounding factor per se, the delay in and quality of SAE form completion and the real-time medical analysis by the Inserm Safety Department were major issues in the quick identification of potential safety signals. To conduct a high-quality clinical trial and ensure patient safety, all stakeholders must take their roles and responsibilities.

Rare predicted loss-of-function variants of type I IFN immunity genes are associated with life-threatening COVID-19

BACKGROUND

We previously reported that impaired type I IFN activity, due to inborn errors of TLR3- and TLR7-dependent type I interferon (IFN) immunity or to autoantibodies against type I IFN, account for 15-20% of cases of life-threatening COVID-19 in unvaccinated patients. Therefore, the determinants of life-threatening COVID-19 remain to be identified in ~ 80% of cases.

METHODS

We report here a genome-wide rare variant burden association analysis in 3269 unvaccinated patients with life-threatening COVID-19, and 1373 unvaccinated SARS-CoV-2-infected individuals without pneumonia. Among the 928 patients tested for autoantibodies against type I IFN, a quarter (234) were positive and were excluded.

RESULTS

No gene reached genome-wide significance. Under a recessive model, the most significant gene with at-risk variants was TLR7, with an OR of 27.68 (95%CI 1.5-528.7, P = 1.1 × 10-4) for biochemically loss-of-function (bLOF) variants. We replicated the enrichment in rare predicted LOF (pLOF) variants at 13 influenza susceptibility loci involved in TLR3-dependent type I IFN immunity (OR = 3.70[95%CI 1.3-8.2], P = 2.1 × 10-4). This enrichment was further strengthened by (1) adding the recently reported TYK2 and TLR7 COVID-19 loci, particularly under a recessive model (OR = 19.65[95%CI 2.1-2635.4], P = 3.4 × 10-3), and (2) considering as pLOF branchpoint variants with potentially strong impacts on splicing among the 15 loci (OR = 4.40[9%CI 2.3-8.4], P = 7.7 × 10-8). Finally, the patients with pLOF/bLOF variants at these 15 loci were significantly younger (mean age [SD] = 43.3 [20.3] years) than the other patients (56.0 [17.3] years; P = 1.68 × 10-5).

CONCLUSIONS

Rare variants of TLR3- and TLR7-dependent type I IFN immunity genes can underlie life-threatening COVID-19, particularly with recessive inheritance, in patients under 60 years old.

Rare predicted loss-of-function variants of type I IFN immunity genes are associated with life-threatening COVID-19

Background

We previously reported inborn errors of TLR3- and TLR7-dependent type I interferon (IFN) immunity in 1-5% of unvaccinated patients with life-threatening COVID-19, and auto-antibodies against type I IFN in another 15-20% of cases.

Methods

We report here a genome-wide rare variant burden association analysis in 3,269 unvaccinated patients with life-threatening COVID-19 (1,301 previously reported and 1,968 new patients), and 1,373 unvaccinated SARS-CoV-2-infected individuals without pneumonia. A quarter of the patients tested had antibodies against type I IFN (234 of 928) and were excluded from the analysis.

Results

No gene reached genome-wide significance. Under a recessive model, the most significant gene with at-risk variants was TLR7 , with an OR of 27.68 (95%CI:1.5-528.7, P= 1.1×10 -4 ), in analyses restricted to biochemically loss-of-function (bLOF) variants. We replicated the enrichment in rare predicted LOF (pLOF) variants at 13 influenza susceptibility loci involved in TLR3-dependent type I IFN immunity (OR=3.70 [95%CI:1.3-8.2], P= 2.1×10 -4 ). Adding the recently reported TYK2 COVID-19 locus strengthened this enrichment, particularly under a recessive model (OR=19.65 [95%CI:2.1-2635.4]; P= 3.4×10 -3 ). When these 14 loci and TLR7 were considered, all individuals hemizygous ( n =20) or homozygous ( n =5) for pLOF or bLOF variants were patients (OR=39.19 [95%CI:5.2-5037.0], P =4.7×10 -7 ), who also showed an enrichment in heterozygous variants (OR=2.36 [95%CI:1.0-5.9], P =0.02). Finally, the patients with pLOF or bLOF variants at these 15 loci were significantly younger (mean age [SD]=43.3 [20.3] years) than the other patients (56.0 [17.3] years; P= 1.68×10 -5 ).

Conclusions

Rare variants of TLR3- and TLR7-dependent type I IFN immunity genes can underlie life-threatening COVID-19, particularly with recessive inheritance, in patients under 60 years old.

Tutorial for $DESIGN in NONMEM: Clinical trial evaluation and optimization

This NONMEM tutorial shows how to evaluate and optimize clinical trial designs, using algorithms developed in design software, such as PopED and PFIM 4.0. Parameter precision and model parameter estimability is obtained by assessing the Fisher Information Matrix (FIM), providing expected model parameter uncertainty. Model parameter identifiability may be uncovered by very large standard errors or inability to invert an FIM. Because evaluation of FIM is more efficient than clinical trial simulation, more designs can be investigated, and the design of a clinical trial can be optimized. This tutorial provides simple and complex pharmacokinetic/pharmacodynamic examples on obtaining optimal sample times, doses, or best division of subjects among design groups. Robust design techniques accounting for likely variability among subjects are also shown. A design evaluator and optimizer within NONMEM allows any control stream first developed for trial design exploration to be subsequently used for estimation of parameters of simulated or clinical data, without transferring the model to another software. Conversely, a model developed in NONMEM could be used for design optimization. In addition, the $DESIGN feature can be used on any model file and dataset combination to retrospectively evaluate the model parameter uncertainty one would expect given that the model generated the data, particularly if outliers of the actual data prevent a reasonable assessment of the variance‐covariance. The NONMEM trial design feature is suitable for standard continuous data, whereas more elaborate trial designs or with noncontinuous data‐types can still be accomplished in optimal design dedicated software like PopED and PFIM.

Endpoints for randomized controlled clinical trials for COVID-19 treatments

BACKGROUND

Endpoint choice for randomized controlled trials of treatments for novel coronavirus-induced disease (COVID-19) is complex. Trials must start rapidly to identify treatments that can be used as part of the outbreak response, in the midst of considerable uncertainty and limited information. COVID-19 presentation is heterogeneous, ranging from mild disease that improves within days to critical disease that can last weeks to over a month and can end in death. While improvement in mortality would provide unquestionable evidence about the clinical significance of a treatment, sample sizes for a study evaluating mortality are large and may be impractical, particularly given a multitude of putative therapies to evaluate. Furthermore, patient states in between "cure" and "death" represent meaningful distinctions. Clinical severity scores have been proposed as an alternative. However, the appropriate summary measure for severity scores has been the subject of debate, particularly given the variable time course of COVID-19. Outcomes measured at fixed time points, such as a comparison of severity scores between treatment and control at day 14, may risk missing the time of clinical benefit. An endpoint such as time to improvement (or recovery) avoids the timing problem. However, some have argued that power losses will result from reducing the ordinal scale to a binary state of "recovered" versus "not recovered."

METHODS

We evaluate statistical power for possible trial endpoints for COVID-19 treatment trials using simulation models and data from two recent COVID-19 treatment trials.

RESULTS

Power for fixed time-point methods depends heavily on the time selected for evaluation. Time-to-event approaches have reasonable statistical power, even when compared with a fixed time-point method evaluated at the optimal time.

DISCUSSION

Time-to-event analysis methods have advantages in the COVID-19 setting, unless the optimal time for evaluating treatment effect is known in advance. Even when the optimal time is known, a time-to-event approach may increase power for interim analyses.

Dolutegravir and lamivudine maintenance therapy in HIV-1 virologically suppressed patients: results of the ANRS 167 trial (LAMIDOL)

OBJECTIVES

To evaluate the dolutegravir+lamivudine combination in virologically suppressed patients living with HIV.

METHODS

The ANRS 167 LAMIDOL trial was an open-label, single arm, multicentre trial assessing once-daily dolutegravir (50 mg)+lamivudine (300 mg) in virologically suppressed HIV-1 patients on first-line triple-drug regimens. The main criteria for inclusion in the trial were plasma viral load (pVL) ≤50 copies/mL for ≥2 years, CD4 nadir >200 cells/mm3 and WT HIV prior to treatment initiation. From week -8 (W-8) to day 0 (D0) (Phase 1), the current third agent was switched to dolutegravir. From D0 to W48 (Phase 2), patients received once-daily dolutegravir+lamivudine, except if intolerant or if pVL >50 copies/mL during Phase 1. Virological failure was defined as pVL >50 copies/mL in two consecutive samples. The study was designed to show that the strategy had an efficacy of ≥80%, assuming a 90% success rate with a type I error of 5% and a power of 90%.

RESULTS

In total, 104 of 110 patients enrolled in Phase 1 were included in Phase 2. These 104 patients were 86% male, 72% MSM and 87% CDC stage A. Their characteristics were (median): age 45 years, CD4 nadir 339 cells/mm3, baseline CD4 743 cells/mm3 and duration of viral suppression 4.5 years. The overall success rate at W48 was 97% (95% CI: 94%-100%), meeting the design expectation/assumption. Three therapeutic failures occurred: one virological failure at W4, one lost to follow-up at W32 and one interruption of therapeutic strategy at W40 after a blip (pVL 59 copies/mL but control pVL <50 copies/mL). Three viral blips occurred in two additional patients. Neither M184V nor integrase resistance mutations were detected after failure or blips.

CONCLUSIONS

Dolutegravir+lamivudine is a promising maintenance therapy in HIV-1-infected patients with controlled virological suppression.

Clinical and virological data of the first cases of COVID-19 in Europe: a case series

Background

On Dec 31, 2019, China reported a cluster of cases of pneumonia in people at Wuhan, Hubei Province. The responsible pathogen is a novel coronavirus, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We report the relevant features of the first cases in Europe of confirmed infection, named coronavirus disease 2019 (COVID-19), with the first patient diagnosed with the disease on Jan 24, 2020.

Methods

In this case series, we followed five patients admitted to Bichat-Claude Bernard University Hospital (Paris, France) and Pellegrin University Hospital (Bordeaux, France) and diagnosed with COVID-19 by semi-quantitative RT-PCR on nasopharyngeal swabs. We assessed patterns of clinical disease and viral load from different samples (nasopharyngeal and blood, urine, and stool samples), which were obtained once daily for 3 days from hospital admission, and once every 2 or 3 days until patient discharge. All samples were refrigerated and shipped to laboratories in the National Reference Center for Respiratory Viruses (The Institut Pasteur, Paris, and Hospices Civils de Lyon, Lyon, France), where RNA extraction, real-time RT-PCR, and virus isolation and titration procedures were done.

Findings

The patients were three men (aged 31 years, 48 years, and 80 years) and two women (aged 30 years and 46 years), all of Chinese origin, who had travelled to France from China around mid-January, 2020. Three different clinical evolutions are described: (1) two paucisymptomatic women diagnosed within a day of exhibiting symptoms, with high nasopharyngeal titres of SARS-CoV-2 within the first 24 h of the illness onset (5·2 and 7·4 log₁₀ copies per 1000 cells, respectively) and viral RNA detection in stools; (2) a two-step disease progression in two young men, with a secondary worsening around 10 days after disease onset despite a decreasing viral load in nasopharyngeal samples; and (3) an 80-year-old man with a rapid evolution towards multiple organ failure and a persistent high viral load in lower and upper respiratory tract with systemic virus dissemination and virus detection in plasma. The 80-year-old patient died on day 14 of illness (Feb 14, 2020); all other patients had recovered and been discharged by Feb 19, 2020.

Interpretation

We illustrated three different clinical and biological types of evolution in five patients infected with SARS-CoV-2 with detailed and comprehensive viral sampling strategy. We believe that these findings will contribute to a better understanding of the natural history of the disease and will contribute to advances in the implementation of more efficient infection control strategies.

Funding

REACTing (Research & Action Emerging Infectious Diseases).

Bayesian Individual Dynamic Predictions with Uncertainty of Longitudinal Biomarkers and Risks of Survival Events in a Joint Modelling Framework: a Comparison Between Stan, Monolix, and NONMEM

Given a joint model and its parameters, Bayesian individual dynamic prediction (IDP) of biomarkers and risk of event can be performed for new patients at different landmark times using observed biomarker values. The aim of the present study was to compare IDP, with uncertainty, using Stan 2.18, Monolix 2018R2 and NONMEM 7.4. Simulations of biomarker and survival were performed using a nonlinear joint model of prostate-specific antigen (PSA) kinetics and survival in metastatic prostate cancer. Several scenarios were evaluated, according to the strength of the association between PSA and survival. For various landmark times, a posteriori distribution of PSA kinetic individual parameters was estimated, given individual observations, with each software. Samples of individual parameters were drawn from the posterior distribution. Bias and imprecision of individual parameters as well as coverage of 95% credibility interval for PSA and risk of death were evaluated. All software performed equally well with small biases on individual parameters. Imprecision on individual parameters was comparable across software and showed marked improvements with increasing landmark time. In terms of coverage, results were also comparable and all software were able to well predict PSA kinetics and survival. As for computing time, Stan was faster than Monolix and NONMEM to obtain individual parameters. Stan 2.18, Monolix 2018R2 and NONMEM 7.4 are able to characterize IDP of biomarkers and risk of event in a nonlinear joint modelling framework with correct uncertainty and hence could be used in the context of individualized medicine.

Diabetes and dyslipidaemia are associated with oxidative stress independently of inflammation in long-term antiretroviral-treated HIV-infected patients

AIM

Ageing HIV-infected patients controlled by antiretroviral therapy (ART) frequently present age-related comorbidities, such as cardiovascular (CV) events, diabetes, dyslipidaemia, hypertension and chronic kidney disease (CKD). The prevalence of these comorbidities was evaluated in a cohort of long-term-monitored ART-controlled HIV-infected patients, then followed by a search into whether oxidative stress, like inflammation, might be associated with metabolic parameters and/or comorbidities.

METHODS

Included were 352 long-term ART patients who started with protease inhibitors (PIs) in 1997-1999. They were evaluated at their final visit, 11 years later, for previous CV events, prevalence of diabetes, LDL-related and atherogenic (high TG/HDL) dyslipidaemias, hypertension and CKD. Also measured were circulating biomarkers to explore oxidative stress (Lp-PLA2, oxLDL, oxLDL/LDL ratio, paraoxonase and arylesterase activities), inflammation/immune activation (hsCRP, hsIL-6, D dimer, soluble CD14, β2 microglobulin, cystatin C), adipokines and insulin resistance. Levels were compared in patients with and without each comorbidity or condition using non-parametric correlation tests and multivariate adjusted analyses.

RESULTS

At the final visit, 81.5% of patients were male and were aged (median, IQR) 49 years (45-56); BMI was 23.0 kg/m² (21.1-25.4), CD4+ lymphocytes were 620 cells/mm³ (453-790) and 91.5% had undetectable HIV-1 viral loads. The prevalence of diabetes was 11%, and LDL-related dyslipidaemia 28%, atherogenic dyslipidaemia 9%, hypertension 28%, CKD 9% and previous CV events 9%. Diabetes and atherogenic dyslipidaemia were associated with increased oxidative stress and independently with inflammation. LDL-related dyslipidaemia and impaired fasting glucose were associated with increased oxidative stress. No association of these biomarkers was detected with hypertension, CKD and previous CV events.

CONCLUSION

In long-term-treated HIV-infected patients with frequent comorbid conditions, oxidative stress could be contributing to diabetes and LDL-related and atherogenic dyslipidaemias independently of inflammation.

Correction: Experimental Treatment with Favipiravir for Ebola Virus Disease (the JIKI Trial): A Historically Controlled, Single-Arm Proof-of-Concept Trial in Guinea

[This corrects the article DOI: 10.1371/journal.pmed.1001967.].

Clinical and biomarker evaluations of sunitinib in patients (pts) with advanced well-differentiated grade 3 (G3) and poorly differentiated neuroendocrine neoplasms (PD-NEN)

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Background: Angiogenesis is extensively developed in well-differentiated pancreatic neuroendocrine tumors (PNET) where sunitinib was showed to prolong progression-free survival leading to FDA and EMA approval. However, clinical experience in pts with well-differentiated G3 & PD-NEN remains limited. Methods: This prospective phase II trial evaluate potential biomarkers correlating with sunitinib activity in pts with advanced well differentiated G3 or PD-NEN. Sunitinib was given at the dose of 37.5 mg/d as a continuous daily dosing until progression or unacceptable toxicity. Evaluation of activity was based on RECIST1.1. Safety was evaluated according to NCI-CTCAEv4. Pharmacokinetics (PK) of sunitinib and SU12662 (main active metabolite) were evaluated. Tumor biomarkers (PDGFR-b, VEGFR2, Carbonic Anhydrase 9, Ki67 and p-AKT) were evaluated in tumor tissues, quantified in tumor cells and stroma (vessels, fibroblasts) using immunohistochemistry and correlated with response by RECIST. Results: Among 31 pts (M/F: 18/13, median age 61), 13 pancreatic, 5 gastric, 5 rectal, 4 colonic, and 4 other G3 & PD-NEN were entered. 27 pts had previous treatment with chemotherapy (mainly platinum/VP16). Among 26 pts evaluable for safety and activity, 7 pts (23%, 95%CI: 6.9%-39.3%), including 3 pts classified as well-differentiated G3 neoplasms) experienced partial responses and tumor stabilizations (clinical benefit). Safety and PK exposure to sunitinib and SU12662 in those pts was consistent with that experienced in PNET. Among the above evaluated tumor biomarkers, only Ki67 correlated with sunitinib activity. The median Ki67 was 20% and 77.5% in pts with CB versus non-responders (p=.002), respectively. ROC curves showed correlations between lower Ki67 in tumors and sunitinib activity (OR:0.9; IC95%:0.831-0.9, p=.039). With a threshold value of Ki67 of 47%, sensitivity and specificity were 80%, the predictive positive value was 67% and the negative predictive value was 86%. Conclusions: In pts with well-differentiated G3 & PD-NEN, sunitinib showed evidence of activity that was more pronounced in pts with Ki67<47%. Clinical trial information: NCT01215578.

The Diagnostic and Prognostic Performance of Urinary FGFR3 Mutation Analysis in Bladder Cancer Surveillance: A Prospective Multicenter Study

OBJECTIVE

To assess the diagnostic and prognostic performance of a noninvasive FGFR3 mutation analysis. After transurethral resection (TUR) of noninvasive bladder transitional cell carcinoma (B-TCC), recurrence occurs in 70% of patients, thus justifying cystoscopic surveillance.

MATERIALS AND METHODS

A prospective multicenter study was carried out with a 2-year follow-up of patients with superficial B-TCC. Urine samples were collected before TUR and then before each cystoscopy during follow-up. Screening for the most prevalent FGFR3 mutations was done using urinary cells. The prognostic significance of an FGFR3 mutation at the time of the initial diagnosis was determined. The performance of the test in diagnosing and/or predicting recurrence during follow-up was assessed by calculating sensitivity and specificity.

RESULTS

Of 191 patients studied, 74 (39%) had a positive analysis before TUR (FGFR3 mutation group). The presence of an FGFR3 mutation at the time of diagnosis was associated with a shorter time to recurrence (P = .02). During follow-up, 68 patients from the FGFR3 mutation group were evaluated. FGFR3 mutation analysis showed a sensitivity of 0.73 and a specificity of 0.87 when compared with the results of cystoscopy. A positive urine test was predictive of recurrence either at the time of the positive result or later during the 2-year follow-up, with a sensitivity of 0.70 and a specificity of 0.87.

CONCLUSION

Among patients with an FGFR3 mutation in the initial tumor, a noninvasive urine test during follow-up can be valuable in diagnosing or predicting subsequent recurrence.

Profile of French general practitioners providing opportunistic primary preventive care--an observational cross-sectional multicentre study

BACKGROUND

Preventive services provided opportunistically by GPs are insufficient. Reasons are most often gathered through GPs' self-reports, rather than through independent observation.

OBJECTIVE

To assess with passive observers, the degree to which French GPs opportunistically perform primary preventive care during routine consultation.

METHODS

Observational cross-sectional multicentre ancillary study of the French ECOGEN study. The study period extended from 28 November 2011 to 30 April 2012. The inclusion criteria were patients seen by GPs at surgery and home consultations in non-randomized pre-determined half-day blocks per week. The non-inclusion criteria were patient's refusal and consultations initially focused on primary prevention in response to patient's request (ancillary study's specific criterion). Using passive observers, data were collected based on the second version of International Classification of Primary Care. Preventive consultations were defined if at least one problem/diagnosis was considered by consensus as definitely related to primary prevention. For each one of the 128 participating GPs, aggregation of data was performed from all his/her consultations. Determinants of the proportion of preventive consultations per GP were assessed by multivariate linear regression.

RESULTS

Considering 19003 consultations, the median proportion of preventive consultations per GP was 14.9% (range: 0-78.3%). It decreased with increased proportion of patients aged 18 or less (P = 0.006), with increased proportion of home visits (P = 0.008) and with increased proportion of consultations lasting under 10 minutes (P = 0.02). None of the GPs' personal characteristics were significantly associated.

CONCLUSION

Primary preventive care activity was related to the characteristics of GPs' patients and practice organizational markers and not to GPs' personal characteristics.

Preventive services recommendations for adults in primary care settings: agreement between Canada, France and the USA--a systematic review

OBJECTIVE

To analyze the level of agreement between recommendations on preventive services developed by Canada, France and the USA.

METHODS

We gathered recommendations on primary and secondary preventive services to adults up to November 3rd, 2011 from Canadian and US Task Forces, and equivalent French agencies. We excluded recommendations on immunization, long-term diseases or pregnancy.

RESULTS

Among 250 recommendations, 84 (34%) issued by a single country could not be compared; 43 (26%) of the remaining 166 were in strong agreement (strictly identical grades between advising countries); 25 of 43 resulted in a proposal to be implemented in clinical practice, two others not to be implemented in clinical practice and 16 were indeterminate about implementation. Strong agreement was more frequent for recommendations concerning history-taking and physical examination than for those concerning interventions (odds ratio (OR)=11.3, 95%CI: 1.6-241.2; p=0.04), and for recommendations concerning a high-risk population than for those concerning the general population (OR=3.1, 95%CI: 1.4-7.0; p=0.006). Agreement did not differ either according to maximum time range between recommendations' publication or according to the advising country.

CONCLUSION

Agreement between recommendations is low particularly on those concerning non-clinical preventive services or non-high-risk individuals.

Electronic sensors for assessing interactions between healthcare workers and patients under airborne precautions

Background

Direct observation has been widely used to assess interactions between healthcare workers (HCWs) and patients but is time-consuming and feasible only over short periods. We used a Radio Frequency Identification Device (RFID) system to automatically measure HCW-patient interactions.

Methods

We equipped 50 patient rooms with fixed sensors and 111 HCW volunteers with mobile sensors in two clinical wards of two hospitals. For 3 months, we recorded all interactions between HCWs and 54 patients under airborne precautions for suspected (n = 40) or confirmed (n = 14) tuberculosis. Number and duration of HCW entries into patient rooms were collected daily. Concomitantly, we directly observed room entries and interviewed HCWs to evaluate their self-perception of the number and duration of contacts with tuberculosis patients.

Results

After signal reconstruction, 5490 interactions were recorded between 82 HCWs and 54 tuberculosis patients during 404 days of airborne isolation. Median (interquartile range) interaction duration was 2.1 (0.8–4.4) min overall, 2.3 (0.8–5.0) in the mornings, 1.8 (0.8–3.7) in the afternoons, and 2.0 (0.7–4.3) at night (P<10⁻⁴). Number of interactions/day/HCW was 3.0 (1.0–6.0) and total daily duration was 7.6 (2.4–22.5) min. Durations estimated from 28 direct observations and 26 interviews were not significantly different from those recorded by the network.

Conclusions

The RFID was well accepted by HCWs. This original technique holds promise for accurately and continuously measuring interactions between HCWs and patients, as a less resource-consuming substitute for direct observation. The results could be used to model the transmission of significant pathogens. HCW perceptions of interactions with patients accurately reflected reality.

Comparison of model-based tests and selection strategies to detect genetic polymorphisms influencing pharmacokinetic parameters

We evaluate by simulation three model-based methods to test the influence of a single nucleotide polymorphism on a pharmacokinetic parameter of a drug: analysis of variance (ANOVA) on the empirical Bayes estimates of the individual parameters, likelihood ratio test between models with and without genetic covariate, and Wald tests on the parameters of the model with covariate. Analyses are performed using the FO and FOCE method implemented in the NONMEM software. We compare several approaches for model selection based on tests and global criteria. We illustrate the results with pharmacokinetic data on indinavir from HIV-positive patients included in COPHAR 2-ANRS 111 to study the gene effect prospectively. Only the tests based on the EBE obtain an empirical type I error close to the expected 5%. The approximation made with the FO algorithm results in a significant inflation of the type I error of the LRT and Wald tests.

Cardiovascular remodelling and extracellular fluid excess in early stages of chronic kidney disease

BACKGROUND

Patients with a mild to moderate decrease of glomerular filtration rate (GFR) are at risk of cardiovascular (CV) events and CV remodelling has been demonstrated in patients with advanced chronic kidney disease (CKD). However, early stages of CKD and the mechanisms involved in these modifications have not been studied.

METHODS

A total of 104 patients with early CKD (mean GFR 60+/-21 ml/min/1.73 m(2)) had cardiac and vascular ultrasound study and measurement of extracellular fluid by multifrequence spectroscopic bioimpedance.

RESULTS

GFR decline was associated with left ventricular (LV) remodelling or hypertrophy in 58 and 68% of DOQI-2 and DOQI-3 patients, respectively and impaired LV diastolic function. GFR decrease was also associated with common carotid remodelling and increased aorta stiffness. Cardiac and vascular remodelling were significantly associated with an excess of extracellular fluid (ECFe) evidenced as early as DOQI-2 stage. In multivariate analysis with adjustment for GFR, ECFe, age and systolic blood pressure (sBP), GFR was no longer independently associated with cardiac and vascular remodelling, whereas ECFe was an independent determinant of LV hypertrophy, left atrium enlargement, common carotid diameter and intima media thickness.

CONCLUSION

This study shows that CV remodelling and ECF excess occurred at a very early stage of CKD. The independent association between ECF excess and cardiac and vascular remodelling and hypertrophy may be instrumental in the increased cardiovascular risk in CKD patients. Early therapeutic control of ECF may reduce CV events in CKD patients.

Assessment of the cough reflex after propofol anaesthesia for colonoscopy

BACKGROUND

Dysfunction of the cough reflex as a result of the lingering effects of anaesthetics may lead to aspiration pneumonia or retained secretions after general anaesthesia. It is unknown whether low concentrations of propofol alter the cough reflex in the early period after anaesthesia. The objective of this study was to investigate the effect of low concentrations of propofol on the cough reflex sensitivity as assessed by the cough reflex threshold to an inhaled irritant.

METHODS

Fifteen, ASA I-II, non-smoking patients undergoing elective colonoscopy were studied. Anaesthesia was induced and maintained with a blood target-controlled propofol infusion. Cough reflex threshold was measured with citric acid. Increasing concentrations of nebulized citric acid (2.5, 5, 10, 20, 40, 80, 160, 320, and 640 mg ml(-1)) were delivered during inspiration until a cough was evoked. The citric acid concentration eliciting one cough (C1) was defined as the cough reflex threshold. C1 was log transformed for statistical analysis (Log C1). Log C1 was measured before anaesthesia and during the recovery period with estimated decreasing propofol concentrations of 1.2, 0.9, 0.6, and 0.3 microg ml(-1).

RESULTS

Log C1 (median; interquartile range) measured with propofol concentrations of 1.2, 0.9, 0.6, 0.3, and 0 microg ml(-1) were 1.9 (0.6), 1.9 (1.0), 1.9 (1.1), 1.9 (0.6), and 1.9 (0.7) mg ml(-1) (NS), respectively. However, light sedation was observed with propofol concentrations of 1.2 and 0.9 microg ml(-1).

CONCLUSION

This study indicates that residual sedation after propofol anaesthesia for colonoscopy does not adversely affect the cough reflex.

Maintenance therapy with cotrimoxazole for toxoplasmic encephalitis in the era of highly active antiretroviral therapy

To reduce the number of daily pills for improving adherence to antiretrovirals, 17 protease inhibitor-treated patients receiving toxoplasmic encephalitis (TE) standard maintenance therapy were instead given cotrimoxazole 960 mg twice daily. After a median follow-up of 31 months, one relapsed after three months, TE relapse incidence = 2.1 cases per 100 patient-years (95% confidence interval, 0.05-11.3). This strategy could be useful for patients awaiting immune reconstitution which allows the interruption of TE maintenance therapy.

Once-daily dosing of saquinavir soft-gel capsules and ritonavir combination in HIV-1-infected patients (IMEA015 study)

This was a prospective pilot study evaluating a saquinavir (SQV) soft-gel capsules (SGC)/ritonavir (RTV)-containing once-daily regimen over a follow-up of 3 months. The primary end-point was to determine the number of patients both remaining on treatment at month 3 and with trough SQV plasma concentration 24 h after the last intake (C24h) exceeding the inhibition of 95% of viral replication in vitro (IC95). The secondary end-points were to investigate the immuno-virological efficacy and safety of SQV-SGC/RTV once daily, and to explore SQV concentrations in peripheral blood mononuclear cells (PBMCs). Twenty-three antiretroviral-naive and 17 protease inhibitors (PIs) experienced HIV-1-infected patients with plasma HIV-1 RNA level below 200 copies/ml were enrolled. They were assigned to SQV-SGC/RTV (1600/100 mg once daily) combined with nucleoside and/or non-nucleoside reverse transcriptase inhibitors. In a subgroup of 13 patients, both plasma and intracellular SQV concentrations were determined. By intent to treat analysis the percentage of success at month 3 was 87.5% (confidence interval: 73.2-95.8%) with 78.3% in naive and 100% in PI-experienced patients. SQV C24h and intracellular concentrations [median (range, n)] were 241 ng/ml (40-1209, 35) and 323 ng/ml (168-475, 12), respectively. Intracellular concentrations showed an accumulation of SQV in PBMCs persisting during 24 h. Neither immunological nor virological failure was observed. Clinical and biological tolerance was acceptable in all patients but three with adverse effects leading to discontinuation. These data confirmed the short-term efficacy of SQV-SGC/RTV once-daily regimen based on SQV therapeutic drug monitoring.

Cerebral uptake of mefloquine enantiomers with and without the P-gp inhibitor elacridar (GF1210918) in mice

1. Mefloquine is a chiral neurotoxic antimalarial agent showing stereoselective brain uptake in humans and rats. It is a substrate and an inhibitor of the efflux protein P-glycoprotein. 2. We investigated the stereoselective uptake and efflux of mefloquine in mice, and the consequences of the combination with an efflux protein inhibitor, elacridar (GF120918) on its brain transport. 3. Racemic mefloquine (25 mg kg(-1)) was administered intraperitoneally with or without elacridar (10 mg kg(-1)). Six to seven mice were killed at each of 11 time-points between 30 min and 168 h after administration. Blood and brain concentrations of mefloquine enantiomers were determined using liquid chromatography. 4. A three-compartment model with zero-order absorption from the injection site was found to best represent the pharmacokinetics of both enantiomers in blood and brain. (-)Mefloquine had a lower blood and brain apparent volume of distribution and a lower efflux clearance from the brain, resulting in a larger brain/blood ratio compared to (+)mefloquine. Elacridar did not modify blood concentrations or the elimination rate from blood for either enantiomers. However, cerebral AUC(inf) of both enantiomers were increased, with a stronger effect on (+)mefloquine. The efflux clearance from the brain decreased for both enantiomers, with a larger decrease for (+)mefloquine. 5. After administration of racemic mefloquine in mice, blood and brain pharmacokinetics are stereoselective, (+)mefloquine being excreted from brain more rapidly than its antipode, showing that mefloquine is a substrate of efflux proteins and that mefloquine enantiomers undergo efflux in a stereoselective manner. Moreover, pretreatment with elacridar reduced the brain efflux clearances with a more pronounced effect on (+)mefloquine.

Evolution of human immunodeficiency virus type 1 (HIV-1) resistance mutations in nonnucleoside reverse transcriptase inhibitors (NNRTIs) in HIV-1-infected patients switched to antiretroviral therapy without NNRTIs

We studied the evolution of nonnucleoside reverse transcriptase inhibitor (NNRTI) resistance mutations among 29 human immunodeficiency virus type 1 (HIV-1)-infected patients who experienced virologic failure when receiving an NNRTI-containing regimen (nevirapine, delavirdine, or efavirenz) and subsequently switched to antiretroviral therapy without NNRTIs. Genotypic resistance was determined from plasma samples collected at the time of NNRTI withdrawal (baseline) and during follow-up. At baseline, 83% of patients had more than two thymidine analog resistance mutations (TAMs), and all had NNRTI resistance mutations. Mutations at codons 103, 181, and 190 were found in 62, 62, and 34% of the patients, respectively. Follow-up samples were available after a median time of 6 months in all patients and at 12 months in 22 patients. The mean number of resistance mutations to NNRTIs was significantly lower at months 6 (1.34 +/- 1.04) and 12 (1.18 +/- 1.05) than at month 0 (2.03 +/- 1.02) (P < 0.009). The percentages of patients with at least one NNRTI resistance mutation were 100, 76, and 73% at baseline, month 6, and month 12, respectively (P < 0.0044). Overall, 70% of the patients had a mutation at codon 103 or 181 at month 12. The mean number of TAMs did not vary significantly during follow-up. Our data show that, in the context of maintained antiretroviral therapy, NNRTI resistance mutations persist in two-thirds of the patients in spite of NNRTI withdrawal. These results argue for the low impact of NNRTI resistance mutations on viral fitness and suggest that resistance mutations to different classes of drugs are associated on the same genome, at least in some of the resistant strains.

Once-Daily Dosing of Saquinavir Soft-Gel Capsules and Ritonavir Combination in HIV-1-Infected Patients (Imea015 Study)

This was a prospective pilot study evaluating a saquinavir (SQV) soft-gel capsules (SGC)/ritonavir (RTV)-containing once-daily regimen over a follow-up of 3 months. The primary end-point was to determine the number of patients both remaining on treatment at month 3 and with trough SQV plasma concentration 24 h after the last intake (C24h) exceeding the inhibition of 95% of viral replication in vitro (IC95). The secondary end-points were to investigate the immuno-virological efficacy and safety of SQV-SGC/RTV once daily, and to explore SQV concentrations in peripheral blood mononuclear cells (PBMCs). Twenty-three antiretroviral-naive and 17 protease inhibitors (PIs) experienced HIV-1-infected patients with plasma HIV-1 RNA level below 200 copies/ml were enrolled. They were assigned to SQV-SGC/RTV (1600/100 mg once daily) combined with nucleoside and/or non-nucleoside reverse transcriptase inhibitors. In a subgroup of 13 patients, both plasma and intracellular SQV concentrations were determined. By intent to treat analysis the percentage of success at month 3 was 87.5% (confidence interval: 73.2–95.8%) with 78.3% in naive and 100% in PI-experienced patients. SQV C24h and intracellular concentrations [median (range, n)] were 241 ng/ml (40–1209, 35) and 323 ng/ml (168–475, 12), respectively. Intracellular concentrations showed an accumulation of SQV in PBMCs persisting during 24 h. Neither immunological nor virological failure was observed. Clinical and biological tolerance was acceptable in all patients but three with adverse effects leading to discontinuation. These data confirmed the short-term efficacy of SQV-SGC/RTV once-daily regimen based on SQV therapeutic drug monitoring.

This work was presented in part at the 2nd International Conference on Clinical Pharmacology of HIV Infection, Noordwijk, the Netherlands, 2-4 April 2001 (Abstract 3.16); and at the 1st International Conference on HIV Pathogenesis & Treatment, Buenos Aires, Argentina, 8–11 July 2001 (Abstract 344).

Emergence of resistance in normal human aerobic commensal flora during telithromycin and amoxicillin-clavulanic acid treatments

Mean fecal global yeast counts increased similarly during 7 days of treatment with telithromycin (800 mg once daily) or amoxicillin-clavulanic acid (amoxiclav) (1 g of amoxicillin and 125 mg of clavulanic acid 3 times daily) in human volunteers and decreased slowly thereafter. On skin, coagulase-negative staphylococci of decreased susceptibility (DS) to telithromycin increased in the telithromycin group, whereas those with DS to methicillin increased in the amoxiclav group. A similar antibiotic-related shift towards homologous DS was observed for oral nongroupable streptococci (NGS), but in addition, the prevalence of NGS resistant to both classes of antibiotics was significantly greater in the amoxiclav group at days 8 (P < 0.01) and 45 (P < 0.015).

Effect of efflux inhibition on brain uptake of itraconazole in mice infected with Cryptococcus neoformans

Itraconazole is a fungistatic agent that, although highly lipophilic, shows poor transport through the blood brain barrier that may be due to efflux proteins. The combined administration of an efflux inhibitor with itraconazole should increase cerebral itraconazole concentrations and therefore, improve the treatment of Cryptococcus neoformans meningitis with this antifungal agent. To test this hypothesis, we have studied the influence of murine cerebral infection with C. neoformans and the inhibition of efflux by intraperitoneal injection of a P-glycoprotein inhibitor, GF120918 [N-(4-[2-(1,2,3,4-tetrahydro-6,7-dimethoxy-2-isoquinolinyl)-ethyl]-phenyl)9,10-dihydro-5-methoxy-9-oxo-4-acridine carboxamide], on the pharmacokinetics of itraconazole in plasma and brain after a single intraperitoneal itraconazole injection. We also investigated the influence of efflux inhibition on the efficacy of repeated doses of itraconazole in this murine model. The results showed that in healthy and infected mice pretreated or not with GF120918, plasma itraconazole values of area under the curve (AUC) were similar. In contrast, cerebral values of AUC were higher in infected mice compared with healthy mice. Moreover, the pretreatment of infected mice with GF120918 significantly increased cerebral itraconazole values of area under the curve and decreased weight loss in the treatment with itraconazole of a cerebral infection with C. neoformans.

Hand contamination before and after different hand hygiene techniques: a randomized clinical trial

The efficacy of alcohol-based handrubs (ABH) for hand hygiene (HH) compared with handwashing (HW) remains to be established in the clinical setting. Factors associated with severe hand contamination before HH techniques were medical ward, physician and not wearing gloves. Forty-three healthcare workers [HCW, 26 nurses (N), nine nurse assistants (NA) and eight physicians (P)] each performed six HH techniques in random order, immediately after a patient care activity: HW with non-antiseptic soap for 10 (US10) and 30 (US30) s; HW with antiseptic (polyvidone iodine- or chlorhexidine-based) soap for 10 (AS10), 30 (AS30) or 60 (AS60) s; and ABH (Sterillium, Bode Chemie, Germany). The fingertips of the dominant hand were pressed on to agar for culture before and after each HH technique. Five hundred and sixteen specimens were obtained. Log(10)-transformed bacterial count reductions after HH were 0.74, 0.51, 1.13, 1.14, 1.21 and 1.40 for US10, US30, AS10, AS30, AS60 and ABH, respectively; both AS and ABH were significantly better than US. Qualitative assessment showed that 11 of the 256 pre-HH specimens (4.3%) had pathogenic bacteria, and that two of these 11 remained positive after HH (US in both instances).

Anticoagulant (fluindione)-aspirin combination in patients with high-risk atrial fibrillation. A randomized trial (Fluindione, Fibrillation Auriculaire, Aspirin et Contraste Spontané; FFAACS)

BACKGROUND

A combination of low-dose aspirin with anticoagulants may provide better protection against thromboembolic events compared to anticoagulants alone in high-risk patients with atrial fibrillation.

OBJECTIVE

Evaluation of the preventive efficacy against nonfatal thromboembolic events and vascular deaths of the combination of the oral anticoagulant fluindione and aspirin (100 mg) in patients with high-risk atrial fibrillation.

METHODS

A multicenter, placebo-controlled, double-blind, randomized trial was conducted at 49 investigating centers in France. Atrial fibrillation patients with a previous thromboembolic event or older than 65 years and with either a history of hypertension, a recent episode of heart failure or decreased left ventricular function were included in the study. Patients were treated with fluindione plus placebo (i.e. anticoagulant alone) or fluindione plus aspirin (i.e. combination therapy), with an international normalized ratio target of between 2 and 2.6. The combined primary endpoint was stroke (ischemic or hemorrhagic), myocardial infarction, systemic arterial emboli or vascular death. The secondary endpoint was the incidence of hemorrhagic complications.

RESULTS

The 157 participants (average age 74 years; 52% women; 42% with paroxysmal atrial fibrillation) were followed for an average of 0.84 years. Three nonfatal thromboembolic events were observed (1 in the anticoagulation group, 2 in the combination group) and 6 patients died (3 in the anticoagulation group, 3 in the combination group), none of them from a thromboembolic complication. However, 3 deaths were secondary to severe hemorrhagic complications (1 in the anticoagulation group, 2 in the combination group). Nonfatal hemorrhagic complications occurred more often in the combination group (n = 10, 13.1%) compared to the anticoagulation group (n = 1, 1.2%) (p = 0.003).

CONCLUSION

The combination of aspirin with anticoagulant is associated with increased bleeding in elderly atrial fibrillation patients. The effect on thromboembolism and the overall balance of benefit to risk could not be accurately assessed in this study due to the limited number of ischemic events.

Pharmacokinetic and pharmacodynamic modeling of mizolastine in healthy volunteers with an indirect response model

OBJECTIVE

The aim of this work was to model the pharmacokinetic and pharmacodynamic relationship of mizolastine, a new H1-receptor antagonist obtained from histamine-induced wheal and flare inhibition test.

METHODS

Fifteen healthy volunteers participated in this double-blind crossover study and randomly received single doses of 5, 10, 15, and 20 mg of mizolastine and placebo at 1 week intervals. Simultaneous histamine tests and blood samples were performed before and at 9 different times up to 24 hours after each dosing. Pharmacokinetic and pharmacodynamic modeling were performed subject by subject for the 4 doses altogether by nonlinear regression. First, plasma concentrations were fit according to a two-compartment open model with zero order absorption and first order elimination. Then an indirect response model with inhibition of the formation rate was developed to describe the pharmacodynamic relationships between flare or wheal raw areas and plasma concentrations with the use of the pharmacokinetic parameters that were previously estimated.

RESULTS

Mizolastine dose dependently inhibited the histamine-induced wheal and flare formation with a submaximum effect attained after 10 mg. The mean values of the pharmacodynamic parameters of apparent zero-order rate constant for the flare or wheal spontaneous appearance (k(in)), the first-order rate constant for the flare or wheal disappearance, the mizolastine concentration that produced 50% suppression of the maximum attainable inhibition of k(in), and the maximum attainable inhibition of the effect production were 14.1 cm2/h (coefficient of variation [CV], 32%), 0.68 h(-1) (CV, 24%), 21.1 ng/mL (CV, 77%), and 0.92 (CV, 8%), respectively, for the flare and 1.9 cm2/h (CV, 64%), 0.63 h-1 (CV, 39%), 43.9 ng/mL (CV, 68%), and 0.87 (CV, 12%), respectively, for the wheal inhibition.

CONCLUSION

Pharmacokinetic and pharmacodynamic relationships of mizolastine were reliably described with the use of an indirect pharmacodynamic model; this led to an accurate prediction of the pharmacodynamic activity of mizolastine.

Pharmacokinetic analysis of mizolastine in healthy young volunteers after single oral and intravenous doses: noncompartmental approach and compartmental modeling

This paper presents the analysis of the kinetics of a new antihistamine, mizolastine, in 18 healthy volunteers, from concentrations measured after an intravenous infusion and two different oral administrations: tablet and capsule. Two approaches were used to analyze these data: (i) a noncompartmental approach implemented in PHARM-NCA; (ii) a compartmental modeling approach implemented in a new S-PLUS library, NLS2, which allows the estimation of variance parameters simultaneously with the kinetic parameters. For the compartmental modeling approach, two-compartment open models were used. According to the Akaike criterion, the best model describing the kinetics of mizolastine after oral administration was the zero-order absorption model. The kinetic parameters obtained with PHARM-NCA and NLS2 were similar. The estimated duration of absorption was greater for the tablets than for the capsules (with means equal to 1.13 hr and 0.84 hr respectively). After an intravenous infusion, the mean estimated clearance was 4.9 L/hr, the mean lambda 2-phase apparent volume of distribution was 89.6 L and the mean terminal half-life was 12.9 hr.

Sparse sampling for assessment of drug exposure in toxicological studies

In support of animal toxicity testing of new drugs, toxicokinetics is designed to assess the systemic exposure of the animals to the drug across dose levels, genders, and periods of the study. In small rodents, repeated sampling may alter the health of the animals and jeopardize the toxicity evaluation. One conventional way to circumvent this limitation is to collect serial samples from satellite animals maintained as the main study animals but not monitored for toxicity. We evaluated, on a real example, whether the exposure could be assessed in the main animals from sparse samples. The only acceptable designs consisted of one single sample per animal repeated on two or three study days. In the rat 13-week oral toxicity study of a new chemical entity, both serial sampling in the satellite animals and sparse sampling in the main animals were applied. Similar measures of exposure and qualitative conclusions were derived from the two groups of animals. The very sparse design applied to the main group yielded adequate estimation of the animal exposure, even with a very simple non-compartmental approach. The population pharmacokinetics analysis of the sparse data with NONMEM provided additional information about drug disposition and the influence of the covariates.

The use of population pharmacokinetics in drug development

Currently, there is an increasing focus on the implementation of pharmacokinetic-pharmacodynamic (PK-PD) studies and modelling as essential tools for drug development. Strategies involving specifically the population approach, which are based on relatively recent statistical methodology (e.g. nonlinear mixed effects modelling, NONMEM) have been advocated for investigating pharmacokinetic and pharmacodynamic variability as well as dose-concentration-effect relationships. The present article outlines this approach, and discusses how it can be implemented within the framework of the studies currently performed as part of the clinical phases of new drug development. It also considers study design and performance, based on real-life experiences. Population approaches, if designed carefully and early, as part of the planning of the drug development programme, are expected to play a significant role at every phase of the programme and to contribute to providing information that is valuable for registration purposes. Statistical methodology and software are now widely available. However, practical issues such as integration of the population approach within existing protocols, quality control of the data, timing of laboratory and statistical analyses, as well as resource allocation, remain legitimate concerns to be considered in prospective studies.

Practical experience and issues in designing and performing population pharmacokinetic/pharmacodynamic studies

An expert meeting to discuss issues relating to the design of population pharmacokinetic/pharmacodynamic (PK/PD) studies was held in Brussels in March 1995, under the auspices of the European Co-operation in Science and Technology (COST), Medicine (B1) programme. The purpose of the meeting was to discuss the experts' experience in designing and performing population PK/PD studies. The topics discussed were current practice, logistical issues, ensuring the accuracy of data, covariate assessment, communication, and protocol design.

Worldwide demographics and future trends of the management of renal failure in the elderly

Aging will be a serious social problem in the future. The number of patients of 75 years and over with end-stage renal disease (ESRD) is bound to increase. The time has come to pay greater attention to their problems before and during dialysis treatment. Prevention of ESRD is an important challenge, especially in the field of vascular diseases which are the main cause of ESRD in the elderly. The exact number of elderly patients who will require dialysis in the next few years is difficult to foresee. It is only when the incidence of patients starting dialysis at 75 and over levels off that we may assume that elderly patients are no longer rejected from treatment; we could then assess the actual need in dialysis facilities. In elderly dialysis patients, mortality remains high. Improvements in geriatric medicine and dialysis techniques should contribute to better results in future years. As it is almost impossible to predict the survival and how an elderly patient will adapt to treatment, it appears more ethical to propose a trial of dialysis treatment, except in cases of severe dementia or malignancy. This large acceptance rate implies admitting that withdrawal from dialysis must sometimes be considered.

Necrotizing crescentic glomerulonephritis without significant immune deposits: a clinical and serological study

To determine the spectrum of systemic diseases associated with pauci-immune necrotizing crescentic glomerulonephritis, we have analysed extra-renal manifestations, occurrence of extra-glomerular vasculitis and incidence and specificity of antinuclear cytoplasmic antibodies (ANCA) in 40 patients selected only on renal histological criteria. Extra-renal symptoms were unexpectedly observed in all patients but one, and were suggestive of vasculitis in 24. Extra-glomerular vasculitis was seen in 18 kidney biopsies and four biopsies from other organs. Among the 33 patients with suspected or established vasculitis, 13 had presumed or biopsy-proven Wegener's granulomatosis, three had a macroscopic form of polyarteritis nodosa and 17 could not be adequately classified. An additional patient had clinical signs of Wegener's granulomatosis without clinical and histological evidence of vasculitis. ANCAs were detected in 28 of 33 and 25 of 34 sera tested by immunofluorescence and enzyme-linked immunoassay, respectively: 19 contained anti-myeloperoxidase antibodies and six had anti-proteinase 3 activity. Anti-myeloperoxidase and anti-proteinase 3 antibodies were present in all clinical subgroups but with various frequencies: anti-myeloperoxidase antibodies were more common (six of 12) than anti-proteinase 3 (four of 12) in patients with suspected or histologically proven Wegener's granulomatosis. Anti-proteinase 3 antibodies were 3- to 4-fold more common in patients with Wegener's granulomatosis than in those with systemic vasculitis of other causes (one of 12) or necrotizing crescentic glomerulonephritis without evidence of extra-renal vasculitis (one of 10). These results strongly suggest that pauci-immune necrotizing crescentic glomerulonephritis belongs to the broad spectrum of necrotizing vasculitides affecting glomerular capillaries. This study shows substantial improvement in renal prognosis and life expectancy with aggressive immunosuppressive therapy despite the older age of the patients, dissemination of the vasculitic process and often delayed diagnosis.