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Paul Landais

Publications and source records attributed to Paul Landais.

34 records · Page 2Linked to original sources
PubMed2004

Meta-regression detected associations between heterogeneous treatment effects and study-level, but not patient-level, factors.

OBJECTIVE: Two investigations evaluate Bayesian meta-regression for detecting treatment interactions. STUDY DESIGN AND SETTING: The first compares analyses of aggregate and individual patient data on 1,860 subjects from 11 trials testing angiotensin converting enzyme (ACE) inhibitors for nondiabetic kidney disease. The second explores meta-regression for detecting treatment interaction on 671 covariates, including the baseline risk, from 232 meta-analyses of binary outcomes compiled from the Cochrane Collaboration and the medical literature. RESULTS: In the ACE inhibitor study, treatment effects were homogeneous so meta-regression identified no interactions. Analysis of individual patient data using a multilevel model, however, discovered that treatment reduced glomerular filtration rate (GFR) more among patients with higher baseline proteinuria. The second investigation found meta-regression most effective for detecting treatment interactions with study-level factors in meta-analyses with >10 studies, heterogeneous treatment effects, or significant overall treatment effects. Under all three conditions, 46% of meta-regressions produced strong interactions (posterior probability >0.995) compared with 6% otherwise. Baseline risk was associated with the odds ratio in 6% of meta-analyses, half the rate found using maximum likelihood. CONCLUSION: Meta-regression can detect interactions of treatment with study-level factors when treatment effects are heterogeneous. Individual patient data are needed for patient-level factors and homogeneous effects.

Adult↗
PubMed2003

Treatment of CD40 ligand deficiency by hematopoietic stem cell transplantation: a survey of the European experience, 1993-2002.

CD40 ligand (CD40L) deficiency causes recurrent sinopulmonary infection, Pneumocystis carinii pneumonia, and Cryptosporidium parvum infection. Approximately 40% to 50% of patients survive to the third decade: long-term survival is unclear. Hematopoietic stem cell transplantation (HSCT) is curative. We present a retrospective analysis of 38 European patients undergoing HSCT for CD40L deficiency in 8 European countries between 1993 and 2002. Donor stem cell source included 14 HLA-identical siblings, 22 unrelated donors, and 2 phenotypically matched parental stem cells (12 T-cell depleted). Of the patients, 34 engrafted and 26 (68%) survived; 3 had autologous reconstitution, 22 (58%) were cured, and 1 engrafted but has poor T-cell immune reconstitution. There were 18 evaluated patients who responded to vaccination. Of the patients, 12 (32%) died from infection-related complications, with severe cryptosporidiosis in 6. Grades 2 to 4 graft-versus-host disease (GvHD) associated with infection occurred in 6 of 12 fatal cases. HSCT cured 58% of patients, 72% of those without hepatic disease. Early T-cell function following whole marrow HSCT may limit cryptosporidial disease, but survival was similar after T-cell-depleted HSCT. Preexisting lung damage was the most important adverse risk factor. Further studies will determine optimal timing and type of HSCT.

Adolescent↗
PubMed2003

[The impact of fusafungine on the prescription of antibiotics in the treatment of rhinopharyngitis].

OBJECTIVE: The analysis in France, during the period 01/12/99 to 30/11/2000, of the prescription of systemic antibiotics in patients with rhinopharyngitis and of the variables statistically related to such prescriptions and the potential role of fusafungine in the form of a rhinopharyngeal spray. METHODS: A retrospective study, based on a panel of 1,010 general practitioners, in a cohort of 30,568 patients presenting with rhinopharyngitis. The fusafungine group consisted of 16,076 patients who had rhinopharyngitis and in whom fusafungine was prescribed. The control group consisted of 14,492 patients with rhinopharyngitis without prescription of fusafungine. The overall rate of antibiotic prescription was documented. A stepwise statistical analysis was conducted to specify the variables statistically associated with the prescription of a systemic antibiotic. The rate of prescription of a systemic antibiotic and the cost of the treatment were also compared within both groups. RESULTS: The overall rate of systemic antibiotic prescription was 52.9%, falling from 60.4% in the group without fusafungine down to 46.2% in the group with fusafungine (p<0.01) whichever the systemic antibiotic prescribed. The stepwise analysis documented various variables that appear to be related to the systemic antibiotic prescription. A saving of 0.7 euros per prescription was noted in the fusafungine group. CONCLUSION: Although various variables appear to influence systemic antibiotic prescription in patients with rhinopharyngitis, our study shows that prescription of fusafungine in spray from led to statistically significant reduction in systemic antibiotic prescription.

Adolescent↗
PubMed2003

Long-term survival and transplantation of haemopoietic stem cells for immunodeficiencies: report of the European experience 1968-99.

BACKGROUND: Transplantation of allogeneic haemopoietic stem cells can cure several primary immunodeficiencies. This European report focuses on the long-term results of such procedures done between 1968 and December, 1999, for primary immunodeficiencies. METHODS: The report includes data from 37 centres in 18 countries, which participated in a European registry for stem-cell transplantation in severe combined immuno deficiencies (SCID) and in other immunodeficiency disorders (non-SCID). 1082 transplants in 919 patients were studied (566 in 475 SCID patients, 512 in 444 non-SCID patients; four procedures excluded owing to insufficient data). Minimum follow-up of 6 months was required. FINDINGS: In SCID, 3-year survival with sustained engraftment was significantly better after HLA-identical than after mismatched transplantation (77% vs 54%; p=0.002) and survival improved over time. In HLA-mismatched stem-cell transplantation, B(-) SCID had poorer prognosis than B(+) SCID. However, improvement with time occurred in both SCID phenotypes. In non-SCID, 3-year survival after genotypically HLA-matched, phenotypically HLA-matched, HLA-mismatched related, and unrelated-donor transplantation was 71%, 42%, 42%, and 59%, respectively (p=0.0006). Acute graft versus host disease predicted poor prognosis whatever the donor origin except in related HLA-identical transplantation in SCID. INTERPRETATION: The improvement in survival over time indicates more effective prevention and treatment of disease-related and procedure-related complications--eg, infections and graft versus host disease. An important factor is better prevention of graft versus host disease in the HLA-non-identical setting by use of more efficient methods of T-cell depletion. For non-SCID, stem-cell transplantation can provide a cure, and grafts from unrelated donors are almost as beneficial as those from genetically HLA-identical relatives.

Child, Preschool↗
PubMed2003

Efficacy of etanercept for the treatment of juvenile idiopathic arthritis according to the onset type.

OBJECTIVE: To assess the efficacy of etanercept in patients with juvenile idiopathic arthritis (JIA), and to assess the tolerance of these patients to etanercept. METHODS: All JIA patients with active chronic polyarthritis, who were first treated with etanercept between November 1999 and June 2001 in 18 French centers because of poor response or intolerance to methotrexate, were included in this open-label, prospective, multicenter study. A standardized questionnaire was sent to the treating physicians. We assessed the validated international core-set score for JIA activity every 3 months and performed an intent-to-treat analysis. We also compared the risk of treatment failure in patients defined as having systemic-onset, oligoarticular-onset, or polyarticular-onset JIA. RESULTS: Sixty-one patients were enrolled and were followed up for a median of 13 months. Treatment had to be stopped in 1 patient who became pregnant and in 12 patients due to severe side effects, including neurologic or psychiatric disorders, retrobulbar optic neuropathy, major weight gain, severe infection, cutaneous vasculitis with systemic symptoms, hemorrhagic diarrhea, uveitis flare, and pancytopenia. All of these side effects disappeared after discontinuation of etanercept. Crohn's disease was subsequently diagnosed in 1 child. Scores improved by > or =30% in 73% of patients after 3 months, but this proportion decreased to 39% after 12 months. The response rate was significantly lower in patients with systemic-onset JIA than in those with oligoarticular- or polyarticular-onset JIA. CONCLUSION: Treatment of JIA with etanercept may be associated with a wide spectrum of severe side effects. Although most patients initially respond to etanercept, this initial response is not always followed by sustained improvement over longer periods of time. In addition, the higher rate of treatment failure in the group with systemic-onset JIA indicates that these patients in particular may require alternative treatments.

Adolescent↗
PubMed2003

Improving estimates of event incidence over time in populations exposed to other events: application to three large databases.

The Kaplan-Meier (KM) method is commonly used to estimate the incidence of an event over time. It assumes independence between the event of interest and any competing event that precludes the event of interest to occur. However, when the competing event is death without the event of interest, censoring these patients will affect the incidence of the event of interest by modifying the number of exposed patients, so that KM results will be misleading. Three prospective cohorts were studied: (1) 657 renal transplant recipients, (2) 262 children with acute leukemia who received bone marrow transplants, and (3) 8,353 intensive care patients. The main outcome measures were kidney graft loss, leukemia relapse, and ICU-acquired infection, respectively, with death before the main outcome as the competing event. The incidence of each main outcome was overestimated by the KM method. The magnitude of overestimation ranged from 3% to 30%, and varied with baseline patient characteristics and follow-up duration, with most of this variation being related to the rate of the competing event. A competing-risk approach must be used to analyze the risk of events other than death in cohort studies, particularly when mortality rates are high.

Acute Disease↗
PubMed2003

Steroid-sensitive nephrotic syndrome: from childhood to adulthood.

BACKGROUND: The clinical presentation, treatment, and outcome of steroid-sensitive nephrotic syndrome (SSNS) during childhood have been extensively studied. Conversely, few data regarding the outcome in adulthood of childhood SSNS have been published previously. We undertook to conduct a retrospective study of the outcome in adulthood of a large cohort of patients diagnosed with an SSNS during childhood. METHODS: We identified all children born between 1970 and 1975 who had been admitted to our institution for an SSNS. Data regarding the outcome in adulthood of these patients were obtained through mailed questionnaires or phone calls to patients and/or their parents or through attending physicians. RESULTS: One hundred seventeen patients were identified. Data regarding the outcome of SSNS in adulthood were available for 102 patients (87.2%). Forty-three patients (42.2%) experienced at least one relapse of nephrotic syndrome in adulthood. By univariate analysis, young age at onset (<6 years) and more severe disease in childhood, indicated by a greater number of relapses (12.9 for adulthood relapsers versus 5.4 for adulthood nonrelapsers; P < 0.0001) and more frequent use of immunosuppressors (74.4% versus 31.6%; P < 0.0001) or cyclosporine (42.9% versus 7.3%; P < 0.0001) were predictive of the occurrence of SSNS relapse in adulthood. Conversely, relapse rate in the first 6 months of disease was not predictive of further relapses in adulthood. By multivariate analysis, only number of relapses during childhood was predictive of adulthood relapses (P < 0.0058). Long-term side effects of steroids were found in 44.2% of adulthood relapsers; the most frequent were osteoporosis and excess weight. CONCLUSION: The incidence of childhood SSNS relapses in adulthood was relatively high in our study. Further studies are required to assess long-term complications in adults with relapses and a history of prolonged steroid and immunosuppressor use.

Adolescent↗
PubMed2003

A dynamic Web application within an n-tier architecture: a Multi-Source Information System for end-stage renal disease.

A Multi-Source Information System (MSIS) has been designed for the Renal Epidemiology and Information Network (REIN) dedicated to End-Stage Renal Disease. Interoperability has been considered at 4 levels: semantics, network, formats and contents. An n-tier architecture has been chosen at the network level. It is made out of a universal client, a dynamic Web server connected to a production database and to a data warehouse. The MSIS is patient-oriented, based on a regional organization. Its implementation in the context of a regional experimentation is presented with insights on the design and underlying technologies. The n-tier architecture is a robust model and flexible enough to aggregate multiple information sources and integrate modular developments. The data warehouse is dedicated to support health care decision-making.

Data Display↗
PubMed2002

Treatment of chronic granulomatous disease with myeloablative conditioning and an unmodified hemopoietic allograft: a survey of the European experience, 1985-2000.

Treatment of chronic granulomatous disease (CGD) with myeloablative bone marrow transplantation is considered risky. This study investigated complications and survival according to different risk factors present at transplantation. The outcomes of 27 transplantations for CGD, from 1985 to 2000, reported to the European Bone Marrow Transplant Registry for primary immunodeficiencies were assessed. Most transplant recipients were children (n = 25), received a myeloablative busulphan-based regimen (n = 23), and had unmodified marrow allografts (n = 23) from human leukocyte antigen (HLA)-identical sibling donors (n = 25). After myeloablative conditioning, all patients fully engrafted with donor cells; after myelosuppressive regimens, 2 of 4 patients fully engrafted. Severe (grade 3 or 4) graft-versus-host disease (GVHD) disease developed in 4 patients: 3 of 9 with pre-existing overt infection, 1 of 2 with acute inflammatory disease. Exacerbation of infection during aplasia was observed in 3 patients; inflammatory flare at the infection site during neutrophil engraftment in 2: all 5 patients belonged to the subgroup of 9 with pre-existing infection. Overall survival was 23 of 27, with 22 of 23 cured of CGD (median follow-up, 2 years). Survival was especially good in patients without infection at the moment of transplantation (18 of 18). Pre-existing infections and inflammatory lesions have cleared in all survivors (except in one with autologous reconstitution). Myeloablative conditioning followed by transplantation of unmodified hemopoietic stem cells, if performed at the first signs of a severe course of the disease, is a valid therapeutic option for children with CGD having an HLA-identical donor.

Adolescent↗
PubMed2002

Clinical trials, immunosuppression and renal transplantation: new trends in design and analysis.

Clinical trials provide a framework to search for more effective and less toxic immunosuppressive agents to control renal transplant rejection. Some methodological aspects are presented. Patient selection and the choice of study endpoints are discussed with emphasis on standardized definitions and classification of histopathology, and on qualification and quantification of chronic rejection. Choosing a Bayesian or a frequentist approach and the afferent hypotheses is discussed together with the interpretation of a P-value and a confidence interval. Strategies for limiting the number of patients, increasing power and feasibility are reviewed, including discussion of surrogate endpoints. New approaches to statistical analysis are then presented, including intention-to-treat versus per-protocol analysis, analysis of correlated data, dependent censoring, and meta-analysis applied to renal transplantation. Pharmacoeconomics are finally introduced as necessary for implementation of decision making regarding therapeutic strategies. Reporting research increases its standards, and the CONSORT (Consolidated Standards of Reporting Trials) and QOROM (Quality of Reporting of Meta-analyses) criteria are to be integrated in the process of clinical trial procedures. In conclusion, observational studies are presented as part of an evidence-based approach in the hierarchy of evidence, keeping in mind that high quality, randomized, controlled trials are still necessary to decrease uncertainty in the field of renal transplantation.

Child↗
PubMed2002

Outcome of suprarenal localized masses diagnosed during the perinatal period: a retrospective multicenter study.

BACKGROUND: The growing use of abdominal ultrasonography during pregnancy and in the postnatal period is leading to the discovery of an increasing number of suprarenal masses. The optimal diagnosis and treatment of these masses has not yet been determined. METHODS: The authors reviewed the files of patients with suprarenal masses detected prenatally or during the first 3 months of life, between 1986 and 1999, in the pediatric surgery and oncology departments of Paris hospitals. RESULTS: Thirty masses were detected prenatally and 23 postnatally. In the latter group of patients, the diagnosis was based on ultrasound in 8 cases and on the palpation of a mass in 15 cases, 13 of which were neuroblastoma. At birth, the masses were cystic in 19 cases, solid in 17, and mixed in 13. Sensitivities of methyliodobenzylguanidine and urinary catecholamine assay were 70% and 52% respectively. Surgery was performed in 38 cases with a median age of 42 days. Histologic analysis showed 31 neuroblastomas, 1 adrenal hemorrhage, 2 necrotic masses, 1 bronchogenic cyst, and 3 sequestrations. All the patients were alive and disease free, at a follow-up ranging from 3 months to 13 years. CONCLUSIONS: In this series, 58% of the suprarenal masses diagnosed perinatally were localized neuroblastoma with a favorable outcome. All other cases either regressed spontaneously or turned out to be benign lesion. Thus, the management of these masses must strike a compromise between aggressive treatment and a wait-and-see attitude. This requires appropriate initial assessment and a close follow-up in a specialized center.

Adrenal Gland Neoplasms↗
PubMed2002

[SIMS REIN: a multi-source information system for end-stage renal disease].

In France, the prevalence of End-Stage Renal Disease (ESRD) is not precisely known. The sources of information are scattered and not coordinated. Consequently, care is ill adapted to meet the demand. The Multi-Source Information System is the basis of the Renal Epidemiology and Information Network (REIN). It is dedicated to improve and organise our medical and epidemiological knowledge of ESRD and to aid public health decision-making in this area. The proposed approach is based on the datawarehouses. This model allows a unified vision of scattered data into distinct databases, for a better management, be it particular (patient follow-up) or global (regional follow-up), with a finality of aid in decision-making. Several categories of problems were considered: the global conception of the information system, the organisation of the datawarehouse, which offers different viewpoints of the data, the integration of heterogeneous data coming from different sources, data exchange and definition of a specific ontology.

Computer Communication Networks↗
PubMed2002

Association between genetically determined pancreatic status and lung disease in adult cystic fibrosis patients.

STUDY OBJECTIVES: The association between genotype and phenotype in cystic fibrosis (CF) has been clearly established for pancreatic status, but not for lung disease. DESIGN: Retrospective study. SETTING: A respiratory unit of a teaching hospital. PATIENTS: We studied 51 adult CF patients for whom current data and genotype were available. Thirty-seven patients carried two severe mutations associated with pancreatic insufficiency phenotype (group S). Fourteen patients carried at least one mild (and dominant) mutation associated with pancreatic sufficiency phenotype (group M). MEASUREMENTS: We compared the course of the disease between the two groups, looking for a genotype/phenotype association for lung disease. RESULTS: The mean age of the population was 30 years. Patients with two severe mutations presented more severe disease with earlier onset (1.7 years vs 7.9 years, p = 0.0001). They presented with a more severe respiratory impairment, with a lower mean FEV(1) (29% of predictive value vs 58% of predictive value, p < 0.001); a higher Pseudomonas colonization rate (97% vs 57%, p < 0.01); a more frequent end-stage respiratory insufficiency, defined by a FEV(1) < 30% (73% vs 29%, p < 0.05); and a more marked yearly decline of FEV(1) (3% vs 1.4%, p < 0.001). By multivariate logistic regression analysis, carrying two severe mutations was the only independent predictor of a terminal respiratory insufficiency (relative risk, 6.75; 95% confidence interval, 1.79 to 26.50; p = 0.003). CONCLUSION: This study suggests that pulmonary disease appears to be associated with the severity of CF transmembrane regulator mutations.

Adolescent↗
PubMed2002

Retinal hemangioblastoma in von Hippel-Lindau disease: a clinical and molecular study.

PURPOSE: To assess the natural history of retinal manifestations in von Hippel-Lindau (VHL) disease and to study the genotype-phenotype correlation. METHODS: Data concerning 103 patients with VHL retinal manifestations and 108 patients without VHL retinal manifestations were extracted from the French VHL database. A retrospective study was performed by questionnaire. Patients were classified into three visual morbidity groups. Molecular analysis of the VHL gene was performed in 196 patients. RESULTS: The mean age of ocular manifestations detection was 24.8 years. In half of the cases, the ocular manifestations revealed the disease. Half of the cases had bilateral involvement. Visual morbidity was significantly associated with the retinal hemangioblastoma count but not with other ocular or general characteristics. One third of the patients were classified in the worst visual morbidity group at the end of follow-up. Mutations were detected in 81% of patients with retinal hemangioblastomas and in 71% of patients without retinal involvement. Using a Poisson model and a marginal approach, the number of hemangioblastomas, age-adjusted, was 2.1 times higher in patients who had a substitution than in patients with a truncation (95% CI, 1.05-4.44; P < 0.05). CONCLUSIONS: Visual loss remains one of the major complications of VHL disease, confirming the importance of early ophthalmologic screening. Visual morbidity was not related to the type of extraocular manifestation but appeared to be related to the type of germline mutation. However, only further genetic and clinical studies in a larger series of patients will clearly determine the genotype-phenotype relationship.

Adolescent↗