[Evolution of the access to the kidney transplantation in France of foreign patients and French patients living in overseas territories]. / Évolution de l'accès à la greffe rénale en France des patients étrangers ou résidant outre-mer.

In France, foreign patients, whether resident or not in France, can register on the national waiting list under administrative and financial conditions. We performed a retrospective analysis to evaluate the access to kidney transplantation on a cohort 2004-2008, using the national registry. Among the 14,732 patients registered during this period, 15.3% are of non-French nationality (3.4% other European, 5.9% North African, 3.9% sub-Saharan African, 2.9% other). Among the 84.6% of French nationality, 3.3% are living in French overseas territories. Compared to the 17.6-month median waiting time of the cohort, median waiting time differs significantly between groups, from 15.7 months for mainland French patients to 36 months for sub-Saharan African patients. Despite the regular development of the allocation rules, these disparities in access to transplantation are mainly, but not completely, explained by blood group or HLA matching difficulties. After adjustment for the other factors known to be significantly linked to a difficult access to transplantation, North and sub-Saharan African patients have the worst difficulties. Future research should consider nonmedical factors, such as socio-economic or socio-cultural factors, potentially relevant to avoid disparities in access to transplantation and should aim at developing specific interventions.

Impact of endometrial preparation on early pregnancy loss and live birth rate after frozen embryo transfer: a large multicenter cohort study (14 421 frozen cycles).

STUDY QUESTION: Does the endometrial preparation protocol (artificial cycle (AC) vs natural cycle (NC) vs stimulated cycle (SC)) impact the risk of early pregnancy loss and live birth rate after frozen/thawed embryo transfer (FET)? SUMMARY ANSWER: In FET, ACs were significantly associated with a higher pregnancy loss rate and a lower live birth rate compared with SC or NC. WHAT IS KNOWN ALREADY: To date, there is no consensus on the optimal endometrial preparation in terms of outcomes. Although some studies have reported a higher pregnancy loss rate using AC compared with NC or SC, no significant difference was found concerning the pregnancy rate or live birth rate. Furthermore, no study has compared the three protocols in a large population. STUDY DESIGN SIZE DURATION: A multicenter retrospective cohort study was conducted in nine reproductive health units in France using the same software to record medical files between 1 January 2012 and 31 December 2016. FET using endometrial preparation by AC, modified NC or SC were included. The primary outcome was the pregnancy loss rate at 10 weeks of gestation. The sample size required was calculated to detect an increase of 5% in the pregnancy loss rate (21-26%), with an alpha risk of 0.5 and a power of 0.8. We calculated that 1126 pregnancies were needed in each group, i.e. 3378 in total. PARTICIPANTS/MATERIALS SETTING METHODS: Data were collected by automatic extraction using the same protocol. All consecutive autologous FET cycles were included: 14 421 cycles (AC: n = 8139; NC: n = 3126; SC: n = 3156) corresponding to 3844 pregnancies (hCG > 100 IU/l) (AC: n = 2214; NC: n = 812; SC: n = 818). Each center completed an online questionnaire describing its routine practice for FET, particularly the reason for choosing one protocol over another. MAIN RESULTS AND THE ROLE OF CHANCE: AC represented 56.5% of FET cycles. Mean age of women was 33.5 (SD ± 4.3) years. The mean number of embryos transferred was 1.5 (±0.5). Groups were comparable, except for history of ovulation disorders (P = 0.01) and prior delivery (P = 0.03), which were significantly higher with AC. Overall, the early pregnancy loss rate was 31.5% (AC: 36.5%; NC: 25.6%; SC: 23.6%). Univariable analysis showed a significant association between early pregnancy loss rate and age >38 years, history of early pregnancy loss, ovulation disorders and duration of cryopreservation >6 months. After adjustment (multivariable regression), the early pregnancy loss rate remained significantly higher in AC vs NC (odds ratio (OR) 1.63 (95% CI) [1.35-1.97]; P < 0.0001) and in AC vs SC (OR 1.87 [1.55-2.26]; P < 0.0001). The biochemical pregnancy rate (hCG > 10 and lower than 100 IU/l) was comparable between the three protocols: 10.7% per transfer. LIMITATIONS REASONS FOR CAUTION: This study is limited by its retrospective design that generates missing data. Routine practice within centers was heterogeneous. However, luteal phase support and timing of embryo transfer were similar in AC. Univariable analysis showed no difference between centers. Moreover, a large number of parameters were included in the analysis. WIDER IMPLICATIONS OF THE FINDINGS: Our study shows a significant increase in early pregnancy loss when using AC for endometrial preparation before FET. These results suggest either a larger use of NC or SC, or an improvement of AC by individualizing hormone replacement therapy for patients in order to avoid an excess of pregnancy losses. STUDY FUNDING/COMPETING INTERESTS: The authors declare no conflicts of interest in relation to this work. G.P.-B. declares consulting fees from Ferring, Gedeon-Richter, Merck KGaA, Theramex, Teva; Speaker's fees or equivalent from Merck KGaA, Ferring, Gedeon-Richter, Theramex, Teva. N.C. declares consulting fees from Ferring, Merck KGaA, Theramex, Teva; Speaker's fees or equivalent from Merck KGaA, Ferring. C.R. declares a research grant from Ferring, Gedeon-Richter; consulting fees from Gedeon-Richter, Merck KGaA; Speaker's fees or equivalent from Merck KGaA, Ferring, Gedeon-Richter; E.M.d'A. declares Speaker's fees or equivalent from Merck KGaA, MSD, Ferring, Gedeon-Richter, Theramex, Teva. I.C-D. declares Speaker's fees or equivalent from Merck KGaA, MSD, Ferring, Gedeon-Richter, IBSA. N.M. declares a research grant from Merck KGaA, MSD, IBSA; consulting fees from MSD, Ferring, Gedeon-Richter, Merck KGaA; Speaker's fees or equivalent from Merck KGaA, MSD, Ferring, Gedeon-Richter, Teva, Goodlife, General Electrics. TRIAL REGISTRATION NUMBER: N/A.

[Adverse obstetric and perinatal outcome with in vitro fertilization technology: A French nationwide population-based study]. / Risques de morbidité maternelle et périnatale en fécondation in vitro : une étude nationale de cohorte française.

OBJECTIVES: The objective of this study was to quantify the risk of maternal and perinatal morbidity with in vitro fertilization (IVF) technology compared to non-IVF pregnancies in a recent French national cohort. METHOD: The data was extracted from the hospital information data system, including all pregnancies with a delivery from 2013 to 2016. The risks of preterm birth, maternal morbidity (venous and arterial thrombosis, gestational diabetes, vascular disorders, placenta previa, placenta abruption), hypotrophy and congenital malformation were compared in both groups in univariate and multivariate analysis after adjustment on the characteristics of women (age, parity, obesity, tobacco dependence, history of diabetes or high blood pressure), multiple deliveries and sex of children. RESULTS: In all, 2,875,662 pregnancies and 2,922,712 births were analyzed, of which 49,224 were derived from IVF (1.7%). In multivariate analysis, all risks were significantly higher in IVF: premature deliveries (ORajusted=1.28; CI95%=1.24-1.32), maternal morbidity (ORajusted=1.24; CI95%=1.21-2.28), (mainly for thrombosis venous, placenta previa and placenta abruption). The risks of hypotrophy (ORajusted=1.13; CI95%=1.10-1.16) and congenital malformations (ORajusted=1.11; CI95%=1.05-1.17) were slightly increased. CONCLUSION: The results of this study on a large cohort of recent births in France confirm that there was an increased risk of maternal and perinatal morbidities in IVF. These risks were similar to those published in the international literature. This study is the starting point for a forthcoming surveillance.

A simple clinico-histopathological composite scoring system is highly predictive of graft outcomes in marginal donors.

The predictive value of pre-implantation biopsies versus clinical scores has not been studied extensively in marginal donors. Pre-implantation biopsies were performed in 313 kidneys from donors that were > or = 50 years of age (training set, n = 191; validation set, n = 122). The value of the donor clinical parameters and histological results in predicting 1-year estimated glomerular filtration rate (eGFR) <25 mL/min/1.73 m(2) was retrospectively evaluated. In multivariate analysis, the only clinical parameters associated with low eGFR were donor hypertension and a serum creatinine level > or =150 micromol/L before organ recovery. Clinical scores (Nyberg and Pessione) were not significantly associated with graft function. Regarding histological parameters, univariate analysis showed that glomerulosclerosis (GS) (p = 0.02), arteriolar hyalinosis (p = 0.03) and the Pirani (p = 0.02) and chronic allograft damage index (CADI) (p = 0.04) histological scores were associated with low eGFR. The highest performance in predicting low eGFR was achieved using a composite score that included donor serum creatinine (> or =150 micromol/L or <150 micromol/L), donor hypertension and GS (> or =10% or <10%). The validation set confirmed the critical importance of taking into account biopsy and clinical parameters during marginal donor evaluation. In conclusion, clinical scores are weak predictors of graft outcomes with marginal donors. Instead, a simple and convenient composite score strongly predicts graft function and survival and may facilitate optimal allocation of marginal donors.

[Analysis of prenatal follow-up strategies for trisomy 21 affected pregnancies in France]. / Analyse du parcours de dépistage prénatal des femmes ayant donné naissance en France à un enfant atteint de trisomie 21.

OBJECTIVE: The main objective of this study was to screen the prenatal follow-up of women with live birth trisomy 21 child in order to evaluate the proportion of prenatal screening failure versus cases where the women refused either the screening or the prenatal diagnosis of Down syndrome. This study covers the period of time from 2009 to 2012 when the national prenatal screening policy changed from second to first trimester and allows for a comparative assessment of the nationwide efficiency of the various maternal serum marker based strategies. METHOD: All authorized cytogenetic laboratories sent required data for all cases of trisomy 21 diagnosed in FRANCE in new-borns (less than 1-year-old) from January 2010 to July 2013. RESULTS: A total of 1253 cases of trisomy 21 were diagnosed before 1 year of age whose mother did not had prenatal diagnosis. For 861 of them, information on the prenatal follow-up was available, with 72% of cases where a prenatal screening was organized either by maternal serum marker or by ultrasound. Results of the screening strategy was positive with maternal serum marker in 28% of cases (calculated risk≥1/250), positive because of abnormal ultrasound in 5% and negative with maternal marker screening (whatever the strategy used) in 67% of cases. Detection rate over the period of the study was 82%, with similar efficiency of first and second trimester strategies (83%) but significantly lower with sequential association of first trimester Nuchal translucency measurement and second trimester serum screening (70%). CONCLUSION: Switching from second trimester to first trimester screening strategy, with as many trisomy 21 foetuses diagnosed with half invasive procedures fulfilled national health policy objectives. Analysis of these data gives useful insights to elaborate a future screening policy involving cell-free foetal DNA sequencing.

Cardiac metaiodobenzylguanidine uptake in patients with moderate chronic heart failure: relationship with peak oxygen uptake and prognosis.

OBJECTIVES: This prospective study was undertaken to correlate early and late metaiodobenzylguanidine (MIBG) cardiac uptake with cardiac hemodynamics and exercise capacity in patients with heart failure and to compare their prognostic values with that of peak oxygen uptake (VO2). BACKGROUND: The cardiac fixation of MIBG reflects presynaptic uptake and is reduced in heart failure. Whether it is related to exercise capacity and has better prognostic value than peak VO2 is unknown. METHODS: Ninety-three patients with heart failure (ejection fraction <45%) were studied with planar MIBG imaging, cardiopulmonary exercise tests and hemodynamics (n = 44). Early (20 min) and late (4 h) MIBG acquisition, as well as their ratio (washout, WO) were determined. Prognostic value was assessed by survival curves (Kaplan-Meier method) and uni- and multivariate Cox analyses. RESULTS: Late cardiac MIBG uptake was reduced (131+/-20%, normal values 192+/-42%) and correlated with ejection fraction (r = 0.49), cardiac index (r = 0.40) and pulmonary wedge pressure (r = -0.35). There was a significant correlation between peak VO2 and MIBG uptake (r = 0.41, p < 0.0001). With a mean follow-up of 10+/-8 months, both late MIBG uptake (p = 0.04) and peak VO2 (p < 0.0001) were predictive of death or heart transplantation, but only peak VO2 emerged by multivariate analysis. Neither early MIBG uptake nor WO yielded significant insights beyond those provided by late MIBG uptake. CONCLUSIONS: Metaiodobenzylguanidine uptake has prognostic value in patients with wide ranges of heart failure, but peak VO2 remains the most powerful prognostic index.

Preemptive renal transplantation in adults.

Recent studies have clearly demonstrated that preemptive renal transplantation is associated with better graft and patient survival. It improves the quality of life and is a cost-effective option compared to conventional transplantation. We report our experience with this concept and review the literature. We retrospectively analyzed all adult kidney transplantations performed in our center between March 1986 and May 2004: among 463 renal transplantations 44 were preemptive (9.5%). Mean follow-up was 45.7 +/- 6 months in preemptive versus 62.3 +/- 2.6 months in the other group. At the end of the study, graft survivals were 93.2% and 77.1%, respectively (P = .02). Patient survival rates were similar in both groups. In the preemptive group, grafts were more likely to come from living donors (P < .001) and cold ischemia time was shorter (P = .02). A subgroup case-control study showed that cost saving for dialysis in the preemptive group was about 119,000 Euros per patient. More preemptive patients had professional activity before (P = .0002) and after transplantation (P = .02). Our results and data from the literature support the place of preemptive transplantation as the optimal mode of renal replacement therapy for medical and socioeconomic reasons.

Comparison of the long-term prognostic value of peak exercise oxygen pulse and peak oxygen uptake in patients with chronic heart failure.

OBJECTIVE: To evaluate the ratio of peak oxygen consumption to peak heart rate (peak oxygen pulse) as a predictor of long term prognosis in chronic heart failure. PATIENTS AND SETTING: 178 consecutive heart failure patients recruited to the cardiology department of a tertiary referral centre between 1986 and 1993. DESIGN: Bicycle ergometry with measurement of respiratory exchange. Mean (SD) follow up was 32 (25) months. RESULTS: Patients who died had a lower peak oxygen consumption (16.0 (5.5) v 18.0 (5.5) ml/min/kg, p = 0.05), lower indexed peak oxygen consumption (52 (14) v 60 (16)%, p = 0.006) but similar peak oxygen pulse (8.4 (2.6) v 8.4 (3.0) ml/beat, NS). The following variables were associated with a good long term prognosis: New York Heart Association class II, non-ischaemic heart failure, peak oxygen consumption > or = 17 ml/min/kg, indexed peak oxygen consumption > 63%. Peak oxygen pulse did not have predictive value. Only indexed peak oxygen consumption remained an independent predictor of survival in multivariate analysis. CONCLUSIONS: Peak oxygen pulse has lower prognostic value than peak oxygen consumption, especially when the latter is indexed to predicted values.

Relationship between alcohol and tobacco dependencies among alcoholics who smoke.

Outpatients followed in an alcoholic clinic and who fulfilled DSM-III-R criteria for alcohol dependence and had used both tobacco (at least one cigarette every day) and alcohol in the preceding week were studied. For each patient, two experimenters assessed: (1) the amount of tobacco and alcohol used; (2) the severity of dependence for each product. Results showed that: (a) The prevalence of smoking in this population of current alcohol dependents was 88%; (b) 91.6% of this sample of smoker alcoholics were dependent on nicotine; (c) the amount of tobacco smoked was correlated to the amount of alcohol consumed and the severity of alcohol dependence; and (d) there was a correlation between the severity of alcohol and nicotine dependencies. The results of this study may help to clarify the difficulty of treating tobacco dependence in alcoholics.

Prompting alcoholics to be referred to an alcohol clinic: the effectiveness of a simple letter.

Many patients received in emergency units (EU) of hospitals present alcohol-related problems. Most are alcohol dependent or abusers and enter for drunkenness, stay a few hours and return home. To assess the effectiveness of a letter referring these patients to an outpatient alcoholism treatment clinic, we performed a randomized study. For 6 months, all the patients who had been diagnosed as alcoholic, who had an address and who had not consulted a physician for alcoholism in the 6 previous months were selected from the records of the EU of a French university hospital. At least 2 days after their stay in the EU, we sent a letter to 181 patients of an experimental group (group E) suggesting they make an appointment with a physician specializing in alcoholism. No letter was sent to 181 patients in a control group (group C). Six months later, 21 patients (11.2%) of group E had called the outpatient alcoholism treatment clinic to make an appointment and came to a consultation. Two of the 181 patients of group C came to the consultation. The effectiveness of this method for referring alcoholics to a clinic had been controlled by another prospective study. We concluded that sending a letter 2 days after the passage of an alcoholic to an EU for drunkenness is a useful method of referral to an outpatient alcoholism treatment clinic.

Relationships between haemodynamic alterations and the development of ascites or refractory ascites in patients with cirrhosis.

OBJECTIVE: In patients with cirrhosis, the relationships between haemodynamic alterations and the development of ascites or the occurrence of refractory ascites are unknown. The aim of the present study was to compare haemodynamic measurements obtained in patients with non-refractory ascites to haemodynamic measurements obtained in patients without ascites and in patients with refractory ascites. METHODS: A cohort of 121 patients was prospectively studied, of whom 29 patients did not have ascites, 45 had non-refractory ascites and 47 had refractory ascites. Splanchnic, renal and systemic haemodynamics were measured in all patients. RESULTS: The hepatic venous pressure gradient was significantly higher in patients with non-refractory ascites than in patients without ascites (18.5 +/- 0.8 mmHg versus 15.8 +/- 0.7 mmHg). Renal and systemic haemodynamics did not significantly differ between patients with non-refractory ascites and patients without ascites. The glomerular filtration rate and renal blood flow were significantly lower in patients with refractory ascites than in patients with non-refractory ascites (77 +/- 4 versus 107 +/- 5 ml/min and 867 +/- 62 versus 1,008 +/- 68 ml/min, respectively). Splanchnic and systemic haemodynamics did not significantly differ between patients with refractory ascites and patients with non-refractory ascites. CONCLUSIONS: In patients with cirrhosis, an increase in portal hypertension was the sole haemodynamic alteration related to the development of ascites. Renal vasoconstriction (and subsequent renal hypoperfusion and hypofiltration) was the only haemodynamic alteration related to the occurrence of refractory ascites. The development of ascites or refractory ascites was not associated with any alteration in systemic haemodynamics.

Homogeneity of relative risk against two-step alternatives.

In this paper the computational aspects of testing the null hypothesis of homogeneity of relative risk against two-step alternatives are examined. This representation is the same as that introduced by Anderson and Senthilselvan (Appl. Stat. 31 (1982) 44-51), i.e. a two-step model. Such alternatives may be used to represent decay in effect or, perhaps, inversion of the regression effect or crossing hazards. For such models inferential aspects are slightly more involved than for instance with proportional hazards models having fixed effects, even when time dependent as in O'Quigley and Pessione (Biometrics 45 (1989) 135-144). The necessary techniques for carrying out tests based on the two-stage model have recently been developed (O'Quigley and Pessione (Biometrics (1990) (in press] and in this paper we outline the necessary steps to be taken in the construction of algorithms to implement the proposed procedures. Programs enabling analyses based on the assumption of homogeneity of risk are very widely available. These include software packages such as BMDP, SAS, SPSS and GLIM. In the output of these packages, as well as that from most other standard routines, is contained all the necessary information to carry out the tests proposed by O'Quigley and Pessione. Here we detail the explicit formulae needed for carrying out the calculations in practice. The special cases of crossing hazards are considered in detail.

[Prognosis of spontaneous ascitic infection in cirrhotic patients]. / Pronostic de l'infection spontanée d'ascite chez le cirrhotique.

The aim of this retrospective study was to define prognostic factors for cure and survival after spontaneous bacterial peritonitis. In a 4-year period from 1982 to 1986, spontaneous bacterial peritonitis was diagnosed in 38 consecutive hospitalized cirrhotic patients (positive ascites culture and polymorphonuclear cell concentration greater than 250 cells per mm3). Twenty-five patients recovered from their infection (69 p. 100) in a mean time of 9 +/- 7 days. The cumulative survival was 68 p. 100 at one week, 50 p. 100 at one month, and 25 p. 100 at one year. The best independent prognostic factors for lack of cure from peritonitis were a low ascitic pH value (p less than 0.001), an elevated serum creatinine level (p = 0.01) and the presence of hepatocellular carcinoma (p less than 0.05). The best prognostic factors for death were low ascitic pH value (p = 0.001) and gastrointestinal hemorrhage (p = 0.005). A low ascitic pH value was correlated with other signs of severe infection (signs of generalized infection, ongoing infection during the first week after diagnosis), with signs of severe liver disease (encephalopathy, hepatocellular carcinoma) or severe renal dysfunction (high serum creatinine level, low arterial pH value). Because of the late high-death rate associated with spontaneous bacterial peritonitis, liver transplantation should be considered in these patients.

[Patients with alcoholic liver disease hospitalized in gastroenterology. A national multicenter study]. / Maladies alcooliques du foie hospitalisées en Hépato-Gastroentérologie. Enquête multicentrique nationale.

OBJECTIVES: To describe the characteristics of in-patients with alcoholic liver disease in Hepatogastroenterology and to evaluate whether geographic location was a risk factor for cirrhosis. METHODS: A French, national, multicenter, prospective investigation was performed in the last quarter of 1997. To be included in the study, patients had to have drunk at least 50 g of alcohol per day for the past year or to have cirrhosis. RESULTS: Seventeen centers included 802 patients, 20% had histologically proven cirrhosis or probable cirrhosis. Thirty-five percent had undergone liver biopsy. Twenty five percent of these patients had cirrhosis without acute alcoholic hepatitis and 37% had cirrhosis with acute alcoholic hepatitis. After dividing France along a Bordeaux-Strasbourg axis, there was more histologically proven or probable cirrhosis in the North (46%) than in the South (36%) (P<0.005) while daily alcohol intake was greater the South (150 +/- 6 g) than in the North (129 +/- 4 g) (P<0.0001). When the six variables (age, sex, daily consumption of alcohol over the past 5 years, presence of hepatitis B surface antigen and antibodies to hepatitis C virus, total duration of alcohol abuse) were considered together in stepwise logistic regression analysis, geographic location changed the prediction of cirrhosis. The odds ratio for cirrhosis in patients living to the North of the Bordeaux-Strasbourg axis was 1.9 (95% confidence interval range 1.1-3.2) (P<0.02), suggesting the role of nutritional factors.

[Chlamydia trachomatis: risk factors in women in the Parisian region. Importance of smoking and cervical ectropion]. / Chlamydia trachomatis: facteurs de risque chez les femmes de la région parisienne. Importance du tabagisme et de l'ectropion cervical.

A study of chlamydial infection and its clinical correlates was undertaken collaboratively among french women attending sexually transmitted disease (STD, prenatal, and teen clinics (n = 148). A complete sexual and gynecologic history and pelvic exam was performed on all women. Endocervical and urethral cultures were obtained for C. trachomatis and N. gonorrhoeae. Reason for visit included suspected STD in 97% of STD, 5% of prenatal and 17% of teen women. N. gonorrhoeae was isolated from STD clinic patients only (17%). C. trachomatis was found in 22% of teen, 17% of STD and 2% of prenatal clinic women. C. trachomatis was significantly associated with smoking, a history of urethral discharge in the male partner, and endocervical ectopy > 50% of total cervical surface.

[Problem drinking]. / Les consommateurs d'alcool à problème.

The seriousness and the difficult care of the alcohol-dependent persons often occult an other category of persons drinking too much: the problem drinkers. Nevertheless, these persons are as many in the practice of all the physicians and their various pathologies concern all the medical specialties. Their identifying is based on the self declared consumption. Their lack of dependence and their attendance with their general practitioner make their care easier. A brief intervention aiming to reduce their consumption is a primary or secondary prevention which is more often enough to resolve all or part of their complaints.

Post-transplant lymphoproliferative disorders occurring after renal transplantation in adults: report of 230 cases from the French Registry.

Post-transplant lymphoproliferative disorders (PTLD) are a rare but serious complication after organ transplantation. A French Registry of PTLD was set up in a nationwide population of kidney transplant recipients. We prospectively enrolled all adult kidney recipients developing PTLD between January 1, 1998, and December 31, 2003. We analyzed the incidence, risk and prognostic factors of PTLD by Kaplan-Meier and Cox analyses. Totally 230 cases of PTLD were referred to the French Registry. Cumulative incidence was 1.18% after 5 years. Older age (per year, AHR = 2.19, CI = 1.22-3.94) and recipient Epstein-Barr virus seronegativity (AHR = 3.01, CI = 1.57-5.08) were associated with an increased risk of PTLD. Patients with PTLD had a reduced survival rate (61% at 5 years). Graft PTLD had the best prognosis with an 81% survival rate after 5 years. Infection with hepatitis C or B virus (HCV or HBV), late-onset PTLD, multiple sites involvement and high Ann Arbor staging were risk factors for patient death. Use of azathioprine was associated with a poorer survival rate. PTLD incidence and risk factors in French recipients are in line with the international or American PTLD series. We highlighted the role of HBV or HCV in patient mortality and described the relevant prognosis factors for patients with post-transplant lymphoproliferations.

Retrospective follow-up of transplantation of kidneys from 'marginal' donors.

The organ shortage has led to extend the procurement to kidneys from 'marginal' donors. As a result, an increasing number of kidneys are discarded, but an extended analysis of the validity of the clinical decision to accept or decline a marginal graft remains to be determined. We have retrospectively analyzed the outcome of 170 kidney transplantations, performed in eight renal transplantation centers between 1992 and 1998. Study group included transplantation from donors accepted after refusal for poor donor or graft quality by at least two centers. Control group included 170 paired recipients from kidneys unanimously accepted by all centers. Main causes of kidney refusal included impaired donor hemodynamics (28%), abnormal pre-harvesting serum creatinine (22%), advanced age in donors (15%), and donor atheroma (14%). The 5-year patient survival (88.2% in the study group and 88.9% in controls) and graft survival (70.4% in the study group and 76.7% in controls, P=0.129) were not significantly different. Delayed graft function occurred significantly more often in the study group patients than in controls patients (63 vs 32%, P<0.0001). Primary non-functioning kidneys were significantly more frequently observed in study patients than in controls (7.7 vs 1.8%, P=0.01). Mean creatinine clearance was significantly lower in the study group patients compared with controls during the post-transplant course. Our results suggest that these initially discarded kidneys provide satisfactory survival rates despite their impaired early functional recovery and poorer long-term renal function, and therefore might be considered acceptable for transplantation in the context of organ shortage.

The problem of a covariate-time qualitative interaction in a survival study.

We introduce a test for the equality of two survival distributions against the specific alternative of crossing hazards. Although this kind of alternative is somewhat rare, designing a test specifically aimed at detecting such departures from the null hypothesis in this direction leads to powerful procedures, upon which we can call in those few cases where such departures are suspected. Furthermore, the proposed test and an approximate version of the test are seen to suffer only moderate losses in power, when compared with their optimal counterparts, should the alternative be one of proportional hazards. Our interest in the problem is motivated by clinical studies on the role of acute graft versus host disease as a risk factor in leukemic children and we discuss the analysis of this study in detail. The model we use in this work is a special case of the one introduced by Anderson and Senthilselvan (1982. Applied Statistics 31, 44-51). We propose overcoming an inferential problem stemming from their model by using the methods of Davies (1977, Biometrika 64, 247-254; 1987, Biometrika 74, 33-43) backed up by resampling techniques. We also look at an approach relying directly on resampling techniques. The distributional aspects of this approach under the null hypothesis are interesting but, practically, its behaviour is such that its use cannot be generally recommended. Outlines of the necessary asymptotic theory are presented and for this we use the tools of martingale theory.

Score tests for homogeneity of regression effect in the proportional hazards model.

A simple model, containing the proportional hazards regression model as a special case, is presented. The purpose of the model is to provide a framework in which specific alternatives to the proportional hazards assumption may be tested. Rank-invariant score tests for linear, quadratic, or exponential trends can, for instance, all be undertaken within this framework. In the case of the two-sample problem the required calculations are shown to take a particularly simple form. Special consideration is given to the two-sample case in which there is an inversion of the regression effect, i.e., where the hazard functions cross at some given point. Both of the motivating examples are concerned with this problem. Computational aspects are relatively straightforward and some discussion on this is provided.