C. Vigneau

Three kidneys, two diseases, one antibody?

Anti-factor H antibody has been recently described as responsible for thrombotic microangiopathies (TMA) as well as membranoproliferative glomerulonephritis (MPGN). We report here, for the first time, the case of a woman with an anti-factor H antibody, who developed MPGN on native kidney, rapid recurrence on first graft, and TMA on second graft despite immunosuppressive therapy and plasma exchanges. This case supports the hypothesis that MPGN and TMA are closely linked by common pathogenic mechanisms and the need for complete exploration of complement pathway including factor H activity and autoantibody in front of any MPGN.

Angiotensin-2 receptors (AT1-R and AT2-R), new prognostic factors for renal clear-cell carcinoma?

Background:The growth factor Angiotensin-2 signals through Angiotensin receptor type 1 (AT1-R) in a broad range of cell types and tumours and through the type-2 receptor (AT2-R) in a more restricted group of cell types. Although numerous forms of cancer have been shown to overexpress AT1-R, expression of AT1-R and AT2-R by human renal clear-cell carcinoma (RCCC) is not well understood. In this study, the expression of both angiotensin receptors was quantified in a retrospective series of RCCC and correlated with prognostic factors.Methods:Angiotensin receptor type 1 and AT2-R expressions were quantified on tumour tissues by immunohistochemistry (IHC), western blot and quantitative reverse transcriptase PCR (qRT–PCR). IHC results were correlated to Fuhrmans grade and patient progression-free survival (PFS).Results:A total of 84 RCCC were analysed. By IHC, AT1-R and AT2-R were expressed to a greater level in high-grade tumours (AT1-R: P<0.001, AT2-R: P<0.001). Univariate analysis showed a correlation between PFS and AT1-R or AT2-R expression (P=0.001). By multivariate analysis, only AT2-R expression correlated with PFS (HR 1.021, P=0.006) and cancer stage (P<0.001). By western blot, AT1-R and AT1-R were also found to be overexpressed in higher Fuhrmans grade (P<0.01 and P=0.001 respectively). By qRT–PCR, AT1-R but not AT2-R mRNA were downregulated (P=0.001 and P=0.118, respectively).Conclusion:Our results show that AT1-R and AT2-R proteins are overexpressed in the most aggressive forms of RCCC and that AT2-R expression correlates with PFS. AT1-R or AT2-R blockage could, therefore, offer novel directions for anti-RCCC therapy.

Voies moléculaires dans le cancer du rein : de la biologie aux traitements de demain

The medical treatment of renal-cell carcinoma, and of its most frequent subtype, clear cell renal-cell carcinoma, has recently been drastically changed by the emergence of targeted therapies. The development of these drugs has been made possible by more precise knowledge of molecular mechanisms involved in the carcinogenesis of these tumors. We present in this article the molecular pathways linked to targeted therapies for clear cell renal-cell carcinoma: VHL/HIF/VEHF and PI3K/AkT/mTOR pathways. We also describe succinctly the EGFR pathways, and the molecular mechanisms involved in other histological subtypes. Then, we briefly describe how these targeted therapies work. We finally discuss how biology could improve the use of these therapies, by developing new prognostic factors, and predictive factors of response to treatment.

[Signalling pathways in renal-cell carcinoma: from the molecular biology to the future therapy].

The medical treatment of renal-cell carcinoma, and of its most frequent subtype, clear cell renal-cell carcinoma, has recently been drastically changed by the emergence of targeted therapies. The development of these drugs has been made possible by more precise knowledge of molecular mechanisms involved in the carcinogenesis of these tumors. We present in this article the molecular pathways linked to targeted therapies for clear cell renal-cell carcinoma: VHL/HIF/VEHF and PI3K/AkT/mTOR pathways. We also describe succinctly the EGFR pathways, and the molecular mechanisms involved in other histological subtypes. Then, we briefly describe how these targeted therapies work. We finally discuss how biology could improve the use of these therapies, by developing new prognostic factors, and predictive factors of response to treatment.

Combination of Temsirolimus and tyrosine kinase inhibitors in renal carcinoma and endothelial cell lines.

PurposeMultitargeted tyrosine kinase inhibitors (TKIs) (such as Sunitinib and Sorafenib) and mTOR inhibitors (such as Temsirolimus) are effective in treating metastatic clear-cell renal cell carcinoma (CCRCC), by acting on different pathways in both tumour and endothelial cells. A study of their combined effect could be of major interest.MethodsWe studied endothelial and CCRCC cell lines treated with Sunitinib, Sorafenib, Temsirolimus and 2 drug combinations: Sunitinib–Temsirolimus and Sorafenib–Temsirolimus. We studied inhibition of proliferation with an MTT assay under normoxia and hypoxia, VEGF expression by quantitative RT–PCR and ELISA, and angiogenesis with a Matrigel assay.ResultsTKIs and Temsirolimus inhibited proliferation of endothelial and tumour cell lines and inhibited angiogenesis. Anti-proliferative effects were more significant on cell lines with VHL gene inactivation and under hypoxic conditions. VEGF expression was induced by TKIs, but inhibited by Temsirolimus. The Sunitinib/Temsirolimus combination had synergistic or additive effects on the proliferation of tumour and endothelial cell lines. The Sorafenib–Temsirolimus combination had additive effects on the proliferation of most tumour cell lines, but not endothelial cell lines. Both combinations had additive effects on the inhibition of angiogenesis.ConclusionIn our model, Sunitinib, Sorafenib and Temsirolimus had anti-tumour and anti-angiogenic effects. The combinations of Sunitinib or Sorafenib with Temsirolimus had additive or synergistic effects on the inhibition of tumour and endothelial cell proliferation, and on the inhibition of angiogenesis. This work could lead to new trials with lower-dose combinations to prevent side effects and enhance efficacy.

Spatial distribution of end-stage renal disease (ESRD) and social inequalities in mixed urban and rural areas: a study in the Bretagne administrative region of France

Background Several studies have investigated the implication of biological and environmental factors on geographic variations of end-stage renal disease (ESRD) incidence at large area scales, but none of them assessed the implication of neighbourhood characteristics (healthcare supply, socio-economic level and urbanization degree) on spatial repartition of ESRD. We evaluated the spatial implications of adjustment for neighbourhood characteristics on the spatial distribution of ESRD incidence at the smallest geographic unit in France. Methods All adult patients living in Bretagne and beginning renal replacement therapy during the 2004–09 period were included. Their residential address was geocoded at the census block level. Each census block was characterized by socio-economic deprivation index, healthcare supply and rural/urban typology. Using a spatial scan statistic, we examined whether there were significant clusters of high risk of ESRD incidence. Results The ESRD incidence was non-randomly spatially distributed, with a cluster of high risk in the western Bretagne region (relative risk, RR = 1.28, P-value = 0.0003). Adjustment for sex, age and neighbourhood characteristics induced cluster shifts. After these adjustments, a significant cluster (P = 0.013) persisted. Conclusions Our spatial analysis of ESRD incidence at a fine scale, across a mixed rural/urban area, indicated that, beyond age and sex, neighbourhood characteristics explained a great part of spatial distribution of ESRD incidence. However, to better understand spatial variation of ESRD incidence, it would be necessary to research and adjust for other determinants of ESRD.

Influence of Socio-Economic Inequalities on Access to Renal Transplantation and Survival of Patients with End-Stage Renal Disease

Background Public and scientific concerns about the social gradient of end-stage renal disease and access to renal replacement therapies are increasing. This study investigated the influence of social inequalities on the (i) access to renal transplant waiting list, (ii) access to renal transplantation and (iii) patients’ survival. Methods All incident adult patients with end-stage renal disease who lived in Bretagne, a French region, and started dialysis during the 2004–2009 period were geocoded in census-blocks. To each census-block was assigned a level of neighborhood deprivation and a degree of urbanization. Cox proportional hazards models were used to identify factors associated with each study outcome. Results Patients living in neighborhoods with low level of deprivation had more chance to be placed on the waiting list and less risk of death (HR = 1.40 95%CI: [1.1–1.7]; HR = 0.82 95%CI: [0.7–0.98]), but this association did not remain after adjustment for the patients’ clinical features. The likelihood of receiving renal transplantation after being waitlisted was not associated with neighborhood deprivation in univariate and multivariate analyses. Conclusions In a mixed rural and urban French region, patients living in deprived or advantaged neighborhoods had the same chance to be placed on the waiting list and to undergo renal transplantation. They also showed the same mortality risk, when their clinical features were taken into account.

Association between daily haemodialysis, access to renal transplantation and patients' survival in France

Daily haemodialysis improves patients quality of life and blood purification, but its effect on survival remains controversial. The aim of this study was to analyze the association between daily haemodialysis and renal transplantation and survival in France.

Treatment plans and outcomes in elderly patients reaching advanced chronic kidney disease

BackgroundnElderly patients with advanced chronic kidney disease require accurate outcome descriptions to make treatment decisions.nnnMethodsnThe PSPA [Parcours de soins des personnes âgées (Treatment pathways for elderly patients)] prospective multicentre cohort study included 573 such patients with a median age of 82 [interquartile range (IQR) 79-86] years and a median estimated glomerular filtration rate of 14 (IQR 11-17) mL/min/1.73 m2 and studied their 5-year outcomes according to the dialysis component of their treatment plans.nnnResultsnMean follow-up for the overall cohort was 34.5u2009±u200921u2009months and the 5-year survival rate was 27%. During follow-up, 288 (50%) patients started dialysis and 237 (42%) died before dialysis. At baseline, the four possible dialysis plans were dialysis when needed (38%), stable without mention of a dialysis plan (40%) and dialysis specifically excluded by the patients (9%) or nephrologists decision (12%). These baseline plans were associated with death and dialysis start. Follow-up plans were those decided during the study period: dialysis when needed for 47%, stable without mention of a dialysis plan for 20% and dialysis excluded at any time for 32%. For the subgroup of patients who started dialysis, those whose follow-up plan was dialysis started under better conditions than those who had stable or no dialysis follow-up plans before starting. However, survival afterwards did not differ significantly.nnnConclusionsnThese findings indicate that nephrology care should accommodate changes over time in older patients treatment preferences and plans concerning dialysis. These changes are associated with whether, when and how these patients initiate dialysis but are not necessarily associated with post-dialysis survival.