Social deprivation reduced registration for kidney transplantation through markers of nephrological care: a mediation analysis

OBJECTIVES

We assessed the direct and indirect effect of social deprivation mediated by modifiable markers of nephrological follow-up on registration on the renal transplantation waiting-list.

STUDY DESIGN AND SETTINGS

From the Renal Epidemiology and Information Network, we included French incident dialysis patients eligible for a registration evaluation between January 2017 and June 2018. Mediation analyses were conducted to assess effects of social deprivation estimated by quintile 5 (Q5) of the European Deprivation Index on registration defined as wait-listing at dialysis start or within the first 6 months.

RESULTS

Among the 11655 included patients, 2410 were registered. Q5 had a direct effect on registration (OR 0.82 [0.80-0.84]) and an indirect effect mediated by emergency start dialysis (OR 0.97 [0.97-0.98]), hemoglobin < 11 g/dL and/or lack of EPO (OR 0.96 [0.96-0.96]) and albumin < 30 g/L (OR 0.98 [0.98-0.99]).

CONCLUSION

Social deprivation was directly associated with a lower registration on the renal transplantation waiting-list but its effect was also mediated by markers of nephrological care, suggesting that improving the follow-up of the most deprived patients should help to reduce disparities in access to transplantation.

Perception of social inequities in the access to the kidney transplant waiting list by nephrology trainees: a national survey

BACKGROUND

Social inequalities in health are responsible for disparities in access to the kidney transplant waiting list (KTWL). The perception of disparities by nephrologists has consequences for the registration on the KTWL. The purposes of our study were to assess the perception of the factors implicated in the disparities in access to the KTWL by nephrology trainees and to assess the quality of the questionnaire.

METHODS

A questionnaire was developed to assess the perception of the determinants of the inequities in access to waitlisting. Continuous variables were described by median, 1st and 3rd quartiles. Categorical variables were described by frequencies and percentages. A principal component analysis and a hierarchical cluster analysis were performed to approach the correlation between the variables. A scree plot and a factor analysis were performed to determine the dimensions of the questionnaire. The internal consistency was estimated by Cronbach's coefficient.

RESULTS

The response rate was 98/110 (89%). The determinants of inequities in the access to KTWL not perceived by the nephrology trainees were "female sex", "income level" and "the centre provision to adapt the information to all of the patients" (18,3%, 36,7, 47% respectively). "Age", "being born abroad", "place of living", "education level", "transplant centre", "the health care provider" were determinants of disparities perceived by most of the trainees (85,7%, 75,5%, 82,6%, 78,6%, 73,5% et 78,5% respectively). Items related to the transplant centre were positively correlated, as well as "being born abroad", "education level" and "income level". The Cronbach's coefficient was 0,60.

CONCLUSION

Social inequalities in health are partially perceived by nephrology trainees. A teaching session could raise nephrologists' awareness of this issue and could help reduce the impact of these disparities on the course of ESKD (end-stage kidney disease) patients.

Women's Access to Kidney Transplantation in France: A Mixed Methods Research Protocol

Kidney transplantation is the best renal replacement therapy (medically and economically) for eligible patients with end-stage kidney disease. Studies in some French regions and in other countries suggest a lower access to the kidney transplant waiting listing and also to kidney transplantation, once waitlisted, for women. Using a mixed methods approach, this study aims to precisely understand these potential sex disparities and their causes. The quantitative study will explore the geographic disparities, compare the determinants of access to the waiting list and to kidney transplantation, and compare the reasons and duration of inactive status on the waiting list in women and men at different scales (national, regional, departmental, and census-block). The qualitative study will allow describing and comparing women's and men's views about their disease and transplantation, as well as nephrologists' practices relative to the French national guidelines on waiting list registration. This type of study is important in the current societal context in which the reduction of sex/gender-based inequalities is a major social expectation.

Effect of social deprivation on peritoneal dialysis uptake: A mediation analysis with the data of the REIN registry

BACKGROUND

Social deprivation could act as a barrier to peritoneal dialysis (PD). The objective of this study was to assess the association between social deprivation estimated by the European deprivation index (EDI) and PD uptake and to explore the potential mediators of this association.

METHODS

From the Renal Epidemiology and Information Network registry, patients who started dialysis in 2017 were included. The EDI was calculated based on the patient's address. The event of interest was the proportion of PD 3 months after dialysis initiation. A mediation analysis with a counterfactual approach was carried out to evaluate the direct and indirect effect of the EDI on the proportion of PD.

RESULTS

Among the 9588 patients included, 1116 patients were on PD; 2894 (30.2%) patients belonged to the most deprived quintile (Q5). PD was associated with age >70 years (odds ratio (OR) 0.79 [95% confidence interval (CI): 0.69-0.91]), male gender (0.85 [95% CI: 0.74-0.97]), cardiovascular disease (OR 0.86 [95% CI: 0.86-1.00]), chronic heart failure (OR 1.34 [95% CI: 1.13-1.58]), active cancer (OR 0.67 [95% CI: 0.53-0.85]) and obesity (OR 0.75 [95% CI: 0.63-0.89]). In the mediation analysis, Q5 had a direct effect on PD proportion OR 0.84 [95% CI: 0.73-0.96]. The effect of Q5 on the proportion of PD was mediated by haemoglobin level at dialysis initiation (OR 0.96 [95% CI: 0.94-0.98]) and emergency start (OR 0.98 [95% CI: 0.96-0.99]).

CONCLUSION

Social deprivation, estimated by the EDI, was associated with a lower PD uptake. The effect of social deprivation was mediated by haemoglobin level, a proxy of predialysis care and emergency start.

Paternity in male kidney transplant recipients: a French national survey, the PATeRNAL study

Background

There is concern about the impact of immunosuppressive agents taken by male kidney transplant (KT) recipients on the risk of foetal malformations. The aim of our survey was to estimate the paternity rate and the outcomes of pregnancies fathered by kidney transplanted males.

Methods

This survey analysed 1332 male KT recipients older than 18 years, followed in 13 centres in France. A self-reported questionnaire was used to collect data on the patients, treatments at the time of conception and the pregnancy outcomes.

Results

The study included data on 349 children from 404 pregnancies fathered by 232 male KT recipients. The paternity rate was 17% (95% CI [15–20]). There were 37 (9%, 95% CI [7–12]) spontaneous abortions, 12 (3%, 95% CI [2–5]) therapeutic abortions, 2 (0.5%, 95% CI [0.1–1]) still births, and 13 (4%, 95% CI [2–6]) malformations reported. Compared to the general population, there was no difference in the proportion of congenital malformations nor unwanted outcomes whether the father was exposed or not to immunosuppressive agents.

Conclusions

This survey does not provide any warning signal that pregnancies fathered by male patients exposed to immunosuppressive agents, notably the debated MMF/MPA, have more complications than pregnancies in the general population.

Supplementary Information

Supplementary information accompanies this paper at 10.1186/s12882-020-02115-x.

Is self-care dialysis associated with social deprivation in a universal health care system? A cohort study with data from the Renal Epidemiology and Information Network Registry

BACKGROUND

Socioeconomic status is associated with dialysis modality in developed countries. The main objective of this study was to investigate whether social deprivation, estimated by the European Deprivation Index (EDI), was associated with self-care dialysis in France.

METHODS

The EDI was calculated for patients who started dialysis in 2017. The event of interest was self-care dialysis 3 months after dialysis initiation [self-care peritoneal dialysis (PD) or satellite haemodialysis (HD)]. A logistic model was used for the statistical analysis, and a counterfactual approach was used for the causal mediation analysis.

RESULTS

Among the 9588 patients included, 2894 (30%) were in the most deprived quintile of the EDI. A total of 1402 patients were treated with self-care dialysis. In the multivariable analysis with the EDI in quintiles, there was no association between social deprivation and self-care dialysis. Compared with the other EDI quintiles, patients from Quintile 5 (most deprived quintile) were less likely to be on self-care dialysis (odds ratio 0.81, 95% confidence interval 0.71-0.93). Age, sex, emergency start, cardiovascular disease, chronic respiratory disease, cancer, severe disability, serum albumin and registration on the waiting list were associated with self-care dialysis. The EDI was not associated with self-care dialysis in either the HD or in the PD subgroups.

CONCLUSIONS

In France, social deprivation estimated by the EDI is associated with self-care dialysis in end-stage renal disease patients undergoing replacement therapy.

Transplant center characteristics associated with living-donor kidney transplantation: a cohort study with a hierarchical modeling approach

Transplant center organization, that is a modifiable factor, may affect the access to living-donor kidney transplantation (LDKT). The objective of this study was to identify the center characteristics associated with LDKT using a hierarchical analysis. This was a retrospective multicenter observational study of 8701 patients who received a first renal graft between 2010 and 2014 in 32 transplantation centers of France. Hierarchical modeling was used to estimate the center effect and organization associated with LDKT. Among 8507 patients, 1225 (12%) were transplanted with a LD kidney. There was a transplant center effect on the proportion of LDKT. After adjustment for patient and center characteristics, the random effect variance decreased by 47%. Patients transplanted at a center with more than four nephrologists [1.81 (95% CI: 1.10-2.95)] and more than 1.5 nurse transplant coordinators [1.98 (95% CI: 1.26-3.13)] were more likely to be transplanted with a LD kidney. ABO-incompatible program was associated with LDKT [2.23 (95% CI: 1.22-4.06)]. There was a transplant center effect on the proportion of LDKT that could be decreased by modifiable center characteristics. Our study suggests the importance of the transplant team organization on the LDKT utilization.

[Socioeconomic inequalities and kidney transplantation]

Studies at the population level must take into account the effect of social insecurity and socioeconomic inequalities on the patient outcomes. Socioeconomic inequalities depend on many determinants that are socially determined. In renal transplantation, these social determinants are not registered in the databases. The European Deprivation Index (EDI) is a composite index of social vulnerability with a French version. The EDI is an ecological measure of deprivation including the individual perception of basic needs for daily life that is called "subjective poverty". The Townsend index, Carstairs index and the Index of Multiple Deprivation are other ecological index available. It has been demonstrated in the United States that socioeconomic indicators of deprivation were associated with both the access to the waiting list for renal transplantation and transplantation failure. In France, socioeconomic deprivation may also affect the access to the waiting list and outcome of transplantation. This article is a review about deprivation and renal transplantation.

Pathogenic Variants in Complement Genes and Risk of Atypical Hemolytic Uremic Syndrome Relapse after Eculizumab Discontinuation

BACKGROUND AND OBJECTIVES

The complement inhibitor eculizumab has dramatically improved the outcome of atypical hemolytic uremic syndrome. However, the optimal duration of eculizumab treatment in atypical hemolytic uremic syndrome remains debated. We report on the French atypical hemolytic uremic syndrome working group's first 2-year experience with eculizumab discontinuation in patients with atypical hemolytic uremic syndrome.

DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS

Using the French atypical hemolytic uremic syndrome registry database, we retrospectively identified all dialysis-free patients with atypical hemolytic uremic syndrome who discontinued eculizumab between 2010 and 2014 and reviewed their relevant clinical and biologic data. The decision to discontinue eculizumab was made by the clinician in charge of the patient. All patients were closely monitored by regular urine dipsticks and blood tests. Eculizumab was rapidly (24-48 hours) restarted in case of relapse.

RESULTS

Among 108 patients treated with eculizumab, 38 patients (nine children and 29 adults) discontinued eculizumab (median treatment duration of 17.5 months). Twenty-one patients (55%) carried novel or rare complement genes variants. Renal recovery under eculizumab was equally good in patients with and those without complement gene variants detected. After a median follow-up of 22 months, 12 patients (31%) experienced atypical hemolytic uremic syndrome relapse. Eight of 11 patients (72%) with complement factor H variants, four of eight patients (50%) with membrane cofactor protein variants, and zero of 16 patients with no rare variant detected relapsed. In relapsing patients, early reintroduction (≤48 hours) of eculizumab led to rapid (<7 days) hematologic remission and a return of serum creatinine to baseline level in a median time of 26 days. At last follow-up, renal function remained unchanged in nonrelapsing and relapsing patients compared with baseline values before eculizumab discontinuation.

CONCLUSIONS

Pathogenic variants in complement genes were associated with higher risk of atypical hemolytic uremic syndrome relapse after eculizumab discontinuation. Prospective studies are needed to identify biomarkers predictive of relapse and determine the best strategy of retreatment in relapsing patients.

Eculizumab: safety and efficacy after 17 months of treatment in a renal transplant patient with recurrent atypical hemolytic-uremic syndrome: case report

In a recent study, eculizumab, a humanized monoclonal antibody which targets complement factor C5, appeared to resolve hemolysis and thrombocytopenia leading to recovery of renal function in a transplant patient during an episode of an atypical hemolytic uremic syndrome. We report the efficacy of eculizumab in a patient who presented with a recurrence of atypical hemolytic syndrome at 3 years after renal transplantation. After 17 months of eculizumab treatment, and without concomitant plasma therapy, renal function was maintained, the need for blood transfusions reduced, and acute thrombotic microangiopathy and hemolysis controlled. These data suggested that eculizumab should be considered to be a permanent treatment for this patient.