Gender differences in renal transplant graft survival

Impact of Medicaid expansion on kidney transplantation in the State Oklahoma

BACKGROUND

There is no data evaluating the impact of Medicaid expansion on kidney transplants (KT) in Oklahoma.

AIM

To investigate the impact of Medicaid expansion on KT patients in Oklahoma.

METHODS

The UNOS database was utilized to evaluate data pertaining to adult KT recipients in Oklahoma in the pre-and post-Medicaid eras. Bivariate analysis, Kaplan Meier analysis was used to estimate, and cox proportional models were utilized.

RESULTS

There were 2758 pre- and 141 recipients in the post-Medicaid expansion era. Post-expansion patients were more often non-United States citizens (2.3% vs 5.7%), American Indian, Alaskan, or Pacific Islander (7.8% vs 9.2%), Hispanic (7.4% vs 12.8%), or Asian (2.5% vs 8.5%) (P < 0.0001). Waitlist time was shorter in the post-expansion era (410 vs 253 d) (P = 0.0011). Living donor rates, pre-emptive transplants, re-do transplants, delayed graft function rates, kidney donor profile index values, panel reactive antibodies levels, and insurance types were similar. Patients with public insurance were more frail. Despite increased early (< 6 months) rejection rates, 1-year patient and graft survival were similar. In Cox proportional hazards model, male sex, American Indian, Alaskan or Pacific Islander race, public insurance, and frailty category were independent risk factors for death at 1 year. Medicaid expansion was not associated with graft failure or patient survival (adjusted hazard ratio: 1.07; 95%CI: 0.26-4.41).

CONCLUSION

Medicaid expansion in Oklahoma is associated with increased KT access for non-White/non-Black and non-United States citizen patients with shorter wait times. 1-year graft and patient survival rates were similar before and after expansion. Medicaid expansion itself was not independently associated with graft or patient survival outcomes. Ongoing research is necessary to determine the long-term effects of Medicaid expansion.

Gender differences in cardiovascular outcomes of kidney transplant recipients: A retrospective cohort study

The purpose of this study was to investigate gender differences in cardiovascular outcomes of kidney transplant recipients (KTRs). Here, a retrospective cohort study was conducted, and data from the National Health Insurance Research Database in Taiwan were used. In total, 2904 patients who had end-stage renal disease (ERSD) and received kidney transplantation (KT) were identified by propensity score matching (PSM) and were enrolled from 1997 to 2012, with follow-up ending in 2013. Besides, major adverse cardiovascular events (MACEs) were defined as a composite of all-cause mortality, nonfatal myocardial infarction, and nonfatal strokes. Apart from that, hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated by Cox regression, while the Bayesian network model was constructed to assess the importance of risk factors for MACEs. Furthermore, the original cohort was a sensitivity analysis. Women had a lower risk of MACEs compared with men (hazard ratio [HR]: 0.84; 95% CI: 0.72-0.98; P = .024). Beyond that, stratified analysis of age and waiting time for KT showed that the risk of MACEs was significantly lower in women than in men among KTRs aged > 50 years (HR: 0.79; 95% CI: 0.62-1.0; P = .05) or waiting time for KT ≤ 6 years (HR: 0.85; 95% CI: 0.72-0.99; P = .04). Bayesian network indicated that age is an important determinant of cardiovascular outcomes in KTRs, regardless of gender. In Taiwan, women had a lower risk of adverse cardiovascular outcomes than men in KTRs aged > 50 years or with a waiting time for KT ≤ 6 years. Furthermore, age is an important independent determinant for the prognosis of KTRs.

Outcomes of Deceased Donor Kidney Recipients From the Same Donor Based on Donor-Recipient Sex Discordance

INTRODUCTION

Outcomes of deceased donor kidney transplant (DDKT) recipients from the same donor with donor-recipient sex discordance have been studied with inconsistent results.

METHODS

Adult DDKT where both kidneys from the same donor occurred at our center in two different recipients of different sexes were included. Outcomes were analyzed separately for male and female donors, based on the concordance or discordance between donor-recipient sex: Male-male (M-m) versus Male to female (M-f) or vice versa, F-f versus F-m. Acute rejection (AR) and uncensored graft failure were primary outcomes of interest. The univariate and multivariate risks for AR and graft failure were conducted using the Cox proportional hazards model and log-rank tests.

RESULTS

A total of 130 donors, 84 male and 46 female fulfilled our selection criteria and were transplanted in 260 recipients. With respect to the concordant groups (M-m or F-f), sex discordance was not significantly associated with the risk of rejection in multivariate analysis (M-f vs. M-m HR 1.15 [0.53-2.53, P = 0.72]; F-m vs. F-f HR 1.77 [0.71-4.39, P = 0.23]). Sex discordance was also not significantly associated with graft failure in multivariate analysis. Interestingly, risk factors for AR differed among male donors and female donors. The higher calculated panel reactive antibodies (cPRA) and nonwhite recipients were at increased risk for AR in F-m, but not in M-f.

CONCLUSIONS

Donor-recipient sex discordance was not significantly associated with AR or graft failure. Risk factors for AR may differ across male and female donors.

Sclerotherapy of the Post renal Transplant Lymphoceles: A Meta-Analysis

PURPOSE

This study evaluated the effectiveness of sclerotherapy in treating lymphoceles after kidney transplantation, focusing on factors such as recurrence rates and procedural success.

MATERIALS AND METHODS

Retrospective studies using sclerotherapy as the only form of treatment for postrenal transplant lymphoceles were included. All studies used percutaneous transcatheter sclerotherapy as treatment, and the success rate of the intervention was recorded. Sixty-one references were obtained by manually searching the MEDLINE (n = 20), Embase (n = 41), and Cochrane Library databases (n = 0) for retrospective research studies that included the keywords "sclerotherapy post renal transplant lymphoceles." After removing 3 duplicates, 50 of the remaining articles were excluded after the screening, and the remaining studies were extracted for demographic data and our primary outcome of the success rate of sclerotherapy.

RESULTS

A descriptive analysis of the outcomes and complication rates associated with sclerotherapy interventions for lymphoceles is provided. A high degree of variation across the different studies was observed. According to the Kruskal-Wallis test, there was no correlation between the sclerosant used and the sclerotherapy complication rate (P = .472) or the success rate (P = .591). There was also no correlation between the gender of the patient and the success rate; however, there was a significant difference in the complication rate by gender (P < .005).

CONCLUSIONS

In conclusion, different sclerosant products have been used for therapy with no consensus on the most efficacious product because the success rate has been variable. In addition, the gender of the patient may influence the complication rates associated with sclerotherapy for lymphoceles in patients post-kidney transplant.

Sex-specific time trends of long-term graft survival after kidney transplantation - a registry-based study

BACKGROUND

Sex-specific trends over time with respect to kidney graft survival have scarcely been described in earlier studies. The present study aimed to examine whether kidney graft survival differs between women and men over time.

METHODS

This study was based on prospectively collected data extracted from a quality registry including all kidney transplant patients between January 1965 and September 2017 at the transplantation center of a university hospital in Sweden. The transplantation center serves a population of approximately 3.5 million inhabitants. Only the first graft for each patient was included in the study resulting in 4698 transplantations from unique patients (37% women, 63% men). Patients were followed-up until graft failure, death, or the end of the study. Death-censored graft survival analysis after kidney transplantation (KT) was performed using Kaplan-Meier analysis with log-rank test, and analysis adjusted for confounders was performed using multivariable Cox regression analysis.

RESULTS

Median age at transplantation was 48 years (quartiles 36-57 years) and was similar for women and men. Graft survival was analyzed separately in four transplantation periods that represented various immunosuppressive regimes (1965-1985, 1986-1995, 1996-2005, and 2006-2017). Sex differences in graft survival varied over time (sex-by-period interaction, p = 0.026). During the three first periods, there were no significant sex differences in graft survival. However, during the last period, women had shorter graft survival (p = 0.022, hazard ratio (HR) 1.71, 95% confidence interval (CI) 1.1-2.7, adjusted for covariates). Biopsy-proven rejections were more common in women.

CONCLUSIONS

In this registry-based study, women had shorter graft survival than men during the last observation period (years 2006-2017).

Utilization of the emergency department by kidney transplant recipients: a retrospective cohort study from a high-volume transplant center

This study aims to assess the trends of emergency department (ED) visits among kidney transplant recipients in a high-volume transplant centre.

Methods

This retrospective cohort study targeted patients who underwent renal transplantation at a high-volume transplant centre from 2016 to 2020. The main outcomes of the study were ED visits within 30 days, 31-90 days, 91-180 days, and 181-365 days of transplantation.

Results

This study included 348 patients. The median (interquartile range) age of patients was 45.0 years (30.8, 58.2). Over half of the patients were male (57.2%). There was a total of 743 ED visits during the first year after discharge. 19% (n=66) were considered high-frequency users. High-volume ED users tended to be admitted more frequently as compared to those with low frequencies of ED visits (65.2% vs. 31.2%, respectively, P<0.001).

Conclusion

As evident by the large number of ED visits, suitable coordination of management through the ED remains a pivotal component of post-transplant care. Strategies addressing prevention of complications of surgical procedures or medical care and infection control are aspects with potential for enhancement.

Long-term mortality in pediatric solid organ recipients-A nationwide study

BACKGROUND

The present study aimed at investigating long-term mortality of patients who underwent solid organ transplantation during childhood and at identifying their causes of death.

METHODS

A cohort of 233 pediatric solid organ transplant recipients who had a kidney, liver, or heart transplantation between 1982 and 2015 in Finland were studied. Year of birth-, sex-, and hometown-matched controls (n = 1157) were identified using the Population Register Center registry. The Causes of Death Registry was utilized to identify the causes of death.

RESULTS

Among the transplant recipients, there were 60 (25.8%) deaths (median follow-up 18.0 years, interquartile range of 11.0-23.0 years). Transplant recipients' risk of death was nearly 130-fold higher than that of the controls (95% CI 51.9-1784.6). The 20-year survival rates for kidney, liver, and heart recipients were 86.1% (95% CI 79.9%-92.3%), 58.5% (95% CI 46.2%-74.1%), and 61.4% (95% CI 48.1%-78.4%), respectively. The most common causes of death were cardiovascular diseases (23%), infections (22%), and malignancies (17%). There were no significant differences in survival based on sex or transplantation era.

CONCLUSION

The late mortality is still significantly higher among pediatric solid organ recipients in comparison with controls. Cardiovascular complications, infections, and cancers are the main causes of late mortality for all studied transplant groups. These findings emphasize the cruciality of careful monitoring of pediatric transplant recipients in order to reduce long-term mortality.

Vasopressin for Post-kidney Transplant Hypotension

Introduction

Hypotension after deceased donor kidney transplant (DDKT) is a risk factor for delayed graft function (DGF) and poor graft survival (GS). We hypothesize that vasopressin use in hypotensive DDKT recipients (DDKTRs) to increase blood pressure (BP) reduces DGF rates and is safe without increasing mortality.

Methods

Group with vasopressin "study group" (n = 45) was defined as DDKTRs between 2012 and 2017 who required vasopressin for hypotension systolic BP (SBP) <120 mm Hg or diastolic BP (DBP) <60 mm Hg. DDKTRs with no-vasopressin "comparison group" (n = 90) were propensity score-matched DDKTRs between 2012 and 2017 without vasopressin use. Primary outcomes were GS, creatinine and allograft biopsy rate at 1 year, DGF rate, and death during transplant hospitalization.

Results

Vasopressin group had lower mean maximum and minimum SBP and DBP in the operating room (OR). Median vasopressin start time post-DDKT was 2 hours (interquartile range [IQR] 1-6), and duration of use was 42 hours (IQR 24-63). DGF, creatinine at 1 year, and allograft biopsy rates were comparable. No deaths occurred during transplant hospitalization. Multivariable analysis did not find an effect of vasopressin use on GS.

Conclusion

Treatment of hypotensive DDKTRs with vasopressin is safe and facilitated similar graft function and survival with that of nonhypotensive patients. In the absence of a randomized control trial, our study supports the safety of vasopressin therapy to prevent the adverse effects of hypotension.

Risk Factors of Rejection in Renal Transplant Recipients: A Narrative Review

Multiple factors influence graft rejection after kidney transplantation. Pre-operative factors affecting graft function and survival include donor and recipient characteristics such as age, gender, race, and immunologic compatibility. In addition, several peri- and post-operative parameters affect graft function and rejection, such as cold and warm ischemia times, and post-operative immunosuppressive treatment. Exposure to non-self-human leucocyte antigens (HLAs) prior to transplantation up-regulates the recipient’s immune system. A higher rate of acute rejection is observed in transplant recipients with a history of pregnancies or significant exposure to blood products because these patients have higher panel reactive antibody (PRA) levels. Identifying these risk factors will help physicians to reduce the risk of allograft rejection, thereby promoting graft survival. In the current review, we summarize the existing literature on donor- and recipient-related risk factors of graft rejection and graft loss following kidney transplantation.

Sex and Gender Differences in Kidney Transplantation

Sex and gender often are used interchangeably, but are two distinct entities, with sex being the biological attribute and gender including the social, psychological, and cultural aspects of one's identity. Kidney transplantation has been proven to be the best treatment for end-stage kidney disease, improving both quality of life and life-expectancy for most patients. However, gender disparities in access to and outcomes of kidney transplantation remain despite the plethora of evidence showing the advantages of kidney transplantation to our patients. Data have shown that women are less likely to be waitlisted for a kidney transplant and to receive a deceased donor or a living donor kidney. On the other hand, women are more likely than men to become living kidney donors. Although some state the latter is the result of the female gender to nurture and care for loved ones, others believe this observation is because women often are incompatible with their spouse or child because pregnancy is a strong sensitizing event, which stems from the biological rather than the social differences between the sexes. Influence of sex and gender is not limited to access to kidney transplantation, but rather exist in other areas of transplant medicine, such as the difference observed in transplant outcomes between the sexes, variability in immunosuppression metabolism, and even in more contemporary areas such as recent data showing sex-based differences in outcomes of kidney transplant recipients with coronavirus disease-2019, with males having an increased incidence of acute kidney injury and death.

Renal Outcomes After Simultaneous Liver-Kidney Transplantation: Results from the US Multicenter Simultaneous Liver-Kidney Transplantation Consortium

Simultaneous liver-kidney transplantation (SLKT) is increasingly common in the United States. However, little is known about the renal-related outcomes following SLKT, which are essential to maximize the health of these allografts. We examined the factors impacting renal function following SLKT. This is an observational multicenter cohort study from the US Multicenter SLKT Consortium consisting of recipients of SLKT aged ≥18 years of transplantations performed between February 2002 and June 2017 at 6 large US centers in 6 different United Network for Organ Sharing regions. The primary outcome was incident post-SLKT stage 4-5 chronic kidney disease (CKD) defined as <30 mL/minute/1.73 m² or listing for kidney transplant. The median age of the recipients (n = 570) was 58 years (interquartile range, 51-64 years), and 37% were women, 76% were White, 33% had hepatitis C virus infection, 20% had nonalcoholic steatohepatitis (NASH), and 23% had alcohol-related liver disease; 68% developed ≥ stage 3 CKD at the end of follow-up. The 1-year, 3-year, and 5-year incidence rates of post-SLKT stage 4-5 CKD were 10%, 12%, and 16%, respectively. Pre-SLKT diabetes mellitus (hazard ratio [HR], 1.45; 95% CI, 1.00-2.15), NASH (HR, 1.58; 95% CI, 1.01-2.45), and delayed kidney graft function (HR, 1.72; 95% CI, 1.10-2.71) were the recipient factors independently associated with high risk, whereas the use of tacrolimus (HR, 0.44; 95% CI, 0.22-0.89) reduced the risk. Women (β = -6.22 ± 2.16 mL/minute/1.73 m² ; P = 0.004), NASH (β = -7.27 ± 3.27 mL/minute/1.73 m² ; P = 0.027), and delayed kidney graft function (β = -7.25 ± 2.26 mL/minute/1.73 m² ; P = 0.007) were independently associated with low estimated glomerular filtration rate at last follow-up. Stage 4-5 CKD is common after SLKT. There remains an unmet need for personalized renal protective strategies, specifically stratified by sex, diabetes mellitus, and liver disease, to preserve renal function among SLKT recipients.

Treatment optimization of maintenance immunosuppressive agents in pediatric renal transplant recipients

Introduction: Graft survival in pediatric kidney transplant patients has increased significantly within the last three decades, correlating with the discovery and utilization of new immunosuppressants as well as improvements in patient care. Despite these developments in graft survival for patients, there is still improvement needed, particularly in long-term care in pediatric patients receiving grafts from deceased donor patients. Maintenance immunosuppressive therapies have narrow therapeutic indices and are associated with high inter-individual and intra-individual variability.Areas covered: In this review, we examine the impact of pharmacokinetic variability on renal transplantation and its association with age, genetic polymorphisms, drug-drug interactions, drug-disease interactions, renal insufficiency, route of administration, and branded versus generic drug formulation. Pharmacodynamics are outlined in terms of the mechanism of action for each immunosuppressant, potential adverse effects, and the utility of pharmacodynamic biomarkers.Expert opinion: Acquiring abetter quantitative understanding of immunosuppressant pharmacokinetics and pharmacodynamic components should help clinicians implement treatment regimens to maintain the balance between therapeutic efficacy and drug-related toxicity.

Keratinocyte Cancer Mortality in Kidney Transplant Recipients

BACKGROUND

Kidney transplant recipients are at increased risk of developing and dying from keratinocyte cancer. Risk factors for keratinocyte cancer death have not been previously described.

METHODS

In a cohort of kidney transplant recipients transplanted in Queensland 1995-2014, we identified keratinocyte cancer deaths by searching national transplant and state death registries to March 2020. Standardized keratinocyte cancer mortality rates and mortality ratios were calculated. We used a competing risks model to identify factors associated with keratinocyte cancer death and calculated relative risks (RRs) and 95% confidence intervals (CIs).

RESULTS

There were 562 deaths in 1866 kidney transplant recipients (62% males; 86% Caucasian) with 25 934 person-years of follow-up, of which 36 were due to squamous cell carcinoma (SCC) and 1 to basal cell carcinoma (BCC) with standardized mortality rates of 78 (95% CI 53-111) and 2 (95% CI 0.1-11) per 100,000 person-years respectively. The standardized mortality ratio for keratinocyte cancer was 23 (95% CI 23-24). Besides Caucasian ethnicity (associated with 100% of keratinocyte cancer deaths), male sex (RR 3.24 95% CI 1.26-8.33), and older age at transplantation (≥ 50 versus <50 years RR 3.09 95% CI 1.38-6.89) were associated with increased risk of keratinocyte cancer death.

CONCLUSIONS

Keratinocyte cancer mortality in kidney transplant recipients is over 20 times higher than in the general population. Most keratinocyte cancer deaths are due to cutaneous SCC, however, BCC can be fatal. Education in skin cancer prevention is essential to avoid unnecessary deaths from keratinocyte cancer amongst kidney transplant recipients.

African American polycystic kidney patients receive higher risk kidneys, but do not face increased risk for graft failure or post-transplant mortality

African Americans (AA) are disproportionately affected by end-stage renal disease (ESRD) and have worse outcomes following renal transplantation. Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic condition leading to ESRD necessitating transplant. We explored this population with respect to race by conducting a retrospective analysis of the UNOS database between 2005 and 2019. Our study included 10,842 (AA n = 1661; non-AA n = 9181) transplant recipients whose primary diagnosis was ADPKD. We further stratified the AA ADPKD population with respect to blood groups (AA blood type B n = 295 vs AA non-B blood type n = 1366), and also compared this cohort to AAs with a diagnosis of DM (n = 16,706) to identify unique trends in the ADPKD population. We analyzed recipient and donor characteristics, generated survival curves, and conducted multivariate analyses. African American ADPKD patients waited longer for transplants (924 days vs 747 days P < .001), and were more likely to be on dialysis (76% vs 62%; p < .001). This same group was also more likely to have AA donors (21% vs 9%; p < .001) and marginally higher KDPI kidneys (0.48 vs 0.45; p < .001). AA race was a risk factor for delayed graft function (DGF), increasing the chance of DGF by 45% (OR 1.45 95% CI 1.26-1.67; p < .001). AA race was not associated with graft failure (HR 1.10 95% CI 0.95-1.28; p = .21) or patient mortality (HR 0.84 95% CI 0.69-1.03; p = .09). Racial disparities exist in the ADPKD population. They should be continually studied and addressed to improve transplant equity.

Effectiveness of Maintenance Immunosuppression Therapies in a Matched-Pair Analysis Cohort of 16 Years of Renal Transplant in the Brazilian National Health System

The maintenance of patients with renal transplant typically involves two or more drugs to prevent rejection and prolong graft survival. The calcineurin inhibitors (CNI) are the most commonly recommended medicines in combinations with others. While immunosuppressive treatment regimens are well established, there is insufficient long-term effectiveness data to help guide future management decisions. The study analyzes the effectiveness of treatment regimens containing CNI after renal transplantation during 16 years of follow-up with real-world data from the Brazilian National Health System (SUS). This was a retrospective study of 2318 SUS patients after renal transplantion. Patients were propensity score-matched (1:1) by sex, age, type and year of transplantation. Kaplan-Meier analysis was used to estimate the cumulative probabilities of survival. A Cox proportional hazard model was used to evaluate factors associated with progression to graft loss. Multivariable analysis, adjusted for diabetes mellitus and race/color, showed a greater risk of graft loss for patients using tacrolimus plus mycophenolate compared to patients treated with cyclosporine plus azathioprine. In conclusion, this Brazilian real-world study, with a long follow-up period using matched analysis for relevant clinical features and the representativeness of the sample, demonstrated improved long-term effectiveness for therapeutic regimens containing cyclosporine plus azathioprine. Consequently, we recommend that protocols and clinical guidelines for renal transplantation should consider the cyclosporine plus azathioprine regimen as a potential first line option, along with others.

Predictive value of procalcitonin in chronic allograft dysfunction in kidney transplant recipients

The present study was designed to determine the potential role of circulating procalcitonin (PCT) in predicting chronic allograft dysfunction (CAD) in kidney transplant recipients (KTRs). A total of 87 KTRs were retrospectively analyzed and divided into a CAD and a non-CAD (normal renal function) group. Clinical features and inflammatory markers were compared between the groups, including PCT, white blood cell count, C-reactive protein, neutrophil percentage (N%) and lipoprotein(a) [Lp(a)], and the receiver operating characteristic (ROC) curve for CAD prediction was plotted. Univariate and multivariate logistic regression analyses were used to analyze the relevant risk factors for CAD. The results indicated that i) the values of these indicators in the CAD group, including the male ratio, years after transplantation, PCT, N% and Lp(a), were significantly higher than those in the non-CAD group, while the body mass index, aspartate aminotransferase, high-density lipoprotein and low-density lipoprotein were significantly lower; ii) PCT and Lp(a) were able to predict CAD with an area under the ROC curve of 0.893 and 0.770, respectively; iii) multivariate logistic regression analysis of factors influencing CAD in KTRs suggested that elevated PCT was an independent risk factor. In KTRs, PCT was identified as a potential biomarker for predicting CAD.

Endovascular Treatment of Transplant Renal Artery Stenosis: Evaluation of Postoperative Outcomes and Risk Factors for Recurrence

Angioplasty with or without stenting has become a well-established procedure to treat transplant renal artery stenosis (TRAS). We evaluated our experience on postoperative outcomes following the intervention and identified potential predictive factors of TRAS recurrence. Consecutive patients who underwent endovascular treatment of TRAS were retrospectively reviewed. The study end points were the technical success, 30-day postoperative complications, and the estimated glomerular filtration rate (eGFR). Thirty-two patients underwent endovascular treatment for TRAS. The technical success rate was 96.6%. Complications were observed for 7 (21.9%) patients: 4 had a dissection, 2 a pseudoaneurysm, and 1 (3.1%) patient developed an acute pulmonary edema. The mean eGFR significantly increased at 7 days, 3 months, and 6 months postintervention (43.1, 44.9, and 44.3 vs 33.9 mL/min/1.73 m2 preoperatively, P < .05). The TRAS recurrence was observed in 7 (21.9%) patients. These patients had significantly higher preoperative peak systolic velocity and systolic rise time (5 vs 4 m/s, P = .0383 and 103 vs 80 milliseconds, P = .0148, respectively). Endovascular treatment of TRAS is associated with high technical success and significant improvement in renal function. Further studies are required to confirm predictive factors of TRAS recurrence following endovascular treatment.

Impact of the pretransplant dialysis modality on kidney transplantation outcomes: a nationwide cohort study

OBJECTIVE

Most patients with uraemia must undergo chronic dialysis while awaiting kidney transplantation; however, the role of the pretransplant dialysis modality on the outcomes of kidney transplantation remains obscure. The objective of this study was to clarify the associations between the pretransplant dialysis modality, namely haemodialysis (HD) or peritoneal dialysis (PD), and the development of post-transplant de novo diseases, allograft failure and all-cause mortality for kidney-transplant recipients.

DESIGN

Retrospective nationwide cohort study.

SETTING

Data retrieved from the Taiwan National Health Insurance Research Database.

PARTICIPANTS

The National Health Insurance database was explored for patients who received kidney transplantation in Taiwan during 1998-2011 and underwent dialysis >90 days before transplantation.

OUTCOME MEASURES

The pretransplant characteristics, complications during kidney transplantation and post-transplant outcomes were statistically analysed and compared between the HD and PD groups. Cox regression analysis was used to evaluate the HR of the dialysis modality on graft failure and all-cause mortality. The primary outcomes were long-term post-transplant death-censored allograft failure and all-cause mortality started after 90 days of kidney transplantation until the end of follow-up. The secondary outcomes were events during kidney transplantation and post-transplant de novo diseases adjusted by propensity score in log-binomial model.

RESULTS

There were 1812 patients included in our cohort, among which 1209 (66.7%) and 603 (33.3%) recipients received pretransplant HD and PD, respectively. Recipients with chronic HD were generally older and male, had higher risks of developing post-transplant de novo ischaemic heart disease, tuberculosis and hepatitis C after adjustment. Pretransplant HD contributed to higher graft failure in the multivariate analysis (HR 1.38, p<0.05) after adjustment for the recipient age, sex, duration of dialysis and pretransplant diseases. There was no significant between-group difference in overall survival.

CONCLUSIONS

Pretransplant HD contributed to higher risks of death-censored allograft failure after kidney transplantation when compared with PD.

Association of Sex with Risk of Kidney Graft Failure Differs by Age

Prior studies of sex differences in kidney graft survival showed conflicting results. We hypothesized that the association between recipient sex and kidney graft failure risk differs by recipient age and donor sex. We evaluated 159,417 patients recorded in the Scientific Registry of Transplant Recipients database who received a first deceased-donor kidney transplant (1995-2013). We used time-varying Cox models to estimate the association between recipient sex and death-censored graft failure. Models, stratified on donor sex and adjusted for potential confounders, included a recipient sex by current age interaction term. Among recipients of male donors, females of all ages had significantly higher graft failure risks than males (adjusted hazard ratios 0-14 years: 1.51 [95% confidence intervals 1.19 to 1.90]; 15-24 years: 1.37 [1.18 to 1.59]; 25-44 years: 1.14 [1.03 to 1.26]; 45 years: 1.05 [1.01 to 1.09]). Among recipients of female-donor grafts, only female recipients aged 15-24 years had a significantly higher graft failure risk than their male counterparts had (1.28 [1.06 to 1.53]). Indeed, female recipients aged ≥45 years had a significantly lower graft failure risk than their male counterparts had (0.95 [0.91 to 0.99]). These observations might be explained by the combined influence of several factors, including recognition of sex-determined minor histocompatibility antigens, influence of sex hormones on immune activation, sex- and age-related differences in medication adherence, and sex-related differences in body size. Additional studies should determine whether sex- and age-specific immunosuppression strategies are warranted for kidney graft recipients.

Organ transplantation and gender differences: a paradigmatic example of intertwining between biological and sociocultural determinants

Organ transplantation, e.g., of the heart, liver, or kidney, is nowadays a routine strategy to counteract several lethal human pathologies. From literature data and from data obtained in Italy, a striking scenario appears well evident: women are more often donors than recipients. On the other hand, recipients of organs are mainly males, probably reflecting a gender bias in the incidence of transplant-related pathologies. The impact of sex mismatch on transplant outcome remains debated, even though donor-recipient sex mismatch, due to biological matters, appears undesirable in female recipients. In our opinion, the analysis of how sex and gender can interact and affect grafting success could represent a mandatory task for the management of organ transplantation.

Sex matters: Systemic complement activity of female C57BL/6J and BALB/cJ mice is limited by serum terminal pathway components

Experimental mouse models have been extensively used to elucidate the role of the complement system in different diseases and injuries. Contribution of gender has revealed an intriguing gender specific difference; female mice often show protection against most complement driven injuries such as ischemia/reperfusion injury, graft rejection and sepsis. Interestingly, early studies to the mouse complement system revealed that female mice have very low total complement activity (CH50), which is related to androgen regulation of hepatic complement synthesis. Here, our aim was to understand at which level the female specific differences in mouse complement resides. We have used recently developed complement assays to study the functional activities of female and male mice at the level of C3 and C9 activation, and furthermore assayed key complement factor levels in serum of age-matched female and male C57BL/6 mice. Our results show that the female mice have normal complement cascade functionality at the level of C3 activation, which was supported by determinations of early complement factors. However, all pathways are strongly reduced at the level of C9 activation, suggesting a terminal pathway specific difference. This was in line with C6 and C9 measurements, showing strongly decreased levels in females. Furthermore, similar gender differences were also found in BALB/cJ mice, but not in CD-1 mice. Our results clearly demonstrate that the complement system in females of frequently used mouse strains is restricted by the terminal pathway components and that the perceived female specific protection against experimental disease and injury might be in part explained by the inability promote inflammation through C5b-9.

Graft survival rate of renal transplantation during a period of 10 years in Iran

BACKGROUND

Kidney transplantation is a preferred treatment for many patients with end-stage renal disease (ESRD) and is far more profitable than hemodialysis. Analyzing renal transplantation data can help to evaluate the effectiveness of transplantation interventions. The aim of this study was to determine the organ survival rate after kidney transplantation during a period of 10 years (March 2001-March 2011) among transplanted patients in Arak, Markazi Province, Iran.

MATERIALS AND METHODS

In this historical cohort study, all recipients of kidney transplantation from Arak, Markazi Province, Iran who had medical records in Valiasr Hospital and "charity for kidney patients" of Arak, Markazi Province, Iran during a period of 10 years from March 2001 to March 2011 were included. Data collected by using checklists were completed from patients' hospital records. Kaplan-Meier method was used to determine the graft cumulative survival rate, log-rank test to compare survival curves in subgroups, and Cox regression model to define the hazard ratio and for ruling out the intervening factors. Statistical analysis was conducted by Statistical Package for the Social Sciences (SPSS) 20 and Stata 11.

RESULTS

Mean duration of follow-up was 55.43 ± 42.02 months. By using the Kaplan-Meier method, the cumulative probability of graft survival at 1, 3, 5, 7, and 10 years was 99.1, 97.7, 94.3, 85.7, and 62.1%, respectively. The number of dialysis by controlling the effect of other variables had a significant association with the risk of graft failure [hazard ratios and 95% confidence interval (CI): 1.47 (1.02-2.13)].

CONCLUSION

This study showed that the graft survival rate was satisfactory in this community and was similar to the results of single-center studies in the world. Dialysis time after transplantation was a significant predictor of survival in the recipients of kidney transplantation that should be considered.

Gender in the allocation of organs in kidney transplants: meta-analysis

OBJECTIVE

To analyze whether gender influence survival results of kidney transplant grafts and patients.

METHODS

Systematic review with meta-analysis of cohort studies available on Medline (PubMed), LILACS, CENTRAL, and Embase databases, including manual searching and in the grey literature. The selection of studies and the collection of data were conducted twice by independent reviewers, and disagreements were settled by a third reviewer. Graft and patient survival rates were evaluated as effectiveness measurements. Meta-analysis was conducted with the Review Manager^® 5.2 software, through the application of a random effects model. Recipient, donor, and donor-recipient gender comparisons were evaluated.

RESULTS

: Twenty-nine studies involving 765,753 patients were included. Regarding graft survival, those from male donors were observed to have longer survival rates as compared to the ones from female donors, only regarding a 10-year follow-up period. Comparison between recipient genders was not found to have significant differences on any evaluated follow-up periods. In the evaluation between donor-recipient genders, male donor-male recipient transplants were favored in a statistically significant way. No statistically significant differences were observed in regards to patient survival for gender comparisons in all follow-up periods evaluated.

CONCLUSIONS

The quantitative analysis of the studies suggests that donor or recipient genders, when evaluated isolatedly, do not influence patient or graft survival rates. However, the combination between donor-recipient genders may be a determining factor for graft survival.

Health related quality of life in patients in dialysis after renal graft loss and effect of gender

BACKGROUND

An increasing number of dialysis patients have returned to dialysis after renal graft loss, and the transition in disease state could likely be associated with reduced health related quality of life (HRQOL). Furthermore, gender differences in HRQOL have been observed in dialysis and kidney transplanted patients, but whether transition in disease state affects HRQOL differently in respect to gender is not known. The aims of this study were to compare HRQOL in dialysis patients with graft loss to transplant naïve dialysis patients, and to explore possible gender differences.

METHODS

In a cross-sectional study, HRQOL was measured in 301 prevalent dialysis patients using the Kidney Disease and Quality of Life Short Form version 1.3. Adjusted comparisons were made between dialysis patients with previous graft loss and the transplant naïve patients. Multiple linear regression analyses were performed with HRQOL as outcome variables. Interaction analyses using product terms were performed between gender and graft loss. HRQOL was analysed separately in both genders.

RESULTS

Patients with renal graft loss (n = 50) did not experience lower HRQOL than transplant naïve patients after multiple adjustments. Among patients with graft loss, women (n = 23) reported lower HRQOL than men (n = 27) in the items physical function (40 vs. 80, p = 0.006), and effect of kidney disease (49 vs. 67, p = 0.017). Women with graft loss reported impaired kidney-specific HRQOL compared to transplant naïve women (n = 79) in the items effect of kidney disease (50 vs. 72, p = 0.002) and cognitive function (80 vs. 93, p = 0.006), and this observation persisted after multiple adjustments. Such differences were not apparent in the male counterparts.

CONCLUSIONS

Patients who resumed dialysis after renal graft loss did not have lower HRQOL than dialysis patients not previously transplanted. However, losing graft function was associated with reduced HRQOL in females, and important interactions were identified between graft loss and gender. This needs to be further explored in prospective studies.