Tricuspid Regurgitation and Kidney Transplant Recipient Outcomes

Rationale & Objective

Kidney function can be adversely affected by significant tricuspid regurgitation (TR) owing to effects on cardiac output and systemic venous congestion. However, the impact of significant TR on short- and long-term kidney function following a kidney transplant remains uncertain.

Study Design

Retrospective observational cohort.

Setting & Participants

Kidney transplant recipients from a single center between 2016 and 2019.

Exposure

Significant TR, defined by at least moderate regurgitation, on echocardiogram before kidney transplantation.

Outcomes

Primary end points included the estimated glomerular filtration rate (eGFR) at the following 3 time points: 2 weeks, 3 months, and 1 year after transplantation. Secondary end points included major adverse cardiac events including nonfatal myocardial infarction, all-cause mortality, and hospitalization owing to cardiovascular disease.

Analytical Approach

Propensity score matching was performed in 1:3 ratio between patients treated with significant TR and controls, within a caliper 0.05 standard deviation of the propensity score, to analyze for the primary end point.

Results

Among 557 kidney transplant recipients, 26 (5%) exhibited significant TR pretransplantation. According to propensity score matching analysis, with 1:3 ratio between 24 patients with significant TR and 72 controls, the presence of significant TR was associated with a lower eGFR posttransplantation. Specifically, the mean eGFR was 41.2 mL/min/1.73 m2 compared to 53.3 mL/min/1.73 m2 at 2 weeks (P < 0.01), 50.0 mL/min/1.73 m2 versus 60.3 mL/min/1.73 m2 at 3 months (P < 0.01), and 49.4 mL/min/1.73 m2 versus 61.2 mL/min/1.73 m2 at 1 year (P < 0.01). Delayed graft function was observed in 41.7% of the patients with significant TR compared to 12.5% of those without significant TR (P < 0.01). No patients with significant TR required dialysis after 1 year. 1-year major adverse cardiac events were nonsignificantly higher among patients with significant TR (20.8% vs 8.1%; P = 0.16).

Limitations

Retrospective design and relatively small TR population.

Conclusions

The presence of significant TR among kidney transplant recipients was associated with a lower eGFR at 2 weeks, 3 months, and 1 year following transplant, although all remained dialysis independent at 1 year.

Improvement in Echocardiographic Indexes of Systolic Heart Failure Post Kidney Transplantation - a retrospective analysis

INTRODUCTION

End-stage renal disease (ESRD) is a major risk factor for cardiovascular morbidity and mortality, which can be partially eliminated by kidney transplantation. Systolic heart failure might be considered as contraindication for kidney transplant although some patients demonstrate myocardial recovery post-transplant. We aim to identify and characterize the phenomenon of reverse myocardial remodelling in kidney transplanted patients.

METHODS

The study is a retrospective cohort of patients undergoing kidney transplant between 2016-2019 (n=604) at Rabin Medical Center. Patients were assessed according to availability of two echocardiographic examinations: pre- and post-kidney transplant. The change in estimated ejection fraction (EF) and possible predictors of myocardial recovery were examined.

RESULTS

Data of 293 patients was available for the final analysis. Eighty-one (28%) patients had a LVEF improvement equal or above 5%, whereas 36 (12%) patients had a LVEF improvement 10% or more post transplantation. Twenty-five patients (8.5%) had moderate or severe systolic heart failure with LVEF reduced to 40% or less at baseline. 13 of them (52%) had a LVEF improvement of ≥5% and 10 patients (40%) had an improvement of ≥10% in their EF. Cox regression analyses identified female gender as the only independent variable associated with LVEF improvement of at least 10%. Conclusion Renal transplantation might lead to improved LV systolic function in some patients.

Multi-phasic eGFR trajectory during follow up and long-term graft failure after kidney transplantation

BACKGROUND

The prevailing assumption is that following kidney transplantation the pattern of kidney function decline is consistent. Nevertheless, numerous factors leading to graft loss may emerge, altering the trajectory of kidney function. In this study, we aim to assess alterations in estimated glomerular filtration rate (eGFR) trajectory over an extended period of follow-up and examine its correlation with graft survival.

METHODS

We calculated eGFR using all creatinine values available from 1-year post transplantation to the end of follow-up. For pattern analysis, we used a piecewise linear model.

RESULTS

Nine hundred eighty-eight patients were included in the study. After a median follow-up of 5.2 years, 297 (30.1%) patients had a multi-phasic eGFR trajectory. Change in eGFR trajectory was associated with increased risk for graft failure (HR 7.15, 95% CI 5.17-9.89, p < .001), longer follow-up time, younger age, longer cold ischemia time, high prevalence of acute rejection, longer hospitalization and a lower initial eGFR. Of the 988 patients included in the study, 494 (50.0%) had a mono-phasic stable trajectory, 197 (19.9%) had a mono-phasic decreasing trajectory, 184 (18.6%) had bi-phasic decreasing trajectory (initial stability and then decline, 46(4.7%) had a bi-phasic stabilized (initial decline and then stabilization) and 67(6.8%) had a more complex trajectory (tri-phasic). Out of the total 144 patients who experienced graft loss, the predominant pattern was a bi-phasic decline characterized by a bi-linear trajectory (66 events, 45.8%).

CONCLUSIONS

Changes in eGFR trajectory during long-term follow-up can serve as a valuable tool for assessing the underlying mechanisms contributing to graft loss.

Bariatric Surgery in Severely Obese Kidney Donors Before Kidney Transplantation: A Retrospective Study

BACKGROUND

Bariatric surgery (BS) is the optimal approach for sustained weight loss and may alter donation candidacy in potential donors with obesity. We evaluated the long-term effects of nephrectomy after BS on metabolic profile, including body mass index, serum lipids and diabetes, and kidney function of donors.

METHODS

This was a single-center retrospective study. Live kidney donors who underwent BS before nephrectomy were matched for age, gender, and body mass index with patients who underwent BS alone and with donors who underwent nephrectomy alone. Estimated glomerular filtration rate (eGFR) was calculated according to Chronic Kidney Disease Epidemiology Collaboration and adjusted to individual body surface area to create absolute eGFR.

RESULTS

Twenty-three patients who underwent BS before kidney donation were matched to 46 controls who underwent BS alone. At the last follow-up, the study group showed significantly worse lipid profile with low-density lipoprotein of 115 ± 25 mg/dL versus the control group with low-density lipoprotein of 99 ± 29 mg/dL ( P  = 0.036) and mean total cholesterol of 191 ± 32 versus 174 ± 33 mg/dL ( P  = 0.046). The second control group of matched nonobese kidney donors (n = 72) had similar serum creatinine, eGFR, and absolute eGFR as the study group before nephrectomy and 1 y after the procedure. At the end of follow-up, the study group had significantly higher absolute eGFR compared with the control group (86 ± 21 versus 76 ± 18 mL/min; P  = 0.02) and similar serum creatinine and eGFR.

CONCLUSIONS

BS before live kidney donation is a safe procedure that could increase the donor pool and improve their health in the long run. Donors should be encouraged to maintain their weight and avoid adverse lipid profile and hyperfiltration.

Coronary Computed Tomography Angiography and Abdominal Aortic Calcification Screening among High-Risk Living Kidney Donors

BACKGROUND

A unique scanning protocol combining coronary computed tomography angiography (CTA) with routine abdominal CTA is being used at the Rabin Medical Center as a method of screening high-risk candidates for living kidney donation. We aim to evaluate the potential impact of coronary CTA on the decision regarding eligibility for kidney donation and its correlation with abdominal aortic calcification (AAC).

METHODS

CCTA and abdominal CTA results of potential living kidney donors evaluated for donation between September 2020 and November 2021 were retrieved. A retrospective analysis of the abdominal CTA was used to calculate the AAC. Patients' demographic, clinical, and imaging data were collected from the electronic files, as well as the final decision regarding eligibility for donation.

RESULTS

A total of 62 potential kidney donors were evaluated for donation using the combined scan. The mean age was 53.8 years, with male predominance (59.7%). Significant coronary artery stenosis (≥70% luminal stenosis) was present in two patients (3.2%), whereas five patients (8%) had moderate stenosis (50-69%). Thirteen patients (21%) were disqualified from donation due to moderate-to-significant coronary artery disease or abdominal atherosclerosis. The correlation between the coronary artery calcium score and the AAC was found to be positive, with a Pearson correlation coefficient of 0.88 (p < 0.001).

CONCLUSIONS

The use of coronary CTA in the evaluation of potential kidney donors may has a potential impact on the decision regarding eligibility for donation. A high correlation between the coronary artery calcium score and the AAC was found.

Exposure to tacrolimus trough levels below 6 ng/ml during the first year is associated with inferior kidney graft survival

BACKGROUND

Accumulating data indicate that sub-therapeutic levels of tacrolimus are associated with long-term kidney graft loss. However, elevated doses increase the risk of infection and drug toxicity, which also threaten graft and patient longevity. We sought to determine the minimal tacrolimus level required to maintain graft survival.

METHODS

We conducted a single-center historical cohort study. The first-year post-transplant exposure time was calculated for each of the five tacrolimus trough level intervals. This measure was adjusted to the exposure time below a given interval level, allowing us to define the threshold for the optimal tacrolimus level as the upper limit of the interval. We then determined the association between the adjusted exposure time at each tacrolimus level interval and our primary outcome, death-censored graft loss.

RESULTS

One thousand four hundred and seventeen patients with a median follow-up of 5.3 years were included in the final cohort. The tacrolimus level interval of 5-6 ng/ml was the highest interval, which demonstrated a statistically significant association between adjusted exposure time and increased risk of graft loss (HR 1.58, per log days, p = .002). Cumulative exposure time above 14 days with a tacrolimus level below 6 ng/ml was associated with an increased rate of graft loss in most studied subgroups, except for recipients with pre transplant diabetes.

CONCLUSIONS

Maintaining tacrolimus levels above 6 ng/ml during the first-year post-transplant might improve kidney graft survival.

A Comparison of Recalled Pain Memory Following Living Kidney Donation Between Directed and non-Directed, Altruistic Donors

Introduction: Pain following donor nephrectomy for living kidney donation is common. In Israel, non-directed, altruistic donations account for 45% of all kidney transplants. Design: This cross-sectional, retrospective survey included 2 groups of donors derived from the data of Israel Transplant, namely directed and non-directed, altruistic donors, who donated between 2015 to 2018. The degree of recalled pain memory post-surgery was assessed using the Visual Analog Scale at 5 time points: immediately post-surgery, after 1 week, 1 month and 3 months post-surgery and in the month preceding completion of the questionnaire. In addition, continued requirement for analgesics for more than one-month post-surgery, the degree of interference with daily activities in the month preceding the questionnaire and the recalled time to return to full-time employment were also noted. Results: In total, 246 (131 directed and 115 non-directed, altruistic) donors were included in the study. Non-directed, altruistic donors reported statistically significantly lower degrees of recalled pain memory at all time points, a lower requirement for prolonged analgesic use and less recalled interference with daily activities due to pain. In addition, these donors recalled returning significantly earlier to full-time employment. Finally, no significant differences in the degree of recalled pain memory were noted for directed donors according to their relation to the recipient, apart from donation to a spouse. Conclusion: These unique findings, if validated in a prospective study, could provide important information to potential non-directed, altruistic donors regarding the expected level of post-surgical pain and their return to full-time employment.

The prognostic value of pre-operative coronary evaluation in kidney transplanted patients

Aims

Non-invasive coronary assessment using single-photon emission computerized tomography (SPECT) testing for potential cardiac ischemia is an essential part of the evaluation of kidney transplant candidates. We aimed to examine the prognostic value of preoperative SPECT test results in kidney transplanted patients.

Methods and results

We retrospectively analyzed the pre-surgical nuclear SPECT test results in a registry of kidney transplanted patients. Follow-up at 1 month and 1 year recorded major adverse cardiac events (MACE) including non-fatal myocardial infarction, all-cause mortality and hospitalization due to cardiovascular disease following the renal transplantation. Of 577 patients available for analysis, 408 (70.9%) patients underwent nuclear SPECT test pre-transplant and 83 (20.3%) had abnormal results with either evidence of ischemia or infarct. A significantly higher incidence of post-operative MACE at 1 month was evident among patients with abnormal SPECT test compared to patients with no evidence of ischemia (10.8 vs. 4.3% respectively; P = 0.019). Differences were mostly derived from significantly increased rates of myocardial infarction events (8.4 vs. 1.8%; P = 0.002). Yet, MACE rate was not statistically different at 1 year (20.5 vs. 13.1%; P = 0.88). Importantly, the prognostic impact of an abnormal SPECT was significantly attenuated for all outcomes following multivariable adjusting for conventional cardiovascular risk factors and coronary revascularization.

Conclusion

Pre-surgical cardiac risk assessment of kidney transplant candidates with nuclear SPECT test was found to be predictive of post-operative MACE, yet apparently, its prognostic value was significantly attenuated when adjusted for cardiac risk factors.

The Role of Early Sequential Biopsies in Delayed Renal Graft Function of Transplanted Kidney Is Reduced in Modern Immunosuppression Era

BACKGROUND

Delayed graft function (DGF) immediately after kidney transplantation is considered a risk factor for acute rejection. According to clinical guidelines, a weekly allograft biopsy should be performed until DGF resolves. Based on clinical evidence, the first biopsy is considered appropriate. However, the recommendation for further biopsies is based on sparse evidence from era of earlier immunosuppression protocols, and the benefit of the second and further biopsies remains uncertain. The aim of this study was to reevaluate this policy.

METHODS

The database of a transplant medical center was retrospectively reviewed for all patients who underwent kidney transplantation in 2011-2020. Those with DGF who performed two or more graft biopsies within the first 60 days after transplantation were identified. Clinical data were collected from the medical files. The rates of diagnosis of acute rejection at the second and subsequent biopsies were analyzed relative to the previous ones.

RESULTS

Kidney transplantation was performed in 1,722 patients during the study period, of whom 225 (13.07%) underwent a total of 351 graft biopsies within 60 days after transplantation, mostly due to DGF. A second biopsy was performed in 32 patients (14.2%), and a third biopsy in 8, at weekly intervals. In 2 patients (6.25%), the diagnosis changed from the first biopsy (acute tubular necrosis or toxic damage) to acute rejection in the second biopsy. In both, the rejection was borderline. Third and fourth biopsies did not add information to the previous diagnosis.

CONCLUSIONS

The common practice of performing sequential biopsies during a postoperative course of DGF seems to be of low benefit and should be considered on a case-by-case basis.

Second pregnancy following kidney transplantation is not associated with an increased risk of graft loss in a single center retrospective cohort study

INTRODUCTION

Previous studies on first pregnancy following kidney transplantation (KT) show no association with decreased graft survival. This study examined patients with multiple gestations compared to a single pregnancy following KT and evaluated the risk of graft function deterioration.

METHODS

A retrospective cohort study on fertile female kidney transplant recipients (KTRs) from Rabin Medical Center between January 2001 and December 2017 was performed. Data were collected on patients' comorbidities, pregnancy complications, graft loss, mortality, and lab results. Time-varying COX analysis was performed - second pregnancy being the time-related variable.

RESULTS

Fifty-two KTRs split into 30 single pregnancy and 22 multiple pregnancy patients following KT. Single pregnancy patients were older during their first pregnancy and had a higher caesarian section rate. During a median follow-up period of 5.6 years, multiple pregnancies, compared to a single pregnancy, were not associated with an increased rate of graft loss. No significant difference was seen between first and second pregnancy in gestational age, birth weight, graft function, and proteinuria rates.

CONCLUSIONS

Second pregnancy following KT was not shown to be associated with a decreased graft survival. In addition, obstetrical, maternal, and fetal complication rates are not increased in second compared to first pregnancy following KT.

The Impact of Obesity and Associated Comorbidities on the Outcomes after Renal Transplantation with a Living Donor vs. Deceased Donor Grafts

Background: Obesity among kidney transplant (KT) recipients can lead to metabolic comorbidity-associated deaths. This study compares post-KT survival between obese and non-obese patients and outcomes of living donor (LD) and deceased donor (DD) grafts. Methods: Between January 2005−May 2019, 1403 KT recipients from a single center were included in the study, as well as 314 patients (22.4%) with obesity (BMI > 30 kg/m2), 137 DD transplants, and 177 LD transplants. Of the 1089 (77.6%) in the control group (BMI ≤ 30 kg/m2), 384 were DD transplants and 705 LD transplants. The Kaplan−Meier method was used for survival analysis and a Cox regression was used to identify risk factors for graft loss and mortality. Propensity score matching analysis adjusting for age, IHD, and T2DM was performed. Results: The study group had higher incidence of obesity related comorbidities, delayed graft function and primary non function (p < 0.001). One-, 5-and 10-year patient and graft survival were lower in the study group (p < 0.001). Subgroup analysis of graft survival according to type of graft shows a difference in the DD (p = 0.002) but not in the LD group (p = 0.220). However, mortality was higher in both groups (LD, p = 0.045; DD, p = 0.004). Risk factors for mortality were age, T2DM, IHD, and DD, and for graft failure: IHD, BMI, donor age, re-transplant, and DD. Propensity score analysis shows an odds ratio of 0.81 for graft failure and 0.93 for death in the study group (95% CI = 0.55, 1.21, p = 0.3 and CI = 0.59, 1.46, p = 0.7, respectively). Conclusions: Recipient age and metabolic comorbidities should be emphasized when evaluating patients with obesity. We suggest considering weight loss interventions using the new GLP-1 inhibitors and bariatric procedures in selected patients to prepare overweight patients for transplant.

Immune Response to Third Dose BNT162b2 COVID-19 Vaccine Among Kidney Transplant Recipients-A Prospective Study

Immune response to two SARS-CoV-2 mRNA vaccine doses among kidney transplant recipients (KTRs) is limited. We aimed to evaluate humoral and cellular response to a third BNT162b2 dose. In this prospective study, 190 KTRs were evaluated before and ∼3 weeks after the third vaccine dose. The primary outcomes were anti-spike antibody level >4160 AU/ml (neutralization-associated cutoff) and any seropositivity. Univariate and multivariate analyses were conducted to identify variables associated with antibody response. T-cell response was evaluated in a subset of participants. Results were compared to a control group of 56 healthcare workers. Among KTRs, we found a seropositivity rate of 70% (133/190) after the third dose (37%, 70/190, after the second vaccine dose); and 27% (52/190) achieved levels above 4160 AU/ml after the third dose, compared to 93% of controls. Variables associated with antibody response included higher antibody levels after the second dose (odds ratio [OR] 30.8 per log AU/ml, 95% confidence interval [CI]11-86.4, p < 0.001); and discontinuation of antimetabolite prior to vaccination (OR 9.1,95% CI 1.8-46.5, p = 0.008). T-cell response was demonstrated in 13% (7/53). In conclusion, third dose BNT162b2 improved immune response among KTRs, however 30% still remained seronegative. Pre-vaccination temporary immunosuppression reduction improved antibody response.

OUP accepted manuscript

Data regarding immunogenicity of mRNA severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines among kidney transplant recipients in the months following vaccination are lacking. We aimed to investigate humoral immune response at 3–4 months post-vaccination among a cohort of kidney transplant recipients, compared with a control group of dialysis patients. Anti-spike antibodies were tested at 1 and 3–4 months after vaccination. Of 259 kidney transplant recipients tested at a median time of 110 days from second vaccine dose, 99 (38%) were seropositive, compared with 83% (101/122) of control patients. Younger age, better renal function and lower immunosuppression levels were associated with seropositivity. A total of 14% (13/94) of participants seropositive at 1 month became seronegative at follow-up and 11% (18/165) became seropositive. The latter were mainly individuals with higher antibody levels at 1 month. Antibody levels at 3–4 months were significantly reduced in both study groups, although the decline was more pronounced in the control group. Kidney transplant recipients present poor antibody response to mRNA SARS-CoV-2 vaccination, with only 38% seropositive at 3–4 months. Nevertheless, the decay in antibody response over time is modest, and some patients may present delayed response, reaching adequate antibody levels at 3–4 months. Low seropositivity rates in this group call for investigating other immunization strategies.

Long-Term Results of Kidney Transplantation in the Elderly: Comparison between Different Donor Settings

With scarce organ supply, a selection of suitable elderly candidates for transplant is needed, as well as auditing the long-term outcomes after transplant. We conducted an observational cohort study among our patient cohort >60 years old with a long follow up. (1). Patients and Methods: We used our database to study the results after transplant for 593 patients >60 years old who underwent a transplant between 2000–2017. The outcome was compared between live donor (LD; n = 257) recipients, an old-to-old (OTO, n = 215) group using an extended criteria donor (ECD) kidney, and a young-to-old (YTO, n = 123) group using a standard-criteria donor. The Kaplan−Meir method was used to calculate the patient and graft survival and Cox regression analysis in order to find risk factors associated with death. (2). Results: The 5- and 10-year patient survival was significantly better in the LD group (92.7% and 66.9%) compared with the OTO group (73.3% and 42.8%) and YTO group (70.9% and 40.6%) (p < 0.0001). The 5- and 10-year graft survival rates were 90.3% and 68.5% (LD), 61.7% and 30.9% (OTO), and 64.1% and 39.9%, respectively (YTO group; p < 0.0001 between the LD and the two DD groups). There was no difference in outcome between patients in their 60’s and their 70’s. Factors associated with mortality included: age (HR-1.060), DM (HR-1.773), IHD (HR-1.510), and LD/DD (HR-2.865). (3). Conclusions: Our 17-years of experience seems to justify the rational of an old-to-old allocation policy in the elderly population. Live-donor transplant should be encouraged whenever possible. Each individual decision of elderly candidates for transplant should be based on the patient’s comorbidity and predicted life expectancy.

Short versus prolonged antibiotic treatment for complicated urinary tract infection after kidney transplantation

There is no consensus regarding the optimal duration of antibiotic therapy for urinary tract infection (UTI) following kidney transplantation (KT). We performed a retrospective study comparing short (6-10 days) versus prolonged (11-21 days) antibiotic therapy for complicated UTI among KT recipients. Univariate and inverse probability treatment weighted (IPTW) adjusted multivariate analysis for composite primary outcome of all-cause mortality or readmissions within 30 days and relapsed UTI 180 days were performed. Overall, 214 KT recipients with complicated UTI were included; 115 short-course treatment (median 8, interquartile range [IQR] 6-9 days), 99 prolonged course (median 14, IQR 12-21 days). The composite outcome occurred in 33 (28.6%) in the short-course group and 30 (30%) in the prolonged-course group; relapsed UTI occurred in 19 (16.5%) vs. 21 (21%), respectively. Duration of antibiotic treatment was not associated with any of these outcomes. The only risk factor for mortality/readmissions in multivariate analysis was deceased donor. No differences between groups were demonstrated for length of hospital stay, rates of bacteraemia, resistance development, and serum creatinine at 30 and 90 days. In conclusion, we found no difference in clinical outcomes between KT recipients treated for complicated UTI with short-course antibiotic (6-10 days) versus longer course (11-21 days).

Immunosuppression reduction when administering a booster dose of the BNT162b2 mRNA SARS-CoV-2 vaccine in kidney transplant recipients without adequate humoral response following two vaccine doses: protocol for a randomised controlled trial (BECAME study)

INTRODUCTION

Inadequate antibody response to mRNA SARS-CoV-2 vaccination has been described among kidney transplant recipients. Immunosuppression level and specifically, use of antimetabolite in the maintenance immunosuppressive regimen, are associated with inadequate response. In light of the severe consequences of COVID-19 in solid organ transplant recipients, we believe it is justified to examine new vaccination strategies in these patients.

METHODS AND ANALYSIS

BECAME is a single-centre, open-label, investigator-initiated randomised controlled, superiority trial, aiming to compare immunosuppression reduction combined with a third BNT162b2 vaccine dose versus third dose alone. The primary outcome will be seropositivity rate against SARS-CoV-2. A sample size of 154 patients was calculated for the seropositivity endpoint assuming 25% seropositivity in the control group and 50% in the intervention group. A sample of participants per arm will be also tested for T-cell response. We also plan to perform a prospective observational study, evaluating seropositivity among ~350 kidney transplant recipients consenting to receive a third vaccine dose, who are not eligible for the randomised controlled trial.

ETHICS AND DISSEMINATION

The trial is approved by local ethics committee of Rabin Medical Center (RMC-0192-21). All participants will be required to provide written informed consent. Results of this trial will be published; trial data will be available. Protocol amendments will be submitted to the local ethics committee.

TRAIL REGISTRATION NUMBER

NCT04961229.

Apixaban Level and Its Influence on Immunosuppression and Graft Outcome in Kidney Transplant Recipients With Atrial Fibrillation

BACKGROUND

Currently, there is limited information on the level of apixaban in kidney transplant (KT) patients with atrial fibrillation and the influence of apixaban therapy on the level of immunosuppression and graft function.

METHODS

This was a cross-sectional prospective study of 19 KT patients treated with apixaban. The levels of apixaban were measured using a chromogenic assay calibrated for apixaban and compared with those predicted by the manufacturer. Mean immunosuppression trough levels before and after apixaban treatment initiation were calculated using 3 consecutive measurements. Apixaban levels were compared with a historical control group comprising of 20 nontransplant patients with atrial fibrillation who were treated with the standard 5-mg bid apixaban dosage.

RESULTS

All KT patients should have been treated with the standard 5-mg bid apixaban dosage according to the clinical parameters; however, 7 were inappropriately treated with a reduced dosage (2.5-mg bid). There was no significant difference in apixaban level between KT patients treated with the 5-mg bid dosage and nontransplant patients. No KT patient administered the standard dose had out-of-range levels. Peak GM level was significantly lower in KT patients administered an inappropriately reduced dose (P = 0.05). Two patients had below-range peak levels. Apixaban treatment initiation had minimal influence on the level of immunosuppression. Furthermore, it had no adverse impact on graft function.

CONCLUSIONS

Similar to nontransplant patients, KT patients administered the standard 5-mg bid dosage had apixaban levels that were well within the recommended manufacturers' expected ranges. In addition, this dosage had minimal influence on immunosuppression and no effect on graft function.

Post-transplantation erythrocytosis in kidney transplant recipients-A retrospective cohort study

OBJECTIVES

To characterize risk factors for the development of post-transplant erythrocytosis (PTE), and its long-term effect on mortality, graft failure, and thrombosis.

METHODS

Retrospective study including all kidney transplant recipients in Rabin Medical Center (RMC) during the years 2005-2014. The primary outcome was a composite outcome of all-cause mortality or graft failure at the end of follow-up. Secondary outcomes included death censored graft loss, venous thromboembolism, major adverse cardiovascular events, and mortality. A matched control group was also evaluated. Univariate and multivariate time-varying Cox model analyses were conducted for outcome evaluation.

RESULTS

A total of 1304 patients were included, 169 of whom were diagnosed with PTE (12.9%). PTE was associated with male gender, higher glomerular filtration rate (GFR), and polycystic kidney disease. PTE was found to be associated with a reduced risk of the primary outcome (HR 0.355, CI 95% 0.151-0.89, P = .027) in a univariate time-varying Cox analysis, but was not associated with the composite outcome in a multivariate analysis. There was no difference in the primary outcome when the PTE group was compared with the matched control.

CONCLUSION

PTE was not found to be associated with long-term outcomes of graft failure and poor survival.

The Association Between Exposure to Low Magnesium Blood Levels After Renal Transplantation and Cardiovascular Morbidity and Mortality

Background: Serum magnesium levels are associated with cardiovascular disease and all-cause mortality in the general population and chronic kidney disease patients, but the association between serum magnesium levels and cardiovascular risk after kidney transplantation is not established. We sought to evaluate whether exposure to low serum magnesium levels after renal transplantation is related to cardiovascular morbidity and mortality.

Methods: We conducted a single center retrospective study that included all transplanted patients who had a functioning graft for at least 6 months after transplantation between January 2001 and December 2013. We calculated exposure to magnesium using time weighted average for serum magnesium levels, using all values available during the follow-up. Several statistical methods were used, including liner regression analysis, χ² test, and multivariate Cox proportional hazard model.

Results: Four hundred ninety-eight patients were included. Median follow-up was 5.26 years. High time weighted average of serum magnesium was associated with a hazard ratio of 1.94 for all-cause mortality and major cardiovascular outcome compared to low levels (95% CI 1.18–3.19, p = 0.009). The high quartile of time weighted average of serum magnesium was associated with death censored major cardiovascular outcome (hazard ratio 2.13, 95% CI 1.17–3.86, p = 0.013) in multivariate analysis.

Conclusions: Exposure to low serum magnesium levels in renal transplant recipients was associated with a lower risk for all-cause mortality and major cardiovascular outcome. These findings contrast the higher risk found in the general population.

Antibody response to SARS-CoV-2 mRNA vaccine among kidney transplant recipients: a prospective cohort study

OBJECTIVES

We aimed to evaluate the rates of antibody response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccine among kidney transplant recipients, and to identify factors associated with reduced immunogenicity.

METHODS

This was a prospective cohort study including consecutive kidney transplant recipients in a single referral transplant centre. Participants were tested for anti-spike (anti-S) antibodies 2-4 weeks after a second vaccine dose. Primary outcome was rate of seropositivity. Univariate and multivariate analyses were conducted to identify factors associated with seropositivity.

RESULTS

Of 308 kidney transplant recipients included, only 112 (36.4%) tested positive for anti-S antibodies 2-4 weeks after receiving the second dose of BNT162b2 vaccine. Median antibody titre was 15.5 AU/mL (interquartile range (IQR) 3.5-163.6). Factors associated with antibody response were higher estimated glomerular filtration rate (eGFR) (odds ratio (OR) 1.025 per mL/min/1.73 m², 95% confidence interval (CI) 1.014-1.037, p < 0.001), lower mycophenolic acid dose (OR 2.347 per 360 mg decrease, 95%CI 1.782-3.089, p < 0.001), younger age (OR 1.032 per year decrease, 95%CI 1.015-1.05, p < 0.001) and lower calcineurin inhibitor (CNI) blood level (OR 1.987, 95%CI 1.146-3.443, p 0.014). No serious adverse events resulting from the vaccine were reported.

CONCLUSIONS

Kidney transplant recipients demonstrated an inadequate antibody response to SARS-CoV-2 mRNA vaccination. Immunosuppression level was a significant factor in this response. Strategies to improve immunogenicity should be examined in future studies.

Microalbuminuria After Kidney Transplantation Predicts Cardiovascular Morbidity

Background: Microalbuminuria is a well-characterized marker of kidney malfunction, both in diabetic and non-diabetic populations, and is used as a prognostic marker for cardiovascular morbidity and mortality. A few studies implied that it has the same value in kidney transplanted patients, but the information relies on spot or dipstick urine protein evaluations, rather than the gold standard of timed urine collection.

Methods: We revisited a cohort of 286 kidney transplanted patients, several years after completing a meticulously timed urine collection and assessed the prevalence of major cardiovascular adverse events (MACE) in relation to albuminuria.

Results: During a median follow up of 8.3 years (IQR 6.4–9.1) 144 outcome events occurred in 101 patients. By Kaplan-Meier analysis microalbuminuria was associated with increased rate of CV outcome or death (p = 0.03), and this was still significant after stratification according to propensity score quartiles (p = 0.048). Time dependent Cox proportional hazard analysis showed independent association between microalbuminuria and CV outcomes 2 years following microalbuminuria detection (HR 1.83, 95% CI 1.07–2.96).

Conclusions: Two years after documenting microalbuminuria in kidney transplanted patients, their CVD risk was increased. There is need for primary prevention strategies in this population and future studies should address the topic.

Association of obesity and muscle mass with risk of albuminuria in renal transplant recipients

BACKGROUND

Increased albuminuria is a predictor of graft loss in kidney graft recipients. It is unknown whether obesity is an independent risk factor for the development of increased albuminuria in this population. The aim of this study was to elucidate the association between obesity and albuminuria in renal transplant recipients.

METHODS

We enrolled 330 renal transplant recipients and prospectively collected demographic, anthropomorphic, clinical and laboratory variables susceptible to influence albumin excretion. The outcome was albuminuria, measured using accurately timed urine collections. Data from 201 patients were analyzed after exclusion of participants with missing data and patients enrolled less than 6 months since renal transplantation. Analysis was carried out for an early and a late period, defined according to the 2.4-year median follow-up time.

RESULTS

Body mass index (BMI), waist circumference and urinary creatinine excretion rate were independent predictors of albuminuria in the late post-transplant period, indicating that the predictive value of body mass index for albuminuria is related to both increased abdominal fat mass and increased muscle mass. BMI was an independent predictor of microalbuminuria. Waist circumference and urinary creatinine were independent predictors of microalbuminuria for values above certain cutoffs: 110% of the accepted thresholds defining abdominal obesity and 1500 mg/day, respectively.

CONCLUSIONS

These associations, which have not previously been reported, suggest, but do not prove, that an imbalance between metabolic demand and nephron mass may be responsible for increased albuminuria in the renal transplant population.

Bariatric Surgery Is Efficacious and Improves Access to Transplantation for Morbidly Obese Renal Transplant Candidates

BACKGROUND

The surgical risk of morbidly obese patients is high and even higher for kidney transplant candidates. A BMI > 35-40 kg/m² is often a contraindication for that surgery. The safety, feasibility, and outcome of bariatric surgery for those patients are inconclusive.

METHODS

We conducted a retrospective chart review of prospectively collected data on morbidly obese renal transplant candidates who underwent laparoscopic sleeve gastrectomy (LSG) or laparoscopic Roux-en-Y gastric bypass (LRYGB) in our institution between January 2009 and September 2017. The reported outcome included body weight and graft status after a mean follow-up of 47 months (range 0.5-5 years).

RESULTS

Twenty-four patients (8 females, 16 males, average age 54 years, average preoperative BMI 41 kg/m² [range 35-51]) underwent LSG (n = 17) or LRYGB (n = 7). Sixteen of them (67%) proceeded to kidney transplantation. Of the 8 pre-transplant and post-bariatric surgery patients, 5 are on the waitlist, and 2 patients died (one of staple line leakage, and one from sepsis unrelated to the bariatric surgery). The average time from bariatric surgery to transplantation was 1.5 years (range 1 month to 4.3 years). The average pre-transplantation BMI was 28 kg/m² (range 19-36). The mean percentage of excess weight loss was 66% (n = 21), and the total percentage of weight loss was 29% (n = 21). Comorbidities (type 2 diabetes, hypertension, and dyslipidemia) improved significantly following both surgical approaches.

CONCLUSIONS

LSG and LRYGB appear to effectively address obesity issues before kidney transplantation and improve surgical access. Morbidly obese transplant candidates would benefit from prior bariatric surgery.

Temporal changes of proteinuria after kidney transplantation: association with cardiovascular morbidity and mortality

BACKGROUND

Proteinuria is common in kidney transplant recipients and has been established as a risk factor for graft-loss and mortality. In the general population, proteinuria has also been tied to a higher risk of cardiovascular disease. There is limited data exploring the association between changes in proteinuria over time and cardiovascular disease in kidney transplant recipients.

METHODS

In this retrospective cohort study we evaluated proteinuria as a time-varying covariate using urine dipstick protein values at 6 month intervals post-transplant. The primary outcome was the occurrence a major cardiovascular event (MACE). Univariate and multivariate time varying Cox model was used.

RESULTS

579 patients were included in the final cohort. 120 episodes of MACE were documented in 98 patients. Time varying proteinuria was associated with MACE by univariate and multivariate analysis (HR 2.63, 95% CI 1.76-3.93, p < 0.001) and (HR 2.33, 95% CI 1.53-3.54, p < 0.001). Reduction of proteinuria to normal was associated with reduced risk of MACE compared with active proteinuria (HR 0.44, 95% CI 0.28-0.69, p < 0.001) and (HR 0.47, 95% CI 0.3-0.76, p = 0.002) for univariate and multivariate analyses. Exposure to proteinuria for more than 1 year was significantly associated with an increased risk of MACE for univariate and multivariate analysis (HR 2.33, 95% CI 1.48-3.68, p < 0.001) and (HR 2.18, 95% CI 1.37-3.45, p = 0.002) respectively, in comparison to exposure of less than 1 year.

CONCLUSION

These findings may suggest that we should consider applying clinical interventions that are known to reduce cardiovascular morbidity in these patients.

Acute Kidney Injury and Long-Term Risk for Cardiovascular Events in Patients after Kidney Transplantation

BACKGROUND

Acute kidney injury (AKI) was found to be associated with an increased risk of major adverse cardiovascular events (MACE) in the general population. Patients after kidney transplantation are prone to AKI events and are also at an increased risk of cardiovascular (CV) disease. The association between AKI and MACE in kidney transplant patients is yet to be studied.

METHODS

This retrospective single-center cohort study reviewed 416 adult renal allograft recipients transplanted between 2005 and 2010. AKI events were recorded starting 2 weeks after transplantation, or following discharge with a functioning graft. AKI was defined, according to the KDIGO criteria. The primary outcome was the composite of MACE starting 6 months after transplantation and all-cause mortality. For survival analysis, we used univariate and multivariate time varying Cox proportional hazard model.

RESULTS

One hundred and twenty-four patients (29.8%) had at least one episode of AKI. During the median follow-up time of 7.2 years (interquartile range 4.3-9.1), 144 outcome events occurred. By time varying Cox regression analysis, AKI was associated with an increased rate of CV outcomes or death (hazard ratio [HR] 1.96, 95% CI 1.36-2.81, p < 0.001), and the association remained significant by multivariate adjusted model (HR 1.76, 95% CI 1.18-2.63, p = 0.005). As for the different components of MACE, all-cause mortality and CV mortality were the only outcomes that were significantly associated with AKI. No interaction between AKI timing and MACE was found.

CONCLUSION

AKI in kidney transplant recipient is associated with an increased risk of CV disease.

Structural and Functional Echocardiographic Changes Following Kidney Transplantation: The Role of Allograft Function

BACKGROUND

Kidney transplantation is associated with early improvement in cardiac function and structure; however, data on cardiac adaptation and its relation to kidney allograft function remain sparse.

OBJECTIVES

To investigate the relationship between post-transplant kidney function and echocardiographic measures in patients with normal/preserved pre-transplant cardiac structure and function.

METHODS

The study included 113 patients who underwent kidney transplantation at a single tertiary medical center from 2000 to 2012. The patients were evaluated by echocardiography before and after transplantation, and the relation between allograft function and echocardiographic changes was evaluated. Echocardiography was performed at a median of 510 days after transplantation.

RESULTS

The post-transplantation estimated glomerular filtration rate (eGFR) was directly correlated with left ventricular (LV) systolic function and inversely correlated with LV dimensions, LV wall thickness, left atrial diameter, and estimated systolic pulmonary arterial pressure. In patients with significant allograft dysfunction (eGFR ≤ 45 ml/min), LV hypertrophy worsened, with no improvement in LV dimensions. In contrast, in patients with preserved kidney function, there was a significant reduction in both LV diameter and arterial pulmonary systolic pressure.

CONCLUSIONS

Our results show that in kidney transplant recipients, allograft function significantly affects cardiac structure and function. Periodic echocardiographic follow-up is advisable, especially in patients with kidney graft dysfunction.

Reduction of exposure to tacrolimus trough level variability is associated with better graft survival after kidney transplantation

PURPOSE

High tacrolimus trough drug level variability was found to be associated with reduced graft survival. The primary goal of this study was to find whether reduction of exposure to high tacrolimus trough level variability in patients in which previously had high variability was associated with better graft survival.

METHODS

All tacrolimus drug level values in patients that underwent kidney transplantation at our center between 2006 and 2015 were collected. Exposure to variability was calculated using a time-weighted coefficient of variability (TWCV). Time-dependent univariate and multivariate Cox proportional hazard models were used to analyze the primary outcome of graft survival and to determine a cutoff value for TWCV as a predictor of this outcome.

RESULTS

A total of 878 patients were included in the study with a median follow-up of 1263 days. TWCV above 25% was significantly associated with reduced graft survival (HR3.66, 95% CI 2.3-5.8, p < 0.001). Of the 480 patients (54.7%) who had a cumulative TWCV of > 25% at a certain time during the follow-up, 110 (22.9%) later returned to a cumulative TWCV of less than 25%. Reduction of TWCV to values below 25% was associated with a hazard of graft loss that was not different from patients who had cumulative TWCV of less than 25% during the entire follow-up period (HR 1.81, 95% CI 0.71-4.62, p = 0.218 and HR 1.08, 95% CI 0.39-2.99, p = 0.780) in univariate and multivariate analyses, respectively.

CONCLUSIONS

Monitoring TWCV can help detect the high-risk patients. Interventions intended to reduce variability on long-term graft survival may have a positive effect on graft survival.

Post renal transplant anemia: severity, causes and their association with graft and patient survival

Background

Post transplantation anemia (PTA) is common among kidney transplant patients. PTA is associated with increased graft loss and in most studies with increased mortality. However, the effect of the severity of anemia on this associations was not thoroughly evaluated.

Methods

Patients who underwent kidney transplantation in Rabin Medical Center (RMC) were included in the study. Data were collected during the years 2002–2016. Anemia was defined as hemoglobin (Hb) level less than 12 g/dL in women and less than 13 g/dL in men, in accordance with World Health Organization (WHO) criteria. Severe anemia was defined as hemoglobin lower than 11 g/dL. Primary outcome was a composite of patient and graft survival. We used univariate and multivariate models to evaluate association between severity and specific causes of anemia with the outcomes. As the risk associated with anemia changed over time we analyzed the risk separately for the early and the late period (before and after 1251 days).

Results

Our cohort included 1139 patients, 412 (36.2%) of which had PTA and 134 (11.7%) had severe anemia. On multivariable analysis, severe anemia was highly associated with the primary outcome at the early period (HR 6.26, 95% CI 3.74–10.5, p < 0.001). Anemia due to either AKI & acute rejection (11.9% of patients) or infection (16.7%), were associated with primary outcome at the early period (HR 9.32, 95% CI 5.3–26.41, p < 0.001 and HR 3.99, 95% CI 2.01–7.95, p < 0.001, respectively). There was non-significant trend for association between anemia due to Nutritional deficiencies (29.1%) and this outcome (HR 3.07, 95% CI 0.93–10.17, p = 0.067).

Conclusion

PTA is associated with graft loss and mortality especially during the first three years. Anemia severity affects this association. An anemia workup is recommended for PTA.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1244-y) contains supplementary material, which is available to authorized users.

Association between anemia at three different time points and new-onset diabetes after kidney transplantation--a retrospective cohort study

PURPOSE

Anemia has been reported to be associated with diabetes, but the association between new-onset diabetes after transplantation (NODAT) and anemia has not been reported.

METHODS

Patients who underwent kidney transplantation and did not have diabetes prior to transplantation were included in this study. Hemoglobin levels and the prevalence of anemia (hemoglobin <12 g/dL in females and <13 g/dL in males) were evaluated at three time points (prior to transplantation, 6 months following transplantation or 1 month before the development of NODAT, 2 years following transplantation, or following the development of NODAT) and were compared between those who developed NODAT and those who did not. Variables associated with the development of anemia were compared between the two groups.

RESULTS

A total of 266 kidney transplant recipients were included, of which 71 (27%) developed NODAT during the time of the follow-up. Hemoglobin and hematocrit levels and the prevalence of anemia were similar in those with and without NODAT at all three time points evaluated. Ferritin levels, prior to transplantation and mean corpuscular volume (MCV) posttransplantation post-NODAT development, were slightly but significantly lower in those with NODAT, although both were within the normal range.

CONCLUSIONS

Pretransplantation ferritin levels and posttransplantation post-NODAT development MCV are inversely associated with the development of NODAT in kidney transplants.

New onset diabetes after kidney transplantation is associated with increased mortality-A retrospective cohort study

OBJECTIVE

Clinical outcomes in individuals with new onset diabetes after transplantation (NODAT) and the optimal treatment for this complication are poorly characterized. This study was intended to better define these issues.

METHODS

Patients who underwent kidney transplantation and did not have diabetes prior to transplantation were included in the study. Clinical outcomes were compared between those who developed NODAT and those who did not. In those who developed NODAT, oral therapy was compared with insulin based therapy.

RESULTS

A total of 266 kidney transplant recipients were included, of which 71 (27%) developed NODAT during the time of the follow-up. Using Cox multivariate analysis adjusted for age and gender, hazard ratio for overall mortality among patients with NODAT versus those without NODAT was 2.69 (95% CI 1.04-7.01). Among patients who developed NODAT, 29 patients (40%) were treated with an insulin-based regimen. At the end of follow-up, no difference was found in mean HbA1c, and therapy regimen was not associated with greater mortality.

CONCLUSIONS

New onset diabetes in kidney transplanted patients is associated with increased mortality compared with kidney transplanted patients without NODAT.

Association of the combination of time-weighted variability of tacrolimus blood level and exposure to low drug levels with graft survival after kidney transplantation

Background

The variability of tacrolimus blood levels has been shown to be associated with inferior graft survival. However, the effect of variability during the early post-transplantation period has not been evaluated. We sought to evaluate the association between time-weighted variability in the early post-transplantation period and graft survival. We also explored the interaction between drug level variability and exposure to inadequate drug levels.

Methods

This retrospective cohort study included all patients who underwent kidney transplantation in the Rabin Medical Center and were treated with tacrolimus. Time-weighted coefficient of variability (TWCV) was defined as time-weighted standard deviation divided by the mean drug level. Univariate and multivariate Cox proportional hazard model was used with the primary outcome of patients and graft survival.

Results

The study population included 803 patients who underwent kidney transplantation between 1 January 2000 and 29 September 2013. The high tertile of TWCV of tacrolimus blood levels was associated with reduced graft survival by univariate and multivariate analyses [hazard ratio (HR) 1.69, 95% confidence interval (CI) 1.14-2.53, P = 0.01 and HR 1.74, 95% CI 1.14-2.63, P = 0.01, respectively]. The interaction between high TWCV and exposure to inadequately low drug levels was significantly associated with reduced survival (P = 0.004), while the interaction between TWCV and high drug blood levels was not. One hundred and thirty patients (16.2%) had the combination of high TWCV and exposure to low drug values (<5 ng/mL). These patients had reduced graft survival by univariate and multivariate analyses (HR 2.42, 95% CI 1.57-3.74, P < 0.001 and HR 2.6, 95% CI 1.65-4.11, P < 0.001, respectively).

Conclusions

The combination of high TWCV and exposure to low drug levels might identify high-risk patients in the early post-transplantation period.

Derivation and Implementation of a Protocol in Israel for Organ Donation after Cardio-Circulatory Death

BACKGROUND

Strategies aimed at expanding the organ donor pool have been sought, which has resulted in renewed interest in donation after cardio-circulatory death (DCCD), also known as non-heart beating donors (NHBDs).

OBJECTIVES

To describe the derivation and implementation of a protocol for DCCD in Israel and report on the results with the first six cases.

METHODS

After receiving approval from an extraordinary ethics committee, Ministry of Health, the steering committee of the National Transplant Center defined and reached consensus on the unique challenges presented by a DCCD program. These protocol included medical aspects (construction of a clinical pathway), social and ethical aspects (presentation of the protocol at a public gathering(, legal/ethical aspects (consent for organ preservation procedures being either implied if the donor had signed an organ donor card or received directly from a surrogate decision maker), and logistical aspects (pilot study confined to kidney retrieval and to four medical centers). Data regarding organ donors and recipients were recorded.

RESULTS

The protocol was implemented at four medical centers. Consent for organ donation was received from four of the six potential donors meeting criteria for inclusion, in all cases, from a surrogate decision maker. Of the eight kidneys retrieved, only four were suitable for transplantation, which was carried out successfully for four recipients. Graft function remained normal in all cases in 6-12 months follow-up.

CONCLUSIONS

The DCCD program was successfully implemented and initial results are encouraging, suggesting that expansion of the program might further aid in decreasing the gap between needs and availability of organs.

Posttransplantation anemia in kidney transplant recipients: A retrospective cohort study

We sought to assess the frequency and predictors of early and late posttransplantation anemia (PTA). In addition, we aimed to assess the outcomes of patients with anemia and to assess the impact of anemia on mortality, graft function, and graft failure.Patients who underwent kidney transplantation in a single center during a 4-year period were included. Predictors associated with the development of anemia at 6 months (early PTA) or 2 years (late PTA) were evaluated in a univariate and multivariate analyses. The effects of anemia and other variables on mortality and graft function were assessed.A total of 266 kidney transplant recipients were included. The prevalence of PTA at 6 months (early PTA) was 51.3% and at 2 years (late PTA) was 36.6%. Female sex was significantly associated with early PTA. Patients with early PTA proceeded to late PTA. Patients with both early and late PTA had a higher mortality rate at 4 years compared to patients without anemia. On multivariable analysis, lower Hb at 2 years posttransplantation (hazard ratio [HR] 0.716, 95% confidence intervals [CI] 0.541-0.948, for every increment of 1 g/dL) was significantly associated with mortality. Patients with late PTA suffered a decline in eGFR compared to patients without anemia (P = .026). Furthermore, a lower Hb at 2 years posttransplantation was also associated with graft failure (HR 0.775, 95% CI 0.619-0.969, for every increment of 1 g/dL).Post-transplantation anemia is significantly associated with late mortality, with a decline in graft function and with an increased incidence of graft failure.

[ABO INCOMPATIBLE KIDNEY TRANSPLANTATION]

INTRODUCTION

With the introduction of new therapies, the ABO barrier for kidney transplantation has been breached. In the recent decade the reported results with ABO incompatible (ABOi) kidney transplantation are similar to ABO compatible transplantation. We report on our initial experience with ABOi kidney transplantation performed at the Rabin Medical Center.

METHODS

During the period 3/2010 to 4/2015, 22 patients with PRA 0% underwent ABOi living-donor kidney transplantation. This group was compared to 325 non-sensitized live-donor transplant recipients of ABO-match transplants performed at the same period. The desensitization protocol included rituximab (375mg/kg/m2) and three sets of plasmapheresis every other day with IVIG (0.5g/kg) after each plasmapheresis. We compared graft and patient survivals, antibody mediated rejection (AMR) and graft function between the two groups.

RESULTS

Graft survival rates at 1, 3 and 5 years in the ABOi group were 95.5% at all intervals and 99.4% for the 1st year and 97.9% at 3 and 5 years after transplant (p=ns). Patient survival rates were 100% at all intervals and 100%, 98.3% and 97.5% at 1,3, and 5 years (p=ns). Two patients (9.1%) in the ABOi group experienced antibody mediated rejection (AMR), one lost his graft. In the ABO-matched group only two patients (0.85%) experienced AMR (p<0.05). Creatinine levels at followup were not statistically different between the groups.

CONCLUSIONS

ABO incompatible kidney transplantation provides an additional option for transplant with excellent results. Strict monitoring of antibody levels should be conducted after ABOi transplantation to timely intervene and prevent AMR.

Serum Lactate Dehydrogenase is Elevated in Ischemic Acute Tubular Necrosis but Not in Acute Rejection in Kidney Transplant Patients

Background:

Serum lactate dehydrogenase (LDH) levels may help to distinguish ischemic acute tubular necrosis (ATN) from acute rejection after kidney transplantation.

Methods:

All kidney biopsies performed in the years 2010 to 2012 were reviewed. Serum LDH, creatinine level, clinical variables, and presence of donor-specific antibodies were recorded before the biopsy.

Results:

Overall 150 biopsies were included. Ischemic ATN was diagnosed in 45 biopsies and acute cellular-mediated rejection and/or antibody-mediated rejection in 59 biopsies, 38 of which were accompanied by ATN. Serum LDH was elevated in 23 (51%) of 45 cases with ischemic ATN versus 15 (14%) of 105 cases with other diagnoses ( P < .0001). Median serum LDH was 478 U/L (range 277-2018) for ischemic ATN and 372 U/L (range 191-748) for all other diagnoses ( P < .001). When delayed graft function or primary nonfunctioning grafts were caused by ischemic ATN, serum LDH was elevated in 58% of cases, but when caused by acute rejection, LDH was normal in 88% of cases ( P = .02).

Conclusions:

There is a strong association between elevated serum LDH 1 to 3 days before performing kidney biopsy and the diagnosis of ischemic ATN after kidney transplantation, especially at the immediate posttransplantation period. Normal serum LDH at this period should raise a suspicion of acute rejection.

Prevalence and clinical characteristics of adrenal incidentalomas in potential kidney donors

BACKGROUND

The prevalence of adrenal incidentalomas (AIs) in asymptomatic individuals is unknown. This study evaluated the prevalence of AIs in healthy kidney donors in whom pre-operative computed tomography (CT) is performed routinely.

METHODS

All potential kidney donors evaluated at the Rabin Medical Center who had routine abdominal CT were identified and their medical records were retrospectively reviewed. Subjects who had normal CT scans were compared with those with a finding of an AI, evaluating demographic (age, body mass index, systolic and diastolic blood pressure) and laboratory variables (glucose, sodium, potassium, calcium, phosphorus, albumin and creatinine). In addition, prevalence of hypertension, rate of donation and surgical mortality were compared between the two groups.

RESULTS

CT was performed in 673 potential kidney donors. Of these, 645 had a normal CT and 28 (4.2%) had evidence of an AI. Those with AIs had a similar prevalence of hypertension, kidney donation and surgical mortality as those with a normal CT. Those with AIs were older (50.93 ± 11.1 versus 43.76 ± 11.1 years) but other demographic variables were similar; laboratory variables were also similar except for slightly lower albumin and creatinine in those with AIs.

CONCLUSIONS

The prevalence of AIs is high even in healthy asymptomatic individuals.

The impact of the israeli transplantation law on the socio-demographic profile of living kidney donors

The Israeli transplantation law of 2008 stipulated that organ trading is a criminal offense, and banned the reimbursement of such transplants by insurance companies, thus decreasing dramatically transplant tourism from Israel. We evaluated the law's impact on the number and the socio-demographic features of 575 consecutive living donors, transplanted in the largest Israeli transplantation center, spanning 5 years prior to 5 years after the law's implementation. Living kidney donations increased from 3.5 ± 1.5 donations per month in the pre-law period to 6.1 ± 2.4 per month post-law (p < 0.001). This was mainly due to a rise in intra-familial donations from 2.1 ± 1.1 per month to 4.6 ± 2.1 per month (p < 0.001). In unrelated donors we found a significant change in their socio-demographic characteristics: mean age increased from 35.4 ± 7.4 to 39.9 ± 10.2 (p = 0.001), an increase in the proportion of donors with college level or higher education (31.0% to 63.1%; p < 0.001) and donors with white collar occupations (33.3% to 48.3%, p = 0.023). In conclusion, the Israeli legislation that prohibited transplant tourism and organ trading in accordance with Istanbul Declaration, was associated with an increase in local transplantation activity, mainly from related living kidney donors, and a change in the profile of unrelated donors into an older, higher educated, white collar population.

Haemoglobin variability in the early post-transplant period: association with graft survival and mortality

AIM

Haemoglobin (Hb) variability is associated with poor survival in patients with chronic kidney disease. Association of Hb variability after kidney transplantation with patients' and graft survival has not been adequetly studied.

METHODS

This retrospective study used registry data to examine the association between Hb variability in the early post-transplant period (first 6 months) and graft survival after kidney transplantatin. Kaplan-Meier and Cox regression analyses were used for univariate and multivariate associations between mortality, death censored graft survival and the composite outcome of both, in 752 patients after kidney transplantation. Hb values were collected each month during the first 6 months after transplantation, and Hb variavility was calculated using the residual standard deviation method.

RESULTS

The highest quartile of Hb variability was associated with inferior graft and patients' survival in univariate (hazard ratio (HR) 2.18; 95% confidence interval (CI) 1.51 to 3.13; P < 0.001) and multivariate models (HR 1.5; 95% CI 1.029 to 2.18; P = 0.035). This association was mainly due to increased death censored graft failure in the high variability group (HR 2.75; 95% CI 1.73 to 4.38; P < 0.001) and (HR 1.67; 95% CI 1.023 to 2.74; P = 0.04) in the univariate and multivariate models, respectively. There was no association between Hb variability and the risk of death (HR 1.51; 95% CI 0.88 to 2.57; P = 0.132).

CONCLUSION

High Hb variability is independently associated with inferior graft survival in patients after kidney transplantation.

[Pathology of organ transplantation: experience of the Rabin Medical Center]

Solid organ transplantation is currently the treatment of choice for renal, heart, and pancreas insufficiency and selected bowel diseases. Thanks to advances in medical technology, the lifespan of transplanted organs is currently about 10 years. To prevent graft rejection, patients need to take immunosuppressive drugs, usually for the rest of their Lives. Pathologists play a crucial role in organ transplantation. They are responsible for recognizing allograft rejection, both acute and chronic, differentiating rejection from drug toxicity, and identifying recurrent disease. In addition, pathologists identify new diseases in the graft, opportunistic infections in the transplanted organ or other organs, and the development of malignant tumors, which are more common in immunocompromised patients. Accordingly, transplant pathologists require a wide range of knowledge in many complex laboratory techniques, such as immunofluorescence, electron microscopy, immunohistochemical analysis, and molecular pathology. These tests are performed in dedicated Laboratories in departments of pathology. TranspLant pathology is an inseparable part of the field of transplantation medicine and greatly assists clinicians in the diagnosis of disease processes in transplanted organs and in the selection of appropriate treatment.

Sequential liver and kidney transplantation from a single living donor in two young adults with primary hyperoxaluria type 1

Using living donor organs for sequential liver and kidney transplantation (SeqLKT) in patients with primary hyperoxaluria type 1 (PH1) has emerged as a viable approach. Taking both organs from a single donor, however, is rare. There are 8 reported cases of SeqLKT in the literature, and in all but 1 case, children were the recipients. We present our experience with SeqLKT in 2 young adults with PH1. In the first case, with an interval between procedures of 4.5 months, SeqLKT was performed with a right liver lobe from a 47-year-old father for his 19-year-old son with PH1 who was on dialysis for 2 years before transplantation. Both the donor and the recipient had an uneventful recovery, although there was re-exploration for the control of bleeding in the recipient after liver transplantation. Thirty-three months after transplantation, the patient had normal liver and renal function. In the second case, with an interval between procedures of 22 days, SeqLKT was performed with organs from a 45-year-old father for his 19-year-old daughter with PH1 who was on dialysis for 8 months. The recipient procedures, including right liver lobe transplantation and kidney transplantation, were uneventful. The donor underwent percutaneous drainage of a subphrenic collection and subsequently fully recovered. Eighteen months after transplantation, the recipient's liver and renal allograft function was normal. In conclusion, because of the severe organ shortage, living related SeqLKT using the same donor should be carefully considered for young adults with PH1.

Post-transplantation lymphoproliferative disorder in pediatric kidney-transplant recipients - a national study

PTLD is the most common malignancy in pediatric kidney-transplant recipients. We examined the prevalence, clinical features, and outcome of PTLD in Israel. Twelve (4.4%) of 272 pediatric (<19 yr) kidney-transplant recipients retrieved from a search of the NIKTR for 1991-2008 had acquired PTLD at a median of 3.2 yr post-transplantation. PTLD-affected patients were younger at transplantation (4.2 vs. 12.5 yr, p = 0.02), had a higher rate of OKT3 therapy for acute rejection (25% vs. 4%, p = 0.015), and 5/12 were EBV-seropositive at transplantation. Graft dysfunction was the presenting sign in six (50%). PTLD was predominantly abdominal (83%) and B-cell type (67%); T-cell PTLD occurred exclusively in EBV-seropositive patients. Treatment consisted of immunosuppression cessation (6/12, 50%), antiviral agents (7/12, 58%), anti-CD20 monoclonal antibodies (4/12, 33%), and chemotherapy (6/12, 50%). Survival was 100% in the EBV-naïve patients and 40% in the EBV-seropositive patients. Graft loss occurred in three of eight survivors (37.5%). PTLD-associated mortality risk was older age: 11.2 vs. 3.4 yr, longer dialysis: 15 vs. 6.5 months, T-cell type disease (75%), later PTLD onset: 6.35 vs. 1.9 yr post-transplantation and era of transplantation (43% mortality before vs. 20% after 2001). Pretransplantation EBV-seronegative status might confer a survival benefit with early detected PTLD. EBV-seropositive patients are at risk for aggressive late-onset lethal PTLD.