Elevated hemoglobin levels in renal transplant recipients with polycystic kidney disease versus other etiologies: exploring mechanisms and implications for outcomes

BACKGROUND

Autosomal dominant polycystic kidney disease (ADPKD)-related end-stage kidney disease (ESKD) often necessitates transplantation. However, the impact of ADPKD on post-transplant outcomes, specifically hemoglobin levels, remains unknown.

METHODS

We retrospectively analyzed 513 Kidney Transplant Recipients (KTRs), of whom 81 had ESKD due to ADPKD (20 with pre-transplant native nephrectomy and 61 without). Hemoglobin levels were evaluated at multiple time intervals post-transplant.

RESULTS

Kidney transplant recipients with ADPKD vs. KTRs with ESKD due to other causes exhibited significantly higher hemoglobin levels in repeated measurement analysis. Multivariable analyses confirmed ADPKD as an independent predictor for elevated hemoglobin levels. In a multivariable logistic regression analysis, the odds for maximum hemoglobin > 15 mg/dL at 3-12 months post-transplant were more than twice as high in ADPKD patients vs. all the other KTRs (Odds Ratio [OR] 2.31, 95% Confidence Interval [CI] 1.3-4.13, p < 0.001). Pre-transplant native nephrectomy revealed a trend toward lower hemoglobin levels. Elevated hemoglobin levels were linked to improved estimated glomerular filtration rate (eGFR) at one year post-transplant. Patient survival was enhanced among KTRs with ADPKD compared to other ESKD causes.

CONCLUSIONS

Kidney transplant recipients with ADPKD exhibited elevated hemoglobin levels post-transplant, possibly due to prolonged native kidney erythropoietin production. These elevated hemoglobin levels were linked to improved outcomes, including allograft function and patient survival. Future research should further investigate the underlying mechanisms driving favorable ADPKD KTR outcomes.

The Impact of the Donor Card Holder Prioritization Program on Kidney Allocation in Israel

BACKGROUND

Since 2014, as part of a priority program within the Israeli Transplant Law, additional points were given to waitlisted candidates with donor cards. We assessed the impact on deceased donor kidney allocation.

METHODS

This study enrolled all patients older than 18 y who underwent deceased donor kidney transplantation (January 2016-December 2019). Data were obtained from the National HLA Tissue Laboratory registry at the Sheba Medical Center. Patients were grouped by donor card status (ADI group) (not signed, 0 points; relative signed, 0.1 points; patient signed, 2 points; and relative donated, 9 points). The primary outcome was waiting time until kidney transplantation with and without the additional score.

RESULTS

Four hundred forty-four patients underwent kidney transplantation during the study period: 281 (63%) were donor card holders (DCH) and 163 (37%) were not DCH. DCH with extra points waited 68.0 (±47.0) mo on average, compared with 94.6 (±47.3) mo for not DCH (P < 0.001). Donor card signers had a shorter time until transplant in a multivariable model. Without extra points, 145 recipients (32.6%) would have missed organs allocated to higher-scored candidates. Allocation changes occurred in 1 patient because of an additional 0.1 points, in 103 candidates because of an additional 2 points, and in 41 candidates because of an additional 9 points.

CONCLUSIONS

Additional DCH scores improved allocation and reduced waiting time for donor card signers and those with donating relatives. To enhance fairness, consideration should be given to reducing the score weight of this social criterion and raising scores for other factors, especially dialysis duration.

Assessing Health-Related Quality of Life in Non-Directed Versus Directed Kidney Donors: Implications for the Promotion of Non-Directed Donation

Living kidney donation has increased significantly, but little is known about the post-donation health-related quality of life (HRQoL) of non-directed donors (NDs) vs. directed donors (DDs). We thus examined the outcomes of 112 living kidney donors (82 NDs, 30 DDs). For the primary outcomes-namely, the mean physical component summary (PCS) and mental component summary (MCS) scores of the 12-item Short Form Survey (SF-12) questionnaire-scores were significantly higher for the NDs vs. the DDs (PCS: +2.69, MCS: +4.43). For secondary outcomes, NDs had shorter hospital stays (3.4 vs. 4.4 days), returned to physical activity earlier (45 vs. 60 days), exercised more before and after donation, and continued physical activity post-donation. Regression analyses revealed that donor type and white blood cell count were predictive of the PCS-12 score, and donor type was predictive of the MCS-12 score. Non-directed donation was predictive of a shorter hospital stay (by 0.78 days, p < 0.001) and the odds of having PCS-12 and MCS-12 scores above 50 were almost 10 and 16 times higher for NDs, respectively (p < 0.05). These findings indicate the safety and potential benefits of promoting non-directed donation. However, careful selection processes must be maintained to prevent harm and exploitation.

[ORGAN TRANSPLANT HISTORY IN ISRAEL]

INTRODUCTION

Organ transplantation is an innovative field that was pioneered in the middle of the last century with the development of surgical techniques, advances in the understanding of immunological processes that cause rejection, introduction of drugs to prevent rejection and improved methods for organ preservation. In Israel, the first heart transplantation and kidney transplantation were performed in the mid-1960's followed by pancreas, lung and liver transplantation that were conducted for the first time in the late 1980's and early 1990's. The significant change that has led to an increase in the number of transplants in Israel and rising success rates after transplant has occurred with the introduction of the new generation of anti-rejection drugs, Cyclosporine and subsequently Tacrolimus (Prograf ®). Another milestone was the founding of The National Transplant Center in 1994. This led to the formation of national transplant candidate lists for each organ, the establishment of professional committees that determine organ allocation policy and the creation of a governmental ethics committee to oversee the performance of live-donor transplantation. In 2008, about a month before the signing of the Istanbul Declaration, the Transplantation Law was enacted to regulate organ transplantation in Israel, which included clauses restricting organ trade in the spirit of the Istanbul Declaration. These measures increased the number of transplants performed in Israel and significantly reduced the number of transplants of Israelis abroad. The establishment of Matanat Chaim Organization in 2012 is another milestone that has led to a significant increase in the number of kidney transplants, most of which are currently performed from altruistic donations. However, today there is still a shortage of organs for transplantation from deceased donors and there is a long way to go to close the gap between organ need and supply. This review will indicate the introduction of the first transplants performed in Israel and the measures undertaken to increase the number of transplants. In addition, the review will note the laws and regulations of organ allocation.

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.

The Clinical Manifestation of Immunosuppressive Therapy as a Tool to Improve Immune Monitoring in Renal Transplant Recipients

INTRODUCTION

Metrics for posttransplant immune monitoring to prevent over or under immunosuppression in renal transplant recipients (RTRs) are lacking.

METHODS

We surveyed 132 RTRs, 38 in the first year posttransplant and 94 >1-year posttransplant, to study the clinical expression of immunosuppressive therapy. A questionnaire administered to these RTRs was divided into physical (Q physical) and mental (Q mental) symptoms.

RESULTS

In multivariable models for the association between the calculated Q physical and Q mental scores and different clinical and biochemical variables in the 38 RTRs who filled out the questionnaire 130 times during the first year posttransplant, it was found that mycophenolic acid (MPA) and prednisone use increased the mean Q physical score by 0.59 (95% CI: 0.21-0.98, p = 0.002) and 0.53 (95% CI: 0.26-0.81, p = 0.00), respectively, while MPA use increased the mean Q mental score by 0.72 (95% CI: 0.31-1.12, p = 0.001). Among the 94 RTRs who each completed the questionnaire only once, the odds for the mean Q mental score to be above the median value were more than 3 times higher for RTRs treated versus non-treated with MPA (OR 3.38, 95% CI: 1.1-10.3, p = 0.03). MPA-treated RTRs had higher mean scores for questions related to sleep disorders (1.83 ± 1.06 vs. 1.32 ± 0.67 for not treated, p = 0.037), to difficulty falling asleep (1.72 ± 1.11 vs. 1.16 ± 0.5, p = 0.02), and to depression and anxiety.

CONCLUSION

We concluded that prednisone and MPA use are associated with an increased Q physical and Q mental scores in RTRs. Routine monitoring of physical and mental status of RTRs should be implemented to improve the diagnosis of overimmunosuppression. Dose reduction or discontinuation of MPA should be considered in RTRs who report sleep disorders, depression, and anxiety.

Predictors and Adverse Outcomes of Acute Kidney Injury in Hospitalized Renal Transplant Recipients

Data about in-hospital AKI in RTRs is lacking. We conducted a retrospective study of 292 RTRs, with 807 hospital admissions, to reveal predictors and outcomes of AKI during admission. In-hospital AKI developed in 149 patients (51%). AKI in a previous admission was associated with a more than twofold increased risk of AKI in subsequent admissions (OR 2.13, p &lt; 0.001). Other major significant predictors for in-hospital AKI included an infection as the major admission diagnosis (OR 2.93, p = 0.015), a medical history of hypertension (OR 1.91, p = 0.027), minimum systolic blood pressure (OR 0.98, p = 0.002), maximum tacrolimus trough level (OR 1.08, p = 0.005), hemoglobin level (OR 0.9, p = 0.016) and albumin level (OR 0.51, p = 0.025) during admission. Compared to admissions with no AKI, admissions with AKI were associated with longer length of stay (median time of 3.83 vs. 7.01 days, p &lt; 0.001). In-hospital AKI was associated with higher rates of mortality during admission, almost doubled odds for rehospitalization within 90 days from discharge and increased the risk of overall mortality in multivariable mixed effect models. In-hospital AKI is common and is associated with poor short- and long-term outcomes. Strategies to prevent AKI during admission in RTRs should be implemented to reduce re-admission rates and improve patient survival.

Humoral Response to the Fourth BNT162b2 Vaccination and Link Between the Fourth Dose, Omicron Infection, and Disease Severity in Renal Transplant Recipients

BACKGROUND

The effectiveness of the fourth BNT162b2 vaccination in reducing the rate and severity of coronavirus disease 2019 (COVID-19) caused by the Omicron variant in renal transplant recipients (RTRs) is unknown.

METHODS

Interviews were conducted with 447 RTRs regarding the status and timing of the fourth vaccination, prior vaccinations, and preceding COVID-19 infection. RTRs with polymerase chain reaction-confirmed COVID-19 infection from December 1, 2021, to the end of March 2022 were considered to have been infected with the Omicron variant and were interviewed to determine their disease severity. In a subgroup of 74 RTRs, the humoral response to the fourth dose was analyzed. In 30 RTRs, microneutralization assays were performed to reveal the humoral response to wild-type, Delta, and Omicron variant isolates before and after the fourth dose.

RESULTS

Of 447 RTRs, 144 (32.2%) were infected with the Omicron variant, with 71 (49.3%) of the infected RTRs having received the fourth vaccine dose. RTRs who did not receive the fourth dose before the infection had more serious illness. In a subgroup of 74 RTRs, the fourth dose elicited a positive humoral response in 94.6% (70/74), with a significant increase in geometric mean titer for receptor-binding domain immunoglobulin G and neutralizing antibodies ( P  < 0.001). The humoral responses to the Omicron variant before and after the fourth dose were significantly lower than the responses to the wild-type and the Delta variants.

CONCLUSIONS

Overall, the fourth BNT162b2 dose was effective in reducing the rate and severity of Omicron disease in RTRs, despite the reduced humoral response to the variant.

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.

BNT162b2 Third Booster Dose Significantly Increases the Humoral Response Assessed by Both RBD IgG and Neutralizing Antibodies in Renal Transplant Recipients

Background: An impaired humoral response to full dose of BNT162b2 vaccine was observed in renal transplant recipients (RTR).

Methods: To reveal predictors for humoral response to third vaccine, patients were stratified to positive (N = 85) and negative (N = 14) response groups based on receptor-binding domain (RBD) IgG ≥1.1 and neutralizing antibodies (NA) ≥ 16 dilution versus RBD IgG <1.1 or NA < 16, respectively. NA were detected using a SARS-CoV-2 pseudo-virus.

Results: Response rate increased from 32.3% (32/99) before the third dose to 85.9% (85/99) post-third vaccine with a significant rise in geometric mean titers (GMTs) for RBD IgG and NA [0.79 (95% CI 0.65–0.96) vs. 3.08 (95% CI 2.76–3.45), p < 0.001 and 17.46 (95% CI 12.38–24.62) vs. 362.2 (95% CI 220.7–594.6), p < 0.001 respective. 80.6% (54/67) seroconverted and 96.9% (31/32) remained positive following the vaccine with a significant increase in GMTs for RBD IgG and NA. Age, ESRD secondary to diabetic nephropathy (DN) and renal allograft function were independent predictors for antibody response in RTR. Mycophenolic acid (MPA) use and dose had no impact on humoral response following the third booster. AEs were recorded for 70.1% of RTR population. Systemic AEs were more common in recipients with a positive humoral response as opposed to non-responders (45.2% versus 15.4% respectively, p = 0.04).

Conclusion: 85.9% of RTR develop NA to BNT162b2 third vaccine, found effective in both negative and positive responders prior to the vaccine. Antigenic re-exposure overcame the suppressive effect of MPA on antibody response in RTR.

The Effect of Priority Given to Donor Card Holders on the Allocation of Livers for Transplant-Evidence From 7 Years of the Israeli Priority Program

BACKGROUND

The Israeli Transplant Law grants priority in organ allocation to patients signing a donor card. Liver transplant candidates get additional 2 points on their Model for End Stage Liver Disease score for signing a donor card, 0.1 points for a relative holding a card, and 5 points if a relative donated an organ. We studied the effect of the priority program on waiting list mortality and allocation changes due to priority.

METHODS

Using Israeli Transplant data of 531 adult liver transplant candidates with chronic liver disease listed between 2012 and 2018 we compared waitlist mortality and transplant rate of candidates with and without priority. Then we analyzed liver allocations resulting from additional priority points and followed outcome of patients who were skipped in line.

RESULTS

Of the 519 candidates, 294 did not sign a donor card, 82 signed, 140 had a relative sign, and for 3, a relative donated an organ. The rates of waitlist mortality in these 4 groups were 22.4%, 0%, 21.4%, and 0%, respectively, and the transplant rates were 50%, 59.8%, 49.3%, and 100%, respectively. Of the 30 patients who were skipped because of priority, 24 subsequently underwent transplant, 2 are on the waiting list, and 4 died within 0.75, 1.75, 7, and 17 mo.

CONCLUSIONS

The 2 points added to the Model for End Stage Liver Disease score were associated with lower waitlist mortality and higher transplant rate for candidates signing a donor card without significantly affecting access to transplant during allocation. Further research and consideration of optimal policy when granting priority for candidates signing a donor card should continue.

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.

Humoral Response of Renal Transplant Recipients to the BNT162b2 SARS-CoV-2 mRNA Vaccine Using Both RBD IgG and Neutralizing Antibodies

BACKGROUND

Data about SARS-CoV-2 vaccines efficacy in renal transplant recipients (RTR) are lacking.

METHODS

To reveal predictors for humoral response to BNT162b2 vaccine among RTR, patients were divided into positive (N = 42) and negative (N = 78) response groups based on receptor-binding domain (RBD) immunoglobulin G (IgG) ≥1.1 and neutralizing antibodies (NA) ≥16 dilution versus RBD IgG <1.1 or NA <16, respectively. NA were detected using a SARS-CoV-2 pseudo-virus.

RESULTS

NA were detected in only 42 of 120 (35%) of RTR versus 197 of 202 (97.5%) immunocompetent controls (P < 0.001). NA geometric mean titers in RTR were significantly lower versus the control group {83.7 (95% confidence interval [CI], 50.5-138.8) versus 482 (95% CI, 411-566), P < 0.001}. In a multivariable analysis, mycophenolic acid (MPA) dose and hemoglobin level were found to be independent predictors for antibody response in RTR. A positive response rate of 27% versus 63% was observed in patients on and off MPA, respectively. An increase in MPA dose by 1 mg/kg weight reduced the odds for a positive response by 17% (odds ratio = 0.83; 95% CI, 0.75-0.92; P < 0.001). Geometric mean titers for RBD IgG were significantly reduced as MPA daily dose increased. Hemoglobin blood level <13 g/dL reduced the antibody response by 63% (P = 0.04). Pain at the injection site after the second vaccine dose was significantly higher in the responders versus nonresponders (20.5% versus 5.5%, P = 0.01).

CONCLUSIONS

Only 35% of RTR develop NA to the BNT162b2 mRNA vaccine. MPA is a major suppressor of antibody response in RTR.

BNT162b2 mRNA COVID-19 vaccination in immunocompromised patients: A prospective cohort study

BACKGROUND

Trials of the Pfizer-BioNTech BNT162b2 mRNA vaccine showed 95% efficacy in preventing symptomatic disease; however, the trials excluded immunocompromised patients (ICPs). We aim at analyzing antibody response in ICPs.

METHODS

A prospective cohort study was conducted at Sheba Medical Center, Israel, between January and April 2020, in 1274 participants who received the vaccine, including 1002 ICPs and 272 immunocompetent healthcare workers (HCWs). Antibodies were measured two-four weeks after vaccination by SARS-CoV-2 anti-receptor binding domain IgG antibodies (RBD IgG) and pseudo-virus neutralization assays. Multivariable logistic regression analyses were used to identify factors associated with vaccine-induced antibody response. Adverse events (AEs) were monitored.

FINDINGS

RBD-IgG antibodies were detected in 154/156 (98.7%) of patients with HIV, 75/90 (83.3%) with solid malignancies, 149/187 (79.7%) with myeloma, 83/111 (74.8%) following hematopoietic stem cell transplants, 25/36 (69.4%) following liver transplantation, 26/43 (60.5%) with myelodysplastic syndrome, 96/188 (51.0%) with chronic lymphocytic leukemia/non-Hodgkin's lymphoma, 50/110 (45.5%) following kidney transplantation, 15/80 (18.8%) following heart transplantation, and 269/272 (98.9%) in controls. There was a significant correlation r = 0.74 (95%CI 0.69,0.78) between RBD-binding IgG and neutralizing antibodies in all groups. Multivariate logistic regression analysis showed that age > 65 years (OR 0.41,95%CI 0.30,0.57) and underlying immunosuppression (OR 0.02,95%CI 0.01,0.07) were significantly associated with a non-reactive response of IgG antibodies. HIV patients showed a similar immunological response as healthy adults. The vaccine was safe without any episodes of rejection, graft-versus-host disease (GVHD) or allergy. Immunocompetent HCWs experienced significantly more AEs than ICPs.

INTERPRETATION

Antibody response to the Pfizer-BioNTech vaccine was highly variable among different ICPs; thus, individual recommendations should be provided for the different immunosuppression states.

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).

Can uric acid blood levels in renal transplant recipients predict allograft outcome?

Background

Hyperuricemia is common after renal transplantation, especially in those receiving calcineurin inhibitors. Little, however, is known about the relationship between uric acid (UA) levels and allograft outcome.

Methods

We conducted a retrospective single-center analysis (N = 368) in order to assess UA blood levels post-transplant association with allograft outcome. For this study, a median serum UA level of all measured UA levels from 1 month to 1 year post renal transplantation was calculated.

Results

Patients were divided into 2 groups based on the median UA level measured between 1 and 12 months post-transplant. Those with median UA level ≥ 7 and ≥ 6 mg/dL (N = 164) versus median UA level < 7 and < 6 mg/dL for men and women respectively (N = 204) had lower GFR values at 1, 3 and 5 years posttransplant (mean GFR ± SD of 43.4 ± 20.6 and 58 ± 19.9 at 3 years post-transplant, p < 0.001). In multivariate models, UA levels were no longer significantly associated with renal allograft function. In a multivariate cox proportional hazard model, UA level was found to be independently associated with increased risk for death-censored graft loss (HR of 1.3, 95% CI 1.0–1.7, p < 0.05 for every increase of 1 mg/dL in UA level).

Conclusion

Hyperuricemia was found to be associated with increased death- censored graft loss but not with allograft function. Increased UA levels were not found to be an independent predictor of long-term allograft function despite the known association of hyperuricemia with the progression of cardiovascular and renal disease.

Long-term outcomes during 37 years of pediatric kidney transplantation: a cohort study comparing ethnic groups

BACKGROUND

This study aimed to evaluate short- and long-term outcomes of kidney transplantation over 37 years in a national referral center and compare outcomes between Israeli Jewish and Arab children.

METHODS

Data on 599 pediatric transplantations performed in 545 children during 1981-2017, including demographic parameters, kidney failure disease profile, and pre-transplant dialysis duration, were retrieved from our computerized database and patient files. Patient and graft survival were estimated using the Kaplan-Meier method.

RESULTS

Twenty-year patient survival was 91.4% for live donor (LD) and 80.2% for deceased donor (DD) kidney recipients. Respective 10-year and 20-year graft survival rates for first kidney-only transplants were 75.2% and 47.0% for LD and 60.7% and 38.4% for DD grafts. Long-term graft survival improved significantly (p < 0.001) over the study period for recipients of both LD and DD allografts and reached 7-year graft survival of 92.0% and 71.3%, respectively. The proportion of DD transplantations was higher in the Arab subpopulation: 73.8% vs. 48.4% (p < 0.001). Graft survival was not associated with age at transplantation and did not differ between the Arab (N = 202) and Jewish children (N = 343). Median (IQR) waiting time on dialysis did not differ significantly between the Arab and Jewish children: 18 (10-30) and 15 (9-30) months, respectively (p Mann-Whitney = 0.312).

CONCLUSIONS

Good and progressively improving long-term results were obtained in pediatric kidney transplantation at our national referral center, apparently due to expertise gained over time and advances in immunosuppression. Equal access to DD kidney transplant and similar graft survival were found between ethnic groups.

Generation of vascular chimerism within donor organs

Whole organ perfusion decellularization has been proposed as a promising method to generate non-immunogenic organs from allogeneic and xenogeneic donors. However, the ability to recellularize organ scaffolds with multiple patient-specific cells in a spatially controlled manner remains challenging. Here, we propose that replacing donor endothelial cells alone, while keeping the rest of the organ viable and functional, is more technically feasible, and may offer a significant shortcut in the efforts to engineer transplantable organs. Vascular decellularization was achieved ex vivo, under controlled machine perfusion conditions, in various rat and porcine organs, including the kidneys, liver, lungs, heart, aorta, hind limbs, and pancreas. In addition, vascular decellularization of selected organs was performed in situ, within the donor body, achieving better control over the perfusion process. Human placenta-derived endothelial progenitor cells (EPCs) were used as immunologically-acceptable human cells to repopulate the luminal surface of de-endothelialized aorta (in vitro), kidneys, lungs and hind limbs (ex vivo). This study provides evidence that artificially generating vascular chimerism is feasible and could potentially pave the way for crossing the immunological barrier to xenotransplantation, as well as reducing the immunological burden of allogeneic grafts.

Long-term outcomes of Roux-en-Y gastric bypass or sleeve gastrectomy in patients with cirrhosis; before, during or after liver transplantation: A single center's experience

BACKGROUND

The increasing prevalence of morbid obesity (MO) results in parallel growth of obesity-associated liver diseases necessitating liver transplantation (LT).

OBJECTIVE

To examine the feasibility and safety of Roux-en-Y gastric bypass or sleeve gastrectomy in the setting of LT.

METHODS

This retrospective chart review included the data on all the MO candidates before and after LT who underwent bariatric surgery (BS) in our institution between 04/2013-09/2016. The reported outcomes were weight change and early and late postoperative complications (mean follow-up: 43 ± 11.1 months).

RESULTS

Eighteen MO peri-LT patients (10 females, 8 males, average age 48 years) were included in the study. Ten had cirrhosis (mean Model of End-stage Liver Disease [MELD] score of 12.5 ± 6.42), three underwent concurrent LT and BS (mean MELD score 23.7 ± 0.58), and five had LT (mean of 56 months from LT). The mean percentage of total and excess weight loss was 31% and 81%, respectively. Six of the eight patients with type 2 diabetes mellitus became normoglycemic after BS. Three patients sustained perioperative complications. Two cirrhotic patients died 1 and 4.5 years after BS with decompensation.

CONCLUSIONS

Bariatric surgery appears to effectively address obesity in cirrhotic and LT patients. The surgical risk is higher than that of the regular BS population.

Impact of "critical lesions" on outcomes following cytoreductive surgery and hyperthermic intra-peritoneal chemotherapy

BACKGROUND

Peritoneal Cancer Index (PCI) and complete cytoreduction are the best outcome predictors following cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC). Lesions in critical areas, regardless of PCI, complicate surgery and impact oncological outcomes. We prospectively defined "Critical lesions" (CL) as penetrating the hepatic hilum, diaphragm at hepatic outflow, major blood vessels, pancreas, or urinary tract.

METHODS

Retrospective analysis of a prospective database of 352 CRS + HIPEC patients from 2015 to 2019. Excluded patients with aborted/redo operation (n = 112), or incomplete data (n = 19). Patients categorized by CL status and compared: operative time, estimated blood loss (EBL), PCI, transfusions, hospital stay, post-operative complications and mortality, overall survival (OS) and disease-free survival (DFS).

RESULTS

Included 221 patients (78 CL; 143 no-CL). No difference in patients' characteristics: age, BMI, gender or co-morbidities noted. Operative time longer (5.3 h vs 4.3 h, p < 0.01), EBL higher (769 ml vs 405 ml, p < 0.01), transfusions higher (1.9 vs 0.7 Units, p < 0.001) and PCI higher (15.5 vs 9.5, p < 0.01) in CL. No difference in major complications. Postoperative complications, CL, OR-time and transfusions were predictive of OS in univariate analysis, while only complications remained on multivariate analysis. Median follow up of 21.4 months, 3-year DFS/OS was 22% vs 30% (p < 0.037) and 73% vs 87% (p < 0.014) in CL and non-CL, respectively. Despite CL complete resection, 17/38 patients (44.7%) that recurred had recurrence at previous CL site.

CONCLUSIONS

Critical lesions complicate surgery and may be associated with poor oncological outcomes with high local recurrence rate, despite no significant difference in complications. Utilizing adjuvant or intra-operative radiation may be beneficial.

Early persistent hyperparathyroidism post-renal transplantation as a predictor of worse graft function and mortality after transplantation

BACKGROUND

Persistent hyperparathyroidism (pHPT) is frequently seen after transplantation contributing to post-transplant complications.

METHODS

We conducted a retrospective single center analysis to explore the relationship of early pHPT and long-term allograft outcome. Patients were divided into high (N = 153) and low (N = 252) PTH groups based on serum parathyroid hormone (PTH) level 3 months post-transplant (PTH ≥ 150 and < 150 pg/mL, respectively).

RESULTS

High PTH was found to be an independent predictor for reduced kidney allograft function up to 3 years post-transplant. eGFR decreased by 11.4 mL/min (P < .001) and the odds of having an eGFR < 60 mL/min 3 years post-transplant were sixfold higher (P < .01) in the high compared to the low PTH group. Subgroup analysis based on eGFR 1 year post-transplant, presence of slow graft function (SGF), and transplant type revealed similar results. High PTH three months post-transplant was also independently associated with an increased risk for overall mortality and for death with a functioning graft (P < .05).

CONCLUSIONS

pHPT three months post-renal transplantation is an independent predictor for a worse allograft function up to 3 years post-transplant and a risk factor for mortality. This relationship remains statistically significant after accounting for baseline allograft function, presence of SGF and serum mineral levels abnormalities.

Wound healing adverse events in kidney transplant recipients receiving everolimus with reduced calcineurin inhibitor exposure or current standard-of-care: insights from the 24-month TRANSFORM study

OBJECTIVES

In TRANSFORM, de novo kidney transplant recipients received either everolimus in combination with reduced-exposure calcineurin inhibitor (EVR+rCNI) at standard EVR pre-dose concentrations of 3-8 ng/mL or mycophenolic acid plus standard-exposure CNI (MPA+sCNI). The authors analyzed the incidence of wound healing adverse events (WHAEs) over the 2-year study period 15.

METHODS

Patients were randomized to either EVR+rCNI or MPA+sCNI, both combined with induction therapy and steroids 19.

RESULTS

The safety population consisted of 2,026 patients (EVR+rCNI: 1,014, MPA+sCNI: 1,012). The proportion of patients with at least 1 WHAE was comparable between EVR+rCNI and MPA+sCNI treatment groups [20.6% vs. 17.3%; risk ratio (RR): 1.19; 95% confidence interval (CI): 0.99, 1.43] at month 24. The numerical difference between EVR+rCNI and MPA+sCNI was mainly caused by an increased proportion of EVR patients with lymphocele and wound dehiscence [7.5% vs. 5.1% (RR: 1.46; 95% CI: 1.04, 2.05) and 3.9% vs. 1.8% (RR: 2.22; 95%CI: 1.28, 3.84), respectively] 20.

CONCLUSION

The immediate introduction of EVR+rCNI after kidney transplantation was associated with an overall comparable incidence of WHAEs versus current standard-of-care over the 24-month study period. There was an increased relative risk of experiencing lymphocele and wound dehiscence but the absolute risks were rather low in both groups 21.

CT.GOV IDENTIFIER

NCT01950819.

Flow-controlled fluoroscopic angiography for the assessment of vascular integrity in bioengineered kidneys

Perfusion decellularization has been proposed as a promising method for generating nonimmunogenic organs from allogeneic or xenogeneic donors. Several imaging modalities have been used to assess vascular integrity in bioengineered organs with no consistency in the methodology used. Here, we studied the use of fluoroscopic angiography performed under controlled flow conditions for vascular integrity assessment in bioengineered kidneys. Porcine kidneys underwent ex vivo angiography before and after perfusion decellularization. Arterial and venous patencies were defined as visualization of contrast medium (CM) in distal capillaries and renal vein, respectively. Changes in vascular permeability were visualized and quantified. No differences in patency were detected in decellularized kidneys compared with native kidneys. However, focal parenchymal opacities and significant delay in CM clearance were detected in decellularized kidneys, indicating increased permeability. Biopsy-induced leakage was visualized in both groups, with digital subtraction angiography revealing minimal CM leakage earlier than nonsubtracted fluoroscopy. In summary, quantitative assessment of vascular permeability should be coupled with patency when studying the effect of perfusion decellularization on kidney vasculature. Flow-controlled angiography should be considered as the method of choice for vascular assessment in bioengineered kidneys. Adopting this methodology for organs premodified ex vivo under normothermic machine perfusion settings is also suggested.

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.

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.

Immunosuppression reduction in kidney transplant recipients during bacterial infection-A retrospective study

BACKGROUND

Immunosuppression reduction is a common practice in the management of bacterial infection among kidney transplant recipients (KTRs). This practice, however, is based on limited evidence.

METHODS

Retrospective study comparing clinical outcomes of KTRs whose antimetabolite was discontinued vs continued during hospitalization due to bacterial infection, considering calcineurin inhibitors (CNI) levels. Primary outcome was a composite of clinical failure at day 5; all-cause mortality; and/or re-hospitalization at 90 days. Multivariable analysis of risk factors for the primary outcome was performed using a propensity-matched cohort.

RESULTS

We included 183 KTRs hospitalized with bacterial infection. Neither discontinuation of antimetabolites nor lower levels of CNI at infection onset were associated with a significant decrease the composite primary outcome. No significant difference in graft loss or rejection was demonstrated between patients with low vs high CNI levels or discontinuation vs continuation of antimetabolite. In multivariable analysis, CNI levels and management of antimetabolite were not significantly associated with adverse outcome.

CONCLUSIONS

Immunosuppression reduction in hospitalized KTRs with bacterial infection did not offer a clinical advantage in terms of mortality, re-hospitalization, or clinical success. An interventional study evaluating continuation of immunosuppression vs reduction should be considered.

Immunosuppression reduction in liver and kidney transplant recipients with suspected bacterial infection: A multinational survey

BACKGROUND

There is no consensus on the optimal management of immunosuppression during bacterial infections among solid organ transplant recipients.

METHODS

A multicenter, cross-sectional survey, of high-volume kidney and liver transplant centers across US and Europe. Structured questionnaires including six multiple-choice questions concerning the management of immunosuppression during infection were distributed among 381 centers.

RESULTS

A total of 124 (33%) centers fully completed the questionnaire: 67 liver, 57 kidney centers. Participating centers reported heterogenous approaches to immunosuppression management for all types of immunosuppressive drugs. Notably, kidney centers reported similar frequencies of either discontinuation (19%), continuation (19%), or dose reduction (17.5%) of antimetabolites; discontinuation only for life-threatening infection (17.5%) or case by case decisions (27%). Calcineurin inhibitors (CNI) management was heterogenous mostly among liver centers, with 8% discontinuing the CNI, 18% continuing, and 22% reducing dose. Heterogenous approaches to management of steroids and inhibitors of the mammalian target of rapamycin were also demonstrated.

CONCLUSIONS

Immunosuppression management during bacterial infection is heterogenous in US and European centers. Immunosupression reduction (ISR) during infection is a common practice, though supported by limited evidence. Demonstrating high heterogeneity in the approach to ISR, together with the equivocal results of clinical studies, support consideration of an interventional clinical trial.

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.

The role of the vasculature niche on insulin-producing cells generated by transdifferentiation of adult human liver cells

Background

Insulin-dependent diabetes is a multifactorial disorder that could be theoretically cured by functional pancreatic islets and insulin-producing cell (IPC) implantation. Regenerative medicine approaches include the potential for growing tissues and organs in the laboratory and transplanting them when the body cannot heal itself. However, several obstacles remain to be overcome in order to bring regenerative medicine approach for diabetes closer to its clinical implementation; the cells generated in vitro are typically of heterogenic and immature nature and the site of implantation should be readily vascularized for the implanted cells to survive in vivo. The present study addresses these two limitations by analyzing the effect of co-implanting IPCs with vasculature promoting cells in an accessible site such as subcutaneous. Secondly, it analyzes the effects of reconstituting the in vivo environment in vitro on the maturation and function of insulin-producing cells.

Methods

IPCs that are generated by the transdifferentiation of human liver cells are exposed to the paracrine effects of endothelial colony-forming cells (ECFCs) and human bone marrow mesenchymal stem cells (MSCs), which are the “building blocks” of the blood vessels. The role of the vasculature on IPC function is analyzed upon subcutaneous implantation in vivo in immune-deficient rodents. The paracrine effects of vasculature on IPC maturation are analyzed in culture.

Results

Co-implantation of MSCs and ECFCs with IPCs led to doubling the survival rates and a threefold increase in insulin production, in vivo. ECFC and MSC co-culture as well as conditioned media of co-cultures resulted in a significant increased expression of pancreatic-specific genes and an increase in glucose-regulated insulin secretion, compared with IPCs alone. Mechanistically, we demonstrate that ECFC and MSC co-culture increases the expression of CTGF and ACTIVINβα, which play a key role in pancreatic differentiation.

Conclusions

Vasculature is an important player in generating regenerative medicine approaches for diabetes. Vasculature displays a paracrine effect on the maturation of insulin-producing cells and their survival upon implantation. The reconstitution of the in vivo niche is expected to promote the liver-to-pancreas transdifferentiation and bringing this cell therapy approach closer to its clinical implementation.

Electronic supplementary material

The online version of this article (10.1186/s13287-019-1157-5) contains supplementary material, which is available to authorized users.

Transplantation of Livers from Old Donors: Pushing the Envelope Beyond the Seventh Decade

BACKGROUND

The lack of organs for liver transplantation has prompted transplant professionals to study potential solutions, such as the use of livers from donors older than 70 years. This strategy is not widely accepted because potential risks of vascular and biliary complications and recurrence of hepatitis C.

OBJECTIVES

To examine the efficacy and safety of liver grafts from older donors for transplantation.

METHODS

A retrospective analysis of data on 310 adults who underwent deceased donor liver transplantation between 2005 and 2015 was conducted. We compared graft and recipient survival, as well as major complications, of transplants performed with grafts from donors younger than 70 years (n=265, control group) and those older than 70 years (n=45, older-donor group), followed by multivariate analysis, to identify risk factors.

RESULTS

There was no significant difference between the control and older-donor group at 1, 5, and 10 years of recipient survival (79.5% vs. 73.3%, 68.3% vs. 73.3%, 59.2% vs. 66.7%, respectively) or graft survival (74.0% vs. 71.0%, 62.7% vs. 71.0%, 54.8% vs. 64.5%, respectively). The rate of biliary and vascular complications was similar in both groups. Significant risk factors for graft failure were hepatitis C (hazard ratio [HR] = 1.92, 95% confidence interval [95%CI] 1.16-2.63), older donor age (HR = 1.02, 95%CI 1.007-1.031), and male gender of the recipient (HR = 1.65, 95%CI 1.06-2.55).

CONCLUSIONS

Donor age affects liver graft survival. However, grafts from donors older than 70 years may be equally safe if cold ischemia is maintained for less than 8 hours.

Bariatric surgery in solid organ transplant patients: Long-term follow-up results of outcome, safety, and effect on immunosuppression

The surgical risk of transplanted patients is high, and the modified gastrointestinal anatomy after bariatric surgery (BS) may lead to pharmacokinetic alterations in the absorption of immunosuppressive drugs. Data on outcomes of BS and the safety and feasibility of maintaining immunosuppression and graft safety among solid organ transplanted patients are scarce. In the current study, weight loss, improvement in comorbidities, and changes in dosage and trough levels of immunosuppression drugs before and after BS were analyzed for all transplanted patients who underwent laparoscopic sleeve gastrectomy (LSG) or laparoscopic Roux-en-Y gastric bypass (LRYGB) in our institution between November 2011 and January 2017. Thirty-four patients (13 females, 21 males, average age 53 years) were included in the study. A successful weight loss (>50% excess weight loss in 28 of them [82%]) was recorded at the last follow-up. Comorbidities improved significantly. Immunosuppressive stability increased from 39% to 47% among all patients. The tacrolimus blood trough levels declined slightly, but remained within therapeutic range. These data suggest that LSG and LRYGB ensure good immunosuppressive maintenance together with significant weight loss and improvement in comorbidities without serious graft rejection or dysfunction. The surgical risk is higher than in the regular BS population.

The Wnt/β-catenin pathway determines the predisposition and efficiency of liver-to-pancreas reprogramming

Transdifferentiation (TD) is the direct reprogramming of adult cells into cells of alternate fate and function. We have previously shown that liver cells can be transdifferentiated into beta-like, insulin-producing cells through ectopic expression of pancreatic transcription factors (pTFs). However, the efficiency of the process was consistently limited to <15% of the human liver cells treated in culture. The data in the current study suggest that liver-to-pancreas TD is restricted to a specific population of liver cells that is predisposed to undergo reprogramming. We isolated TD-predisposed subpopulation of liver cells from >15 human donors using a lineage tracing system based on the Wnt response element, part of the pericentral-specific promoter of glutamine synthetase. The cells, that were propagated separately, consistently exhibited efficient fate switch and insulin production and secretion in >60% of the cells upon pTF expression. The rest of the cells, which originated from 85% of the culture, resisted TD. Both populations expressed the ectopic pTFs with similar efficiencies, followed by similar repression of hepatic genes. Our data suggest that the TD-predisposed cells originate from a distinct population of liver cells that are enriched for Wnt signaling, which is obligatory for efficient TD. In TD-resistant populations, Wnt induction is insufficient to induce TD. An additional step of chromatin opening enables TD of these cells.

CONCLUSION

Liver-to-pancreas TD occurs in defined predisposed cells. These cells' predisposition is maintained by Wnt signaling that endows the cells with the plasticity needed to alter their transcriptional program and developmental fate when triggered by ectopic pTFs. These results may have clinical implications by drastically increasing the efficacy of TD in future clinical uses. (Hepatology 2018).

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.

Stereotactic body radiation therapy (SBRT) for definitive treatment and as a bridge to liver transplantation in early stage inoperable Hepatocellular carcinoma

Background and Purpose

Stereotactic body radiotherapy (SBRT) is an emerging modality for definitive treatment of Hepatocellular carcinoma (HCC).

Materials and Methods

This retrospective study included all early stage HCC patients who were not candidates for primary resection and/or local therapy, treated with SBRT between 11/2011 and 1/2016.

Results

Twenty-three patients were included. The median age was 62 years; 70% males; 30% females; 70% viral hepatitis carriers; 100% cirrhotic; 13 Child Pugh [CP]-A and 10 [CP]-B. The median tumor volume was 12.7cm³ (range, 2.2–53.6 cm³). Treatment was well tolerated. With the exception of one patient who developed RILD, no other patient had significant changes in 12 weeks of laboratory follow-up. SBRT was a bridge to transplantation in 16 patients and 11 were transplanted.. No surgical difficulties or complications were reported following SBRT, and none of the transplanted patients had local progression before transplantation. The median prescribed dose to the tumor was 54Gy (range, 30-54Gy), the median dose to the uninvolved liver was 6.0Gy(range, 1.6–12.6Gy). With a median follow-up time of 12 months, the median overall-survival for the 11 transplanted patients was not reached (range, 2.0–53.7+ months) and was 23 months for the 12 non-transplanted patients. The median progression-free survival for the transplanted patients was not reached (54+ months) and was 14.0 months for the non-transplanted patients. There was no SBRT-related mortality. Liver explant post SBRT revealed pathological complete response in 3(27.3%), pathological partial response in 6(54.5%), and pathological stable disease in 2(18.2%) tumors.

Conclusions

SBRT is safe and effective and can be used as a bridge to transplantation without comprising the surgical procedure.

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.