Water intake, baseline biopsy, and graft function after living donor kidney transplantation

Increased water intake is recommended for kidney transplant recipients; however, its efficacy remains controversial. We hypothesized that pre-existing histological findings of the allograft might modulate the impact of water intake. We retrospectively analyzed 167 adults with living-donor kidney transplants (April 2011-May 2020; median observation period, 77 months) whose baseline biopsy data were available. We compared the chronic-change group (n = 38) with the control group (n = 129) to assess the impact of self-reported daily water intake on the estimated glomerular filtration rate (eGFR). The range distribution of water intake was as follows: - 1000 ml (n = 4), 1000-1500 ml (n = 23), 1500-2000 ml (n = 64), 2000-2500 ml (n = 57), 2500-3000 ml (n = 16), and 3000 - ml (n = 3). Donor age was significantly higher in the chronic-change group. In the control group, the ΔeGFR/year increase was correlated with water intake. However, the increase in the water intake of the chronic-change group significantly decreased ΔeGFR/year (1000-1500 ml: + 1.95 ml/min/1.73 m2 and > 2000 ml: - 1.92 ml/min/1.73 m2, p = 0.014). This study suggested a potential influence of increased water intake on recipients with marginal grafts in living donor kidney transplantation.

Predictors of graft function and survival in second kidney transplantation: A single center experience

BACKGROUND

The increasing kidney retransplantation rate has created a parallel field of research, including the risk factors and outcomes of this advanced form of renal replacement therapy. The presentation of experiences from different kidney transplantation centers may help enrich the literature on kidney retransplantation, as a specific topic in the field of kidney transplantation.

AIM

To identify the risk factors affecting primary graft function and graft survival rates after second kidney transplantation (SKT).

METHODS

The records of SKT cases performed between January 1977 and December 2014 at a European tertiary-level kidney transplantation center were retrospectively reviewed and analyzed. Beside the descriptive characteristics, the survivals of patients and both the first and second grafts were described using Kaplan-Meier curves. In addition, Kaplan-Meier analyses were also used to estimate the survival probabilities at 1, 3, 5, and 10 post-operative years, as well as at the longest follow-up duration available. Moreover, bivariate associations between various predictors and the categorical outcomes were assessed, using the suitable biostatistical tests, according to the predictor type.

RESULTS

Out of 1861 cases of kidney transplantation, only 48 cases with SKT were eligible for studying, including 33 men and 15 women with a mean age of 42.1 ± 13 years. The primary non-function (PNF) graft occurred in five patients (10.4%). In bivariate analyses, a high body mass index (P = 0.009) and first graft loss due to acute rejection (P = 0.025) were the only significant predictors of PNF graft. The second graft survival was reduced by delayed graft function in the first (P = 0.008) and second (P < 0.001) grafts. However, the effect of acute rejection within the first year after the first transplant did not reach the threshold of significance (P = 0.053). The mean follow-up period was 59.8 ± 48.6 mo. Censored graft/patient survival rates at 1, 3, 5 and 10 years were 90.5%/97.9%, 79.9%/95.6%, 73.7%/91.9%, and 51.6%/83.0%, respectively.

CONCLUSION

Non-immediate recovery modes of the first and second graft functions were significantly associated with unfavorable second graft survival rates. Patient and graft survival rates of SKT were similar to those of the first kidney transplantation.

Evaluation of the effect and predictive role of vitamin D and vitamin D receptor expression in CD4 + , CD8 + , CD14 + , CD56 + cells on the development of chronic rejection and graft functions in kidney transplant patients

PURPOSE

It is known that vitamin D has positive effects on graft functions (reduce fibrosis, suppress excessive inflammatory response, improve graft functions). In our study, it was aimed to evaluate the effects and predictive roles of vitamin D, the expression of vitamin D receptor (VDR) in lymphocytes, monocytes, natural killer cells on chronic rejection and graft functions in kidney transplant patients.

METHODS

Seventy one people were included in the study and analyses were made by dividing them into 3 groups. Group 1: Healthy control (n = 29), Group 2: Kidney transplant patients with stable kidney function (n = 17), and Group 3: Kidney transplant patients with chronic rejection diagnosis (n = 25). Serum 25-hydroxycholecalciferol, 1.25 dihydroxycholecalciferol levels and VDR percentages in CD4 + , CD8 + , CD14 + , CD56 + cells were measured in 3 groups. ROC analyses and logistic regression models were performed to predict rejection and long-term graft functions.

RESULTS

The percentage of VDR expression in CD4 + lymphocytes (p < 0.001) and CD14( +) monocytes (p < 0.001), 25-hydroxycholecalciferol and 1.25 dihydroxycholecalciferol levels were lower in group 3 was detected. In ROC analyses and logistic regression models, VDR expression in CD4( +)T lymphocytes was shown to have a statistically significant value in the development of chronic rejection (Odds ratio 0.86: 0.76-0.92; p = 0.001/AUC = 0.941, p < 0.001) and prediction of 5th-year graft functions (Odds ratio 0.93: 0.88-0.98; p = 0.017/AUC = 0.745, p = 0.007).

CONCLUSION

In our study, it was shown that low vitamin D and VDR expression is associated with poor outcome and VDR expression in CD4( +)T lymphocytes is predictive in terms of graft function and rejection.

Systematic review of techniques and devices used to avoid warm ischemia time injury during kidney transplantation

PURPOSE

The lack of a reliable and reproducible technique to ensure a constantly low temperature of the graft during kidney transplantation (KT) may be a cause of renal nonfunction. The aim of this review was to assess all the methods and devices available to ensure hypothermia during vascular anastomosis in KT.

METHODS

A literature search was conducted through May 2022 using PubMed/Medline, Cochrane Library, Embase and Web of Science databases. Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines were followed to identify eligible studies. The review protocol was registered on PROSPERO (CRD42022326550).

RESULTS

A total of 20 studies reporting on four hypothermia techniques met our inclusion criteria. Simple instillation of cold serum is not sufficient, the graft reaching up to 33 ℃ at the end of warm ischemia time (WIT). Plastic bags filled with ice slush have questionable efficiency. The use of a gauze jacket filled with ice-slush was reported in 12/20 studies. It ensures a graft temperature up to 20.3 ℃ at the end of WIT. Some concerns have been linked to potentially inhomogeneous parenchymal cooling and secondary ileus. Novel devices with continuous flow of ice-cold solution around the graft might overcome these limitations, showing a renal temperature below 20 ℃ at all times during KT.

CONCLUSION

The gauze filled with ice slush is the most common technique, but several aspects can be improved. Novel devices in the form of cold-ischemia jackets can ensure a lower and more stable temperature of the graft during KT, leading to higher efficiency and reproducibility.

Rejection and graft outcomes in kidney transplant recipients with and without angiotensin II receptor type 1 antibodies

AIM

Angiotensin II type 1 receptor antibody (AT1R Ab) is a non-Human Leucocyte Antigen (HLA) antibody that is maybe associated with early severe kidney transplant rejection and worse graft outcomes. This study aimed to assess the association between AT1R Ab and kidney transplant rejection and graft outcomes.

METHODS

We performed a retrospective analysis of all adult kidney transplant recipients in an Australian centre who had an AT1R Ab test between 1 January 2015 to 30 June 2020. AT1R Ab positive patients were compared to AT1R Ab negative patients. Primary outcomes were rejection risk, type and histopathological severity scores. Secondary outcomes were 8-week graft function and graft loss.

RESULTS

Of 965 kidney transplants that were performed during the study period, 73 patients had AT1R Ab tested; 16 (22%) were positive and 57(78%) were negative. Positive patients were on average younger and had higher level of donor-specific HLA antibodies. Rejection occurred in 13 (81%) positive patients and 41 (72%) negative patients (P = 0.45). No significant differences in rejection type or severity were found. HLA mismatch and peak panel reactive antibody ≥80%, but not AT1R Ab, independently predicted rejection. Average (132 vs. 177 mmol/L, P = 0.302) and graft loss were not significantly different between groups.

CONCLUSION

The study found no evidence that AT1R Ab is associated with rejection type, severity or worse graft function. Future studies should assess its relationship with graft outcomes to help complement immunological risk assessment and potentially provide therapeutic options to alter outcomes.

Low dose thymoglobulin versus basiliximab in cytomegalovirus positive kidney transplant recipients: Effectiveness of preemptive cytomegalovirus modified strategy

BACKGROUND

We performed a retrospective trial to determine asymptomatic CMV reactivation and CMV disease in kidney allograft recipients with positive CMV serostatus.

METHODS

Preemptive modified strategy under low dose thymoglobulin versus basiliximab induction was evaluated. Patients were monitored by CMV-polymerase chain reaction (PCR); if the viral load was >4000copies/μl, they received valganciclovir adjusted for their renal function.

RESULTS

132 recipients were included in the study, 84 and 48 receiving basiliximab and thymoglobulin induction respectively, and followed up for 12 months. Asymptomatic CMV reactivation was significantly higher for thymoglobulin (77.1% vs. 16.7%, p<0.001). Treatment groups had similar rates of CMV disease (3.6% vs. 2.1%, p 0.538). The significant difference in asymptomatic CMV reactivation between two treatment groups did not have any impact on 1 year graft function (71±26ml/min vs. 74±19ml/min; p=0.475) and no histological differences in protocol biopsies were observed among patients with asymptomatic CMV reactivation vs those without CMV reactivation.

CONCLUSIONS

Due to the high asymptomatic CMV reactivation incidence in patients who received thymoglobulin induction, our results suggest that valganciclovir prophylaxis may be advantageous in CMV seropositive renal transplant recipients after low dose thymoglobulin induction. A preemptive strategy appeared to significantly reduce the likelihood of CMV disease in both groups. Rejection risk and negative impact in renal function associated with asymptomatic CMV reactivation was not found in our series.

TLR10 genotypes affect long-term graft function in tacrolimus-treated solid organ transplant recipients

The present study was conducted to investigate the relationship between single nucleotide polymorphisms (SNPs) in TLR10 and the clinical outcomes of renal transplant patients who took tacrolimus (TAC) as an immunosuppressant, and further confirmed the results in liver transplant patients. A total of 172 renal transplant patients and 145 pairs of liver transplant recipients and donors were included. Nineteen SNPs of TLR10 gene were detected by matrix-assisted laser desorption ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS). The associations of recipient SNPs with TAC-related clinical outcomes were explored in renal transplant recipients. The relationship between recipient and donor SNPs and the clinical outcomes of liver transplant patients were investigated to confirm the results. Three SNPs (rs28393318, rs11466655 and rs11096957) in renal transplant recipients were found to influence the graft function after transplantation (P = 0.00003, 0.001 and 0.000003, respectively). The recipient rs11096957 was also found to affect the TBil, and DBil levels in liver transplant recipients (P = 0.001 and 0.002). In this study, we identified significant association signals from TLR10 polymorphisms with clinical outcomes in TAC-treated transplant patients in a Chinese Han-based sample. We provide some evidence for the effect between rs11096957 in TLR10 gene on the graft functions in both renal and liver transplantation.

Comparative study of the outcomes of the second kidney transplantation from the young deceased donors versus living-unrelated donors

PURPOSE

To compare the kidney graft function and survival in patients who had second kidney transplantation from living donors versus those who had a second transplant from young deceased donors.

METHODS

In this retrospective cohort study, a total of 86 patients who underwent second kidney transplantation in Shariati hospital from 2001 until 2017 were enrolled. Baseline clinical data on the age, sex, type of kidney donor (living unrelated or deceased), duration of pretransplant dialysis, and the length of hospitalization were recorded. As the indicators of the graft function, we used the serum creatinine level and estimated glomerular filtration rate (eGFR) at time intervals during the study. The 1, 5, and 10-year graft survival rates were reported using life tables and the relative hazard ratios of the graft failure were calculated using the forward stepwise Cox proportional hazard model.

RESULTS

Forty-six of our patients were men (53.5%), with a mean ± SD age of 44.3 ± 12.3 years at the time of transplantation. The majority of the enrolled patients received the kidney from living unrelated donors (50 vs. 36 patients). In terms of serum creatinine and eGFR, at time intervals, no significant difference was found between the two recipient groups. In the living donor group, the 1, 5, and 10-year graft survival rates of the second transplant were 91% (95%CI: 73-96%), 87% (95%CI: 69-95%), and 82% (95%CI: 59-92%), and for the deceased donor group were 95% (95% CI: 69-99%), 95% (95%CI: 69-99%), and 79% (95%CI: 31-95%), respectively.

CONCLUSION

Considering the long-term outcomes of the second kidney transplantation, in our experience, the graft function and survival, either from the living or deceased donors, were favorable; and the type of organ donation had no significant effect on the risk of graft failure.

Clinical factors associated with severe hypophosphataemia after kidney transplant

BACKGROUND

The mechanism by which hypophosphataemia develops following kidney transplantation remains debated, and limited research is available regarding risk factors. This study aimed to assess the association between recipient and donor variables, and the severity of post-transplantation hypophosphataemia.

METHODS

We performed a single-centre retrospective observational study. We assessed the association between demographic, clinical and biochemical variables and the development of hypophosphataemia. We used linear regression analysis to assess association between these variables and phosphate nadir.

RESULTS

87.6% of patients developed hypophosphataemia. Patients developing hypophosphataemia were younger, had a shorter time on renal replacement therapy, were less likely to have had a parathyroidectomy or to experience delayed graft function, were more likely to have received a living donor transplant, from a younger donor. They had higher pre-transplantation calcium levels, and lower alkaline phosphatase levels. Receipt of a living donor transplant, lower donor age, not having had a parathyroidectomy, receiving a transplant during the era of tacrolimus-based immunosuppression, not having delayed graft function, higher pre-transplantation calcium, and higher pre-transplantation phosphate were associated with lower phosphate nadir by multiple linear regression.

CONCLUSIONS

This analysis demonstrates an association between variables relating to better graft function and hypophosphataemia. The links with biochemical measures of mineral-bone disease remain less clear.

Association of non-HLA antibodies against endothelial targets and donor-specific HLA antibodies with antibody-mediated rejection and graft function in pediatric kidney transplant recipients

BACKGROUND

Non-HLA antibodies against endothelial targets have been implicated in the pathogenesis of antibody-mediated rejection (ABMR), but data in pediatric patients are scarce.

METHODS

We retrospectively analyzed a carefully phenotyped single-center (University Children's Hospital Heidelberg, Germany) cohort of 62 pediatric kidney transplant recipients (mean age at transplantation, 8.6 ± 5.0 years) at increased risk of graft function deterioration. Patients had received their transplant between January 1, 1999, and January 31, 2010. We examined at time of late index biopsies (more than 1-year post-transplant, occurring after January 2004) the association of antibodies against the angiotensin II type 1 receptor (AT₁R), the endothelin type A receptor (ET_AR), the MHC class I chain-like gene A (MICA), and vimentin in conjunction with overall and complement-binding donor-specific HLA antibodies (HLA-DSA) with graft histology and function.

RESULTS

We observed a high prevalence (62.9%) of non-HLA antibody positivity. Seventy-two percent of HLA-DSA positive patients showed additional positivity for at least one non-HLA antibody. Antibodies against AT₁R, ET_AR, and MICA were associated with the histological phenotype of ABMR. The cumulative load of HLA-DSA and non-HLA antibodies in circulation was related to the degree of microinflammation in peritubular capillaries. Non-HLA antibody positivity was an independent non-invasive risk factor for graft function deterioration (adjusted hazard ratio 6.38, 95% CI, 2.11-19.3).

CONCLUSIONS

Our data indicate that the combined detection of antibodies to HLA and non-HLA targets may allow a more comprehensive assessment of the patients' immune responses against the kidney allograft and facilitates immunological risk stratification.

Cryptococcus neoformans meningitis in kidney transplant recipients: A diagnostic and therapeutic challenge

Cryptococcosis is the third most common invasive fungal infection in solid organ transplant recipients. We describe three cases of neuro-meningeal cryptococcosis occurring among kidney transplant (KT) patients, and discuss the diagnostic and therapeutic challenges in this context. Median time from KT to infection was 6 months [range: 3-9]. The most common clinical manifestations at diagnosis were fever (2/3), headache (2/3), and confusion (2/3); none had extra-neurological involvement. CrAg was positive in all cases at diagnosis both in serum and cerebrospinal fluid (CSF). For two patients, analysis of previous samples showed that CrAg was detected in plasma up to 4 weeks before diagnosis. All patients received induction treatment with liposomal amphotericin-B (L-AmB) and flucytosine for a median duration of 10 days [range: 7-14], followed by fluconazole maintenance therapy. Acute kidney injury secondary to L-AmB therapy was observed in only one case, but all patients had a tacrolimus overdose following initiation of maintenance therapy due to drug-drug interactions between fluconazole and tacrolimus. Among KTR, early detection of Cryptococcus meningitis using serum CrAg is possible. Close monitoring of renal function during treatment is essential due to the nephrotoxicity of L-AmB, but also drug-drug interactions between fluconazole and calcineurin inhibitors.

Feasibility and impact of laparoscopic sleeve gastrectomy after renal transplantation on comorbidities, graft function and quality of life

Background

The aim of this study is to clarify the feasibility and effect of laparoscopic sleeve gastrectomy (LSG) on comorbidities, graft function and quality of life in patients who underwent renal transplantation (RT).

Methods

This is a retrospective review of five patients who underwent LSG after RT. Demographic data, anthropometric parameters, the effect on comorbidities, postoperative course, immunosuppressive medications, causes of RT, renal function, the survival of graft, and quality of life after SG in obese patients with a history of RT were assessed using BAROS–Moorhead–Ardelt survey

Results

From September 2015 to September 2019, 5 renal transplant patients underwent LSG; three female, and two male. Median body mass index (BMI) decreased from 42.17 kg/m² (range 36–55) before surgery to 28.16 kg/m² (range 25–42) after surgery. Improvement in blood pressure, triglyceride, and cholesterol levels was observed, and all cases were able to decrease their medications. Insulin was stopped and replaced with linagliptin in all diabetic patients. Graft function improved, and proteinuria level decreased in all cases. All patients reported to have an excellent quality of life.

Conclusion

LSG showed excellent outcomes in this high-risk group of patients regarding comorbidities, graft function and quality of life

Clinical characteristics, risk factors and outcome of severe Norovirus infection in kidney transplant patients: a case-control study

Background

Human Norovirus (HuNoV) has recently been identified as a major cause of diarrhea among kidney transplant recipients (KTR). Data regarding risk factors associated with the occurrence of HuNoV infection, and its long-term impact on kidney function are lacking.

Methods

We conducted a retrospective case-control study including all KTR with a diagnosis of HuNoV diarrhea. Each case was matched to a single control according to age and date of transplantation, randomly selected among our KTR cohort and who did not develop HuNoV infection. Risk factors associated with HuNoV infection were identified using conditional logistic regression, and survival was estimated using Kaplan-Meier estimator.

Results

From January 2012 to April 2018, 72 cases of NoV diarrhea were identified among 985 new KT, leading to a prevalence of HuNoV infection of 7.3%. Median time between kidney transplantation and diagnosis was 46.5 months (Inter Quartile Range [IQR]:17.8–81.5), and the median duration of symptoms 40 days (IQR: 15–66.2). Following diagnosis, 93% of the cases had a reduction of immunosuppression. During follow-up, de novo Donor Specific Antibody (DSA) were observed in 8 (9%) cases but none of the controls (p = 0.01). Acute rejection episodes were significantly more frequent among cases (13.8% versus 4.2% in controls; p = 0,03), but there was no difference in serum creatinine level at last follow-up between the two groups (p = 0.08). Pre-transplant diabetes and lymphopenia below 1000/mm³ were identified as risks factors for HuNoV infection in multivariate analysis.

Conclusion

HuNoV infection is a late-onset and prolonged infection among KTR. The current management, based on the reduction of immunosuppressive treatment, is responsible for the appearance of de novo DSA and an increase in acute rejection episodes.

The early impact of preformed angiotensin II type 1 receptor antibodies on graft function in a low immunological risk cohort of kidney transplant recipients

Intruduction and aim: Angiotensin II type 1 receptor antibodies (AT1R-Ab) are associated with graft rejection and poor graft outcomes in kidney transplantation (KT). We aimed to assess the frequency of preformed AT1R-Ab and their impact on graft function and survival at 1 year after KT in a low immunological risk cohort.

METHODS

We performed a prospective, observational cohort study in 67 adult KT recipients, transplanted between 2018 and 2019. A cut-off value >10 U/ml was used for AT1R-Ab detection.

RESULTS

The frequency of preformed AT1R-Ab was 10.4% and the median value of their level was 8.4 U/ml (IQR: 6.8-10.4). Donor-specific anti-human leukocyte antigen antibodies (HLA-DSA) were absent, no case of biopsy-proven rejection was reported and the incidence of graft failure was 7.5%. Estimated glomerular filtration rate (eGFR) was significantly reduced in the AT1R-Ab group [35 (29.8-55.2) vs 56.1 (41.3-66.5) ml/min, p = 0.02] at 1 year after KT. After multivariate linear regression analysis, preformed AT1R-Ab were found as an independent determinant of eGFR at 1 year after KT (β: -15.395; 95% CI: -30.49 - -0.30; p = 0.04). By Cox multivariate regression analysis, preformed AT1R-Ab were not associated with graft failure (HR: 1.36; 95% CI:0.10-14.09; p = 0.80).

CONCLUSION

Preformed AT1R-Ab are an independent determinant of graft function but do not impact graft survival at 12 months after transplantation in a prospective low immunological risk cohort of KT recipients.

Blood transcriptomics as non-invasive marker for kidney transplant rejection

In the last decade, a plenitude of potential molecular peripheral blood biomarkers has been developed. In assessing the utility of these markers for clinical practice, it is important to evaluate their diagnostic performance in different clinical scenarios. The higher probability of diagnosing rejection in indication compared to protocol biopsies illustrates that kidney functional parameters (estimated glomerular filtration rate evolution, proteinuria) are inherently already non-invasive biomarkers for rejection, with evident clinical utility. However, by definition, graft functional assessment will miss subclinical rejection. In this paper, we review how some of the most promising peripheral blood molecular biomarkers, like blood transcriptomic markers and donor-derived cell-free DNA measurement, perform in relation to graft functional evaluation. Since the definition of graft dysfunction is relatively arbitrary, we propose using a standardized clinical model for non-invasive diagnosis of allograft rejection, as benchmark and for integration with novel molecular biomarkers.

Should ACE inhibitors or calcium channel blockers be used for post-transplant hypertension?

Arterial hypertension in renal transplant recipients warrants antihypertensive treatment. The preferable choice of antihypertensives that should be used in patients after kidney transplantation remains a matter of debate; however, calcium channel blockers (CCB) and angiotensin-converting enzyme inhibitors (ACEI) are currently the most commonly used antihypertensives. This educational review summarizes the current evidence about the effects of these two classes of medications in transplant recipients. Several studies have demonstrated that both classes of drugs can reduce blood pressure (BP) to similar extents. Meta-analyses of adult randomized controlled trials have shown that graft survival is improved in patients treated with ACEIs and CCBs, and that CCBs increase, yet ACEIs decrease, graft function. Proteinuria is usually decreased by ACEIs but remains unchanged with CCBs. In children, no randomized controlled study has ever been performed to compare BP or graft survival between CCBs and ACEIs. Post-transplant proteinuria could be reduced in children along with BP by ACEIs. The results of the most current meta-analyses recommend that due to their positive effects on graft function and survival, along with their lack of negative effects on serum potassium, CCBs could be the preferred first-line antihypertensive agent in renal transplant recipients. However, antihypertensive therapy should be individually tailored based on other factors, such as time after transplantation, presence of proteinuria/albuminuria, or hyperkalemia. Furthermore, due to the difficulty in controlling hypertension, combination therapy containing both CCBs and ACEIs could be a reasonable first-step therapy in treating children with severe post-transplantation hypertension.

Effect of post-perfusion hyperoxemia on early graft function in renal transplant recipients: a retrospective observational cohort study

BACKGROUND

The effects of hyperoxemia on the transplanted grafts arouse interest nowadays, particularly intraoperative hyperoxemia, on transplant kidney function and survival in the 1-year post-operative period.

AIMS

We aimed to investigate the effect of post-perfusion (5 min after perfusion) hyperoxemia on early graft function and survival in renal transplant recipients.

METHODS

Two hundred forty-seven living donor kidney transplant recipients were included in the study. Patients were divided into the three groups according to their partial arterial oxygen pressure in post-perfusion blood gas samples: group 1: normoxia (n = 52, PaO2 pressure: < 120 mmHg, 103 ± 13); group 2: moderate hyperoxemia (n = 121, PaO2: 120-200 mmHg, 169 ± 21); group 3: severe hyperoxemia (n = 74, PaO2: > 200 mmHg, 233 ± 25). Graft functions (serum creatinine levels, estimated-glomerular filtration rate values, spot urine protein/creatinine ratio), survival rates, and groups' clinical outcomes were compared in the first year after transplantation.

RESULTS

Graft survival rates were similar in the groups and the rate of BK virus viremia was the lowest in the group 3 (groups 1, 2, and 3: 15.4% (n = 8), 6.6% (n = 8), 1.4% (n = 1), respectively, P: 0.009). Serum creatinine and proteinuria levels were lower, and estimated-glomerular filtration rate values were higher in group 3. A negative correlation between partial arterial oxygen pressure and serum creatinine levels and a positive correlation with estimated-glomerular filtration rate value were noted. These results were confirmed by univariate and multivariate analyses.

CONCLUSIONS

We demonstrated that the kidney transplant recipients with post-perfusion hyperoxemia have better early graft functions and lower BK virus viremia rates.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04420897.

Clinicopathological Analysis of Medullary Ray Injury in 1-Year Protocol Paediatric Renal Allograft Biopsies

AIM

Medullary ray injury was recently reported in renal transplant biopsies. This study was performed to clarify the clinicopathological features of medullary ray injury in paediatric living renal transplant recipients.

METHODS

Paediatric recipients who completed a 5-year follow-up after living renal transplantation were enroled. We evaluated the clinical and pathological parameters of the presence or absence of medullary ray injury in their 1-year protocol biopsies.

RESULTS

Of 48 1-year protocol biopsies, 18 (37.5%) showed histological evidence of medullary ray injury. The 48 paediatric recipients were classified as those with medullary ray injury (n = 18; MRI-1Y [+] group) and those without medullary ray injury (n = 30; MRI-1Y [-] group) in the 1-year protocol biopsies. The prevalence of histological evidence of calcineurin inhibitor (CNI) nephrotoxicity, chronic obstruction or reflux nephropathy, and imaging findings of vesicoureteral reflux was 66.7, 22.2, and 7.7% in the MRI-1Y (+) group and 33.3, 13.3, and 15.4% in the MRI-1Y (-) group, respectively. Only the prevalence of CNI nephrotoxicity was significantly different between the 2 groups. There was no significant difference in the mean estimated glomerular filtration rate at 1, 3, or 5 years after transplantation between the 2 groups.

CONCLUSION

In total, 37.5% of 1-year protocol biopsies showed histological evidence of medullary ray injury. This finding suggests that CNI nephrotoxicity might be the main contributor to medullary ray injury in 1-year protocol biopsies. The presence of medullary ray injury had little influence on renal function, at least during the first 5 years after transplantation.

Vitamin D levels in liver transplantation recipients and early postoperative outcomes: Prospective observational DLiverX study

BACKGROUND & AIMS

In critically ill patients with liver disease, vitamin D deficiency is associated with higher disease severity, increased frequency of infections, and worse outcomes. This study sought to describe the trend of vitamin D in orthotopic liver transplantation (OLT) recipients and its association with outcomes.

METHODS

Prospective observational study of 67 consecutive OLT recipients enrolled between September, 2016 and August, 2017 at IRCCS-ISMETT, Palermo (Italy). Trend of vitamin D levels and potential factors influencing it levels were evaluated through a generalized linear mixed regression model.

RESULTS

Sixty-four (95.5%) recipients were vitamin D deficient (<20 ng/ml), with a median value of 8.8 ng/ml [6.2-12.9], and forty-seven of these (70.1%) showed severe deficiency (<12 ng/ml) at baseline, 7.9 ng/ml [5.4-8.9]. The baseline vitamin D showed an inverse correlation with liver disease severity: Child-Pugh, MELD score, bilirubin, INR, and organ failure (p < 0.01) at baseline. Vitamin D increased on postoperative day (POD) 28 compared with POD1: +4.5 ng/ml, C.I. 95% 3.6-5.3 ng/ml, p < 0.01. Lower baseline vitamin D, donor age, transfusion of fresh frozen plasma (negative impact, all p < 0.05), and intra-operative bypass (positive impact at POD 28, p < 0.01) were associated with variation of vitamin D levels after transplantation. Incomplete graft recovery was associated with lower vitamin D on POD28: 8.2 ± 4.4 versus 13.8 ± 9.4 ng/ml, p < 0.01; the odds ratio (OR) was 0.84; CI 95% 0.73-0.97, p = 0.014. The OR for infections within POD 28 was inversely associated with baseline vitamin D: 0.87; CI 95% 0.79-0.98, p = 0.02, and with vitamin D level at baseline <12 ng/ml: OR 6.44; CI 95% 1.66-24.94; p < 0.01.

CONCLUSIONS

Preoperative Vitamin D is correlated with disease severity, and was highly associated with invasive infection in the first 28 PODs. After OLT, the value on POD 28 had a strong association with graft function.

High terminal creatinine donors should not preclude simultaneous kidney and pancreas transplantation

BACKGROUND

Simultaneous pancreas and kidney transplantation (SPK) in the setting of end-stage renal disease offers unmatched outcomes in insulin dependent diabetic patients. Donor pool expansion through the transplantation of kidneys with acute kidney injury (AKI) is controversial.

METHODS

59 SPK transplants were classified by presence of donor AKI, defined as donor terminal creatinine ≥ 1.5x the initial creatinine or donor terminal creatinine > 4.0 mg/dL. Endpoints included graft and patient survival, delayed graft function (DGF), serum creatinine, glomerular filtration rate (GFR), Hemoglobin A1c (HbA1c) and acute rejection.

RESULTS

The donor AKI group (n = 35) had significantly higher rates of DGF (38 v. 9%, p = 0.01). There was no difference in creatinine or GFR at 1, 3, 6 and 12 months. HbA1c was comparable at 3, 6 and 12 months. There was no significant difference in the percentage of patients that required anti-diabetic agents after transplant (14 v. 4%, p = 0.56).

CONCLUSIONS

We observed increased rates of DGF in SPK recipients with donor AKI. However, equivalent outcomes of pancreas and kidney function in both groups were observed.

Combined donor-recipient genotypes of leptin receptor and adiponectin gene polymorphisms affect the incidence of complications after renal transplantation

Background

We aimed to examine whether combined donor/recipient variants in the leptin receptor (LEPR) and adiponectin (ADIPOQ) genes may affect outcomes in renal transplantation.

Methods

A total of 233 donors and their corresponding 307 recipients were genotyped for LEPR rs1805094, rs1137100 and rs1137101, and ADIPOQ rs1501299 and rs224176. Combined donor/recipient genetic scores were created to investigate associations with delayed graft function (DGF), graft loss and estimated glomerular filtration rate (eGFR).

Results

Recipients whose donors carried variant alleles of LEPR rs1137100 and rs1137101 had lower risk of DGF [OR = 0.48 (0.24–0.97), p = 0.040] and [OR = 0.47 (0.23–0.95), p = 0.035], respectively. In addition, rs1137101 also showed an inverse association with lower incidence of graft loss [OR = 0.44 (0.31–0.97), p = 0.040]. The analysis of genetic scores of donor/recipients showed that again rs1137101 was inversely associated with both outcomes: OR = 0.46 (0.23–0.92), p = 0.029 and OR = 0.45 (0.11–0.81), p = 0.009, respectively. With regard to graft function, the T-allele of ADIPOQ rs1501299 in the donor was related to higher eGFR values (75.26 ± 29.01 vs. 67.34 ± 25.39 ml/min for wild-type grafts, p = 0.012). Higher combined genetic scores in this same polymorphism were also associated with better function (78.33 ± 31.87 vs. 68.25 ± 24.32 ml/min, p = 0.018). Finally, eGFR values were similar between paired kidneys but they were different when comparing grafts with or without the rs1501299 T-variant (77.87 ± 26.50 vs. 69.27 ± 26.73 ml/min, p = 0.016).

Conclusions

Our study has shown for the first time to our knowledge that variants in LEPR and ADIPOQ genes of the donors and/or their combination with those in the recipients may affect the outcome of renal transplantation.

Role for contrast-enhanced ultrasound in assessing complications after kidney transplant

Kidney transplantation (KT) is an effective treatment for end-stage renal disease. Despite their rate has reduced over time, post-transplant complications still represent a major clinical problem because of the associated risk of graft failure and loss. Thus, post-KT complications should be diagnosed and treated promptly. Imaging plays a pivotal role in this setting. Grayscale ultrasound (US) with color Doppler analysis is the first-line imaging modality for assessing complications, although many findings lack specificity. When performed by experienced operators, contrast-enhanced US (CEUS) has been advocated as a safe and fast tool to improve the accuracy of US. Also, when performing CEUS there is potentially no need for further imaging, such as contrast-enhanced computed tomography or magnetic resonance imaging, which are often contraindicated in recipients with impaired renal function. This technique is also portable to patients' bedside, thus having the potential of maximizing the cost-effectiveness of the whole diagnostic process. Finally, the use of blood-pool contrast agents allows translating information on graft microvasculature into time-intensity curves, and in turn quantitative perfusion indexes. Quantitative analysis is under evaluation as a tool to diagnose rejection or other causes of graft dysfunction. In this paper, we review and illustrate the indications to CEUS in the post-KT setting, as well as the main CEUS findings that can help establishing the diagnosis and planning the most adequate treatment.

Complement activation and long-term graft function in ABO-incompatible kidney transplantation

BACKGROUND

ABO-incompatible and ABO-compatible kidney transplantation are equivalent in terms of short-term graft and patient survival. This is thought to be the result of ABO-incompatible graft accommodation, which occurs when anti-blood group antibodies re-occur after transplantation but somehow do not yield their detrimental effect. The underlying mechanism is unclear, but one of the hypotheses is that this is the result of complement inhibition. Since virtually all ABO-incompatible graft biopsies are C4d positive, this complement inhibition must occur somewhere in the complement cascade after the formation of C4d has already taken place, but where exactly is unclear. It is also unclear whether complement inhibition is complete. Incomplete accommodation could explain why recent studies have shown that long-term graft function in ABO-incompatible transplantation is somewhat inferior to ABO-compatible kidney transplantation.

AIM

To unravel the relationship between pre-transplant anti-ABO antibodies, complement activation, and long-term graft function.

METHODS

We included all 27 ABO-incompatible transplantations that were performed between 2008 and 2013 at the Academic Medical Center Amsterdam and the University Medical Center Groningen. For each ABO-incompatible transplantation, we included four ABO-compatible controls matched by age, sex, and transplantation date.

RESULTS

Graft and patient survival were not significantly different. The slope of kidney function during five-year follow-up was also not significantly different, but ABO-incompatible recipients did have a lower kidney function at three months (creatinine clearance 58 vs 69 mL/min, P = 0.02, Modification of Diet in Renal Disease 46 vs 52 mL/min/1.73 m², P = 0.08), due to a high rate of early rejection (33% vs 15%, P = 0.03), mostly T-cell mediated. Pre-transplant anti-ABO IgG titers were positively correlated with C5b-9 staining, which itself was positively correlated with the occurrence of T-cell mediated rejection. This may be the result of concurrent C5a formation, which could function as a costimulatory signal for T-cell activation.

CONCLUSION

Co-stimulation of T-cell activation by ongoing complement activation by anti-ABO antibodies may be responsible for an impaired long-term graft function in ABO-incompatible kidney transplantation.

A comparison of laparoendoscopic single-site surgery versus conventional procedures for laparoscopic donor nephrectomy: a Japanese multi-institutional retrospective study

PURPOSE

Laparoendoscopic single-site donor nephrectomy (LESSDN) is a feasible and effective procedure because of its non-invasiveness and better cosmetic outcomes. However, there have been few multi-institutional studies conducted by multiple surgeons on LESSDN. We retrospectively compared the clinical data and outcomes between LESSDN and conventional laparoscopic donor nephrectomy (LDN) at multiple institutes in Japan.

MATERIALS AND METHODS

From 2009 to 2015, the clinical data of 223 donors who underwent LESSDN and 151 donors who underwent LDN were collected from 10 institutes. All LESSDNs were performed transperitoneally, whereas LDNs were performed transperitoneally (P-LDN) in 75 patients and retroperitoneally (R-LDN) in 76 patients.

RESULTS

In the LESSDN group, the single-incision site was pararectal in 155 (69.5%) patients and umbilical in 65 (29.1%) patients. Multiple surgeons (one to eight per institute) performed the LESSDN. No significant differences were observed between the three groups regarding estimated blood loss and warm ischemic time. The operative time was significantly shorter in the LESSDN group than in the R-LDN group (p = 0.018). No significant differences were observed regarding the rates of blood transfusion, open conversion, visceral injuries, and postoperative complications. Furthermore, no significant differences were observed regarding the dose of analgesic and the rate of delayed graft function. One patient required open conversion due to injury to the renal artery. Selection of LESS procedure was not an independent risk factor for the median serum creatinine level of above 1.27 mg/dL in recipients at 1 year after kidney transplantation.

CONCLUSION

The results showed the technical feasibility of LESSDN compared with the standard LDNs in a multi-institutional and multi-surgeon setting. A few observed non-negligible complications and the significantly higher levels of serum creatinine in patients who underwent LESSDN indicate that this procedure should be employed cautiously when performed by surgeons without ample experience in performing LESS procedures.

Systematic Surgical Assessment of Deceased-Donor Kidneys as a Predictor of Short-Term Transplant Outcomes

BACKGROUND

Short-term kidney graft dysfunction is correlated with complications and it is associated with a decreased long-term survival; therefore, a scoring system to predict short-term renal transplant outcomes is warranted.

AIM

The aim of this study is to quantify the impression of the organ procurement surgeon in correlation with the following kidney transplant outcomes: immediate graft function (IGF), delayed graft function (DGF), and primary nonfunction (PNF). Results are compared to factors associated with the 1-year outcome.

METHODS

A regional prospective pilot study was performed using deceased-donor organ assessment forms to be filled out by procurement surgeons after procurement. Data were gathered on kidney temperature, perfusion, anatomy, atherosclerosis, and overall quality.

RESULTS

Included were 90 donors who donated 178 kidneys, 166 of which were transplanted. Variables that were significantly more prevalent in the DGF-or-PNF group (n = 65) are: large kidney size (length, p = 0.008; width, p = 0.036), poor perfusion quality (p = 0.037), lower diuresis (p = 0.039), fewer hypotensive episodes (p = 0.003), and donation-after-circulatory-death donors (p = 0.017). Multivariable analysis showed that perfusion quality and kidney width significantly predicted the short-term outcome. However multivariable analysis of long-term outcomes showed that the first measured donor creatinine, kidney donor risk index, IGF vs. DGF+PNG, and kidney length predicted outcomes.

CONCLUSIONS

Results show that short-term graft function and 1-year graft function indeed are influenced by different variables. DGF and PNF occur more frequently in kidneys with poor perfusion and in larger kidneys. A plausible explanation for this is that these kidneys might be insufficiently washed out, or even congested, which may predispose to DGF. These kidneys would probably benefit most from reconditioning strategies, such as machine perfusion. A scoring system including these variables might aid in decision-making towards allocation and potential reconditioning strategies.

Urinary CXCL9 and CXCL10 Levels and Acute Renal Graft Rejection

BACKGROUND

Monitoring of chemokines, CXCL9 and CXCL10, in serum may present a non-invasive detection method for rejection.

OBJECTIVE

To investigate the relationship between urinary levels of CXCL9 and CXCL10 and graft function following renal transplantation.

METHODS

75 living-related donor renal transplant recipients were studied. Urinary levels of chemokines were collected pre-operatively, on post-operative 1^st day, 7^th day, 1^st month, 3^rd month, and at the time of rejection. Chemokines levels were assayed using and enzyme-linked immunosorbent assay.

RESULTS

Clinical variables were monitored. 10 (15%) patients had biopsy-proven rejection during the follow-up period. The urinary CXCL9 level in those with rejection was significantly higher than that in those with non-rejection group at the 1^st day (p<0.001), 7^th day (p<0.001), and at the time of rejection (p=0.002). The urinary CXCL10 level was also significantly higher in those with rejection compared with non-rejection group at 1^st day (p<0.001), 7^th day (p<0.001), and at the time of rejection (p=0.001). Serum creatinine level was strongly correlated with the urinary CXCL9 and CXCL10 levels at the time of rejection (r=0.615, p=0.002; and r=0.519, p=0.022, respectively). Among those with T cell-mediated rejections the mean urinary CXCL10 level increased to as high as 258.12 ng/mL.

CONCLUSION

Urinary CXCL9 and CXCL10 levels might have a predictive value for T cell-mediated rejection in early post-transplantation period. Measurement of urinary CXCL9 and CXCL10 levels could provide an additional tool for the diagnosis of rejection.

Recurrent urinary tract infections in kidney transplant recipients during the first-year influence long-term graft function: a single-center retrospective cohort study

Urinary tract infections (UTIs) after kidney transplantation are associated with significant morbidity. However, data on the impact of UTI on graft survival are controversial. We conducted a retrospective cohort study of 380 kidney transplant patients. Recipients with symptomatic UTIs during the first year after transplantation were categorized into three groups: early (< 3 episodes from months 1st to 6th), late (< 3 episodes during months 7th to 12th) and recurrent (≥ 3 episodes throughout the whole first year). Graft function at three years was considered the primary outcome. Symptomatic UTIs occurred in 184 (48.4%) kidney transplant recipients during the first year; 83 (21.8%) patients developed early UTIs, 50 (13.2%) late UTIs and 51 (13.4%) recurrent UTIs. We observed a significant improvement in graft function after three years in all patients (P < 0.001) except those who had recurrent UTIs. A Kaplan-Meier analysis showed that recipients with recurrent UTIs had worse graft outcome (eGFR value < 60 mL/min/1.73 m²) (P = 0.01). Recurrent UTIs was an independent predictor of graft function at three years in a model adjusted for DGF and episodes of acute rejection (Hazard Ratio, 2.2; 95% CI, 1.3 to 3.5; P = 0.001). Recurrent symptomatic UTIs during the first year after transplantation have negative impact on long-term graft function.

Platelet number and graft function predict intensive care survival in allogeneic stem cell transplantation patients

Despite significant advances in the treatment of complications requiring intensive care unit (ICU) admission, ICU mortality remains high for patients after allogeneic stem cell transplantation. We evaluated the role of thrombocytopenia and poor graft function in allogeneic stem cell recipients receiving ICU treatments along with established prognostic ICU markers in order to identify patients at risk for severe complications. At ICU admission, clinical and laboratory data of 108 allogeneic stem cell transplanted ICU patients were collected and retrospectively analyzed. Platelet counts (≤ 50,000/μl, p < 0.0005), hemoglobin levels (≤ 8.5 mg/dl, p = 0.019), and leukocyte count (≤ 1500/μl, p = 0.025) along with sepsis (p = 0.002) and acute myeloid leukemia (p < 0.0005) correlated significantly with survival. Multivariate analysis confirmed thrombocytopenia (hazard ratio (HR) 2.79 (1.58-4.92, 95% confidence interval (CI)) and anemia (HR 1.82, 1.06-3.11, 95% CI) as independent mortality risk factors. Predominant ICU diagnoses were acute respiratory failure (75%), acute kidney injury (47%), and septic shock (30%). Acute graft versus host disease was diagnosed in 42% of patients, and 47% required vasopressors. Low platelet (≤ 50,000/μl) and poor graft function are independent prognostic factors for impaired survival in critically ill stem cell transplanted patients. The underlying pathophysiology of poor graft function is not fully understood and currently under investigation. High-risk patients may be identified and ICU treatments stratified according to allogeneic stem cell patients' individual risk profiles. In contrast to previous studies involving medical or surgical ICU patients, the fraction of thrombocytopenic patients was larger and low platelets were a better differentiating factor in multivariate analysis than any other parameter.

A high level of urinary retinol-binding protein is associated with cytomegalovirus infection in kidney transplantation

The indirect effects of cytomegalovirus (CMV) viremia can be related to chronic changes in renal allograft structure, but its real impact in early and late graft function remains speculative. A total of 159 patients undergoing renal transplantation using a preemptive therapeutic strategy to prevent CMV disease were included in the present study. The patients were prospectively followed, with serial measurements of urinary retinol-binding protein (uRBP), a marker of proximal tubule injury. uRBP levels and their dynamic performance were compared according to CMV viremia and the 5-year estimated glomerular filtration rate (eGFR), as measured with the modification of diet in renal disease (MDRD) equation. CMV viremia was detected in 79.9% of the patients, with high uRBP levels being detected in 76.0% of these patients (compared with 40.7% in CMV-, P=0.005). High uRBP was associated with male recipients (P=0.02), the number of mismatches (P=0.02) and CMV infection (P=0.001). Five-year eGFR was worse in patients with high uRBP levels (50.3 ± 25.8 compared with 59.8 ± 26.4 ml/min, P=0.04). In a multivariate model, eGFR <60 ml/min was associated with donor age (P<0.001), the number of mismatches (P=0.04), thymoglobulin dose (P=0.02), the presence of and time with delayed graft function (DGF) (P=0.005 and P=0.04), 1-month tacrolimus levels (P=0.03), and uRBP levels after CMV treatment (P=0.01). Patients with CMV viremia in whom uRBP levels were normalized up to 3 months after treatment showed significantly better 5-year eGFR than those in whom uRBP remained high: 61.0 ± 24.2 compared with 42.3 ± 23.9 ml/min, P<0.001. CMV viremia was associated with high uRBP levels, which represent a profile of proximal tubule injury, and the dynamic performance of uRBP after treatment was associated with long-term kidney graft function.

Optimal immunosuppressor induces stable gut microbiota after liver transplantation

AIM

To study the influence of different doses of tacrolimus (FK506) on gut microbiota after liver transplantation (LT) in rats.

METHODS

Specific pathogen-free Brown Norway (BN) rats and Lewis rats were separated into five groups: (1) Tolerance group (BN-BN LT, n = 8); (2) rejection group (Lewis-BN LT, n = 8); (3) high dosage FK506 (FK506-H) group (Lewis-BN LT, n = 8); (4) middle dosage FK506 (FK506-M) group (Lewis-BN LT, n = 8); and (5) low dosage FK506 (FK506-L) group (Lewis-BN LT, n = 8). FK506 was administered to recipients at a dose of 1.0 mg/kg, 0.5 mg/kg, and 0.1 mg/kg body weight for 29 d after LT to the FK506-H, FK506-M, and FK506-L groups, respectively. On the 30^th day after LT, all rats were sampled and euthanized. Blood samples were harvested for liver function and plasma endotoxin testing. Hepatic graft and ileocecal tissues were collected for histopathology observation. Ileocecal contents were used for DNA extraction, Real-time quantitative polymerase chain reaction (RT-PCR) and digital processing of denaturing gradient gel electrophoresis (DGGE) profiles and analysis.

RESULTS

Compared to the FK506-H and FK506-L groups, FK506-M was optimal for maintaining immunosuppression and inducing normal graft function; the FK506-M maintained gut barrier integrity and low plasma endotoxin levels; furthermore, DGGE results showed that FK506-M induced stable gut microbiota. Diversity analysis indicated that FK506-M increased species richness and rare species abundance, and cluster analysis confirmed the stable gut microbiota induced by FK506-M. Phylogenetic tree analysis identified crucial bacteria associated with FK506-M; seven of the nine bacteria that were decreased corresponded to Bacteroidetes, while increased bacteria were of the Bifidobacterium species. FK506-M increased Faecalibacterium prausnitzii and Bifidobacterium spp. and decreased Bacteroides-Prevotella and Enterobacteriaceae, as assessed by RT-PCR, which confirmed the crucial bacterial alterations identified through DGGE.

CONCLUSION

Compared to the low or high dosage of FK506, an optimal dosage of FK506 induced immunosuppression, normal graft function and stable gut microbiota following LT in rats. The stable gut microbiota presented increased probiotics and decreased potential pathogenic endotoxin-producing bacteria. These findings provide a novel strategy based on gut microbiota for immunosuppressive dosage assessment for recipients following LT.

A dynamic model for predicting graft function in kidney recipients' upcoming follow up visits: A clinical application of artificial neural network

BACKGROUND

Predicting the function of transplanted kidneys would help clinicians in individualized medical interventions. We aimed to develop and validate a predictive tool for a future value of estimated glomerular filtration rate (eGFR) at upcoming visits.

METHODS

We used static and time-dependent covariates as inputs of artificial neural network based prediction models for predicting an eGFR value for an upcoming visit. We included 675 kidney recipients, who received transplant in the Urmia kidney transplant center in 2001-2013 and were longitudinally cared for in 2001-2017. The first 75% of records of longitudinal data of each patient were used to develop the prediction models and the remaining last 25% for evaluating its performance. Models' performances were evaluated by Mean Square Error (MSE) and Mean Absolute Error (MAE).

RESULTS

The development and validation datasets included 18,773 and 7038 records of historical data, respectively. The most accurate model included 3 static covariates of recipients' gender and donors' age and gender as well as 11 dynamic covariates of recipients including current age, time since transplant, serum creatinine, fasting blood sugar, weight and blood pressures available at each visit time. The performance of prediction models in the validation cohort was improved when history window of time dependent variables' recent values was increased from 1 to 10 (an MSE decline from 161 to 99).

CONCLUSIONS

Our best performed model is able to dynamically predict a future eGFR value for kidney recipients' upcoming visits. Integrating such a clinical tool into daily workflow of outpatient clinics can potentially support clinicians in optimal and individualized decision makings.

BKV, CMV, and EBV Interactions and their Effect on Graft Function One Year Post-Renal Transplantation: Results from a Large Multi-Centre Study. EBioMedicine. 2018;34:113-121. [PMID: 30072213 PMCID: PMC6116415 DOI: 10.1016/j.ebiom.2018.07.017]

Background

BK virus (BKV), Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) reactivations are common after kidney transplantation and associated with increased morbidity and mortality. Although CMV might be a risk factor for BKV and EBV, the effects of combined reactivations remain unknown. The purpose of this study is to ascertain the interaction and effects on graft function of these reactivations.

Methods

3715 serum samples from 540 kidney transplant recipients were analysed for viral load by qPCR. Measurements were performed throughout eight visits during the first post-transplantation year. Clinical characteristics, including graft function (GFR), were collected in parallel.

Findings

BKV had the highest prevalence and viral loads. BKV or CMV viral loads over 10,000 copies·mL⁻¹ led to significant GFR impairment. 57 patients had BKV-CMV combined reactivation, both reactivations were significantly associated (p = 0.005). Combined reactivation was associated with a significant GFR reduction one year post-transplantation of 11.7 mL·min⁻¹·1.73 m⁻² (p = 0.02) at relatively low thresholds (BKV > 1000 and CMV > 4000 copies·mL⁻¹). For EBV, a significant association was found with CMV reactivation (p = 0.02), but no GFR reduction was found. Long cold ischaemia times were a further risk factor for high CMV load.

Interpretation

BKV-CMV combined reactivation has a deep impact on renal function one year post-transplantation and therefore most likely on long-term allograft function, even at low viral loads. Frequent viral monitoring and subsequent interventions for low BKV and/or CMV viraemia levels and/or long cold ischaemia time are recommended.

Fund

Investigator Initiated Trial; financial support by German Federal Ministry of Education and Research (BMBF).

Preservation of kidney function in kidney transplant recipients by alkali therapy (Preserve-Transplant Study): rationale and study protocol

Background

Graft survival after kidney transplantation has significantly improved within the last decades but there is a substantial number of patients with declining transplant function and graft loss. Over the past years several studies have shown that metabolic acidosis plays an important role in the progression of Chronic Kidney Disease (CKD) and that alkalinizing therapies significantly delayed progression of CKD. Importantly, metabolic acidosis is highly prevalent in renal transplant patients and a recent retrospective study has shown that metabolic acidosis is associated with increased risk of graft loss and patient death in kidney transplant recipients. However, no prospective trial has been initiated yet to test the role of alkali treatment on renal allograft function.

Methods

The Preserve-Transplant Study is an investigator-initiated, prospective, patient-blinded, multi-center, randomized, controlled phase-IV trial with two parallel-groups comparing sodium bicarbonate to placebo. The primary objective is to test if alkali treatment will preserve kidney graft function and diminish the progression of CKD in renal transplant patients by assesing the change in eGFR over 2 years from baseline. Additionally we want to investigate the underlying pathomechanisms of nephrotoxicity of metabolic acidosis.

Discussion

This study has the potential to provide evidence that alkali treatment may slow or reduce the progression towards graft failure and significantly decrease the rate of end stage renal disease (ESRD), thus prolonging long-term graft survival. The implementation of alkali therapy into the drug regimen of kidney transplant recipients would have a favorable risk-benefit ratio since alkali supplements are routinely used in CKD patients and represent a well-tolerated, safe and cost-effective treatment.

Trial registration

ClinicalTrials.gov NCT03102996. Trial registration was completed on April 6, 2017.

Pancreas Transplantation for Patients with Type 1 and Type 2 Diabetes Mellitus in the United States: A Registry Report

Successful pancreas transplantation is still the only method to restore short-term and long-term insulin independence and good metabolic control for patients with diabetes. Since the first transplant in 1966, tremendous progress in outcome was made; however, transplant numbers have declined since 2004. This article describes the development and risk factors of pancreas transplantation with or without a kidney graft between 2001 and 2016. Patient survival and graft function improved significantly owing to careful recipient and donor selection, which reduced technical failure and immunologic graft loss rates.

Changes of NK cell subsets with time post-transplant in peripheral blood of renal transplant recipients

BACKGROUND

There is evidence that NK cells with low cytotoxicity but strong immunoregulatory characteristics contribute to good graft outcome. We attempted to investigate which NK cell subsets increase post-transplant and might affect graft function.

METHOD

Lymphocyte and NK cell subsets were determined in whole blood using eight-colour-fluorescence flow cytometry in patients pre-transplant and post-transplant. In total, 31 transplant recipients were studied.

RESULTS

When cell numbers were compared in 9 patients pre- and 6 months post-transplant, post-transplant CD56dimCD16+ (p = 0.011) NK cells with the phenotype CD158a+ (p = 0.008), CD158e+ (p = 0.038), NKG2A+ (p = 0.008), NKG2D+ (p = 0.011), IFNyR+ (p = 0.008), perforin+ (p = 0.008), granzymeB+ (p = 0.008), perforin+granzymeB+ (p = 0.008) and perforin-granzymeB- (p = 0.021) were lower than those pre-transplant, indicating a post-transplant reduction of cytotoxic NK cells. In 28 patients NK cell subsets were analyzed with respect to time post-transplant (median 888 days post-transplant). CD56dimCD16+ NK cells co-expressing CD158a (p = 0.014), NKG2D (p = 0.047), IL4R (p = 0.038), IL10R (p = 0.008) and IFNy (p = 0.036) as well as CD56bright NK cells with the phenotype TGFß+ (p = 0.017), TGFR+ (p = 0.035), CD158a+ (p = 0.042) and perforin-granzymeB- (p = 0.048) increased with time post-transplant.

CONCLUSION

Post-transplant, cytotoxic NK cells were lower than pre-transplant and remained low, whereas NK cell subsets with potentially immunoregulatory properties increased.

Quantification of Interstitial Fibrosis in Renal Allografts and Clinical Correlates of Long-Term Graft Function

BACKGROUND

The present study investigated interstitial fibrosis (IF) in 144 kidney recipients 0 h and 1 year post transplantation and assessed relationships with Banff code scores, clinical parameters, and long-term graft function.

METHODS

A quantitative analysis of IF was performed using the computer-assisted imaging of Sirius red-stained biopsy samples. Percent IF (%IF) in the cortical region was assessed at 0 h and 1 year, and an increase in the ratio of %IF from 0 h to 1 year was calculated. The relationship between %IF and Banff code scores was analyzed. Demographics and trough concentrations of tacrolimus were tested as risk factors in the top 20 patients with increases in %IF. The influence of increases in the ratio of %IF at 1 year on long-term graft function and survival was also assessed in these 20 patients.

RESULTS

Median %IF at 0 h and 1 year were 1.55 and 2.80%, respectively. No correlation was found between %IF and Banff code scores. The mean increase in the ratio of %IF from 0 h to 1 year was 4.31-fold. The increase in %IF in the top 20 patients correlated with diabetes mellitus. Graft function, but not graft survival, was lower in the top 20 patients for 10 years post transplantation.

CONCLUSIONS

A correlation was not found between %IF and Banff code scores. Greater increases in %IF within 1 year post transplantation may influence long-term graft survival. Computer-analyzed increases in %IF at 1 year may be a surrogate marker for long-term graft function.

Simultaneous Pancreas and Kidney Transplantation-Is It a Treatment Option for Patients With Type 2 Diabetes Mellitus? An Analysis of the International Pancreas Transplant Registry

PURPOSE OF REVIEW

Pancreas transplantation remains the best long-term treatment option to achieve euglycemia and freedom from insulin in patients with labile diabetes mellitus. It is an approved procedure for type 1 (T1DM), but it is still considered controversial for type 2 diabetes mellitus (T2DM).

RECENT FINDINGS

This study analyzed all primary deceased donor pancreas transplants in patients with T2DM reported to IPTR/UNOS between 1995 and 2015. Characteristics, outcomes, and risk factors over time were determined using univariate and multivariate methods. The focus was on simultaneous pancreas/kidney (SPK) transplants, the most common pancreas transplant category. Patient, pancreas, and kidney graft survival rates increased significantly over time and reached 95.8, 83.3, and 91.1%, respectively, at 3 years posttransplant for transplants performed between 2009 and 2015. SPK is a safe procedure with excellent pancreas and kidney graft outcome in patients with T2DM. The procedure restores euglycemia and freedom from insulin and dialysis. Based on our results, SPK should be offered to more uremic patients with labile T2DM.

Study of The Effects of N-Acetylcysteine on Oxidative Stress Status of Patients on Maintenance-Hemodialysis Undergoing Cadaveric Kidney Transplantation

N-acetylcysteine (NAC) is a potent antioxidant that acts through regenerating glutathione stores and scavenging oxygen-free radicals. This study assesses the short-term effects of NAC in cadaveric kidney transplant (KT) recipients. A double blind, randomized, placebo controlled trial was designed and patients were randomly assigned to receive either NAC or placebo. Glutathione peroxidase (GPX) activity in erythrocytes and serum malondialdehyde (MDA) levels were measured and serum creatinine levels and estimated glomerular filtration rate (eGFR) determined in the early phase after transplantation, were also compared between two study groups. Thirty-seven males and 20 females, with mean ± SD age of 44.6 ± 12.4 years completed the study. Significant difference (P = 0.02) was seen between GPX activity reduction in the placebo group, and that of the NAC group and on the levels of MDA there was no significant difference between two study groups (P = 0.53). Significant improvement in immediate graft function (IGF), (68% versus 40%, P = 0.05) and the first week eGFR were observed in the NAC group compared to the placebo group (52.46 ± 2.77 versus 38.75 ± 19.67 mL/min/1.73 m², P = 0.02). It seems that the protective mechanisms of NAC, other than its antioxidant properties, can be favorable in KT patients.

Paediatric obesity and renal transplantation: current challenges and solutions

The increased incidence of obesity in the paediatric population poses significant challenges to renal transplantation. Whilst the body mass index appears to be widely used as a measure of obesity in adults, there are no standardised definitions in the paediatric population, making comparative analyses difficult. In the paediatric transplant population, obesity is associated with an increased incidence of surgical complications, diabetes, hyperlipidaemia and cardiovascular morbidity, leading to diminished graft function and impacting patient and graft survival. Management of obesity in renal transplantation requires multiple interventions starting with life-style and behavioural modification combined with medical and possibly surgical therapies, representing a unique challenge in the childhood setting. In this review we discuss the current challenges of obesity and potential solutions in the setting of paediatric transplantation.

Portable device for the analysis of liver function: a boon to liver surgery and critical care

Liver biology, liver disease and its management present a myriad of challenges to clinicians. Difficulties arise in determining liver functional capacity, which must be effectively measured in a quantitative reproducible manner. Measurement of indocyanine green (ICG) clearance, an exceptional tool that has been used for decades to assess liver function, has traditionally been cumbersome to perform. New technology now allows for rapid and noninvasive determination of ICG clearance making it clinically accessible. This adds ICG clearance measurement to the armamentarium of physiologic monitors that could be routinely used in the evaluation of patients undergoing liver surgery or in the intensive care setting.

Heme Oxygenase-1 Promoter Polymorphism Protects Liver Allograft

Heme oxygenase-1 has been identified to protect allograft from ischemia/reperfusion and immunologic rejection. Activity of heme oxygenase-1 is regulated by a guanine-thymine dinucleotide length polymorphism in the heme oxygenase-1 gene promoter. In this study, we aimed to explore the impact of the heme oxygenase-1 gene promoter polymorphism of donors and recipients on the orthotopic liver graft function after transplantation. Sixty recipients and their accompanying donors of orthotopic liver allografts were included retrospectively in this study. Heme oxygenase-1 gene promoter polymorphism was assessed using genomic DNA isolated from cryopreserved splenocytes or peripheral blood mononuclear cells and analyzed by genetic analyzer. Small allele of the donor heme oxygenase-1 gene polymorphism significantly prolonged the graft survival (p = 0.017). Recipients of allografts from a class of small-allele carrier had significantly lower serum total bilirubin compared with recipients of a nonclass small-allele donor liver (p < 0.01). Additionally, in recipients of small-carrier allografts, cold ischemia time (<10 h or ≥10 h) did not affect the total bilirubin significantly. Our study suggested a protective function of donor-derived heme oxygenase-1 gene promoter polymorphism on orthotopic liver allograft function after transplantation.

Feasibility and outcomes of laparoscopic sleeve gastrectomy after solid organ transplantation

BACKGROUND

Obesity is common after solid organ transplantation and is associated with worse transplantation-related outcomes. Laparoscopic sleeve gastrectomy (LSG) may be the preferred bariatric operation in transplantation patients over other techniques, such as gastric bypass, given the concerns about medication absorption. However, little is known about LSG outcomes in post-transplantation patients.

OBJECTIVES

We report the outcomes in 10 consecutive patients who underwent solid organ transplantation followed by LSG.

SETTING

An academic medical center.

METHODS

Primary outcomes studied were weight loss, perioperative complications, resolution or improvement of obesity-related co-morbidities, and markers of graft function following LSG.

RESULTS

The types of transplantation before LSG were as follows: liver = 5, kidney = 4, and heart = 1. Mean body mass index (BMI) at LSG was 44.7 ± 1.7 kg/m(2). All patients had hypertension, and 6 had type 2 diabetes. Perioperative complications occurred in 2 patients, and there were no deaths. Excess weight loss at 12 and 24 months after LSG was 45.7% and 42.5%, respectively. At 1 year after LSG, there was a significant reduction in the number of antihypertensive medications (2.4 to 1.5; P = .02). Three patients achieved complete remission of type 2 diabetes, and the other 3 significantly reduced their dosages of insulin. Graft function remained preserved in liver transplantation patients; left ventricular ejection fraction (LVEF) increased by 10% in the heart transplantation subject, and the estimated glomerular filtration rate (eGFR) increased significantly in kidney transplantation patients (53 ± 3 to 82 ± 3 mL/min; P = .03).

CONCLUSIONS

We concluded that LSG, in selected patients with severe obesity after solid organ transplantation, results in significant weight loss, improvement or resolution of obesity-related conditions, and preservation or improvement of graft function. Larger studies are needed to determine tolerability standards.

Effect of high-dose erythropoietin on graft function after kidney transplantation: a meta-analysis of randomized controlled trials

PURPOSE

Current evidence suggests that preconditioning with erythropoietin (EPO) can protect against ischemia reperfusion injury in rodents. However, randomized controlled trials (RCTs) assessing the efficacy and safety of high-dose EPO in kidney transplantation have yielded inconclusive results. Herein, we performed a meta-analysis of RCTs to assess whether the administration of high-dose EPO can improve graft function and the potential adverse events.

METHODS

Relevant RCT studies that investigated high-dose EPO on graft function after kidney transplantation were comprehensively searched in Pubmed, Embase, and Cochrane Library until July 10, 2014. All statistical analyses were performed using Review Manager 5.0 and STATA 12.0.

RESULTS

A total of 4 RCTs involving 356 patients were identified. Comprehensively, a trend of reduction in the incidence of delayed graft function could be observed in the EPO group (EPO vs. placebo groups: RR=0.88); however, the result did not reach the significance level (95% CI, 0.72-1.08; P=0.21). Furthermore, no significant difference in the incidences of adverse events was observed between the two groups.

CONCLUSIONS

The current meta-analysis indicates that the administration of high-dose EPO is, to some extent, prone to protect kidney function without increasing the susceptibility to adverse events.

Impact of calcineurin-inhibitor conversion to mTOR inhibitor on renal allograft function in a prednisone-free regimen

Traditionally, chronic calcineurin inhibitor (CNI) nephrotoxicity has been considered to be one of the main nonimmune mechanisms causing chronic renal allograft dysfunction. CNI minimization and withdrawal strategies have yielded inconsistent results. Few studies address the feasibility of CNI elimination in a prednisone-free regimen. We report a prospective, randomized trial in 200 patients evaluating the impact on renal function and incidence of acute rejection after conversion from tacrolimus (Tac) to sirolimus (SRL). Patients with recent (<3 months) acute rejection episodes or with >0.5 g/day of proteinuria were excluded. All were induced with alemtuzumab, underwent rapid steroid elimination and were maintained on mycophenolate mofetil and Tac. At 12 months posttransplant, patients were randomized 2:1 to SRL (n = 123) or maintained on Tac (n = 64). Mean follow-up was 41.1 ± 15.8 months in the SRL group and 40.7 ± 14.4 months in the Tac group. Biopsy-proven acute rejection at 24 months postrandomization was similar between the groups. Patient survival, graft survival and estimated GFR were also not statistically different. Our study demonstrates that in a prednisone-free immunosuppressive regimen, conversion from Tac to SRL at 12 months posttransplantation is not associated with increased rates of acute rejection and graft loss. However, despite CNI elimination, renal allograft function is equally maintained in both groups.

Major influence of renal function on hyperlipidemia after living donor liver transplantation

AIM: To investigate the impact of renal and graft function on post-transplant hyperlipidemia (PTHL) in living donor liver transplantation (LDLT).

METHODS: A total of 115 adult patients undergoing LDLT from January 2007 to May 2009 at a single center were enrolled. Data were collected and analyzed by the China Liver Transplant Registry retrospectively. PTHL was defined as serum triglycerides ≥ 150 mg/dL or serum cholesterol ≥ 200 mg/dL or the need for pharmacologic treatment at the sixth month after LDLT. Early renal dysfunction (ERD) was defined as serum creatinine ≥ 2 mg/dL and/or the need for renal replacement therapy in the first post-transplant week.

RESULTS: In 115 eligible patients, the incidence of PTHL was 24.3%. Recipients with PTHL showed a higher incidence of post-transplant cardiovascular events compared to those without PTHL (17.9% vs 4.6%, P = 0.037). Serum creatinine showed significant positive correlations with total serum triglycerides, both at post-transplant month 1 and 3 (P < 0.01). Patients with ERD had much higher pre-transplant serum creatinine levels (P < 0.001) and longer duration of pre-transplant renal insufficiency (P < 0.001) than those without ERD. Pre-transplant serum creatinine, graft-to-recipient weight ratio, graft volume/standard liver volume ratio, body mass index (BMI) and ERD were identified as risk factors for PTHL by univariate analysis. Furthermore, ERD [odds ratio (OR) = 9.593, P < 0.001] and BMI (OR = 6.358, P = 0.002) were identified as independent risk factors for PTHL by multivariate analysis.

CONCLUSION: Renal function is closely associated with the development of PTHL in LDLT. Post-transplant renal dysfunction, which mainly results from pre-transplant renal insufficiency, contributes to PTHL.

Evaluating graft function in pediatric recipients for living donor renal transplantation: Is laparoscopic donor nephrectomy safe?

Objective:

To evaluate the surgical and functional outcomes of laparoscopic graft procurement in pediatric patients undergoing renal transplantation.

Materials and Methods:

A retrospective chart review of the cohort records of 54 pediatric living donor renal transplant recipients from 1985 through June 2006 was performed. We compared results of laparoscopic donor nephrectomy (LDN, n = 15) and open donor nephrectomy (ODN, n = 39). Parameters analysed included donor technique and morbidity, operative complications, immediate postoperative renal function, the incidence of early and delayed graft function, and long-term graft survival.

Results:

The mean age of these recipients was 14.8 years (5-18) in the LDN group and 13.9 years (8-18) in ODN group. Serum creatinine (mg/dl) was 1.5 ± 0.7 vs 1.8 ± 1.3 at day 1 (P = 0.20), 1.0 ± 0.3 vs 1.4 ± 1.3 at day 2 (P = 0.12), 1.1 ± 0.9 vs 1.3 ± 1.0 at day 7 (P = 0.25), 1.2 ± 0.5 vs 1.6 ± 1.8 (P = 0.20) at day 14, 1.1 ± 0.7 vs 1.2 ± 1.4 (P = 0.39) at 1 month in LDN vs ODN groups, respectively. Early graft function was 35.7 vs 46.4% in the respective groups. There were two delayed graft function and one graft nonfunction in ODN group. Over all graft and patient survival at 1 year was 86.67 and 82.22% (P = 0.34) in LDN and ODN groups, respectively.

Conclusion:

Pediatric recipients of the LDN grafts have outcomes comparable to those of ODN graft recipients. Laparoscopic donor nephrectomy is safe and efficacious for graft procurement for pediatric recipients.