New Tools for Data Harmonization and Their Potential Applications in Organ Transplantation

In organ transplantation, accurate analysis of clinical outcomes requires large, high-quality data sets. Not only are outcomes influenced by a multitude of factors such as donor, recipient, and transplant characteristics and posttransplant events but they may also change over time. Although large data sets already exist and are continually expanding in transplant registries and health institutions, these data are rarely combined for analysis because of a lack of harmonization. Promoted by the digitalization of the healthcare sector, effective data harmonization tools became available, with potential applications also for organ transplantation. We discuss herein the present problems in the harmonization of organ transplant data and offer solutions to enhance its accuracy through the use of emerging new tools. To overcome the problem of inadequate representation of transplantation-specific terms, ontologies and common data models particular to this field could be created and supported by a consortium of related stakeholders to ensure their broad acceptance. Adopting clear data-sharing policies can diminish administrative barriers that impede collaboration between organizations. Secure multiparty computation frameworks and the artificial intelligence (AI) approach federated learning can facilitate decentralized and harmonized analysis of data sets, without sharing sensitive data and compromising patient privacy. A common image data model built upon a standardized format would be beneficial to AI-based analysis of pathology images. Implementation of these promising new tools and measures, ideally with the involvement and support of transplant societies, is expected to produce improved integration and harmonization of transplant data and greater accuracy in clinical decision-making, enabling improved patient outcomes.

Effects of erector spinae plane block on opioid consumption in patients undergoing hand-assisted laparoscopic donor nephrectomy: a randomized controlled trial

BACKGROUND

The erector spinae plane block is a relatively new regional anesthesia technique that is expected to provide some benefits for postoperative analgesia. This study investigated the effects of erector spinae plane block on postoperative opioid consumption in kidney donors undergoing hand-assisted laparoscopic donor nephrectomy for renal transplantation.

METHODS

Fifty-two donors scheduled for elective hand-assisted laparoscopic donor nephrectomy were randomly divided into the block (25 donors) and control (27 donors) groups. Donors in the block group received 30 mL of 0.25% bupivacaine under ultrasound guidance, whereas the control group received no block treatment. The primary outcome measure was the amount of fentanyl administered via patient-controlled analgesia at 24 h. Secondary outcomes included the duration of stay, opioid consumption in the post-anesthesia care unit, and pain scores during the recording hours.

RESULTS

No significant differences were observed between the groups regarding total opioid consumption converted to intravenous morphine equivalent administered via patient-controlled analgesia (33.3±21.4 mg vs. 37.5±18.5 mg; P=0.27) and in the postanesthesia care unit (1.5±0.9 mg vs. 1.4±0.8 mg; P=0.55). The duration of stay in the postanesthesia care unit (86.3±32.6 min vs. 85.7±33.6 min; P=0.87) was similar between the groups. There was no significant difference between the groups in the postoperative donor-reported NRS pain scores (P>0.05 for all the time points).

CONCLUSIONS

Preoperative erector spinae plane block is not an effective strategy for reducing postoperative pain or opioid consumption in patients undergoing hand-assisted laparoscopic donor nephrectomy. Different block combinations are needed for optimal pain management in hand-assisted laparoscopic donor nephrectomy.

Improving the urine spot protein/creatinine ratio by the estimated creatinine excretion to predict proteinuria in pediatric kidney transplant recipients

BACKGROUND

Since the daily creatinine excretion rate (CER) is directly affected by muscle mass, which varies with age, gender, and body weight, using the spot protein/creatinine ratio (Spot P/Cr) follow-up of proteinuria may not always be accurate. Estimated creatinine excretion rate (eCER) can be calculated from spot urine samples with formulas derived from anthropometric factors. Multiplying Spot P/Cr by eCER gives the estimated protein excretion rate (ePER). We aimed to determine the most applicable equation for predicting daily CER and examine whether ePER values acquired from different equations can anticipate measured 24 h urine protein (m24 h UP) better than Spot P/Cr in pediatric kidney transplant recipients.

METHODS

This study enrolled 23 children with kidney transplantation. To estimate m24 h UP, we calculated eCER and ePER values with three formulas adapted to children (Cockcroft-Gault, Ghazali-Barratt, and Hellerstein). To evaluate the accuracy of the methods, Passing-Bablok and Bland-Altman analysis were used.

RESULTS

A statistically significant correlation was found between m24 h UP and Spot P/Cr (p < .001, r = 0.850), and the correlation was enhanced by multiplying the Spot P/Cr by the eCER equations. The average bias of the ePER formulas adjusted by the Cockcroft-Gault, Ghazali-Barratt, and Hellerstein equations were -0.067, 0.031, and 0.064 g/day, respectively, whereas the average bias of Spot P/Cr was -0.270 g/day obtained by the Bland-Altman graphics.

CONCLUSION

Using equations to estimate eCER may improve the accuracy and reduce the spot urine samples' bias in pediatric kidney transplantation recipients. Further studies in larger populations are needed for ePER reporting to be ready for clinical practice.

Significance of caveolin-1 immunohistochemical staining differences in biopsy samples from kidney recipients with BK virus viremia

BK virus infections which usually remains asymptomatic in healthy adults may have different clinical manifestations in immunocompromised patient population. BK virus reactivation can cause BK virus nephropathy in 8% of kidney transplant patients and graft loss may be seen if not treated. Clathrin or Caveolar system is known to be required for the transport of many viruses from Polyomaviruses family including BK viruses. In this study, kidney transplant patients with BK virus viremia were divided into two groups according to the BK virus nephropathy found in kidney biopsy (Group I: Viremia+, Nephropathy+ / Group II: Viremia+, Nephropathy-). Kidney biopsies were examined with immunohistochemical staining to determine the distribution and density of the Caveolin-1 and Clathrin molecules. Immunohistochemical staining of the 31 pathologic specimens with anti-caveolin-1 immunoglobulin revealed statistically significant difference between group-I and group-II. The number of the specimens stained with anti-caveolin-1 was less in group I. On the other hand, we did not find any difference between the groups regarding the anti-clathrin immunochemical analysis. According to these findings, caveolin-1 expression differences in kidney transplant patients may be important in disease progression.

Oligosymptomatic Kidney Transplant Patients With COVID-19: Do They Pose a Risk to Other Recipients?

The clinical course of viral infections in patients under immunosuppression can be atypical and/or fatal if not diagnosed and treated appropriately. The coronavirus disease 2019 (COVID-19) may also have an atypical presentation. Contrary to the general opinion, transplant patients may be asymptomatic or oligosymptomatic, which could be a risk factor for underdiagnosis and the dissemination of this viral disease.

This study presents the clinical features of 2 oligosymptomatic kidney transplant patients diagnosed with COVID-19. We suggest that new screening algorithms for COVID-19 should be reconsidered for the transplant patient population.

Case report: A kidney transplant patient with mild COVID-19

Coronavirus Disease 2019 (COVID‐19) is currently a pandemic with a mortality rate of 1%‐6% in the general population. However, the mortality rate seems to be significantly higher in elderly patients, especially those hospitalized with comorbidities, such as hypertension, diabetes, or coronary artery diseases. Because viral diseases may have atypical presentations in immunosuppressed patients, the course of the disease in the transplant patient population is unknown. Hence, the management of these patients with COVID‐19 is an area of interest, and a unique approach is warranted. Here, we report the clinical features and our treatment approach for a kidney transplant patient with a diagnosis of COVID‐19. We believe that screening protocols for SARS‐Cov‐2 should be re‐evaluated in patients with solid‐organ transplants.

Risk factors for febrile urinary tract infections in the first year after pediatric renal transplantation

Urinary tract infection is the most common infectious complication following kidney transplant. Anatomic abnormalities, bladder dysfunction, a positive history of febrile urinary tract infection, and recipient age are reported risk factors. The aim of this study was to determine the risk factors for fUTI, which necessitated hospitalization in the first year after renal transplantation in our pediatric transplant population. A retrospective review of 195 pediatric patients who underwent kidney transplant between 2008 and 2017 from a single institution was performed. All patients admitted to the hospital with fUTI were marked for further analyses. The risk factors including age, gender, dialysis type, history of urologic disorders, and preoperative proteinuria for fUTI in the first year after kidney transplantation and graft survivals were investigated. Independent-sample t test and chi-square tests were used for univariate analysis. Exhaustive CHAID algorithm was used for multivariate analysis. The data of 115 male and 80 female patients were retracted. The mean ages of our cohort for males and females were 9.5 ± 5.1 and 10 ± 4.8 years, respectively. The age of the patients at transplant and their gender were found to be a statistically significant risk factors for developing fUTIs. Multivariate analysis showed that fUTI was common in female patients and a subgroup of male patients who had preoperative proteinuria, but no neurogenic bladder had higher risk compared with male patients without proteinuria. Patient surveillance and antibiotic prophylaxis algorithms can be developed to prevent febrile urinary tract infections seen after pediatric kidney transplantation in risky population.

Impact of ureteral stricture and treatment choice on long-term graft survival in kidney transplantation

We aimed to evaluate the influence of urological complications occurring within the first year after kidney transplantation on long-term patient and graft outcomes, and sought to examine the impact of the management approach of ureteral strictures on long-term graft function. We collected data on urological complications occurring within the first year posttransplant. Graft survivals, patient survival, and rejection rates were compared between recipients with and without urological complications. Male gender of the recipient, delayed graft function, and donor age were found to be significant risk factors for urological complications after kidney transplantation (P < .05). Death censored graft survival analysis showed that only ureteral strictures had a negative impact on long-term graft survival (P = .0009) compared to other complications. Death censored graft survival was significantly shorter in kidney recipients managed initially with minimally invasive approach when compared to the recipients with no stricture (P = .001). However, graft survival was not statistically different in patients managed initially with open surgery (P = .47). Ureteral strictures following kidney transplantation appear to be strongly negatively correlated with long-term graft survival. Our analysis suggests that kidney recipients with ureteral stricture should be managed initially with open surgery, with better long-term graft survival.

Ipsilateral versus contralateral placement of the pancreas allograft in pancreas after kidney transplant recipients

BACKGROUND

In a diabetic, uremic kidney transplant recipient that may receive a future pancreas after kidney (PAK) transplant, the kidney is typically implanted on the left side in anticipation of the subsequent pancreas transplant on the right side. In this study, we sought to determine if ipsilateral PAK (iPAK) is as safe as contralateral PAK (cPAK).

METHODS

The 115 PAK transplants (iPAK n = 57, cPAK n = 58) were performed from 1997-2010 and results were compared between the groups.

RESULTS

Kidney graft survival and pancreas graft survival was similar between the two groups. Kidney graft function according to serum creatinine and eGFR was not different between the cPAK and the iPAK groups and there were no episodes of kidney graft thrombosis in either group. Subgroup analyses focusing on donor source also did not show worse outcomes for graft survivals in iPAK group when compared to cPAK group.

CONCLUSIONS

Pancreas and kidney graft survival in PAK transplants is unaffected by the surgical procedure and iPAK is safe.

Pancreas transplantation in older patients is safe, but patient selection is paramount

Pancreas transplant outcomes have progressively improved. Despite this, some centers have continued to employ historical age limits for pancreas transplant candidates. We sought to determine the importance of chronological age in determining patient and graft survival rates after pancreas transplantation. A single-center, retrospective study of adult, deceased donor simultaneous pancreas and kidney (SPK) and solitary pancreas transplants (SP, including pancreas transplant alone and pancreas after kidney transplants) in recipients ≥ 55 years (55 + ), occurring between July 1, 1999, and June 30, 2012, was performed. Seven-hundred and forty patients underwent pancreas transplantation, of which 28 patients were 55 + . Patient survival was comparable for younger and older pancreas transplant recipients. Both non-death-censored and death-censored pancreatic graft survival rates were similar in younger and in older patients. Patients aged 45-54 and those aged 55 +  had more frequent cardiovascular events than younger pancreas transplant recipients. There was no difference in renal graft survival for SPK patients when compared with diabetic kidney transplant alone recipients aged 55 years and older. Older pancreas transplant recipients had acceptable long-term patient and graft survival rates, although complications may occur. Chronological age alone should not exclude a patient for pancreas transplant candidacy.

Evaluation of TH17 and TH1 Immune Response Profile in Patients After Renal Transplant

BACKGROUND

Renal transplantation (RT) is the best treatment option for patients with end-stage renal disease (ESRD) because it improves both quality of life and survival. However, allograft rejection remains the most important barrier to successful transplantation. Underlying immunologic mechanisms should be understood to develop appropriate treatment strategies.

METHODS

In this prospective study, we followed renal transplant recipients for 6 months. The study population comprised 50 recipients of renal transplants, and these were divided into 2 groups: 44 patients with stable graft function (SGF) and 6 patients with rejection (RX). Peripheral blood samples were drawn from patients on the pre-RT day, at post-RT day 7, month 1, and month 6, and on the day of rejection for analysis of the percentages of cytokines interleukin (IL) 17 and interferon (IFN) γ with the use of flow cytometry and enzyme-linked immunosorbent assay.

RESULTS

The percentages of intracellular IFN-γ were not significant in the group with RX compared with SGF. Levels of intracellular IL-17 obtained at the 6th month after RT were significantly higher in the RX group than in the SGF group. Plasma levels of pre-RT IL-17 were also higher in the RX group; therefore, it may be a predictive biomarker of acute rejection of renal transplants.

CONCLUSIONS

The present study provides information about pre-RT and post-RT cytokine profiles of Turkish patients with ESRD. We consider cytokine analysis to be a valuable biomarker panel in the prevention of rejection and in assisting with new treatment strategies for patients undergoing renal transplant.

Does DCD Donor Time-to-Death Affect Recipient Outcomes? Implications of Time-to-Death at a High-Volume Center in the United States

For donation after circulatory death (DCD), many centers allow 1 h after treatment withdrawal to donor death for kidneys. Our center has consistently allowed 2 h. We hypothesized that waiting longer would be associated with worse outcome. A single-center, retrospective analysis of DCD kidneys transplanted between 2008 and 2013 as well as a nationwide survey of organ procurement organization DCD practices were conducted. We identified 296 DCD kidneys, of which 247 (83.4%) were transplanted and 49 (16.6%) were discarded. Of the 247 recipients, 225 (group 1; 91.1%) received kidneys with a time to death (TTD) of 0-1 h; 22 (group 2; 8.9%) received grafts with a TTD of 1-2 h. Five-year patient survival was 88.8% for group 1, and 83.9% for group 2 (p = 0.667); Graft survival was also similar, with 5-year survival of 74.1% for group 1, and 83.9% for group 2 (p = 0.507). The delayed graft function rate was the same in both groups (50.2% vs. 50.0%, p = 0.984). TTD was not predictive of graft failure. Nationally, the average maximum wait-time for DCD kidneys was 77.2 min. By waiting 2 h for DCD kidneys, we performed 9.8% more transplants without worse outcomes. Nationally, this practice would allow for hundreds of additional kidney transplants, annually.

Living Kidney Donors With Adrenal Incidentalomas: Are They Appropriate Donors?

OBJECTIVE

To determine the incidence of adrenal incidentalomas (AIs) in a single-center series of living renal donors, to describe an evaluation algorithm for AIs in this patient population, and to compare the complication rates of hand-assisted laparoscopic donor nephrectomy (HALDN) with those of combined HALDN and adrenalectomy.

METHODS

We performed a single-center, retrospective study of consecutive living kidney donors who underwent laparoscopic nephrectomy for transplantation, with or without simultaneous ipsilateral adrenalectomy, between January 2008 and September 2014.

RESULTS

During the study period, AIs were detected in 18 of 1033 potential living renal donors who underwent computerized tomographic angiography. Application of additional donor selection criteria and of an adrenal mass assessment algorithm resulted in 849 HALDN, of which 13 were combined with simultaneous adrenalectomy. The hospital length of stay (2.4 vs 2.6 days), perioperative (0.025 vs 0.077), early (0.073 vs 0.077), and late (0.014 vs 0.077) postoperative complication rates, and conversion to open donor nephrectomy (0.008 vs 0.00) were not significantly different. Mean operative time was significantly longer in the adrenalectomy group. None of the adrenal masses were malignant.

CONCLUSION

Here, we presented our algorithm to manage the living kidney donors with AIs. Although donor population with AIs was relatively small in number, simultaneous adrenalectomy and ipsilateral nephrectomy seemed to be technically safe and conferred no identifiable increased risk of malignancy for the kidney transplant donor, when the incidentaloma is nonfunctional and less than or equal to 4 cm as assessed by preoperative imaging.

The efficacy of radiographic anatomical measurement methods in predicting success after extracorporeal shockwave lithotripsy for lower pole kidney stones

OBJECTIVES

To assess the impact of lower pole calyceal anatomy on clearace of lower pole stones after extracorporeal shockwave lithotripsy (ESWL) by means of a new and previously defined radiographic measurement method.

MATERIALS AND METHODS

Sixty-four patients with solitary radiopaque lower pole kidney stones were enrolled in the study. Infundibulopelvic angle (IPA), infundibulotransverse angle (ITA), infundibular lenght(IL), and infundibular width (IW) were measured on the intravenous urographies which were taken before the procedure.

RESULTS

48 of 64 patients (75%) were stone-free after a follow-up period of 3 months. The IPA,ITA,IL and IW were determined as statistically significant factors, while age,gender and stone area were found to have no impact on clearance.

CONCLUSION

By the help of radiographic measurement methods related to lower pole kidney anatomy, appropriate patient selection and increment in success after ESWL may be achieved.

Eculizumab for salvage treatment of refractory antibody-mediated rejection in kidney transplant patients: case reports

Antibody-mediated rejection (AMR) in a group of preoperatively desensitized patients may follow a dreadful course and result in loss of the transplanted kidney. In several cases, conventional therapies including plasmapheresis, intravenous immunoglobulin, and anti-CD 20 therapy can resolve AMR successfully. But in some cases the load of immunoglobulins that can activate complement cascade may submerge the routine desensitization therapy and result in the formation of membrane attack complexes. Eculizumab, monoclonal antibody against C5, was reported to be an option in cases with severe AMR that are resistant to conventional therapy. Here, we present two cases of acute-onset AMR in preoperatively desensitized patients. Eculizumab was used as a salvage agent in addition to conventional therapy. Given the bad prognosis for renal transplants displaying acute injury progressing rapidly to cortical necrosis on the biopsy, the prompt use of eculizumab could have the advantage of immediate effects by stopping cellular injury. This can provide a therapeutic window to allow conventional treatment modalities to be effective and prevent early graft loss.

What has changed in pediatric kidney transplantation in Turkey? Experience of an evolving center

INTRODUCTION

Reluctance to perform kidney transplantations on children is an ongoing problem in Turkey. Moreover, urological pathologies still constitute the largest portion of the underlying etiologies in chronic renal failure patients. Herein, we retrospective analyzed the data acquired from our pediatric renal transplantation patients and reviewed the registry of dialysis and transplantation data prepared by the Turkish Society of Nephrology.

MATERIAL AND METHODS

Forty-six living donor kidney transplantations were performed in children between 2008 and 2012. Seventeen of 46 (37%) transplantations were preemptive. The mean age at operation time was 10.8 ± 5 years. The mean patient weight was 31.3 ± 15.8 kg (range, 9.4 to 66.4 kg). A detailed urologic evaluation was performed for every child with an underlying lower urinary tract disease. One enterocystoplasty and 2 ureterocystoplasties were performed for augmentation of the bladder, simultaneously.

RESULTS

One-year death-censored graft survival and patient survival rates were 100% and 97.8%, respectively. The mean serum creatinine level was 0.86 ± 0.32 mg/dL (range, 0.3 to 1.8 mg/dL). None of the patients had vascular complications or acute tubular necrosis. One patient suffered graft-versus-host disease during the second month after renal transplantation and died with a functioning graft. In one patient with massive proteinuria detected after transplantation, recurrence of primary disease (focal segmental glomerulosclerosis) was considered and the patient was treated successfully with plasmapheresis. One child had an acute cellular rejection and was administered pulse steroid treatment.

CONCLUSION

Although challenging, all patients in all pediatric age groups can successfully be operated and managed. With careful surgical technique, close postoperative follow-up, and efforts by the experienced and respectful surgical teams in this country, we could change the negative trends toward perform kidney transplantation in the Turkish pediatric population.