HLA-mismatched renal transplantation without maintenance immunosuppression

Five patients with end-stage renal disease received combined bone marrow and kidney transplants from HLA single-haplotype mismatched living related donors, with the use of a nonmyeloablative preparative regimen. Transient chimerism and reversible capillary leak syndrome developed in all recipients. Irreversible humoral rejection occurred in one patient. In the other four recipients, it was possible to discontinue all immunosuppressive therapy 9 to 14 months after the transplantation, and renal function has remained stable for 2.0 to 5.3 years since transplantation. The T cells from these four recipients, tested in vitro, showed donor-specific unresponsiveness and in specimens from allograft biopsies, obtained after withdrawal of immunosuppressive therapy, there were high levels of P3 (FOXP3) messenger RNA (mRNA) but not granzyme B mRNA.

A prospective, randomized, clinical trial of intraoperative versus postoperative Thymoglobulin in adult cadaveric renal transplant recipients

BACKGROUND

Delayed graft function (DGF) is frequently observed in recipients of cadaveric renal transplants. Previous retrospective or nonrandomized studies have suggested that intraoperative administration of polyclonal antithymocyte preparations may reduce the incidence of DGF, possibly by decreasing ischemia-reperfusion injury.

METHODS

We performed a prospective randomized study of Thymoglobulin induction therapy in adult cadaveric renal transplant recipients. Between January 2001 and January 2002, 58 adult cadaveric renal transplant recipients were randomized to receive intraoperative or postoperative Thymoglobulin induction therapy. Three to six doses of Thymoglobulin (1 mg/kg/dose) were administered during the first week posttransplant. Baseline immunosuppression consisted of tacrolimus (54 of 58) or cyclosporine A (4 of 58), steroids, and mycophenolate mofetil. DGF was defined by the requirement for hemodialysis within the first week posttransplant.

RESULTS

There were no significant differences between the two groups in recipient demographics, donor age, cold ischemia time, or total number of doses of Thymoglobulin administered. Intraoperative Thymoglobulin administration was associated with significantly less DGF and a lower mean serum creatinine on postoperative days 10 and 14 (P<0.05). Posttransplant length of stay was also significantly shorter for the intraoperative Thymoglobulin patient group. The acute rejection rate was also lower in the intraoperative treatment group but this did not achieve statistical significance. There was no difference in the incidence of cytomegalovirus disease between the two groups.

CONCLUSIONS

The results of this study indicate that intraoperative Thymoglobulin administration, in adult cadaveric renal transplant recipients, is associated with a significant decrease in DGF, better early allograft function in the first month posttransplant, and a decreased posttransplant hospital length of stay.

Outcome of kidney transplantation using expanded criteria donors and donation after cardiac death kidneys: realities and costs

Expanded criteria donors (ECDs) and donation after cardiac death (DCD) provide more kidneys in the donor pool. However, the financial impact and the long-term benefits of these kidneys have been questioned. From 1998 to 2005, we performed 271 deceased donor kidney transplants into adult recipients. There were 163 (60.1%) SCDs, 44 (16.2%) ECDs, 53 (19.6%) DCDs and 11 (4.1%) ECD/DCDs. The mean follow-up was 50 months. ECD and DCD kidneys had a significantly higher incidence of delayed graft function, longer time to reach serum creatinine below 3 (mg/dL), longer length of stay and more readmissions compared to SCDs. The hospital charge was also higher for ECD, ECD/DCD and DCD kidneys compared to SCDs, primarily due to the longer length of stay and increased requirement for dialysis (70,030 dollars, 72,438 dollars, 72,789 dollars and 47,462 dollars, respectively, p < 0.001). Early graft survival rates were comparable among all groups. However, after a mean follow-up of 50 months, graft survival was significantly less in the ECD group compared to other groups. Although our observations support the utilization of ECD and DCD kidneys, these transplants are associated with increased costs and resource utilization. Revised reimbursement guidelines will be required for centers that utilize these organs.

Changing pattern of organ donation at a single center: are potential brain dead donors being lost to donation after cardiac death?

Donation after cardiac death (DCD) has proven effective at increasing the availability of organs for transplantation.We performed a retrospective examination of Massachusetts General Hospital (MGH) records of all 201 donors from 1/1/98 to the 11/2008, including 54 DCD, 115 DBD and 32 DCD candidates that did not progress to donation (DCD-dnp). Comparing three time periods, era 1 (01/98-12/02), era 2 (01/03-12/05) and era 3 (01/06-11/08), DCD’s comprised 14.8,48.4% and 60% of donors, respectively (p = 0.002). A significant increase in the incidence of cardiovascular/cerebrovascular as cause of death was evident in era 3 versus eras 1 and 2; 74% versus 57.1% (p<0.001),as was a corresponding decrease in the incidence of traumatic death. Interestingly, we noted an increase in utilization of aggressive neurological management over time, especially in the DCD group.We detected significant changes in the make-up of the donor pool over the past decade. That the changes in diagnosis over time did not differ between DCD and DBD groups suggests this difference is not responsible for the increase in DCD rates. Instead, we suggest that changes in clinical practice, especially in management of patients with severe brain injury may account for the increased proportion of DCD.

Laparoscopic radical prostatectomy in a renal allograft recipient

In the current immunosuppression era, most renal transplant recipients with a functioning allograft are living healthier and longer lives. In men, because of prostate-specific antigen screening, more patients are diagnosed with early prostate cancer and offered curative treatment with radical prostatectomy. Laparoscopic radical prostatectomy is an accepted minimally invasive treatment for a middle-aged man with organ-confined prostate cancer. To our knowledge, laparoscopic prostatectomy has not yet been reported in renal transplant recipients. This is a case report of laparoscopic prostatectomy for biopsy-proven localized prostate cancer in a renal transplant recipient.

Kidney Versus Islet Allograft Survival After Induction of Mixed Chimerism With Combined Donor Bone Marrow Transplantation

We have previously reported successful induction of transient mixed chimerism and long-term acceptance of renal allografts in MHC mismatched nonhuman primates. In this study, we attempted to extend this tolerance induction approach to islet allografts. A total of eight recipients underwent MHC mismatched combined islet and bone marrow (BM) transplantation after induction of diabetes by streptozotocin. Three recipients were treated after a nonmyeloablative conditioning regimen that included low-dose total body and thymic irradiation, horse Atgam (ATG), six doses of anti-CD154 monoclonal antibody (mAb), and a 1-month course of cyclosporine (CyA) (Islet A). In Islet B, anti-CD8 mAb was administered in place of CyA. In Islet C, two recipients were treated with Islet B, but without ATG. The results were compared with previously reported results of eight cynomolgus monkeys that received combined kidney and BM transplantation (Kidney A) following the same conditioning regimen used in Islet A. The majority of kidney/BM recipients achieved long-term renal allograft survival after induction of transient chimerism. However, prolonged islet survival was not achieved in similarly conditioned islet/BM recipients (Islet A), despite induction of comparable levels of chimerism. In order to rule out islet allograft loss due to CyA toxicity, three recipients were treated with anti-CD8 mAb in place of CyA. Although these recipients developed significantly superior mixed chimerism and more prolonged islet allograft survival (61, 103, and 113 days), islet function was lost soon after the disappearance of chimerism. In Islet C recipients, neither prolonged chimerism nor islet survival was observed (30 and 40 days). Significant improvement of mixed chimerism induction and islet allograft survival were achieved with a CyA-free regimen that included anti-CD8 mAb. However, unlike the kidney allograft, islet allograft tolerance was not induced with transient chimerism. Induction of more durable mixed chimerism may be necessary for induction of islet allograft tolerance.

Spleen transplantation in miniature swine: surgical technique and results in major histocompatibility complex-matched donor and recipient pairs

BACKGROUND

Spleen transplantation (Tx) between some strains of rodents can lead to donor-specific tolerance either spontaneously or after a short course of immunosuppression. This study developed a surgical technique for spleen Tx in miniature swine to investigate its immunologic impact in a large animal model.

METHODS

The preferred surgical technique of spleen Tx (n=8) involved excision of the donor spleen with its vascular pedicle to the aorta and portal vein. Carrel patches of donor aorta and portal vein were anastomosed to the abdominal aorta and inferior vena cava, respectively, of the (splenectomized) recipient. The results in four major histocompatibility complex-matched pairs that were mismatched for the porcine allelic antigen are reported. Two recipients were untreated, one received a 12-day course of cyclosporine A (CsA) alone, and one received thymic irradiation (700 cGy) and CsA. Hematopoietic cell chimerism was followed by fluorescence-activated cell sorter, and graft survival was assessed by histology.

RESULTS

Spleen Tx was technically successful. In two untreated pigs, chimerism was detected in the blood (maximum 5% for 17 and 25 days) and lymph nodes (maximum 6% for 28 and 56 days), but both grafts showed histologic rejection by day 28. In two treated pigs, chimerism was present in the blood for 47 and 57 days, and rejection was prevented, with follow-up for 57 and 217 days, respectively.

CONCLUSION

Spleen Tx in major histocompatibility complex-matched pairs treated with CsA+/-thymic irradiation results in prolonged chimerism and is associated with the development of in vivo unresponsiveness to the transplanted spleen.

Nomogram for Predicting Time to Death After Withdrawal of Life-Sustaining Treatment in Patients With Devastating Neurological Injury

Reliable prediction of time of death after withdrawal of life-sustaining treatment in patients with devastating neurological injury is crucial to successful donation after cardiac death. Herein, we conducted a study of 419 neurocritical patients who underwent life support withdrawal at four neurosurgical centers in China. Based on a retrospective cohort, we used multivariate Cox regression analysis to identify prognostic factors for patient death, which were then integrated into a nomogram. The model was calibrated and validated using data from an external retrospective cohort and a prospective cohort. We identified 10 variables that were incorporated into a nomogram. The C-indexes for predicting the 60-min death probability in the training, external validation and prospective validation cohorts were 0.96 (0.93-0.98), 0.94 (0.91-0.97), and 0.99 (0.97-1.00), respectively. The calibration plots after WLST showed an optimal agreement between the prediction of time to death by the nomogram and the actual observation for all cohorts. Then we identified 22, 26 and 37 as cut-points for risk stratification into four groups. Kaplan-Meier curves indicated distinct prognoses between patients in the different risk groups (p < 0.001). In conclusion, we have developed and validated a nomogram to accurately identify potential cardiac death donors in neurocritical patients in a Chinese population.

Laparoscopic vs open donor nephrectomy: Lessons learnt from single academic center experience

AIM

To compare laparoscopic and open living donor nephrectomy, based on the results from a single center during a decade.

METHODS

This is a retrospective review of all living donor nephrectomies performed at the Massachusetts General Hospital, Harvard Medical School, Boston, between 1/1998 - 12/2009. Overall there were 490 living donors, with 279 undergoing laparoscopic living donor nephrectomy (LLDN) and 211 undergoing open donor nephrectomy (OLDN). Demographic data, operating room time, the effect of the learning curve, the number of conversions from laparoscopic to open surgery, donor preoperative glomerular filtration rate and creatinine (Cr), donor and recipient postoperative Cr, delayed graft function and donor complications were analyzed. Statistical analysis was performed.

RESULTS

Overall there was no statistically significant difference between the LLDN and the OLDN groups regarding operating time, donor preoperative renal function, donor and recipient postoperative kidney function, delayed graft function or the incidence of major complications. When the last 100 laparoscopic cases were analyzed, there was a statistically significant difference regarding operating time in favor of the LLDN, pointing out the importance of the learning curve. Furthermore, another significant difference between the two groups was the decreased length of stay for the LLDN (2.87 d for LLDN vs 3.6 d for OLDN).

CONCLUSION

Recognizing the importance of the learning curve, this paper provides evidence that LLDN has a safety profile comparable to OLDN and decreased length of stay for the donor.

Impact of donor kidney recovery method on lymphatic complications in kidney transplantation

INTRODUCTION

Prolonged lymphatic drainage and lymphocele are undesirable complications following kidney transplantation. We evaluated the impact of kidney recovery methods (deceased donor vs laparoscopic nephrectomy) on the lymphatic complications of the kidney transplant recipients.

METHOD

The incidence of lymphatic complications was retrospectively analyzed in recipients of deceased donor kidneys (DD, n = 62) versus laparoscopically procured kidneys from living donors (LP, n = 61). A drain was placed in the retroperitoneal space in all recipients. The drain was maintained until the output became less than 30 mL/d with no evidence of fluid collection by ultrasound examination.

RESULTS

There was no statistically significant difference in the patient demographics (age, gender, and original disease and procedure time) between two groups. The incidence of lymphocele that required therapeutic intervention was comparable in both groups (3.2%). However, the duration of drain placement was significantly longer in the LP group than in the DD group, 8.6 +/- 2.5 days versus 5.4 +/- 2.5 day, respectively (P < .05).

CONCLUSION

The recipients of laparoscopically removed kidneys had a higher incidence of prolonged lymphatic leakage. More meticulous back table preparation may be required in LP kidneys to prevent prolonged lymphatic drainage after kidney transplantation. These observations may indicate that the major source of persistent lymphatic leakage is lymphatics of the allograft rather than severed recipient lymphatics.

Immunological Unresponsiveness in Chimeric Miniature Swine following MHC-Mismatched Spleen Transplantation

BACKGROUND

In rodents, spleen allotransplantation (SpTx) induces tolerance. We investigated the induction of chimerism and donor-specific unresponsiveness following pig SpTx.

METHODS

Thirteen pigs underwent splenectomy (day 0); all received a blood transfusion. In 11/13 pigs, SpTx was performed across a MHC class I (n=1) or full (n=10) barrier; two control pigs received no SpTx. All pigs were monitored for chimerism, and anti-donor immune responses, including suppressor assays. Four pigs (two asplenic controls and two with SpTx) underwent delayed donor-matched kidney transplantation without immunosuppression.

RESULTS

Six of the 11 spleen grafts were lost from rejection (n=5) or splenic vein thrombosis (n=1), and five remained viable. All 11 SpTx recipients developed multilineage chimerism, but chimerism was rapidly lost if the graft failed. Two control pigs showed <6% blood chimerism for 4 and 11 days only. Pigs with functioning spleen grafts had multilineage chimerism in blood, thymus and bone marrow for at least 2-6 months, without graft-versus-host disease. These pigs developed in vitro donor-specific hyporesponsiveness and suppression. In 2 pigs tolerant to the spleen graft, donor MHC-matched kidney grafts survived for >4 and >7 months in the absence of exogenous immunosuppression; in two asplenic pigs, kidney grafts were rejected on days 4 and 15.

CONCLUSIONS

Successful SpTx can result in hematopoietic cell engraftment and in vitro donor-specific unresponsiveness, enabling prolonged survival of subsequent donor-matched kidney grafts without immunosuppression.

Native portal vein embolization for persistent hyperoxaluria following kidney and auxiliary partial liver transplantation

Type 1 primary hyperoxaluria (PH1) causes renal failure, for which isolated kidney transplantation (KT) is usually unsuccessful treatment due to early oxalate stone recurrence. Although hepatectomy and liver transplantation (LT) corrects PH1 enzymatic defect, simultaneous auxiliary partial liver transplantation (APLT) and KT have been suggested as an alternative approach. APLT advantages include preservation of the donor pool and retention of native liver function in the event of liver graft loss. However, APLT relative mass may be inadequate to correct the defect. We here report the first case of native portal vein embolization (PVE) to increase APLT to native liver mass ratio (APLT/NLM-R). Following initial combined APLT-KT, both allografts functioned well, but oxalate plasma levels did not normalize. We postulated the inadequate APLT/NLM-R could be corrected by trans-hepatic native PVE. The resulting increased APLT/NLM-R decreased serum oxalate to normal levels within 1 month following PVE. We conclude that persistently elevated oxalate levels after combined APLT-KT for PH1 treatment, results from inadequate relative functional capacity. This can be reversed by partial native PVE to decrease portal flow to the native liver. This approach might be applicable to other scenarios where partial grafts have been transplanted to replace native liver function.

Histopathology of spleen allograft rejection in miniature swine

Spleen transplantation (SpTx) has established donor-specific tolerance in rodents, but not in large animals or humans. We report the histopathology of rejection in an established model of SpTx in major histocompatibility complex (MHC)-defined miniature swine. Of the 17 SpTx, rejection was observed in two grafts transplanted into untreated, MHC-matched, minor antigen-disparate recipients (group 1, n=4), but not in the two that received a 12-day course of cyclosporin A (CyA). Rejection also occurred in five grafts transplanted into fully MHC-disparate recipients (group 2, n=12), one of which was untreated and four of which received some form of immunosuppressive therapy. One recipient of an MHC class-I-mismatched spleen treated with 12 days of CyA did not show rejection. Following biopsy and/or necropsy, fixed allograft tissue sections were treated with multiple stains, immunohistochemical markers and TUNEL assay. Common features of rejection occurred in grafts from both groups, but with varying time courses. Necrosis developed as early as day 8 in group 2 and day 27 in group 1, ranging from focal fibrinoid necrosis of arteriolar walls and sinusoids to diffuse liquefactive necrosis, usually associated with haemorrhage. Other features of rejection included white pulp expansion by atypical cells and decreased staining of basement membranes and reticular fibres. A doubling of the baseline TUNEL index preceded histologically identifiable rejection. This study establishes histologic guidelines for diagnosing and, perhaps, in future studies, predicting acute rejection of splenic allografts transplanted across known histocompatibility barriers in a large-animal model.

Concordance Between Antibiotic Resistance Genes and Susceptibility in Symptomatic Urinary Tract Infections

PURPOSE

Studies have shown that multiple genes influence antibiotic susceptibility, but the relationship between genotypic and phenotypic antibiotic susceptibility is unclear. We sought to analyze the concordance between the presence of antibiotic resistance (ABR) genes and antibiotic susceptibility results in urine samples collected from patients with symptomatic urinary tract infection (UTI).

PATIENTS AND METHODS

Urine samples were collected from patients presenting to 37 geographically disparate urology clinics across the United States from July 2018 to February 2019. Multiplex polymerase chain reaction was used to detect 27 ABR genes. In samples containing at least one culturable organism at a concentration of ≥ 104 cells per mL, pooled antibiotic susceptibility testing (P-AST), which involves simultaneous growing all detected bacteria together in the presence of antibiotic and then measure susceptibility, was performed against 14 antibiotics. The concordance rate between the ABR genes and the P-AST results was generated for the overall group. The concordance rates for each antibiotic between monomicrobial and polymicrobial infection were compared using chi-square test.

RESULTS

Results from ABR gene detection and P-AST of urine samples from 1155 patients were included in the concordance analysis. Overall, there was a 60% concordance between the presence or absence of ABR genes and corresponding antimicrobial susceptibility with a range of 49-78% across antibiotic classes. Vancomycin, meropenem, and piperacillin/tazobactam showed significantly lower concordance rates in polymicrobial infections than in monomicrobial infections.

CONCLUSION

Given the 40% discordance rate, the detection of ABR genes alone may not provide reliable data to make informed clinical decisions in UTI management. However, when used in conjunction with susceptibility testing, ABR gene data can offer valuable clinical information for antibiotic stewardship.

Competition in liver transplantation: helpful or harmful?

Improved outcomes of liver transplantation have led to increases in the numbers of US transplant centers and candidates on the list. The resultant and ever-expanding organ shortage has created competition among centers, especially in regions with multiple liver transplant programs. Multiple reports now document that competition among the country's transplant centers has led to the listing of increasingly high-risk patients and the utilization of more marginal liver allografts. The transplant and medical communities at large should carefully re-evaluate these practices and promote innovative approaches to restoring trust in the allocation of donor organs and confirming that there is nationwide conformity in the guidelines used for evaluating and listing potential candidates for this scarce resource.

Liver transplantation results in complete neurologic recovery from malignant hypertension secondary to fulminant hepatic failure: a case report

BACKGROUND

Uncontrolled intracranial hypertension can lead to cerebral herniation and death in patients with acute liver failure.

CASE REPORT

A 26-year-old female was admitted for acute liver failure following inadvertent acetaminophen overdose. The pH on admission was 6.9. Her neurologic status precipitously deteriorated and she was listed for liver transplantation. An intracranial pressure (ICP) monitoring catheter was inserted, which revealed a pressure >60 mmHg. After neurointensive care treatment, ICP was lowered and an emergency left lobe living donor liver transplant was performed. Intraoperative management of the ICP, which rose to 80 mmHg during the explant phase, was achieved by therapy with barbiturates and hypothermia. After surgery, hepatic function improved initially, but 7 days post transplantation the graft showed signs of acute failure. The pathology report of a liver biopsy suggested acute rejection and liver retransplantation using a deceased donor liver was then carried out. The postoperative course was uneventful and the patient recovered completely without any residual neurologic deficits.

CONCLUSIONS

This case states that favourable outcomes can result from sub-optimal starting points, and that the human brain has the ability to overcome extremely adverse conditions. Critical in this effort is the role of proper neuromonitoring which helps implement the appropriate treatment measures.

Effect of staff migration on kidney transplant activity in United Network for Organ Sharing region 1 transplant centers

Organ shortage is unquestionably the greatest challenge facing the field of transplantation today. Transplant centers are constantly competing with one another for limited numbers of organs for their recipients. Recruitment of specialized transplant surgical expertise and leadership is thought to enable a center to grow in volume and thus profitability in the increasingly difficult world of health care reimbursement. In this study, the pattern of kidney transplants at 13 different centers in the United Network for Organ Sharing's region 1 is examined: the comparison is between transplant volume before and after changes in the centers' leadership between 2000 and 2011. Each center's kidney transplant volume showed a significant increase after a leadership change that ultimately regressed to the center's baseline. This study is the first to show that behavioral changes in transplant center competition cause transient increases in transplant volume that quickly regress back to mean levels.

Appendicocecal Loop Urinary Diversion in a Transplant Kidney: Case Report, Literature Review

Urinary diversion in renal transplant patients can take a variety of forms - bladder augmentation, continent cutaneous pouch, or intestinal conduits, to name a few. Herein, we present a unique case of an appendicocecal urinary diversion in a patient with history of end stage renal disease, pelvic radiation, and complex surgical history who underwent deceased-donor renal transplantation. During the renal transplant, the transplant ureterovesical anastomosis could not be performed due to inherent anatomical hindrances. A temporary modified cutaneous ureterostomy using a single-J stent was therefore used for drainage of the transplant kidney. Given that the cutaneous ureterostomy was not a durable, long-term option, we sought to develop a creative surgical solution. This report presents a unique case of urinary diversion post renal transplant and reviews the literature of renal transplantation in patients with anatomical abnormalities.

90 Efficacy of Porcine Skin Xenotransplants Indistinguishable from Allograft in First-in-human Clinical Evaluation

Introduction

Human cadaver allograft (HCA) is the current standard of care for temporary wound closure of large burns, but a critical need for high-quality alternatives exists. Porcine skin shares many similarities with human skin, and hyperacute rejection is prevented via a single genetic modification. Like human skin, non-terminally sterilized porcine skin contains viable dermal and epidermal cells and intact vasculature that enables restoration of barrier function. These characteristics are distinct from those of traditional, terminally sterilized “xenografts” and may offer greater therapeutic capability. We report here key efficacy outcomes specific to severe burn care from a first-in-human clinical trial to assess the capability of genetically engineered porcine skin xenotransplants to provide temporary wound closure for severe and extensive deep-partial and full-thickness burn wounds, compared to HCA.

Methods

Split-thickness skin containing epidermal and dermal layers was harvested from Designated Pathogen Free, GalT-KO, porcine donors, cGMP processed to achieve USP< 71 > sterility and cryopreserved to retain >70% cell viability. These were transplanted side by side with HCA on debrided full-thickness burn wounds in six human subjects. Temporary wound closure, incidence of complete wound closure following autografting, and quality of healing, including scarring, contour, and feel of healed skin, normalization of skin markings or pigmentation, were independently assessed.

Results

Across all patients and assessment time points, adherence, vascularity, and overall appearance were indistinguishable between porcine skin xenotransplants and HCA control. After surgical removal, wound beds treated with each type of dressing were perfused and otherwise appeared equivalent and clinically suitable for autografting. Long-term outcomes were comparable between wound sites treated with porcine skin or HCA with no discernable differences in scarring or cosmesis.

Conclusions

Skin xenotransplants effectively provided temporary wound closure and restoration of barrier function via intact native vasculature, active cells, decreased antigenicity, and high-quality tissue architecture unimpacted by cryopreservation and thawing. These results show clinical promise as an interchangeable alternative to HCA in the treatment of severe burns. Expanded clinical evaluation is ongoing.