Faculty Bibliography

A new United Network for Organ Sharing (UNOS) policy mandates special informed consent (SIC) before transplanting organs from donors classified by the Public Health Service/Center for Disease Control (PHS/CDC) as high-risk donors (HRDs); however, concerns remain that this policy may cause suboptimal organ utilization. Currently, consent and disclosure policy is determined by individual centers or surgeons; as such, little is known about current practices. The goals of this study were to quantify consent and disclosure practices for HRDs in the United States, identify factors associated with SIC use and analyze associations between SIC use and HRD organ utilization. We surveyed 422 transplant surgeons about their use of HRD organs and their associated consent and disclosure practices. In total, 52.7% of surgeons use SIC, but there is a high variation in use within centers, between centers and by donor behavior. A defined HRD policy at a transplant center is strongly associated with SIC use at that center (OR = 4.68, p < 0.001 by multivariate hierarchical logistic regression). SIC use is associated with higher utilization of HRD livers (OR 3.37), and a trend toward higher utilization of HRD kidneys (OR 1.74) and pancreata (OR 1.28). We believe our findings support a formalized national policy and suggest that this policy will not result in decreased utilization.

The use of Public Health Service/Centers for Disease Control and Prevention (PHS/CDC) high-risk donor (HRD) organs remains controversial, especially in light of a recent high-profile case of human immunodeficiency virus (HIV) and hepatitis C virus (HCV) transmission. Nucleic acid testing (NAT), while more expensive and time consuming, reduces infectious risk by shortening the period between infection and detectability. The purpose of this study was to characterize HRDs and disposition of their organs by organ procurement organization (OPO), to measure NAT practices by OPO and to examine associations between NAT practices and use of HRD organs. We analyzed 29 950 deceased donors (2574 HRDs) reported to UNOS since July 1, 2004 and May 8, 2008. We then surveyed all OPO clinical directors about their use of NAT, average time to receive NAT results, locations where NAT is performed and percentage of the time NAT results are available for allocation decisions. In total, 51.7% of OPOs always perform HIV NAT, while 24.1% never do. A similar pattern is seen for HCV NAT performance, while the majority (65.6%) never perform HBV NAT. AIDS prevalence in an OPO service area is not associated with NAT practice. OPOs that perform HIV NAT are less likely to export organs outside of their region. The wide variation of current practice and the possibility that NAT would improve organ utilization support consideration for a national policy.

Single-center studies have reported that liver allograft survival is not affected by preservation in histidine-tryptophan-ketoglutarate (HTK) versus University of Wisconsin (UW) solution. We analyzed the UNOS database of liver transplants performed from July, 2004, through February, 2008, to determine if preservation with HTK (n = 4755) versus UW (n = 12 673) impacted graft survival. HTK preservation of allografts increased from 16.8% in 2004 to 26.9% in 2008; this was particularly striking among donor after cardiac death (DCD) allografts, rising from 20.7% in 2004 to 40.9% in 2008. After adjusting for donor, recipient and graft factors that affect graft survival, HTK preservation was associated with an increased risk of graft loss (HR 1.14, p = 0.002), especially with DCD allografts (HR 1.44, P = 0.025) and those with cold ischemia time over 8 h (HR 1.16, P = 0.009). Furthermore, HTK preservation was associated with a 1.2-fold higher odds of early (< 30 days) graft loss as compared to UW preservation (OR 1.20, p = 0.012), with a more pronounced effect on allografts with cold ischemia time over 8 h (OR 1.31, p = 0.007), DCD allografts (OR 1.63, p = 0.09) and donors over 70 years (OR 1.67, p = 0.081). These results suggest that the increasing use of HTK for abdominal organ preservation should be reexamined.

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by age-dependent growth of kidney cysts with end-stage renal disease developing in approximately 50% of affected individuals. Living donors from ADPKD families are at risk for developing ADPKD and may be excluded from renal donation if the diagnosis cannot be conclusively ruled out. Radiographic imaging may be adequate to screen for kidney cysts in most at-risk donors but may fail to identify affected individuals younger than 40 years or older individuals from families with mild disease. In this article, we report a strategy that incorporates genetic testing in the evaluation of live kidney donors at risk for ADPKD whose disease status cannot be established with certainty on the basis of imaging studies alone. We show that DNA diagnostics can be used to enhance safe donation for certain living donor candidates at risk for ADPKD.

Prior single-center studies have reported that pancreas allograft survival is not affected by preservation in histidine-tryptophan-ketoglutarate (HTK) versus University of Wisconsin (UW) solution. To expand on these studies, we analyzed the United Network for Organ Sharing (UNOS) database of pancreas transplants from July 2004, through February 2008, to determine if preservation with HTK (N = 1081) versus UW (N = 3311) impacted graft survival. HTK preservation of pancreas allografts increased significantly in this time frame, from 15.4% in 2004 to 25.4% in 2008. After adjusting for other recipient, donor, graft and transplant center factors that impact graft survival, HTK preservation was independently associated with an increased risk of pancreas graft loss (hazard ratio [HR] 1.30, p = 0.014), especially in pancreas allografts with cold ischemia time (CIT) >or=12 h (HR 1.42, p = 0.017). This reduced survival with HTK preservation as compared to UW preservation was seen in both simultaneous pancreas-kidney (SPK) transplants and pancreas alone (PA) transplants. Furthermore, HTK preservation was also associated with a 1.54-fold higher odds of early (<30 days) pancreas graft loss as compared to UW (OR 1.54, p = 0.008). These results suggest that the increasing use of HTK for abdominal organ preservation should be re-examined.

Desensitized patients are at high risk of developing acute antibody-mediated rejection (AMR). In most cases, the rejection episodes are mild and respond to a short course of plasmapheresis (PP) / low-dose IVIg treatment. However, a subset of patients experience severe AMR associated with sudden onset oliguria. We previously described the utility of emergent splenectomy in rescuing allografts in patients with this type of severe AMR. However, not all patients are good candidates for splenectomy. Here we present a single case in which eculizumab, a complement protein C5 antibody that inhibits the formation of the membrane attack complex (MAC), was used combined with PP/IVIg to salvage a kidney undergoing severe AMR. We show a marked decrease in C5b-C9 (MAC) complex deposition in the kidney after the administration of eculizumab.

In the highly active antiretroviral therapy era of improved survival for patients living with human immunodeficiency virus (HIV), chronic kidney disease now accounts for more than 10% of HIV-related deaths. The role of kidney transplant among HIV-positive patients with end-stage renal disease is under consideration, but concerns remain regarding allocation of kidneys to these patients when long-term benefit has not been firmly established. We evaluated 39,501 patients undergoing a renal transplant between January 1, 2004, and June 30, 2006, identified through the United Network for Organ Sharing national registry and found that, although long-term allograft survival is lower among HIV-positive recipients, controllable risk factors may explain this disparity. With proper donor selection and transplant recipient management, including the avoidance of prolonged cold ischemic time, use of living donors, and determination of optimal immunosuppression dosing before transplant, long-term graft survival comparable to that in HIV-negative patients can be achieved.

C4d deposition in peritubular capillaries is a specific marker for the presence of antidonor antibodies in renal transplant recipients and is usually associated with antibody-mediated rejection (AMR) in conventional allografts. In ABO-incompatible grafts, however, peritubular capillary C4d is often present on protocol biopsies lacking histologic features of AMR; the significance of C4d in this setting remains unclear. For addressing this, data from 33 patients who received ABO-incompatible renal allografts (after desensitization) were retrospectively reviewed. Protocol biopsies were performed at 1 and/or 3 and 6 mo after transplantation in each recipient and at 12 mo in 28 recipients. Twenty-one patients (group A) had strong, diffuse peritubular capillary C4d staining without histologic evidence of AMR or cellular rejection on their initial protocol biopsies. The remaining 12 patients (group B) had negative or weak, focal peritubular capillary C4d staining. Three grafts (two in group B) were lost but not as a result of AMR. Excluding these three patients, serum creatinine levels were similar in the two groups at 6 and 12 mo after transplantation and at last follow-up; however, recipients in group A developed significantly fewer overall chronic changes, as scored by the sum of Banff chronic indices, than group B during the first year after transplantation. These results suggest that diffuse peritubular capillary C4d deposition without rejection is associated with a lower risk for scarring in ABO-incompatible renal allografts; the generalizability of these results to conventional allografts remains unknown.

We present four cases of renal transplant recipients who were treated with bortezomib for four different indications, each of whom had circulating anti-HLA antibodies that were followed serially throughout their courses of bortezomib therapy. It is important to note that each patient was administered bortezomib in conjunction with other agents and therapies traditionally used for desensitization or the treatment of AMR. The results have been mixed. In some cases substantial decreases in HLA-antibody were temporally related to bortezomib therapy. In the one case of recalcitrant AMR there has been no reduction in DSA after 2 cycles of the drug. Bortezomib has been well tolerated. One patient developed reversible peripheral neuropathic pain while another experienced line sepsis, a urinary tract infection, and an invasive fungal skin infection. Again, this patient had also received protracted courses of plasmapheresis combined with T-cell and B-cell depleting agents. The use of these other drugs precludes the ability to rigorously evaluate the efficacy of bortezomib in isolation and points towards a need for large-scale, controlled trials to determine whether the drug's promising mechanism of action is applicable in the setting of solid organ transplantation.

BACKGROUND: Successful ABO-incompatible (ABOi) kidney transplantation of non-A2 renal allografts requires preconditioning to reduce anti-blood group antibody to safe lev-els in order to avoid hyperacute rejection. Unfortunately, early post-transplant acute antibody-mediated rejection remains a problem in these patients and can result in rapid graft loss. A number of investigators have encountered ABOi recipients who have had no evidence of allograft injury in the setting of elevated titers of anti-ABO antibody, a protective phenomenon that has been termed 'accommodation'. Little is known about the time course of accommodation. We report a case of a successful ABOi renal transplant recipient who had evidence of accommodation within the first week following transplantation. CASE REPORT: The patient is a 36-year-old, highly sensitized blood group.woman who underwent live donor transplantation from her human leukocyte antigen-identical blood group A1 brother following therapy with plasmapheresis and low-dose intravenous immunoglobulin for an initial anti-A anti-human globulin antibody titer of 512. Within the first week following transplantation, her anti-A titer rose to 128 without change in her renal function. At 1 month following transplantation, her anti-A titer had risen to 256 at which time a biopsy was per-formed that demonstrated no evidence of antibody-mediated rejection. CONCLUSION: This patient demonstrates that accommodation of the renal allograft following ABOi transplantation may take place in the early postoperative period in the setting of high titer antibody. The implications for postoperative management of the ABOi patient and the need for future investigation in this area are discussed.