Martha Pavlakis

The Medical Evaluation of Living Kidney Donors: A Survey of US Transplant Centers

The use of living donors for kidney transplantation in the United States is common, and long‐term studies have demonstrated the safety of donation by young, healthy individuals. However, transplant programs have little data to guide them in deciding which donors are unacceptable, and which characteristics are associated with kidney disease or poor psychosocial outcomes after donation. To document current practices in evaluating potential donors, we surveyed all US kidney transplant programs. Compared to a survey 12 years ago, medical criteria for donation are more inclusive in several areas. All responding programs now accept living unrelated donors. Most programs no longer have an upper age limit to be eligible. Programs are now more likely to accept donors with treated hypertension, or a history of kidney stones, provided that certain additional criteria are met. In contrast, medical criteria for donation are more restrictive in other areas, such as younger donor age and low creatinine clearance. Overall, significant variability remains among transplant programs in the criteria used to evaluate donors. These findings highlight the need for more data on long‐term outcomes in various types of donors with potential morbidities related to donation.

Donor kidney exchanges.

Kidney transplantation from live donors achieves an excellent outcome regardless of human leukocyte antigen (HLA) mismatch. This development has expanded the opportunity of kidney transplantation from unrelated live donors. Nevertheless, the hazard of hyperacute rejection has usually precluded the transplantation of a kidney from a live donor to a potential recipient who is incompatible by ABO blood type or HLA antibody crossmatch reactivity. Region 1 of the United Network for Organ Sharing (UNOS) has devised an alternative system of kidney transplantation that would enable either a simultaneous exchange between live donors (a paired exchange), or a live donor/deceased donor exchange to incompatible recipients who are waiting on the list (a live donor/list exchange). This Regional system of exchange has derived the benefit of live donation, avoided the risk of ABO or crossmatch incompatibility, and yielded an additional donor source for patients awaiting a deceased donor kidney. Despite the initial disadvantage to the list of patients awaiting an O blood type kidney, as every paired exchange transplant removes a patient from the waiting list, it also avoids the incompatible recipient from eventually having to go on the list. Thus, this approach also increases access to deceased donor kidneys for the remaining candidates on the list.

Antragraft IL-15 transcripts are increased in human renal allograft rejection

IL-15, a novel growth factor made by a variety of cells, stimulates T cell proliferation in a fashion similar to IL-2. IL-2 transcripts are not routinely found in rejecting human renal allografts at the time of clinically evident rejection. However, T cell proliferation continues as the rejection progresses. We postulated that IL-15 may be actively transcribed during clinical rejection and account, at least in part, for the ongoing T cell expansion. RNA was extracted from renal biopsies and reverse transcribed to cDNA which was used as template for competitive PCR. IL-2 mRNA was detected in just 3 of the 45 biopsy samples. IL-15 transcripts were detected in all renal biopsy specimens and was significantly increased in specimens obtained from rejecting as compared with nonrejecting renal allografts. IL-15 transcription correlates with rejection and may play an important role in T cell mediated rejection.

Evaluating living kidney donors: relationship types, psychosocial criteria, and consent processes at US transplant programs.

We conducted a survey of 132 US kidney transplant programs to examine how they evaluate and select potential living kidney donors, focusing on donor‐recipient relationships, psychosocial criteria, and consent processes. There is heterogeneity in donor‐recipient relationships that are considered acceptable, although most programs (70%) will not consider publicly solicited donors. Most programs (75%) require a psychosocial evaluation for all potential living donors. Most programs agree that knowledge of financial reward (90%), active substance abuse (86%), and active mental health problems (76%) are absolute contraindications to donation. However, there is greater variability in how other psychosocial issues are considered in the selection process. Consent processes are highly variable across programs: donor and recipient consent for the donor evaluation is presumed in 57% and 76% of programs, respectively. The use of 13 different informed consent elements varied from 65% (alternative donation procedures) to 86% (description of evaluation, surgery and recuperative period) of programs. Forty‐three percent use a ‘cooling off’ period. Findings demonstrate high variability in current practice regarding acceptable donor‐recipient relationships, psychosocial criteria, and consent processes. Whether greater consensus should be reached on these donor evaluation practices, especially in the context of more expansive use of living donor kidney transplantation, is discussed.

Prevention of primary cytomegalovirus disease in organ transplant recipients with oral ganciclovir or oral acyclovir prophylaxis.

Background: Optimal prophylaxis against cytomegalovirus (CMV) disease for organ transplant patients at risk for primary infection (donor seropositive, recipient seronegative, D+R−) remains to be determined. We hypothesized that prolonged oral ganciclovir therapy following intravenous therapy would provide increased protection.

On the Intraoperative Molecular Status of Renal Allografts after Vascular Reperfusion and Clinical Outcomes

Many hypothesize that subtle inflammation and immune activity detected in the intraoperative period are linked to adverse postkidney transplant clinical outcomes. To this end, renal allografts were analyzed for expression of pro-inflammatory, inflammation-induced adhesion molecules, immune activation as well as anti-apoptotic genes expressed 15 min after vascular reperfusion (zero-hour) to determine whether this analysis can aid in predicting the occurrence of delayed graft function (DGF), acute rejection (AR), and the quality of graft function at 6 mo. Intraoperative biopsies were obtained from 75 consecutively performed renal allografts in which consent was obtained 15 min after vascular reperfusion. These biopsies were analyzed by quantitative real-time PCR for transcription of 15 select genes and by standard histopathology. Posttransplant clinical outcomes were also analyzed in respect to intraoperative transcriptional profiles and clinical parameters available at the time of transplantation. This study demonstrates that a limited and hypothesis-driven PCR-based transcriptional profile of the zero-hour kidney biopsy predicts posttransplant clinical outcomes including DGF, early AR, and the quality of renal function 6 mo posttransplantation. For some clinical endpoints, the combined use of molecular analysis and established clinical indicators available at the time of transplantation further enhances the quality of prognosis. The transcriptional profiling data provide absolutely essential data to the predictive models, particularly with respect to AR and renal function 6 mo posttransplantation.

Granulysin expression is a marker for acute rejection and steroid resistance in human renal transplantation.

Differentiating etiologies of transplant dysfunction without biopsy and optimizing therapy for acute rejection by predicting steroid resistance will reduce patient morbidity. Granulysin is a cytolytic molecule released by CTL and NK cells and coexpressed with effectors of acute allograft rejection, like perforin and granzymes. Granulysin mRNA and protein expression were studied in peripheral blood lymphocytes (PBL; n = 61 total, n = 10 with intercurrent infections) and biopsy tissue from adult and children renal transplant recipients (n = 97) by competitive quantitative-reverse transcriptase-PCR (QC-RT-PCR) and immunohistochemistry. Differences in cell phenotypes were studied in steroid sensitive and resistant acute rejection biopsies. Granulysin was studied in phytohemagglutinin (PHA) stimulated cell lines (donor PBL and CD45RO(+) T cells) by FACS, Western blotting, and RT-PCR after pretreating with cyclosporine A (CSA), azathioprine, mycophenolic acid, and steroids. Granulysin mRNA was significantly increased in patient PBL and transplant biopsies during acute rejection (p < 0.0001) and infection (p < 0.001). Rejecting biopsies alone (n = 53) had mononuclear cell granulysin staining. Steroid resistant biopsies (n = 25) had denser granulysin staining (>2 cells/high power field) and CD45RO(+) lymphocytes, when compared with steroid sensitive (n = 28) rejecting tissue. Granulysin levels were unchanged after azathioprine and mycophenolic acid treatment, decreased after treating activated PBL with steroids and cyclosporine A (CSA), and paradoxically, increased (p < 0.05) after treating CD45RO(+) CTL with CSA. Elevated PBL granulysin is a peripheral marker for acute rejection and infection and dense granulysin staining a tissue marker for steroid resistance. Memory CTL abound in steroid resistant grafts and may have a markedly different response to CSA immunotherapy, suggesting a possible mechanism for steroid resistance.

When should expanded criteria donor kidneys be used for single versus dual kidney transplants

BACKGROUND To increase the utilization of cadaveric donor kidneys, we have recently expanded our acceptable criteria to include aged donors (frequently with a history of hypertension), by selectively using both donor kidneys (dual transplant) into a single recipient. METHODS To define when these expanded criteria donor (ECD) kidneys should be used as a single versus a dual kidney transplant, we retrospectively reviewed 52 recipients of ECD kidneys that had been turned down by all other local centers between 1/1/95 and 11/15/96. Fifteen patients received dual transplants, whereas the remaining 37 received single kidneys. Of the dual kidney recipients, 14 of 15 ECD were > or = 59 years of age, 10 of 15 were hypertensive, and 9 of 15 were both. Of the single recipients, 11 of 37 ECD were > or = 59 years of age, 11 of 37 were hypertensive, and 7 of 37 were both. All patients received cyclosporine-based triple-drug therapy. We compared seven donor (D) and sixteen recipient outcome variables in single versus dual kidney transplants as subgrouped by: (1) donor admission creatinine clearance (D-AdC(Cr)) < 90 ml/min; (2) D-age > or = 59 years; and (3) cold storage (Cld Stg) < or > 24 hr. RESULTS In the group with D-AdC(Cr) < 90, there was a significantly higher incidence of delayed graft function (DGF) in single versus dual recipients (9 of 20 [45%] vs. 1 of 11 [9%]; P=0.04) and worse early graft function based upon mean serum creatinine at 1 and 4 weeks (5.3+/-3.3 and 2.8+/-2.0 vs. 1.7+/-0.6 and 1.4+/-0.5 mg] dl; P<0.05). In the group with D-age > or = 59, recipients of single kidneys had significantly higher mean serum creatinine at 1, 4, and 12 weeks versus recipients of dual kidneys (5.1+/-3.3, 3.4+/-2.1, 2.8+/-1.5 versus 2.8+/-2.5, 1.5+/-0.6, 1.6+/-0.5 mg/dl; P<0.05). Cld Stg time also had an impact on DGF and early outcome. Recipients of dual kidneys stored less than 24 hr had a significantly lower incidence of DGF versus single kidneys stored more than 24 hr (10% vs. 46%; P<0.05) and better early graft function based on mean serum creatinine at 1, 4, and 12 weeks (1.9+/-0.8, 1.3+/-0.4, 1.5+/-0.2 vs. 6.6+/-3.4, 3.0+/-1.6, 2.9+/-1.9 mg/dl; P<0.05). The overall 1-year patient and graft survivals were 96% and 81% vs. 93% and 87% (P=NS) in recipients of single ECD versus dual ECD kidneys. CONCLUSIONS In conclusion, we believe that kidneys from ECD with D-AdC(Cr) < 90 ml/min and D-age > or = 59 should be used as dual kidney transplants, keeping the Cld Stg time at < 24 hr to minimize the effect of Cld Stg on early graft function.

Donor postextubation hypotension and age correlate with outcome after donation after cardiac death transplantation.

Background. Compared with standard donors, kidneys recovered from donors after cardiac death (DCD) exhibit higher rates of delayed graft function (DGF), and DCD livers demonstrate higher rates of biliary ischemia, graft loss, and worse patient survival. Current practice limits the use of these organs based on time from donor extubation to asystole, but data to support this is incomplete. We hypothesized that donor postextubation parameters, including duration and severity of hemodynamic instability or hypoxia might be a better predictor of subsequent graft function. Methods. We performed a retrospective examination of the New England Organ Bank DCD database, concentrating on donor factors including vital signs after withdrawal of support. Results. Prolonged, severe hypotension in the postextubation period was a better predictor of subsequent organ function that time from extubation to asystole. For DCD kidneys, this manifested as a trend toward increased DGF. For DCD livers, this manifested as increased rates of poor outcomes. Maximizing the predictive value of this test in the liver cohort suggested that greater than 15 min between the time when the donor systolic blood pressure drops below 50 mm Hg and flush correlates with increased rates of diffuse biliary ischemia, graft loss, or death. Donor age also correlated with worse outcome. Conclusions. Time between profound instability and cold perfusion is a better predictor of outcome than time from extubation to asystole. If validated, this information could be used to predict DGF after DCD renal transplant and improve outcomes after DCD liver transplant.

Expression of protective genes in human renal allografts: a regulatory response to injury associated with graft rejection.

Background. Long-term survival of a graft requires inhibition of host immune effectors, but protective responses emanating from the graft might be equally important. Expression of the “protective” genes A20, heme-oxygenase-1 (HO-1), and Bcl-xL in rodent allo and xenografts correlates with long-term survival. Little is known of the pattern of expression of such protective genes and the implication thereof in clinical transplantation. Methods. We analyzed, by quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry, expression of A20, HO-1, and Bcl-xL in 31 renal allograft biopsies from patients with suspected rejection. Results. A20 is not expressed in nonrejecting (NR) grafts. Its expression is increased in grafts undergoing acute and chronic rejection (AR and CR) but is weaker in CR. HO-1 is not expressed in NR grafts; it is up-regulated in AR but not CR. Bcl-xL is detected in all biopsies with decreased levels in CR. Expression of A20, HO-1, and Bcl-xL localizes mainly to endothelial, smooth muscle, and infiltrating mononuclear cells. Conclusions. This data demonstrate that A20 and HO-1 are up-regulated in response to immune injury inferred by AR. Given the antiapoptotic and antiinflammatory functions of these genes, we hypothesize that their expression survives to limit graft injury by maintaining cell viability and controlling inflammation. Their reduced expression in CR as compared with AR represents either inadequate response to injury or a sequelae of prior injury that jeopardizes further tissue response to immune attack.