Outcomes of renal transplantation in older high risk recipients: is there an age effect?

BACKGROUND: The purpose of this study was to evaluate long-term outcomes in high risk renal transplant recipients over 60 years of age compared with those younger than 60 years of age. MATERIALS AND METHODS: We analyzed outcomes in 131 consecutive renal transplant recipients at our institution between November 2001 and December 2007. Primary outcomes included incidence of delayed graft function (DGF), acute rejection, graft survival, patient survival, and incidence of infections and neoplasms. RESULTS: Older recipients (Over 60 group, n = 45) received more organs from extended criteria donors (ECD) or donation after cardiac death donors (DCD) compared with younger recipients (Under 60 group, n = 86), 42% versus 17% respectively, P = 0.001. Multivariate analyses revealed that African American ethnicity and DCD donation had the greatest impact on the incidence of DGF in both groups; P < 0.05. Patient survival and graft survival beyond 1 y were similar between the two groups. CONCLUSION: Our data suggest that long-term transplant outcomes in older, high risk renal transplant recipients are similar to those of younger, high risk recipients. Older recipients' age and high-risk characteristics, such as African American ethnicity and increased sensitization, should not be a contraindication to renal transplantation in the elderly.

Rabbit antithymocyte globulin versus basiliximab in renal transplantation.

BACKGROUND: Induction therapy reduces the frequency of acute rejection and delayed graft function after transplantation. A rabbit antithymocyte polyclonal antibody or basiliximab, an interleukin-2 receptor monoclonal antibody, is most commonly used for induction. METHODS: In this prospective, randomized, international study, we compared short courses of antithymocyte globulin and basiliximab in patients at high risk for acute rejection or delayed graft function who received a renal transplant from a deceased donor. Patients taking cyclosporine, mycophenolate mofetil, and prednisone were randomly assigned to receive either rabbit antithymocyte globulin (1.5 mg per kilogram of body weight daily, 141 patients) during transplantation (day 0) and on days 1 through 4 or basiliximab (20 mg, 137 patients) on days 0 and 4. The primary end point was a composite of acute rejection, delayed graft function, graft loss, and death. RESULTS: At 12 months, the incidence of the composite end point was similar in the two groups (P=0.34). The antithymocyte globulin group, as compared with the basiliximab group, had lower incidences of acute rejection (15.6% vs. 25.5%, P=0.02) and of acute rejection that required treatment with antibody (1.4% vs. 8.0%, P=0.005). The antithymocyte globulin group and the basiliximab group had similar incidences of graft loss (9.2% and 10.2%, respectively), delayed graft function (40.4% and 44.5%), and death (4.3% and 4.4%). Though the incidences of all adverse events, serious adverse events, and cancers were also similar between the two groups, patients receiving antithymocyte globulin had a greater incidence of infection (85.8% vs. 75.2%, P=0.03) but a lower incidence of cytomegalovirus disease (7.8% vs. 17.5%, P=0.02). CONCLUSIONS: Among patients at high risk for acute rejection or delayed graft function who received a renal transplant from a deceased donor, induction therapy consisting of a 5-day course of antithymocyte globulin, as compared with basiliximab, reduced the incidence and severity of acute rejection but not the incidence of delayed graft function. Patient and graft survival were similar in the two groups. (ClinicalTrials.gov number, NCT00235300 [ClinicalTrials.gov].).

Nutrition, pregnancy, and transplantation.

One benefit of transplantation, along with the restoration of health, is the opportunity for successful pregnancies. A growing number of pregnancies have been reported among all types of solid-organ recipients. There is an increasing need for practice guidelines that include nutrition information in order to assist practitioners caring for and counseling these high-risk patients. In the transplant community, guidelines for managing pregnancies in transplant recipients have been evolving but lack specific nutrition recommendations. As for all pregnancies, there is a need to optimize nutrition for the mother and her infant, with additional consideration given to the transplant recipient's graft. This article reviews outcomes of posttransplant pregnancies and management guidelines, with special emphasis on nutrition in this unique population.

Assessing relative risks of infection and rejection: a meta-analysis using an immune function assay.

BACKGROUND: Long-term use of immunosuppressants is associated with significant morbidity and mortality in transplant recipients. A simple whole blood assay that has U.S. Food and Drug Administration clearance directly assesses the net state of immune function of allograft recipients for better individualization of therapy. A meta-analysis of 504 solid organ transplant recipients (heart, kidney, kidney-pancreas, liver and small bowel) from 10 U.S. centers was performed using the Cylex ImmuKnow assay. METHODS: Blood samples were taken from recipients at various times posttransplant and compared with clinical course (stable, rejection, infection). In this analysis, 39 biopsy-proven cellular rejections and 66 diagnosed infections occurred. Odds ratios of infection or rejection were calculated based on measured immune response values. RESULTS: A recipient with an immune response value of 25 ng/ml adenosine triphosphate (ATP) was 12 times (95% confidence of 4 to 36) more likely to develop an infection than a recipient with a stronger immune response. Similarly, a recipient with an immune response of 700 ng/ml ATP was 30 times (95% confidence of 8 to 112) more likely to develop a cellular rejection than a recipient with a lower immune response value. Of note is the intersection of odds ratio curves for infection and rejection in the moderate immune response zone (280 ng/ml ATP). This intersection of risk curves provides an immunological target of immune function for solid organ recipients. CONCLUSION: These data show that the Cylex ImmuKnow assay has a high negative predictive value and provides a target immunological response zone for minimizing risk and managing patients to stability.

Apoptosis of allospecifically activated human helper T cells is blocked by calcineurin inhibition.

BACKGROUND: Classical transplantation immunosuppression relies heavily upon the interruption of interleukin-2 (IL-2) signaling by calcineurin inhibition. However, recent evidence in murine models suggests that IL-2 is necessary for activation-induced cell death (AICD) of allograft-specific lymphocytes. METHODS: We examined the apoptotic effects of the calcineurin inhibitor cyclosporine A and mTOR inhibitor rapamycin on the apoptotic alterations that occur in allospecifically activated human lymphocytes in a one-way mixed lymphocyte culture (MLC). RESULTS: Cyclosporine increased caspase-3 activation in MLC, which corresponded with a decrease in lymphocyte apoptosis in MLC. Cyclosporine also reduced apoptosis in the CD4+ helper T cell subset, while CD8+ cells had similar or increased apoptosis when compared to controls. In contrast, rapamycin-treated cultures had normal levels of CD4+ T cell apoptosis when compared to control MLC, with decreases seen in CD8+ T lymphocytes. CONCLUSIONS: In humans, blockade of IL-2 receptor signal with rapamycin allows apoptosis of allospecifically activated CD4+ lymphocytes to occur, while blockade of IL-2 production with cyclosporine results in decreased apoptosis in this T cell subset. As helper T cells are integral to the immune response, these results may explain the tolerogenic effects of rapamycin.

Expression of Dlx and Lhx family homeobox genes in fetal thymus and thymocytes.

Homeobox genes comprise a nearly ubiquitous and highly conserved superfamily of developmental regulatory genes that encode transcription factors involved in the determination of axis and tissue identity. While homeobox gene expression has been well characterized in a variety of embryonic tissues, their expression has not been extensively studied in lymphoid progenitor cells or in sites of lymphogenesis. To examine homeobox gene expression in the developing thymus, we screened an embryonic day 13.5 thymus cDNA library by polymerase chain reaction (PCR) using degenerate oligonucleotides within the highly conserved homeodomain region of eight homeobox gene families. The resulting PCR products were then cloned and sequenced. Transcripts for multiple Dlx family members and Lhx2 were repeatedly detected in this screen. Screening of embryonic day 16.5 and adult murine thymus and Thy1+ thymocytes was performed for selected members of these homeobox gene families. Transcripts encoding Lhx2, Lhx3, and Lhx9, as well as Dlx1 and Dlx2 were detected in both thymus and purified thymocytes. Dlx1 is a member of the distal-less homeobox gene family that has been shown to regulate embryonic craniofacial development. Significantly, Dlx1 is expressed in the third branchial arch, which contributes to the thymus. Although Dlx1 knockout mice did not display any obvious developmental defects in thymus or thymocyte development, the expression of these homeobox genes in neural crest derivatives suggests a possible role in cell migration and development that may overlap with other homeobox genes.

Efficacy of anticoagulation therapy in end-stage renal disease patients with antiphospholipid antibody syndrome.

BACKGROUND: End-stage renal disease (ESRD) patients with antiphospholipid antibody syndrome (APAS) remain at high risk for the development of renal thrombosis without the benefit of anticoagulation therapy. This study examines the efficacy of anticoagulation therapy in this high-risk patient population. METHOD: Of nine APAS renal-transplant patients, seven were treated with coumadin, whereas two were treated with heparin. RESULTS: Of the two patients treated with heparin, one had early allograft loss, whereas the other patient is doing fine at 5 years posttransplant. Of the seven 7 patients treated with coumadin, two patients are doing well at 2 and 3 years posttransplant, two had early allograft loss, the remaining three patients returned to dialysis after they were taken off of the coumadin at 6, 12, and 20 months posttransplant because of bleeding complications. CONCLUSIONS: Anticoagulation therapy is beneficial to some but not all APAS patients. In addition, bleeding complications are a serious side effect of this therapy.

Differential effects of interleukin-2 blockade on apoptosis in naïve and activated human lymphocytes.

BACKGROUND: Certain transplantation immunosuppressive strategies are primarily based on the interruption of interleukin (IL)-2 signaling by calcineurin inhibition or anti-IL-2 receptor-antibody blockade. However, recent evidence suggests that IL-2 is necessary for peripheral deletion of allograft-specific lymphocytes. STUDY DESIGN: In this study, we examined the apoptotic effects of the calcineurin inhibitor, cyclosporine A, the chimeric anti-interleukin-2 receptor monoclonal antibody, basiliximab, and the rabbit antihuman thymocyte preparation Thymoglobulin (rATG) on phytohemagglutinin-activated human lymphocyte models designed to simulate initial exposure to the graft or ongoing rejection of the graft. RESULTS: We found that rATG increases Fas expression, decreases Bcl-2 expression, and induces early apoptosis in naïve lymphocytes. However, rATG has more of a necrotic effect on activated lymphocytes. Basiliximab and cyclosporine had little effect on apoptosis, but did alter Bcl-2 and Fas expression. CONCLUSIONS: Compared with IL-2 pathway inhibitors, rATG increases lymphocyte apoptosis, probably via Bcl-2 pathway inhibition. Because apoptosis is required for the development of graft tolerance, induction strategies that use IL-2-independent pathways may be advantageous.

Safe administration of a humanized murine antibody after anaphylaxis to a chimeric murine antibody.

BACKGROUND: Basiliximab and daclizumab are potent and relatively safe immunosuppressive induction agents used in transplantation. These chimeric or humanized monoclonal antibodies, respectively, act by binding to the alpha chain of interleukin-2 receptors on activated T lymphocytes. Herein, the authors describe successful transplant induction therapy with a humanized murine antibody in a patient with a history of anaphylaxis to a chimeric murine antibody. METHODS: The authors report a 42-year-old woman who received a dose of basiliximab without adverse reaction before an anticipated renal transplant that was canceled. Two weeks later, she received a second dose of basiliximab. Within 10 min of receiving the second dose, she developed chest tightness, shortness of breath, tongue swelling, diffuse pruritic rash, and skin flushing. RESULTS: The authors hypothesized that her anaphylaxis was mediated by immunoglobulin (Ig) E antibodies to basiliximab. Consistent with this hypothesis, intradermal administration of a 1:100 dilution of basiliximab induced a 10 x 10-mm flare. The authors sought to find an alternative immunosuppressive agent for this patient. The patient elicited prick and intradermal skin testing responses to horse and rabbit polyclonal antithymocyte antibody preparations. However, she mounted neither a prick nor an intradermal response to daclizumab. The patient was administered daclizumab without any adverse effects. CONCLUSIONS: The negative skin test and safe administration of daclizumab is surprising because the similarity of these hybrid antibodies would have predicted similar IgE responsiveness and clinical outcome. The authors propose that patients who develop anaphylaxis to basiliximab or other chimeric antibodies may be candidates for treatment with a humanized antibody preparation such as daclizumab in the presence of a negative skin test to the humanized agent.

Decreased lymphocyte apoptosis by anti-tumor necrosis factor antibody in Peyer's patches after severe burn.

Severe burn results in immunosuppression, with increased lymphocyte apoptosis in both the central and peripheral immune system. As atrophy of the small intestine has been described in mouse models and intestinal lymphocytes have been implicated in the burn inflammatory response, we examined the effects of burn and tumor necrosis factor (TNF)-alpha on lymphocytes in intestinal Peyer's patches. Anesthetized C57BL6 mice received a 30% full-thickness scald burn on the upper back. Sham-burned animals served as controls. Anti-TNF or control immunoglobulin (Ig) G antibody (200 microg) was given immediately after the burn. The animals were initially resuscitated with 2 mL of normal saline, and were then sacrificed 12 h postburn. Terminal deoxyuridine nick-end labeling (TUNEL) and proliferative cell nuclear antigen (PCNA) staining was performed. Apoptosis was quantified as apoptotic lymphocytes/high-powered field (hpf). Results, expressed as mean +/- SEM, were compared using analysis of variance (ANOVA) and the Student-Newman-Keuls test. All mice survived the burn. An initial time-course experiment demonstrated maximal Peyer's patch apoptosis 12 h after the burn. Sham mice had 25 +/- 7 TUNEL-stained cells/hpf in Peyer's patches, whereas burned mice had 93 +/- 18 cells/hpf (P < 0.05). In contrast, burned mice receiving anti-TNF antibody had 28 +/- 8 TUNEL-stained cells/hpf (P < 0.05 vs. burn), whereas sham mice receiving anti-TNF antibody had 20 +/- 4 cells/hpf. There were no significant differences in PCNA staining between the groups. Scald burn results in lymphocyte apoptosis in Peyer's patches. This apoptosis can be abrogated by the addition of anti-TNF antibody. Apoptotic changes may lead to the failure of the intestinal immunological barrier and increased risk of sepsis.

Altered expression of vascular endothelial growth factor and its receptors in normal saphenous vein and in arterialized and stenotic vein grafts.

BACKGROUND: Myointimal thickening is a major cause saphenous vein graft failure. The prominence of medial and adventitial microvessels in stenotic vein grafts and the known angiogenic effects of vascular endothelial growth factor (VEGF) lead us to investigate the expression of VEGF and its receptors in vein graft arterialization and stenosis. METHODS: Normal and arterialized vein graft segments were evaluated by reverse transcription-polymerase chain reaction (RT-PCR) for expression of VEGF-R1 (flt), VEGF-R2 (KDR), and neuropilin-1. The cells expressing VEGF, VEGF-R1, VEGF-R2, and neuropilin-1 were identified in normal, stenotic, and arterialized vein graft segments by immunohistochemistry. RESULTS: Vascular endothelial growth factor, detected in the wall in endothelial cells and adventitial microvessels in normal vein, localized to smooth muscle cells, endothelial cells and adventitial microvessels in arterialized and stenotic vein. VEGF-R1 and VEGF-R2 were expressed infrequently on endothelial cells, macrophages, and smooth muscle cells in arterialized and stenotic vein. Neuropilin-1 was detected in all specimens. RT-PCR demonstrated significantly greater expression of neuropilin-1 in normal vein compared with arterialized vein (P <0.05). CONCLUSIONS: The differential expression of VEGF and its receptors in normal, arterialized, and stenotic vein grafts suggests that alterations in VEGF/VEGF-R2/neuropilin-1 interactions may be important determinants of the adaptive response of vein grafts to arterialization.

The use of abdominal computed tomography scan decreases the frequency of misdiagnosis in cases of suspected appendicitis.

BACKGROUND: Despite considerable experience the reported frequency of misdiagnosis in patients undergoing appendectomy continues in the range of 20% to 40% in some populations. METHODS: We developed a clinical guideline that recommended abdominal computed tomography (CT) for all nonpregnant adults in whom the diagnosis of appendicitis was suspected unless the diagnosis could be ruled out clinically. The records of adult patients that underwent appendectomy from July 1998 through October 2001 were reviewed. The clinical guideline was developed in July 2000. RESULTS: There were 194 appendectomies performed, 114 prior to the guideline and 80 after the development of the guideline. The rate of misdiagnosis decreased from 25% to 6% (P <0.05), the rate of CT use increased from 32% to 84% (P <0.05), and the perforation rate remained unchanged. CONCLUSIONS: These results support the effectiveness of a clinical guideline that encourage the use of abdominal CT in decreasing the frequency of misdiagnosis in cases of suspected appendicitis.

Renal cortical adenoma incidentally found during living donor nephrectomy.

We report a living related kidney donor incidentally found to have a renal cortical adenoma at nephrectomy. The patient is a 53-year-old man accepted for living related kidney donation. Predonation workup revealed a solitary left renal artery and, on the right kidney, a main artery with a small accessory artery in theupper pole. No other abnormalities were found in the medical history, physical examination, or laboratory and radiological studies. A left laparoscopic nephrectomy was planned. However, during dissection of the upper pole, a 5-mm mass was noted. The nephrectomy was completed, and the organ was preserved in cold University of Wisconsin solution. Permanent section histology showed that the lesion was mostly likely a renal cortical adenoma. As the risk of malignant transformation with immunosuppression could not be adequately determined, the kidney was not transplanted into the recipient. The donor elected not to have the kidney replaced, and the organ was discarded.

Targeting alloantibody production with bortezomib: does it make more sense?

BACKGROUND: The effectiveness of current therapies for humoral rejection and decreasing antibody production directed against human leukocyte antigens (HLA) remains controversial. Standard regimens are unable to abrogate alloantibody production long term, most likely due to a lack of a direct effect on inhibiting and depleting mature plasma cells. Bortezomib (BZ) may be more effective at removing long-lived plasma cells compared to standard regimens that modulate alloantibody production by different mechanisms. METHODS: We report a kidney transplant recipient with several episodes of mixed antibody mediated and cellular rejection treated with numerous therapies including BZ. Monitoring included serial measurements of donor specific antibodies (DSA) by Luminex assay and repeated allograft biopsies. RESULTS: One cycle of BZ was able to reverse humoral rejection and graft dysfunction. DSA levels to multiple donor HLA antigens which were not affected by previous therapies were reduced to undetectable levels post BZ. Abrogation of DSA was only transient. Despite continued stable renal function post-BZ, the patient had a reemergence of DSA, and evidence of humoral rejection detected by allograft biopsy. CONCLUSIONS: Despite the promise of BZ as a therapy for humoral rejection, current data on how it should be used and its efficacy long-term remains limited.

Report from the National Transplantation Pregnancy Registry: outcomes of pregnancy after transplantation.

Experience in the field of pregnancy posttransplantation has been gained through continued case reports, center reports, and registry data. The NTPR maintains an ongoing active database to study the safety of pregnancy and includes the outcomes of female transplant recipients as well as male recipients who father pregnancies. Analyses are ongoing and include long-term followup of recipients' graft status and of their offspring. For the most part, guidelines proposed in 1976 for counseling recipients remain applicable (30). While these counseling guidelines were formulated for kidney recipients, they may be extrapolated to other organ recipients as well. Organ-specific issues should also be considered in managing and counseling female transplant recipients. Recipients should be in general good health, and graft function should be stable and, ideally, rejection-free. There should be optimal control of comorbid conditions such as hypertension and diabetes prior to conception. While the shortest safe interval from transplant to conception has not been established, 1 year is a reasonable milestone, given the prerequisites of stable, adequate graft function and maintenance-level immunosuppression. During pregnancy, maintenance-medication regimens should be continued with vigilant monitoring for effective drug levels and drug side effects with appropriate dose adjustment. These pregnancies are high-risk and require close maternal and fetal surveillance through coordinated care among maternal-fetal medicine specialists and transplant personnel. Of the live born reported to the NTPR, a higher incidence of structural malformations has been seen with MMF exposures during pregnancy when compared with the overall kidney transplant recipient offspring group. Three of the four defects included microtia (ear deformity), suggesting a pattern of malformations. However, live-born outcomes without structural malformations have also been noted in the MMF cohort. No structural defects have yet been reported with early pregnancy sirolimus exposures in a limited number of recipients evaluated. Limitations in assessing congenital malformation risk and MMF exposure include methodology and potential reporting bias, small sample size, and our inability to exclude other comorbid factors such as non-immunosuppressive drug effects or other susceptibilities in this population. It is incumbent upon transplant professionals to be aware of any additional risk to the fetus from immunosuppressive medications relative to the potential improvement in maternal graft function/survival conferred by each of these agents. Given the ongoing concerns with the newer immunosuppressive agents, clinicians are responsible for providing pregnancy counseling in all pre- and post-transplant recipients of childbearing age. Centers are encouraged to report all pregnancy exposures in transplant recipients to the NTPR. Future analyses from the NTPR are directed at potential effects of these newer immunosuppressive regimens, not only from immediate exposure but also from continued exposure that may occur from breastfeeding. As the registry study design allows for contact between registry staff and recipients and their health care providers, efforts are ongoing to analyze the long-term outcomes of parents and children. Continued close collaboration among specialists will help to better identify potential pregnancy risks in these populations, particularly as new immunosuppressive agents are developed. The fiftieth anniversary of the first post-transplant pregnancy (reported by Joseph Murray et al.) (31) will be in March 2008. With this important date approaching and with ongoing pregnancy issues concerning post-transplant pregnancy safety, this is an ideal time to raise awareness of the need for continued worldwide cooperation for data collection. Enhanced assessment of pregnancy safety is essential to the development of guidelines for counseling and management of pregnancy in the transplant population.