Non-heart-beating organ donation: a defense of the required determination of death

The family of a patient who is unconscious and respirator-dependent has made a decision to discontinue medical treatment. The patient had signed a donor card. The family wants to respect this decision, and agrees to non-heart-beating organ donation. Consequently, as the patient is weaned from the ventilator, he is prepped for organ explantation. Two minutes after the patient goes into cardiac arrest, he is declared dead and the transplant team arrives to begin organ procurement. At the time retrieval begins, it is not certain that the patient's brain is dead or that cardiac function cannot be restored. Procurement follows uneventfully, and two transplantable kidneys are retrieved.

Many people now consider such cases of non-heart-beating organ donation to be ethically permissible. However, widespread disagreement persists as to how such practices are to be justified and whether such practices are compatible with the Uniform Declaration of Death Act (UDDA). In this paper, I argue that non-heart-beating organ donation can be ethically justified, that in the justified cases the patients are in fact dead, and that the early declarations of death required for such donation do comply with the UDDA.

Z-plasty closure of the donor defect of the radial forearm free flap

The radial forearm is a popular free flap site for reconstruction of head and neck defects, because of its abundant, pliable, skin component and an available, extended, vascular pedicle. In addition, vascularized composite flaps, including a segment of radius, can be designed for skeletal stabilization. The donor-site defect can involve various complications, including loss of skin graft, unsatisfactory appearance, numbness, and radial fracture. Recent advances in reducing donor-site defect problems have included the use of rotation skin flaps, local muscle rotation, and soft-tissue expansion; however, each of these has its own limitations. Two cases are presented in which radial forearm donor site defects, measuring less than 4 cm x6 cm, were primarily closed successfully with z-plasties based on the longitudinal skin incision. Each patient has regained preoperative mobility, and prompt primary healing was achieved without complications.

[Liver transplantation from elderly donors]

This retrospective, case-controlled study compared the outcome of 17 OLTs (group A) using livers donated by subjects over 70 years of age with 17 OLTs (group B) with livers from donors under 40. Clinical data were used form the period 1996-1998. The following variables were considered in the analysis: donor clinical and laboratory parameters, cold ischemic periods, intra-operative blood and plasma replacement, 30-day mortality rate, incidence of primary graft dysfunction, acute rejection and arterial complication and long term survival. The main post-operative parameters were also included. Liver biopsy, performed in 9/17 of group A, revealed minimal steatosis. There were 2 post-operative deaths in group A and 1 in group B (p = NS). Two arterial complications were observed in group A (p = NS) and only one patient required retransplantation (p = NS). The only other difference found among clinical variables was the amount of total bilirubin at post-operative days 8 and 10, aPTT at days 6 and 13 and albumin at days 5 and 6. A two-year follow-up showed survival rates to be 88.2% and 94.1% for groups A and B, respectively (p = NS). Candidates over 70 years of age should be excluded as liver donors. In such cases, greater care needs to be placed on pathological vascular conditions related to advanced stage atherosclerosis such as calcified plaques on the hepatic artery, a possible factor in severe postoperative complications.

DNA typing for HLA-A and HLA-B identifies disparities between patients and unrelated donors matched by HLA-A and HLA-B serology and HLA-DRB1

High incidences of graft failure and graft-versus-host disease in the recipients of bone marrow transplantations (BMT) from unrelated donors (URD) may reflect the existence of allelic disparities between the patient and the URD despite apparent HLA identity at HLA-A, HLA-B, and HLA-DRB1 loci. To identify the extent and pattern of allelic disparities at HLA-A and HLA-B loci, 128 patients and 484 potential URD were evaluated by DNA typing. DNA typing for HLA-A, HLA-B, and HLA-DRB1 was performed at Memorial Sloan Kettering Cancer Center. HLA-A and HLA-B serotyping on URD was provided by the registries. By original typing (serology for HLA-A and HLA-B; DNA typing for DRB1) 187, 164, and 133 URD were 6/6, 5/6, and 4/6 matches, respectively. Following DNA typing, however, only 52.9% of the originally 6/6 matched URD remained 6/6, while 38.5%, 7.5%, and 1.1% were found to be 5/6, 4/6, and 3/6 matches. The level of disparity was higher in the originally 5/6 (P <.01) and 4/6 (P <.01) matched URD. A higher level of disparity was seen for HLA-B as compared to HLA-A. In addition, a serotype related variation was also noticed. For example, 24.1% of HLA-A2 and 60.1% of HLA-B35 seromatched URD were genotypically disparate, but no disparities were seen for HLA-A1 and HLA-B8. A higher percentage of HLA-A (67. 4%) compared with HLA-B (35.4%) serologic homozygous URD remained genotypically homozygous (P =.01). The level of allelic disparity was lower (P <.01 for 6/6; P =.02 for 5/6) if the patient had one of the 15 most common haplotypes (A1B8DR3, A2B7DR15, A3B7DR15, etc) in comparison to the rest of the group. Outcome studies will answer the question whether these disparities are associated with a higher rate of immunological complications seen with URD-BMT.

Keratolimbal allograft: recommendations for tissue procurement and preparation by eye banks, and standard surgical technique

PURPOSE

To facilitate increased use of keratolimbal allograft transplantation (KLAL) for severe ocular surface disease (OSD) by informing clinicians and eye banks of differences in tissue requirements and preparation for the procedure and to describe the surgical technique of KLAL transplantation.

METHODS

The protocol of the Minnesota Lions Eye Bank is described for procuring and preparing tissue for KLAL transplantation. The surgical technique is described in detail.

RESULTS

Over the last several years, we have modified our eye-banking procedures as well as our surgical technique to improve the success of KLAL transplantation.

CONCLUSION

KLAL transplantation for patients with severe ocular-surface disease is an important management option. Success is influenced by the ability to obtain appropriate tissue; this requires clinicians and eye banks to expand current procurement guidelines.

Glucose sensitivity of porcine and human islets in vitro

Preliminary experiments about the suitability of different commonly used culture media in our laboratory indicated, that prolonged exposure to high glucose concentrations during low temperature culture (LTC) impairs the viability of long term cultured human islets. As a consequence of the heterogeneity of tested media the present study was aimed to evaluate the influence of different glucose concentrations on survival, viability and in-vitro function of cultured human islets in order to optimize islet survival until transplantation and to compare species dependent differences in glucose sensitivity. Quantified aliquots of freshly isolated (digestion-filtration, ficoll gradient purification) islets from consecutively processed human (n=6) and porcine (n=11) pancreata were subjected to different glucose concentrations (human islets: 500, 750, 1000 and 2000 mg/l; porcine islets: 1000 and 2000 mg/l) in CMRL (22 degrees C) for 8-10 days. After LTC survival, viability and glucose-stimulated insulin release of incubated tissue was assessed. A reduction of glucose concentration promotes survival and viability of human islets but impairs in vitro function at the same time, presumably due to a reduced glucose oxidation as expressed by the significantly reduced stimulation index. In contrast to these findings in the human, elevated glucose concentration in porcine islet culture increases survival but reduces the glucose-stimulated insulin release and the viability of cultured islets. The contradiction of the results in regard to islet survival related to islet viability are still unclear in the pig and needs further evaluation.

Renal artery rupture secondary to pretransplantation Candida contamination of the graft in two different recipients

Infected graft transplantation is an unwelcome complication that may lead to serious consequences in the immunosuppressed host. It can be caused by infection of the donor or by contamination of the organ during harvest, preservation and handling, or at transplantation. With current donor evaluation protocols, the risk of transmitting infections by exogenous contaminated grafts seems to be more frequent than true donor-transmitted infections. Nevertheless, although rare and usually free of clinically significant sequelae, if contamination is by some virulent organisms such as Staphylococcus aureus, gram-negative bacilli, or fungi, severe complications may occur. We report the clinical outcome of liver, heart, and kidney recipients from a single donor. Both renal allografts had to be removed because of renal artery rupture secondary to Candida albicans infection. Careful donor evaluation before transplantation, unusually early presentation of mycosis leading to anastomotic renal artery disruption, the histopathologic findings of the grafts, and the absence of Candida infection in the liver and heart recipients make us believe that exogenous contamination of the grafts occurred during donor procedure, kidney processing, or at transplantation. In summary, because infected grafts can lead to serious complications, besides careful donor screening, it is important to achieve early recognition of contaminated organs by culturing the perfusate to start specific antibiotic or antifungal therapy after transplantation if necessary and avoid the rare but, in this case, fatal consequences of these infections.

Preexisting membranous nephropathy in allograft kidney

A case of membranous nephropathy, preexisting in a donor kidney, will be reported. A 41-year-old man underwent a cadaver renal transplantation. An allograft biopsy specimen obtained during the operation showed spike formation on periodic acid-silver methenamine staining and deposition of IgG along the glomerular capillary loop on immunoperoxidase staining. Immunofluorescence staining for IgG remained in the specimens obtained on day 11 and after 4 weeks, but markedly decreased in the specimen obtained 7 weeks after transplantation. Electron-dense deposits also decreased in amount, but irregular thickening of the glomerular basement membrane with spikes, electron-lucent washout lesions, and small amounts of electron-dense deposits remained 20 months after the transplantation. These findings suggest that membranous nephropathy, as well as IgA nephritis and diabetic nephropathy, resolve after renal transplantation and that deposition of IgG markedly decreases within a few months after transplantation, but that complete histological restoration of the basement membrane needs at least a few years.

[Donor leukocyte transfusion in a patient with relapsed chronic myeloid leukemia after allogeneic bone marrow transplantation: analysis of natural killer cell activity and T-cell receptor repertoire in bone marrow T cells that exhibited graft-versus-leukemia activity]

Hematologic relapse of chronic myeloid leukemia developed in 37-year-old man 255 days after allogeneic bone marrow transplantation. The patient received a donor lymphocyte transfusion (DLT) twice at a dose of 5 x 10(6)/kg T cells. He achieved complete cytogenetic response (CCR) 14 weeks after DLT, and has remained in a CCR state for 17 months. Neither acute nor chronic graft-versus-host disease (GVHD) was observed. Natural killer (NK) cell activity was elevated. Also, analysis of the T cell receptor (TCR) repertoire disclosed oligoclonal expansion of T cells of the TCR V beta and J beta subfamilies. These observations provide evidence for the clonal expansion of allogeneic T cells that are capable of mediating antileukemic activity without causing GVHD.

Mixed hematopoietic chimerism induces donor-specific tolerance for lung allografts in rodents

Mixed hematopoietic chimerism is a state in which bone marrow hematopoietic stem cells from two genetically different animals coexist. We investigated whether mixed hematopoietic chimerism, resulting from the transplantation of host and donor bone marrow into a lethally irradiated rat, would confer donor-specific tolerance to lung allografts. Recipient rats (Fisher or or Wistar Furth [WF]) were irradiated (1,100 cGy) and reconstituted with a mixture of T-cell-depleted syngeneic plus allogeneic bone marrow. After mixed chimerism was documented by the presence of donor- and host-derived cells in the peripheral blood 4 wk after bone marrow reconstitution, mixed chimeras underwent orthotopic left lung transplantation with donor-specific and third-party lung allografts. No immunosuppressive agents were administered after lung transplantation. All donor-specific lung allografts were accepted by mixed chimeras (n = 40), while all third-party grafts (n = 7) were rejected within 10 d, a time course similar to that for grafts transplanted into naive recipients (n = 14). Radiation control recipients (n = 7) who did not develop mixed chimerism because the donor bone marrow had failed to engraft, also rejected donor-specific grafts within 10 d. We conclude that mixed hematopoietic chimerism induces donor-specific transplantation tolerance to lung allografts.

HLA-A, -B, -C polymorphism in a UK Ashkenazi Jewish potential bone marrow donor population

To further our knowledge of HLA polymorphism in different ethnic populations and to increase the number of full HLA class I typed potential bone marrow donors on the Anthony Nolan Bone Marrow Trust register, HLA-A, -B and -C polymorphism was characterised in 412 Ashkenazi Jewish potential donors. Serological typings and limited molecular analysis was performed for HLA-A and -B, and molecular typings were performed for HLA-C. Gene and haplotype frequencies were calculated using the maximum likelihood method and compared with UK Caucasoid and other Jewish populations. While the specificities identified were in general overlapping with the UK Caucasoid data, a difference in the frequencies of individual specificities was observed. For example, HLA-B62, a common serotype found in the UK Caucasoid population, is almost absent in the Ashkenazim. HLA-A, -C, -B haplotype frequencies also differ between the two populations with A26-Cw*1203-B38 and A24-Cw*04-B35 significant in the Ashkenazim, whilst A1-Cw*07-B8, a common Caucasoid haplotype, was found to be less frequent. Overall the results for the UK Ashkenazi population were most similar to previous reports on Polish/Russian Jews.

Donor cell induced CD69 expression and intracellular IL-2 and IL-4 production by peripheral blood lymphocytes isolated from kidney transplant recipients

Flow cytometry assays, which measure CD69 activation and intracellular cytokine production, have been used to measure peripheral blood lymphocyte (PBL) responses to in vitro antigen exposure. In the present study, we show that, in healthy individuals and immunosuppressed kidney transplant recipients, CD69 expression and intracellular cytokine production by peripheral blood T cells compare favorably to thymidine uptake as a measure of PBL response to alloantigen in mixed leukocyte culture (MLC). Heparinized whole blood from 23 healthy individuals was incubated for 24-48 h with 3rd party allogeneic monocytes; blood from twelve kidney transplant recipients was incubated with monocytes from their kidney donor and with monocytes from unrelated individuals. The percentage of T cells expressing surface CD69 or intracellular IL-2 or IL-4 was determined by 3-color flow cytometry. We identified 5 donor-specific response patterns in our kidney transplant group. One transplant recipient was hyporesponsive; his cells did not express CD69 or produce IL-2 in response to either donor or 3rd party allogeneic cells. All other transplant recipients expressed CD69 and IL-2 in response to 3rd party allogeneic cells. Two had no response to donor cells (donor-specific hyporesponsiveness), three had donor-specific anergy (CD69 expression without cytokine production in response to donor cells), five had a donor-specific Thl response (CD69 expression and IL-2 production in response to donor cells), and one had a donor-specific Th2 response (CD69 expression and IL-4 but not IL-2 production in response to donor cells). Rapid measures of donor-specific hyporesponsiveness such as CD69 activation antigen expression and intracellular cytokine production may prove valuable in monitoring lymphocyte function and aid in the long-term management of kidney transplant recipients.

Recombinant IFN-gamma abrogates allograft tolerance induced by donor-specific blood transfusion by restoring alloantibody production

Donor-specific tolerance to heart allograft was induced in adult Lewis rats by pregraft donor-specific blood transfusion (DST). We previously showed that this tolerant state is characterized by a dramatic inhibition of T cell and macrophage activation. In addition, tolerant animals could not mount an efficient anti-donor humoral response whereas transfer of sera from rejecting animals triggered rejection in tolerant animals. This tolerance can be abrogated by daily post-graft administration of recombinant IFN-gamma (rIFN-gamma). To elucidate the mechanisms of action of rIFN-gamma, T cell, macrophage and B cell functions were assessed in allograft recipients. IFN-gamma did not restore the expression of Th1-related cytokine mRNA or the activated macrophage product inducible nitric oxide synthase in allografts. Importantly, rIFN-gamma treatment promptly restored the anti-donor humoral response in DST-treated recipients. We conclude that rIFN-gamma treatment in DST-treated allograft recipients cannot reverse the unresponsive state of Th1 cells and macrophages infiltrating the graft, but can provide B cell help for IgG alloantibody production which is lacking in these animals.

Expanding the scope of lamellar keratoplasty

PURPOSE

To investigate whether applications of current technology, such as cryolathe and excimer laser, might improve outcomes and increase use of lamellar keratoplasty.

METHODS

Six studies were performed, beginning with animals and progressing to human subjects. The first study compared cryolathed with hand-dissected rabbit corneas to ascertain which created a smoother donor interface. The second animal pilot study was done to determine whether thickness of donor cornea resection could be accurately predicted with the cryolathe. A prospective animal trial was then undertaken to compare lamellar keratoplasty outcomes using cryolathed versus hand-dissected tissue. The fourth work extrapolated previous animal findings to lamellar keratoplasty in human disease. Finally, two ongoing studies are described. The first explores the possibility of sutureless lamellar keratoplasty. The second utilizes the excimer laser to dissect the recipient stromal bed.

RESULTS

The initial animal pilot study demonstrated a clearer stromal surface in cryolathed versus hand-dissected corneal tissue. The second pilot showed that plano-powered donor tissue could be generated to predetermined thickness. The prospective animal trial revealed that clear grafts of intended thickness could be obtained with cryolathing. Human studies suggested that lamellar keratoplasty using cryolathe-prepared donor tissue may offer superior results to free-hand dissection. Finally, one ongoing study indicates that sutureless lamellar keratoplasty is untenable, and the other shows that clear grafts can be obtained by combining cryolathed donor tissue with recipient photoablation.

CONCLUSION

This body of work demonstrates that use of new lamellar keratoplasty technology may offer expanded scope and better outcomes than traditional lamellar keratoplasty techniques.

Prevention of graft-versus-host disease (GVHD) by elimination of recipient-reactive donor T cells with recombinant toxins that target the interleukin 2 (IL-2) receptor

Graft-versus-host disease (GVHD), due to the presence of recipient-reactive T cells, limits the usefulness of bone marrow transplantation (BMT) and is a major contributor to patient mortality. To prevent GVHD, murine and human T cells were activated by antigen or mitogens and treated with a genetically engineered form of Pseudomonas exotoxin A (PE) directed against the IL-2 receptor. Treatment with the chimeric toxin eliminated alloreactive cytotoxic T lymphocytes (CTL) as determined by cytotoxicity and mixed lymphocyte culture assays. Precursor frequencies of alloreactive cytotoxic T cells and proliferative T cells were reduced up to 100-fold as shown by limiting dilution assays. Flow cytometric analyses revealed that treatment with the chimeric toxin completely eliminated CD25+ cells from the cultures. Toxin treatment had no significant effect on hematopoietic stem and progenitor cells as determined in vitro by colony-forming assays and in vivo by long-term hematopoietic recovery after 950 rad irradiation. Toxin treatment decreased GVHD in transplanted mice to less than 10% (as compared to 88% in untreated controls). Thus, it is possible to prevent life-threatening GVHD after BMT by using a CD25 receptor-directed toxin to eliminate host-reactive T cells from bone marrow grafts.

Privacy issues in second stage genomics

Research that identifies genes useful in the prevention and treatment of disease will require access to biologic samples and medical records protected by traditional notions of privacy and confidentiality. Resolving conflicts between privacy and genomic research will require articulating the ethical rules that should govern such practices and then implementing those rules in the national, regional, or local health systems in which the data of interest exists. As consensus develops about the ethical rules that should govern such research, attention will shift to the practical and political problems of installing and implementing those rules in the agencies and institutions where such research will occur.

Evidence for a significant correlation of donor pancreas morphology and the yield of isolated purified human islets

In clinical islet transplantation to patients with type 1 diabetes mellitus, the number of isolated and purified islet has been identified as a key determinant for functional success of the islet graft. With improved isolation methods based on the original procedure published by Ricordi et al. yield and function of isolated islets were considerably enhanced. However, there is still a large variance in the number, purity, viability and secretory capacity of islets isolated from brain-dead human donor pancreata, significantly hampering utilization of human islet preparations derived from a single donor for one diabetic recipient. The reasons for the limited success in islet isolation and purification have not been clarified in detail yet. Recent studies have indicated, that donor preconditions, and a number of technical factors during organ procurement and the islet isolation process itself are critical to successful islet isolation. This study aimed at identifying distinct morphological and histopathological characteristics of the donor pancreas as determinants for the outcome of human islet isolation and purification.

[Rapid recovery of hemopoiesis and alleviation of symptoms similar to peri-engraftment syndrome after donor leukocyte infusion]

A 28-year-old man who had received an allogeneic bone marrow transplant 7 years earlier experienced a relapse of chronic myelogenous leukemia in an accelerated phase. He was unsuccessfully treated with vincristine (VCR) and interferon-alpha (IFN-alpha), and subsequently received a donor leukocyte transfusion (CD3+ cells: 1.5 x 10(7)/kg). Rapid hematologic recovery was observed and a complete remission was obtained without graft-versus-host disease (GVHD) or bone marrow aplasia. It may be that the preceding regimen of chemotherapy (VCR + IFN-alpha) contributed to the patient's recovery by reducing the tumor burden.