Christina Kaufman

Allospecificity of activated t cells grown from endomyocardial biopsies from heart transplant patients

Studies were conducted to determine the functional characteristics of lymphocytes infiltrating human heart allografts. We have developed methodologies to generate lymphocyte cultures from endomyocardial biopsies. Thirteen biopsies from four heart transplant recipients, obtained at different days during a posttransplant period of less than two months, were cultured in interleukin-2 (IL-2)-containing medium supplemented with irradiated autologous peripheral blood lymphocytes as feeder cells. Lymphocyte cultures were obtained from all 13 biopsies and they exhibited a proliferative response to IL-2, suggesting the presence of activated T cells that express IL-2 receptors. Several cultures consisted of Leu 3 (helper/inducer) T cells, whereas others were primarily Leu 2 (cytotoxic/suppressor) T cells or a mixture of both types of cells. Cultured lymphocytes were also shown to be able to undergo secondary proliferation to donor-specific leukocytes as measured by primed lymphocyte testing (PLT). The PLT specificity of these cells was frequently toward class II HLA antigens of the donor, but certain cultures had PLT specificity associated with class I HLA antigens. These results demonstrate the feasibility of growing functionally active T cells from heart transplant biopsies. An analysis of the phenotypes and allospecificity, as well as a functional characterization of these cells, should generate useful information about the types of T cells involved in cardiac transplant rejection.

Interactions between bronchoalveolar lymphocytes and macrophages in heart-lung transplant recepients

Bronchoalveolar lavages (BAL) were obtained from heart-lung transplant patients. Following transplantation, the number of lymphocytes and macrophages are considerably increased. BAL lymphocytes frequently exhibit donor specific secondary allogeneic proliferation measured in primed lymphocyte testing (PLT) assays. We report our findings regarding a persistence of donor derived macrophages and lymphocytes in BAL during the posttransplant period. The presence of donor specific macrophages causes a proliferative response of alloreactive BAL lymphocytes from the recipient. This Bronchoalveolar Macrophage Lymphocyte Reaction, or BMLR, may represent a unique aspect of in vivo interactions associated with lung allograft responses. Comparative studies showed considerably lower PLT responsiveness of peripheral blood lymphocytes than that of BAL lymphocytes. These studies suggest that functional assays on BAL cells may be useful in monitoring lung transplant rejection and other immunological phenomena that affect pulmonary function of heart-lung transplant patients.

Baboon bone-marrow xenotransplant in a patient with advanced HIV disease: case report and 8-year follow-up.

Background. Xenotransplantation offers a solution to the shortage of organ donors and may offer resistance to human-specific pathogens. Baboons are resistant to productive infection with HIV-1. A baboon bone-marrow transplant (BMT) was performed in an attempt to reconstitute the immune system of a patient with advanced AIDS. The aims of this pilot study were to evaluate the safety of the procedure and develop an approach to prevent and monitor for xenozoonoses. Methods. A source animal was selected on the basis of infectious disease surveillance protocols. Baboon bone marrow, engineered to remove graft-versus-host-disease-producing mature lineages, but to retain hematopoietic stem cells and facilitating cells, was infused into the patient after nonmyeloablative conditioning. Serial clinical, virologic, immunologic, and hematologic evaluations were performed. Results. A 38-year-old male with advanced AIDS, who had failed to respond to triple-drug antiretroviral therapy, underwent baboon BMT in 1995. The patient tolerated the procedure without complication. Baboon cells were detected in the peripheral blood on days 5 and 13 after transplantation. Baboon endogenous virus (BaEV) was detected on day 5 but not subsequently. Antibody to BaEV was not detected. HIV-1 viral load declined 1.5 log and remained low until 11 months. The patient improved clinically, and no adverse events occurred. The patient is alive 8 years after the procedure. Conclusions. Baboon BMT to treat AIDS was attempted using nonmyeloablative conditioning and resulted in transient microchimerism and clinical and virologic improvements. Long-term improvement was not achieved; however, no adverse events occurred, and no evidence of transmission of xenogeneic infections was found.

Propagation of alloreactive lymphocytes from histologically negative endomyocardial biopsies from heart transplant patients: association with subsequent histological evidence of allograft rejection

Endomyocardial biopsies from heart transplant patients were cultured in vitro in the presence of Interleukin-2 and irradiated feeder cells to propagate graft-infiltrating lymphocytes. A correlation was seen between the frequency of lymphocyte growth and the degree of cellular infiltration of the biopsies. In this study, 43 of 113 (38%) histologically negative biopsies obtained from 55 patients during the first month post-transplant yielded lymphocyte cultures. The cumulative incidence of subsequent histological rejection was considerably higher in patients with such grower biopsies than in patients with nongrower biopsies. In the grower group, we were able to obtain data on alloreactivity of 32 lymphocyte cultures assayed by primed lymphocyte testing (PLT). The presence of donor-specific PLT reactivity in the cultured lymphocytes was associated with an additional risk for subsequent histological rejection. These findings suggest that the in vitro culturing of histologically negative endomyocardial biopsies will identify patients at increased risk for developing heart transplant rejection.

Propagation of infiltrating lymphocytes and graft coronary disease in cardiac transplant recipients

The pattern of lymphocyte growth from endomyocardial biopsies in 55 heart transplant recipients was shown to be correlated with the subsequent development of graft coronary disease. Persistent lymphocyte growth was observed in 39 patients, and 15 of these growers (or 41%) developed graft coronary disease. In contrast, only 1 of 15 patients (or 6%) with nongrower biopsies showed subsequent graft coronary disease. Thus, biopsy growth was associated with a higher incidence of subsequent GCD (p = 0.02). A comparison between the group of 15 growers with subsequent graft coronary disease and the 24 growers without subsequent graft coronary disease did not show any differences with respect to patient age, presence of coronary artery disease in the native heart, biopsy histology, donor alloreactivity of biopsy grown lymphocytes, and immunosuppressive drug regimen. On the other hand, the number of treated rejection episodes was significantly lower in the grower group with subsequent graft coronary disease (p = 0.04). These data support the concept that graft coronary disease may involve rejection and that more immunosuppression may lower its incidence. This concept is strengthened by findings showing that alloreactive T cells can be propagated from coronary arteries of cardiac allografts with graft coronary disease.

Characterizaton of Graft Infiltrating Lymphocytes Involved in Cardiac Transplant Rejection

In vitro culturing of graft infiltrating lymphocytes has been useful in studying cell-mediated mechanisms of transplant immunity [1]. These cultures are generated in the presence of Interleukin-2 (IL-2) which induces proliferation of activated T lymphocytes expressing IL-2 receptors. In heart transplant patients, lymphocyte growth from endomyocardial biopsies correlates with the rejection grade assessed by histology [2]. During the first month after transplantation, about one-third of histologically negative biopsies show lymphocyte growth and this is associated with a higher incidence and earlier onset of a subsequent rejection episode [3,4]. During the first three months after transplantation, lymphocyte growth is also associated with a higher incidence of graft coronary disease [5].

Defining Rejection in Vascularized Composite Allotransplantation: More than Just Arguing Semantics

Vascularized composite allotransplantation (VCA), including upper extremity and face transplantation, is increasingly utilized for reconstruction of devastating and disfiguring injuries, with over 200 transplants performed and more reconstructive teams around the world embarking on these reconstructive endeavors. Targeted, immune-mediated tissue destruction or “rejection” is an inevitable challenge of allotransplantation. Recognizing rejection and distinguishing it from other pathologies is essential in order to prevent damage or loss of the allograft. A better understanding of the mechanisms of VCA rejection will help guide the development of treatment and preventative therapies. The patterns of rejection observed in VCA are not well-defined, and a more standardized use of terminology will further our understanding of the process. Here we discuss the clinical and histological features of allograft rejection that have been described to date and review the use of specific terminology to describe features of VCA rejection. Finally, we conclude with several important questions that are central to our understanding of the rejection process.

Alloreactive Lymphocyte Propagation from Endomyocardial Biopsies from Heart Transplant Patients on Different Prophylactic Immunosuppressive Treatment Protocols

Cyclosporin is currently the preferred immunosuppressive drug to treat heart transplant recipients. During the early posttransplant period, an efficient immunosuppressive therapy is essential to reduce allograft rejection and thereby to increase transplant survival. However, infection remains a major complication of immunosuppression. Various prophylactic treatment protocols have been investigated to optimize heart transplant survival. They are based on tapered doses of cyclosporin in combination with prednisone (protocol A) supplemented with azathioprine (protocol B). Two protocols include additional antilymphocyte antibodies, namely rabbit antithymocyte globulin (RATG) (1.5 mg/kg/day) (protocol C) or murine anti-T-lymphocyte monoclonal antibody (OKT3; 5 mg/day) (protocol D).