Biomedical subjects

M A Simpson

Publications and source records attributed to M A Simpson.

At least 19 recordsLinked to original sources

PubMed1991

Sequential interleukin 2 and interleukin 2 receptor levels distinguish rejection from cyclosporine toxicity in liver allograft recipients.

Previous studies of renal transplant recipients have demonstrated that allograft rejection is accompanied by an increase in plasma and urinary levels of interleukin 2 and its soluble receptor before the development of clinical symptoms. After measuring interleukin 2 and interleukin 2 receptor levels in the plasma, bile, and urine of liver transplant recipients, we found that rejection is preceded by elevation of plasma and biliary levels of both substances, that cyclosporine toxicity did not affect either of these levels, and that urinary levels of the substances are unaffected in either condition. Levels of interleukin 2 and interleukin 2 receptors increased in bile earlier than in plasma, and interleukin 2 levels did not overlap among stable patients and those experiencing rejection, whereas levels of interleukin 2 receptors did. Serial measurements of interleukin 2 levels, particularly in the product of the transplanted organ, provide a reliable assessment of the immunologic status of the allograft.

Bile↗

PubMed1991

Prevention of graft-versus-host disease following small bowel transplantation with polyclonal and monoclonal antilymphocyte serum. The effect of timing and route of administration.

Graft-versus-host disease is a potential problem following small bowel transplantation. We have previously shown that a two-day intraperitoneal course of polyclonal antilymphocyte serum completely prevents GVHD without impairing allograft function in a unidirectional rat small bowel transplant model. In the present study we sought to determine the optimum route and timing of ALS administration and whether donor pretreatment with the anti-T cell receptor monoclonal antibody R73 would be similarly effective in preventing GVHD. Both intravenous and intraperitoneal injection of ALS effectively prevent GVHD in this model. ALS must be given to donors at least 48 hr prior to graft procurement for maximum effectiveness. Prevention of GVHD correlates with lymphocyte depletion in mesenteric lymph nodes, as opposed to peripheral blood or small bowel lamina propria. Donor pretreatment with the monoclonal antibody R73 significantly delays the onset of GVHD in this small bowel transplant model but appears less effective than polyclonal ALS.

Animals↗

PubMed1991

Immunologic heterogeneity among potential transplant recipients. Prospects for predicting immune responses to allografts with in vitro tests.

The ability to accurately predict the response of a specific patient to a specific organ allograft has long been a goal of organ transplantation. The role of histocompatibility antigens in determining the acceptance or rejection of an allograft-recipient combination has been thoroughly investigated, but is being reevaluated as improved immunosuppressive agents become available. Early efforts at immunologic monitoring are reviewed in addition to more recent efforts that focus on the cellular and molecular mediators of immunity. The authors' own experience with lymphokine measurements in clinical transplantation is also reviewed, with emphasis on the role of interleukin-2 (IL-2) and its soluble receptor (IL-2R) in various transplant-associated conditions. The authors conclude that information useful in the management of transplant patients may be derived from serial measurements of IL-2 and IL-2R, but that infections, especially CMV, may not be ruled out with certainty by these measurements alone. The available data suggest that study of additional lymphokines such as interferon-gamma (IFN-gamma) and tumor necrosis factor (TNF) may be useful in discriminating rejection from infections in transplant patients.

Antigens, Surface↗

PubMed1991