Induction of specific tolerance to small-bowel allografts.

Background: The induction of specific tolerance would greatly improve survival and functional state of organ transplant recipients. One approach that has recently received attention is the creation of mixed hematopoietic chimerism through the transplantation of allogeneic and syngeneic T-cell-depleted (TCD) bone marrows. In these studies we examined whether tolerance to highly immunogenic small-bowel transplants could be induced by mixed allogeneic chimerism.

Identification of an autoantibody to vascular endothelial cell-specific antigens in patients with systemic vasculitis.

Purpose: Although immunologic mechanisms have been postulated in the pathogenesis of vasculitis, an autoimmune process directed against specific autologous vascular wall antigens has not been previously documented. We examined the role of an immunologic response to vascular endothelial cell (VEC) antigens in patients with vasculitis, because of the observed immunogenicity of VECs in renal and cardiac allograft recipients.

Patients And Methods: The study patients included 21 with systemic vasculitis and four with hypersensitivity vasculitis.

The significance of a donor-specific vessel crossmatch in renal transplantation.

Very early graft rejection is usually attributed to pretransplant sensitization to HLA antigens represented on the lymphocyte. However, it is possible that such rejection episodes are secondary to antibody to a transplant-relevant system that is not represented on the lymphocyte but is represented within the allograft. This study suggests that sensitization to antigens on the VEC is detrimental to allograft success and can occur in the absence of sensitization to HLA antigens on the T or B cell or monocyte.

Immunosuppressive metabolites of cyclosporine in the blood of renal allograft recipients.

Cyclosporine levels by radioimmunoassay (RIA) and high-performance liquid chromatography (HPLC) were monitored in serial blood samples (n = 177) from 11 renal allograft recipients. HPLC analysis revealed three primary metabolites of CsA (M17, M1, and M21) in peak and trough blood samples; M17 was the preponderant metabolite. In 4 patients on whom serial metabolite assays were performed, M17 was found in the blood at 86-2004 ng/ml; M1 and M21 were found at up to 100 ng/ml.

Current trends in histocompatibility: clinical relevance versus laboratory phenomena.

The role of conventionally analyzed data in tissue typing is decreasing in clinical transplantation. Improved immunosuppression seems increasingly capable of overcoming the immune response to known histocompatibility differences. The introduction of the concept of public specificities may improve the correlation between matching and graft outcome.

The association of antivascular endothelial cell antibody with hyperacute rejection: a case report.

Early graft loss almost always occurs when recipients of a renal allograft develop antibody directed against antigens specific for donor vascular endothelial cells (VECs) and peripheral blood monocytes. In studies involving recipients of human leukocyte antigen identical, living-related grafts exhibiting preformed antibody to the VEC antigens of their donors, the median onset of rejection was 3 days after transplantation. Although preformed antibody to VEC antigens has been related in numerous articles to early graft loss, there has never been a published report of anti-VEC antibody leading to hyperacute rejection.

Identification of the antibody to vascular endothelial cells in patients undergoing cardiac transplantation.

Acute cardiac dysfunction occurred in four cardiac allograft recipients with negative donor-specific lymphocyte crossmatches. In two recipients the transplanted heart was removed and the patients were maintained on bypass for several hours until a second cardiac allograft was available. In these patients the second transplanted heart also underwent acute dysfunction.

Role of the vascular endothelial cell antigen system in the etiology of atherosclerosis.

An autoantibody directed against an antigen system that is expressed on the vascular endothelial cell (VEC) was recently identified in random patients with peripheral vascular disease. This VEC antigen system is also present on the peripheral blood monocyte but not on any other cell type studied to date. In a randomized study of 112 patients with peripheral vascular disease at the Albany Medical College, 46% demonstrated an autoantibody against their autologous monocytes and VEC.

The vascular endothelial cell antigen system.

Vascular endothelial cells (VEC) are clearly immunogenic and express antigens unique to vascular endothelial cells. The observation that peripheral blood monocytes also express this VEC antigen system made prospective testing feasible. Preformed antibody to the VEC/monocyte antigen system of the donor usually leads to graft rejection in HLA-identical combinations, but antibody directed against donor monocytes exclusively (monocyte-specific antigens) appears to be benign.

A new technique for placement of catheters for peritoneal dialysis.

We have described a technique for placement of a peritoneal dialysis catheter which involves fixing the end of the catheter to the pelvic wall and creating a peritoneal tunnel near the distal end. This technique prevents malfunction of the catheter due to malposition and rotating superiorly.

The significance of the monocyte crossmatch in recipients of living-related HLA identical kidney grafts.

Monocytes and vascular endothelial cells (VEC) carry a "cell specific" antigen system that has been found to play an important role in the pathogenesis of rejection. In a preliminary study utilizing a standard crossmatch technique with the peripheral blood monocyte as target, recipients of HLA identical living-related grafts who had either pretransplant or who developed posttransplant anti-monocyte antibody, had a high incidence of early graft rejection. This larger study of recipients of HLA identical living-related grafts represents the results of 21 patients from 13 separate transplant centers in the United States.

Hypertensive crisis induced by eating in a patient with pheochromocytoma.

Catecholamines have an important effect on the gastrointestinal tract. Patients with pheochromocytomas frequently have gastrointestinal complaints. We report a 13-year-old girl with a 250-g intra-abdominal pheochromocytoma who presented with symptoms of excessive catecholamines release and hypertensive crisis that was provoked by eating.