rejection


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Related to rejection: Social rejection

rejection

 [re-jek´shun]
the immune response of the recipient to foreign tissue cells (antigens) after homograft transplantation, with the production of antibodies and ultimate destruction of the transplanted organ. In hyperacute rejection, there is an immediate response against the graft because of the presence of preformed antibody, resulting in fibrin deposition, platelet aggregation, and neutrophilic infiltration. In acute rejection, the response occurs after the sixth day and then proceeds rapidly. It is characterized by loss of function of the transplanted organ and by pain and swelling, with leukocytosis and thrombocytopenia. In chronic rejection, there is gradual progressive loss of function of the transplanted organ with less severe symptoms than in the acute form.

re·jec·tion

(rē-jek'shŭn),
1. The immunologic response to incompatibility in a transplanted organ.
2. A refusal to accept, recognize, or grant; a denial.
3. Elimination of small ultrasonic echoes from display.
[L. rejectio, a throwing back]

rejection

/re·jec·tion/ (re-jek´shun) an immune reaction against grafted tissue that results in failure of the graft to survive.

rejection

[rijek′shən]
Etymology: L, re + jacere, to throw
1 an immunological attack against organisms or substances that the immune system recognizes as foreign, including grafts and transplants. See also acute rejection, chronic rejection.
2 the act of excluding or denying affection to another person.

rejection

Immunology An immune reaction evoked by allografted organs; the prototypic rejection occurs in renal transplantation, which is subdivided into three clinicopathologic stages. See Cyclosporin A, Graft rejection, Graft-versus-host disease, Second set rejection, Tacrolimus, Transplant rejection.
Rejection types  
Hyperacute rejection Onset within minutes of anastomosis of blood supply, which is caused by circulating immune complexes; the kidneys are soft, cyanotic with stasis of blood in the glomerular capillaries, segmental thrombosis, necrosis, fibrin thrombi in glomerular tufts, interstitial hemorrhage, leukocytosis and sludging of PMNs and platelets, erythrocyte stasis, mesangial cell swelling, deposition of IgG, IgM, C3 in arterial walls
Acute rejection Onset 2-60 days after transplantation, with interstitial vascular endothelial cell swelling, interstitial accumulation of lymphocytes, plasma cells, immunoblasts, macrophages, neutrophils; tubular separation with edema/necrosis of tubular epithelium; swelling and vacuolization of the endothelial cells, vascular edema, bleeding and inflammation, renal tubular necrosis, sclerosed glomeruli, tubular 'thyroidization' Clinical ↓ Creatinine clearance, malaise, fever, HTN, oliguria
Chronic rejection Onset is late–often more than 60 days after transplantation, and frequently accompanied by acute changes superimposed, increased mesangial cells with myointimal proliferation and crescent formation; mesangioproliferative glomerulonephritis, and interstitial fibrosis; there is in general a poor response to corticosteroids

re·jec·tion

(rĕ-jek'shŭn)
1. The immunologic response to incompatibility of a transplanted organ.
2. A refusal to accept, recognize, or grant; a denial.
3. Elimination of small ultrasonic echoes from display.
[L. rejectio, a throwing back]

Rejection

Rejection occurs when the body recognizes a new transplanted organ as "foreign" and turns on the immune system of the body.

rejection

immunological response induced by donor tissue incompatibility; i.e. recognition of non-self tissue, provoking an acute inflammatory response and ultimate death of donor tissue

rejection

the immune reaction of a recipient to a graft, usually an allograph, after transplantation. The recipient recognizes antigens, particularly major histocompatibility complex antigens that are different from self antigens. The rapidity and severity of the graft rejection parallels the degree of antigenic difference between donor and recipient. The primary rejection of a graft, called first set reaction, typically begins 6 to 10 days after engraftment and in the case of skin is characterized by an erythematous zone around the graft which subsequently shrinks and is rejected. Rejection is predominantly a cell-mediated immune response, particularly Th1 lymphocytes and activated macrophages. If the same recipient receives a second graft from the same donor the graft is rejected more rapidly and the response is more severe, called a second set reaction which is also a cell-mediated response. Lymphocytes from the recipient can be adoptively transferred to a naive recipient which if also given a graft from the same donor responds with a second set reaction.

rejection factors
antibodies, particularly IgM but also IgG, directed against antigenic determinants on the Fc region of other immunoglobulins. When the immunoglobulin binds to antigen, changes occur in the folding of the protein of the Fc region such that new, nonself antigenic determinants are exposed and it is to these that rheumatoid factors, i.e. other antibodies, are directed.
References in periodicals archive ?
Antibody-mediated rejection is a major cause of kidney transplant failure and is often associated with activation of complement, a set of proteins that work with antibodies and play a role in the development of inflammation and tissue damage.
MDS item E0800, Rejection of Care, can be a difficult item for facility staff to code correctly, particularly when a cognitively impaired resident cannot or does not voice her desires.
Keywords: father-child relationship, parental acceptance and rejection, depression, coping, socio-emotional outcomes
The researchers said the study reflects a shift in the field of organ transplantation from short- to long-term rejection concerns, and from invasive to noninvasive methods for detecting chronic rejection early.
Washington, October 17 ( ANI ): There are many kinds of stressors that increase our risk for disease, but the ones that threaten our social standing, such as targeted rejection, seem to be particularly harmful.
Summary: TEHRAN (FNA)- A simple, inexpensive blood test could soon help doctors halt organ rejection before it impairs transplanted hearts and kidneys.
During the two months after the transplant, moderate-to-severe acute rejection episodes were independently associated with lower pretransplant serum 25-hydroxyvitamin D concentrations (p < 0.
Biomarkers in Transplantation, a research initiative that will allow doctors to identify patients rejecting transplanted organs with a simple blood test, is making use of advanced genomic, proteomic, and computational tools to develop the test, which will diagnose rejection before acute organ rejection occurs, allowing doctors to intervene early and to personalize a patient's immunosuppressant therapy.
CellCept is Roche's leading immunosuppressant or "anti-rejection" drug used in combination with other immunosuppressive drugs (cyclosporine and corticosteroids) for the prevention of rejection in patients receiving heart, kidney and liver transplants.
Not dealing can worsen the situation, because the longer you wait to dash someone's hopes, the more intense the feelings of rejection.
He holds this view despite the abundant evidence that adult stem cells have been used successfully for years in curing disease and that embryonic stem cells have the potential of causing tissue rejection and have never cured anyone.
Then we turn on the frown and cease all contact with most of our applicants (perhaps even 90 percent of them), sending a brief and vague rejection letter that conveys a message between the lines: You were not quite good enough for us.