rejection


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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 ?
This isn't what you should let rejections tell you, but you also shouldn't make them push you to be cocky.
The experimenter, who was a postgraduate student at Ningbo University, pretended to score the participants for their results in the interactive game while actually completing the Rejection Sensitivity Questionnaire for College Students (Zhao, Li, & Zhang, 2012).
The poor people are in the losing end here and for sure those who are greedy of the pork barrel are rejoicing, the neoliberal economic managers and militarist US sympathizers, with the rejection of Ma'am Judy)
Two factors might explain these good results: early diagnosis of rejection with repetitive routine biopsies, and aggressive treatment of rejections with plasmapheresis and intravenous immunoglobulins even in subclinical rejections.
Conclusion: Obese adolescent experience more rejection sensitivity and shyness while had less self-worth as compared to non-obese adolescents of their age.
Erozkan (2009) found that all of the attachment styles had a substantial influence on the rejection sensitivity, while rejection sensitivity level of individuals having secure style of attachment is inferior as compared to rejection sensitivity level of persons with preoccupied,and fearful styles of attachment.
The research entitled "The Assay to Detect ksort Renal Transplant Patients at High Risk for Acute Rejection: Results of the Multi-centre Study Aarti", recently published in the journal PLOS Medicine, analysed blood samples from kidney transplant patients to measure 43 genes whose expression levels vary during acute renal rejection.
Since the refusal for assistance is not consistent with his values and goals for health and well-being, it would be considered rejection of care (p.
We sought to replicate these findings in the present study, as well as extend them by examining young adults' coping strategies and social experiences in relation to maternal/paternal acceptance and rejection.
Previous research has shown that people who are on the receiving end of this kind of rejection experience symptoms of depression three times faster than people who are faced with similarly severe life events.
PAR researchers have shown that perceived parental rejection has negative effect on the psychological adjustment and behavioral functioning of both children and adults worldwide.
In the past, we couldn't spot rejection episodes until they harmed the organ," said Atul Butte, MD, PhD, who is co-senior author of the new research and an associate professor of medical informatics and of pediatrics at the Stanford University School of Medicine, in addition to director of the Center for Pediatric Bioinformatics at Lucile Packard Children's Hospital.