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a·cute cel·lu·lar re·jec·tion
graft rejection that usually begins within 10 days after a graft has been transplanted into a genetically dissimilar host. Lesions at the site of the graft characteristically are infiltrated with large numbers of lymphocytes and macrophages that cause tissue damage. See: primary rejection.
Synonym(s): acute rejection
Etymology: L, rejicere, to throw back
after organ transplantation, the rapid reaction against allograft or xenograft tissue that is incompatible. It often occurs a week after treatment, during which the immune response increases in intensity.
rejectionImmunology 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.
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
The early destruction of grafted or transplanted material, usually beginning a week after implantation. Acute rejection is identified clinically by decreased function of the transplanted organ. High-dose corticosteroids are the first treatment of acute rejection; they are typically quite effective. Antilymphocyte globulin (ALG), the monoclonal antibody OKT 3, mycophenolate mofetil, and tacrolimus are used when corticosteroids are not effective. See: suppressive immunotherapy; macrophage processing; major histocompatibility complex; T cell
See also: rejection