TRANSPLANTATION REJECTIONBY

DR.MADINA SIDDIQUE.

CLINICAL STAGES OF REJECTION.

STAGES OF REJECTION:1)Hyperacute rejection.

2)Acute rejection.

3)Chronic rejection.

1-Hyperacute rejection.Tissue is rejected within minutes to hours,(bcz vascularization is rapidly destroyed).

Humoral mediated & occurs bcz the recipient has preexisting Abs againts graft,which can be induced by -prior blood transfusions. -multiple pregnancies. - xerografts against which humans already have Abs.KIDNEY is most susceptible to hyperacute rejection. LIVER is relatively resistant,possibly bcz of dual blood

supply.

Ag Abs complex activate the compliment system,causing massive thrombosis the capillaries which prevents the vascularization of the graft.

Acute cellular rejection.Acute cellular rejection is mediated by lymohocytes that have been activated againt donor Ag,primerily in the lymphoid tissue of the recipient.

The donor dendritic cells(pessenger leucocytes)enters the circulation and function as APCs.

CLINICAL FEATURES OF REJECTION.

Immune system involment and epithelial cells necrosis.Fever in all cases.

Leucocytosis.

•RT-Dyspnea, Cough,Endothelitis and peribronchial inflammation.

CVS-thrombosis, Cellular infilterate absent in endocardiumCardiomegally, decreased ejection fraction to cardiac failureInterstitial infiltrate of lymphocytes,with myocyte damage or necrosis.

•

CLINICAL FEATURES:SKIN-Skin rash,Basal cells destruction, Endothelial swelling and odema.

LIVER-cogestion,haemorrhage,destruction of small bile ducts, jaundice.

GIT-focal crypt lesion,death of basal cells. Pain & tender abdomen, diarrhea.

High death rate.

FACTORS INCREASE THE

RISK OF CHRONIC REJECTION.• Previous episode of acute rejection.

• Inadequate immuno suppression.• Donor related factors(old ag,HPTN).• Reperfussion injury to organ.• Long cold ischemia time.• Recipient related factors

(Diabetes,HPTN,Hyperlipidemia)• Post transplant infection(CMV).