Transplant rejection reactions have been traditionally categorized into:- Hyperacute Acute Chronic rejection based on the clinical tempo of the response and on the mechanisms involved. Acute rejection is characterized by an abrupt onset of azotemia and oliguria, which may be associated with fever and graft tenderness. A needle biopsy would be expected to show Interstitial infiltrates of lymphocytes and macrophages Edema Lymphocytic tubulitis Tubular necrosis. Neutrophilic vasculitis and fibrinoid necrosis (choice D) are seen in hyperacute rejection. Diagnosis: Acute graft rejection