Which of the following statement(s) is/are true concerning clinical syndromes of rejection?

b. The histologic characteristics of acute rejection include lymphocyte infiltration accompanied by plasma cells, eosinophils, or neutrophils

d. Transplantation across major ABO incompatibility will result in hyperacute rejection of a renal or cardiac transplant

Hyperacute rejection is the result of pre-formed antibody binding to the allograft at the time of revascularization in the operating room. Complement is activated resulting in endothelial cell destruction, vascular leak, recruitment of platelets and neutrophils, thrombosis of vessels, and destruction of the graft in a period of minutes to hours. Kidney, heart, pancreas, and lung allografts are all susceptible to hyperacute rejection; however, liver grafts are relatively resistant to this process and are often transplanted across antibody differences and even across an ABO difference. Acute rejection usually occurs days to weeks after transplantation and is initiated by T-cell dependent immunity characterized microscopically by lymphocytic infiltration accompanied by plasma cells, eosinophils, and a few Mast cells or neutrophils. Chronic rejection usually occurs months to years after transplant. It is characterized by loss of normal histologic structure, fibrosis and atherosclerosis. Chronic rejection is the major cause of graft failure and patient loss with all organs.