Immune response following fresh arterial homograft replacement for aortoiliac graft infection

Introduction: this prospective study defines the immune response to fresh a rterial homograft replacement for graft infection. Materials and methods: ten patients who underwent ABO-compatible homograft transplantation were studied for anti-HLA antibody production, and CD3-CD4- CD8-positive lymphocytes subset. Immunological studies were performed preop eratively, and at early (1, 3, 7 days) and late (1, 3, 6, 12, 18, 24 months ) follow-up. All patients received immunosuppressive treatment with cyclosp orine (1-3 mg/kg/day). Abdominal CT scans were performed postoperatively at the 1, 6, 12, 18, 24 months follow-up. Results: preoperatively antibodies could not be detected. Postoperatively, as from Ist month post-transplant, a progressive increase in % PRA was obse rved in ail patients, tip to the 12th month of follow-up. Subsequently, at 18 nod 36 months, a progressive decrease in % PRA teas detected. Data showe d that the recipient antibodies were directed against donor-specific antige ns. During the immediate postoperative period (1, 3, 7 days) CD3- and CD4-p ositive T lymphocytes slightly increased, whereas CD8 simultaneously decrea sed. Later, CD3 and CD4 progressively decreased and CD8 increased. Clinical ly all patients were cured of infection at late follow-up. CT scans showed thickening of the aortic wall (range: 2.5-4.5 mm), with no signs of aneurys mal degeneration. Conclusions: fresh arterial homographs ape immunogenic. Implanted homograft s induce a strong anti-HLA antibody response, similar to chronic rejection, in spite of immunosuppressive treatment.