Current expectations in cardiac transplantation

One hudred thirty transplant procedures have been performed at Stanford University in 124 patients. Four major developments have contributed to increased survival over the past 3 1/2 years (60 patients): (1) transvenous graft biopsy for diagnosis of rejection, (2) antihuman thymocyte globulin of rabbit origin (RATG), (3) immunologic monitoring, and (4) cardiac retransplantation. Right ventricular endomyocardial biopsy is performed every 5 to 7 days for 4 to 6 weeks (830 biopsies in 78 patients without serious morbidity). RATG is given over the first 9 days (total 49 mg. immunoglobulin G per kilogram). Half-lives (T 1/2) of circulating rabbit globulin (RG) are calculated by radioimmune assay. Slow T 1/2 correlates directly with delayed rejection, decreased severity of rejection, and increased survival. RATG is reinstituted for acute rejection and as long-term therapy to reduce toxic maintenance prednisone doses. Its administration is individually modulated by serum RG levels. No serious toxicity has occurred. The primary immunologic monitoring assay is measurement of circulating T-lymphocytes by sheep e-rosette formation. Depression to less than 10% of normal occurs within 6 days. Subsequent rejection episodes are heralded by exponential T-cell rises 1 to 3 days before abnormal graft biopsy. This assay detects early efferent immune response and permits earlier and more efficient immunosuppression. Two indications for retransplantation exist: intractable recurrent rejection and accelerated graft atherosclerosis. Five patients have undergone graft replacement, three successfully. These advances have contributed to present survival rates of 66, 63, and 58% 1, 2, and 3 years after transplantation (90 % rehabilitation). More extended application in selected patients is warranted.