The thymus begins involution in childhood and historically it was thought to b e nonfunctional by adulthood, thus presenting no contraindication to the routine practice of thymectomy during cardiothoracic surgery. More recent data suggest, however, that the thymus remains active into adulthood and is responsible for t he low-level production of normal T cells. We hypothesize, therefore, that inci dental thymectomy during cardiothoracic surgery in infancy causes long-term cha nges in the cellular immune system. To investigate this hypothesis, we quantifie d peripheral T-cell subsets and T-cell recombination excision circles in child ren with congenital heart disease to measure the impact of cardiothoracic surgic al procedures and thymectomy performed during a period of immunologic developmen t.We found that cardiothoracic surgical procedures, especially if they include thymectomy, impair T-cell production and produce long-term decreases in total lymphocyte count and CD4+and CD8+T-cell subsets, suggesting that long-term m aintenance of lymphocyte populations is disturbed.
展开▼
