Methylprednisolone, cortisol and the cell-mediated immune response in children after ventricular septal defect repair.

摘要

BACKGROUND: This study evaluated the effects of methylprednisolone on cortisol and cell-mediated immune response (T-lymphocytes and HLA-DR+ monocytes) in peripheral blood after open-heart surgery with cardiopulmonary bypass (CPB) for ventricular septal defect. METHODS: A prospective observational study was carried out in a tertiary multidisciplinary neonatal and paediatric intensive care unit. Ten children under 2 years of age received methylprednisolone succinate (30 mg/kg body weight) in CPB priming solutions before the CPB system was connected to the patient during surgery. Before and immediately after and at 24 and 96 h after the operation, T-lymphocytes and HLA-DR+ monocytes were measured by flow cytometry, and methylprednisolone, methylprednisolone succinate and cortisol in blood plasma were assayed by liquid chromatography-mass spectrometry. RESULTS: The children were divided into groups with normal cardiac index (CI) and low CI. No significant differences in methylprednisolone and cortisol concentrations before and after surgery were found between the two groups. The normal CI group exhibited more than a three-fold decrease in T-lymphocytes 24 h after surgery and a two-fold decrease in HLA-DR+ monocyte fluorescence immediately after surgery. CONCLUSIONS: Children with normal and low CI were differentiated by T-lymphocytes and HLA-DR+ monocytes. Since no differences in methylprednisolone exposure and cortisol plasma levels between the low-CI and normal-CI groups were found, it can be concluded that factors other than methylprednisolone must contribute to differences in the cell-mediated response.