Macrophage migration inhibitory factor in pediatric patients undergoing surgery for congenital heart repair
Sanah Merchant1, Sumekala Nadaraj, Devyani Chowdhury
1Department of Pediatrics, Schneider Choldren's Hospital, New Hyde Park, New York, USA.
Abstract:
Macrophage migration inhibitory factor (MIF), a proinflammatory mediator, has been shown to be elevated following heart surgery in adults and may be associated with several postoperative complications, including cardiac and pulmonary dysfunction. In this study, we aimed to measure perioperative plasma MIF, interleukin (IL)-8, and free T4 in 20 children age <4 years undergoing surgical repair of congenital heart lesions with left ventricular volume overload, and to determine whether the response of these mediators determined postoperative outcomes. Plasma samples were obtained preoperatively, immediately on arrival in the pediatric intensive care unit (PICU), and at 12, 24, and 48 h. Patients were continuously monitored in the PICU, and data were recorded daily for therapeutic and monitoring procedures that reflected the invasiveness, intensity, and complexity of care rendered (therapeutic interventional scoring system, TISS). Preoperative plasma MIF, IL-8, and free T4 were not different from age-matched healthy children. However, plasma MIF and IL-8 increased significantly 2 h after completion of cardiopulmonary bypass, and then normalized within 24 h. Peak postoperative levels of MIF (48 +/- 24 ng/mL) and IL-8 (79 +/- 57 pg/mL) correlated significantly with duration of cardiopulmonary bypass. The magnitude of the postoperative increase in plasma MIF was associated with increased number of days required for mechanical ventilation (r = 0.553; P = 0.012), and peak plasma IL-8 correlated significantly with the fraction of inhaled oxygen (FiO(2)) required immediately after surgery (r = 0.510; P = 0.02). Higher circulating MIF levels correlated significantly with increased inotropic support requirements on the second postoperative day, whereas higher postoperative IL-8 levels were associated with higher TISS scores, suggesting increased need for postoperative medical care. These data suggest a potential negative effect of high circulating levels of MIF in the immediate postoperative period on respiratory and cardiovascular functions, and support the development of therapeutic strategies targeting MIF function in this clinical setting.
Insights
Elevated macrophage migration inhibitory factor (MIF) and interleukin-8 (IL-8) after pediatric heart surgery correlate with worse outcomes. Targeting MIF may improve respiratory and cardiovascular function post-surgery.
Area of Science:
- Pediatric Cardiology
- Immunology
- Critical Care Medicine
Background:
- Macrophage migration inhibitory factor (MIF) is a proinflammatory mediator implicated in postoperative complications after adult heart surgery.
- Congenital heart disease repair in young children involves cardiopulmonary bypass, potentially triggering inflammatory responses.
Purpose of the Study:
- To measure perioperative plasma MIF, IL-8, and free T4 in children under 4 undergoing congenital heart surgery.
- To determine if these mediator responses correlate with postoperative outcomes, including respiratory and cardiovascular function.
Main Methods:
- Plasma samples collected preoperatively and at multiple time points up to 48 hours post-PICU admission.
- Measured MIF, IL-8, and free T4 levels.
- Correlated mediator levels with clinical data including duration of cardiopulmonary bypass, mechanical ventilation, oxygen requirements, inotropic support, and TISS scores.
Main Results:
- Perioperative MIF and IL-8 levels increased significantly after cardiopulmonary bypass, normalizing within 24 hours.
- Peak MIF and IL-8 levels correlated with cardiopulmonary bypass duration.
- Postoperative MIF increase was associated with longer mechanical ventilation, while peak IL-8 correlated with higher FiO2 requirements.
Conclusions:
- Elevated perioperative MIF and IL-8 levels in young children after congenital heart surgery are linked to adverse respiratory and cardiovascular outcomes.
- These findings suggest MIF plays a negative role in the immediate postoperative period.
- Targeting MIF may offer therapeutic benefits for improving postoperative recovery in this patient population.
