To repair heart defects, surgeons need a bloodless and motionless environment in which to work. They achieve this by diverting blood from the heart and lungs through a machine that infuses the blood with oxygen and pumps it around the body. During this process, known as cardiopulmonary bypass, the patient's blood is in contact with a foreign environment, which can stimulate the immune system to cause inflammation throughout the body (systemic inflammation), leading to widespread cell damage and sometimes death.
A recent study examined the role of molecules known as cytokines in the recovery of children following heart surgery. The study found that girls had higher levels of cytokine IL-10, which meant that they recovered more easily from their operations than boys.
Cytokines are chemicals that can increase or decrease systemic inflammation. Their release is stimulated by the female sex hormone, progesterone.
Andreas Trotter and colleagues from the University of Ulm in Germany decided to look at the levels of progesterone and cytokines in children during and after heart surgery to see if increased levels were associated with the development of systemic inflammations.
The researchers found that female patients had higher levels of cytokine IL-10, both during and after surgery. This is of great interest because IL-10 is thought to be one of the cytokines that suppress inflammation, which may explain why girls recovered more easily than boys.
However, Trotter could not find an association between the levels of progesterone and the recovery of the patients.
These results highlight that the role of sex hormones in systemic inflammation requires further study. They also show that there can be reasons for treating female and male patients differently.
If female sex hormones really protect against the development of systemic inflammation, then corrective cardiac surgery in girls should be carried out in the first weeks after their birth when their sex hormone levels are higher than those found later in infancy.
These results were published in a recent issue of Critical Care and are freely available at this URL.
The research is also discussed in a commentary by Dr. Marie-Christine Seghaye and colleagues in the same issue of Critical Care; this article is available at this URL.
Critical Care is a journal published by BioMed Central, an independent online publishing house committed to providing immediate free access to the peer-reviewed biological and medical research it publishes. This commitment is based on the view that open access to research is essential to the rapid and efficient communication of science.
23-Jan-2002
