From Risk to Protection: Turning PHT Around
CHORI & CHRCO Researchers Team Up to Compare Clinical Differences between Children and Adults with Sickle Cell Disease and Pulmonary Hypertension
CHORI clinical scientist Claudia Morris, MD, and Ward Hagar, MD, her colleague at CHRCO, have determined risk factors associated with pulmonary hypertension (PHT) in children with sickle cell disease (SCD). Their comparative study, published in the December issue of the British Journal of Haematology, revealed some surprising discoveries, including an equally high presence of PHT in children as in adults with SCD.
PHT has emerged within the last 5 years as a major, if not the major, cause of death in the sickle cell population, with a 40 percent increased risk of death. While associations of PHT with factors such as age and end-organ damage have been well-characterized in adults in the last few years, Drs. Hagar and Morris' study represents the first step toward providing an adequate risk profile for PHT in SCD children.
"What was so fascinating about this data was that the clinical profile of children with PHT turned out to be so vastly different than that of the adults," says Dr. Hagar.
In particular, acute chest syndrome (ACS), while a risk factor in children, was found to be protective in adults.
"Once you've had ACS as a complication of SCD, it usually triggers very aggressive treatment with the only two treatments that we currently know effect the underlying disease, which may be why it's protective," explains Dr. Hagar.
"Since ACS is a well known risk factor," adds Dr. Morris, "these patients are receiving the benefits of early care and intervention."
In contrast, children with a history of ACS were potentially too young to have reaped any protective benefit of treatment yet. In addition, sepsis and asthma were also associated with PHT in SCD children, but not adults.
All of which points the finger at the need for greater screening for PHT, regardless of how young a patient might be.
"Anyone with SCD really ought to be screened for PHT and asthma, and any child that has had sepsis should be screened as well," says Dr. Hagar.
Although there is currently no standard of care for the treatment of PHT in SCD, there are NIH guidelines for the treatment of asthma, and these guidelines should be applied to patients with SCD. In addition, the FDA has approved certain drugs for PHT, and CHRCO is one of 11 sites conducting controlled trials. Screening would not only help identify at risk patients who could benefit from such trials, but it could also offer an opportunity to turn the PHT risk to a benefit.
"The fact that ACS morality in adults is now protective is an indication that maybe we can do the same thing here," says Dr. Morris. "Maybe we can turn these risk factors around by identifying them earlier and treating them aggressively so that they, too, become protective."Back
Monday, May 16, 2011 11:33 PM