Intravenous Antibodies Effective In Premature Infants’ Fight Against Infection, UF Researcher Says
GAINESVILLE—A premature baby’s early exit from the womb can leave the child in mortal danger from common infections other infants take in stride. One reason? Too small a helping of the mother’s disease-fighting antibodies.
Fortunately, another source is available: New research shows that a mixture of antibodies pooled from hundreds of blood donors improves a baby’s chances of surviving serious bacterial infection nearly sixfold when it is added to conventional antibiotic treatment.
University of Florida and University of Texas scientists hope their work will shed new light on a therapy that has been controversial because its effectiveness had not been clearly demonstrated. Earlier studies showed differing results from the use of intravenous immune globulin (IVIG) for the treatment of infections known as sepsis.
Sepsis affects two to four of every 1,000 newborns, with babies weighing less than 2 pounds at substantially greater risk. Fifteen to 20 percent of those afflicted die, sometimes within hours.
IVIG, derived from blood plasma, contains antibodies that specifically target varieties of bacteria a new baby has not yet acquired immunity to, such as streptococcal strains. Such bacteria are prevalent in the birth canal as well as the world at large. For those who cannot fight off the infection, the bacteria can lead to vague symptoms such as lethargy and irritability to more serious problems, including fever and vomiting.
“The idea here is to give them ‘passive resistance’–they can be protected by the antibodies other people have developed,” said Brad Pollock, associate professor and director of epidemiology in the department of health policy and epidemiology at UF’s College of Medicine.
That idea has been around awhile–and used with some effectiveness in treating other illnesses, including AIDS–but it’s been unclear whether the theory worked in battling sepsis. From 1986 to 1992, four studies were published on the topic, but because of their small sample sizes, no clear benefit was established.
In an article published earlier this year on the Internet version of the journal Pediatrics, Pollock and Dr. Hal B. Jenson, chief of pediatric infectious diseases at the University of Texas Health Science Center at San Antonio, analyzed the earlier studies using a statistical technique known as meta-analysis. One of the four studies was omitted from the analysis because it did not meet the researchers’ strict criteria for inclusion.
“Through meta-analysis, we often can shed light on what is really going on,” Pollock said. “We can numerically combine the studies, effectively creating one large group of patients. This larger group, which includes 110 infants, is more likely to give us meaningful answers.”
Their analysis showed that babies who were given IVIG in addition to routine treatment, such as antibiotics, were almost six times more likely to survive septic infection than infants who were given conventional treatment alone.
What effect their work will have on hospital practices remains to be seen.
“This analysis substantiates what many neonatologists are already doing,” Jenson said. “And for neonatologists who have been waiting for objective data that there is a benefit, this meta-analysis provides a basis for IVIG treatment.”
The researchers also analyzed conflicting studies that considered whether IVIG could be used to prevent–not simply treat–sepsis. They concluded, however, that IVIG was of minimal benefit in prevention. That finding could result in substantial savings, as some hospitals had been administering it widely in the hope it would do some good.
“For treatment, IVIG seems to work pretty well,” Pollock said. “For prevention, it doesn’t appear to work.”
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Victoria White