PURPOSE OF THE STUDY.
The authors measured changes in plasma osteopontin (OPN) and serum basal tryptase (sBT) in children undergoing 1 year of bee or wasp venom immunotherapy (VIT).
Children with a history of large local reactions (n = 18) or systemic reactions (n = 24) after wasp or bee stings were recruited for this Turkish study. They were matched to 16 controls who had a history of a sting but no adverse reactions.
Study patients were identified through clinical history and allergy testing to wasp and bee venom. Serum biomarker measurements were performed before start of VIT and 6 and 12 months after it was started.
Plasma OPN levels from children who experienced large local reactions were significantly higher than those with SR and healthy control subjects. A significant increase in plasma OPN and interleukin-10 levels was determined after the 1 year of VIT. sBT of children with systemic reactions were significantly higher than those with large local reactions and controls. There was no significant change in sBT levels nor venom serum immunoglobulin E after 1 year of VIT.
There were higher baseline levels of OPN in children with LLR. Rising serum interleukin-10 while on VIT in the study patients indicate successful immune modulation. Increased OPN levels after 1 year of VIT suggests OPN may be a useful biomarker for assessing immune tolerance.
It has always been a challenge to determine when to stop VIT; the ideal test would be to re-sting the patient and monitor for reactions afterward. Although more familiarly known as an extracellular matrix protein involved in bone remodeling, OPN may play a role in the Th1-associated responses that build immune tolerance. This study suggests that obtaining baseline osteopontin levels before initiating VIT and following levels over time may help physicians determine adequate venom desensitization. Additional studies would help determine if there is a standardized range of serum osteopontin levels for deciding when VIT is no longer needed.
- Copyright © 2015 by the American Academy of Pediatrics