Changes in exhaled nitric oxide levels with immunotherapy.
The mechanisms by which immunotherapy (IT) modulates allergic airway response are not entirely clear. Exhaled nitric oxide (eNO) is a sensitive marker of airway inflammation in allergic respiratory disorders. We hypothesize that eNO may serve as a barometer of the immunomodulatory changes occurring during IT. We aimed to characterize the pattern of eNO levels in children undergoing traditional IT (TradIT) and rush IT (RushIT). Off-line measurements of eNO were obtained in children electing to undergo RushIT or TradIT at a University-based Allergy/Asthma Clinic. The eNO was measured before IT (pre-IT, week 0) was initiated, and at 2, 4, 6, 8, and 12 weeks after starting IT. Nine children received TradIT and 10 children received RushIT. Pre-IT eNO in the RushIT group averaged 12.6 parts per billion (ppb). This was followed by a rise to 17.7 ppb at week 2. The elevated eNO levels persisted till week 8, and then dramatically dropped below the pre-IT values to 8.9 ppb at week 12 (p = 0.038). Similar changes in eNO were not seen in the TradIT group. The difference in eNO levels between the two groups was most marked at 4 weeks (p = 0.014). Initiation of IT produces significant immunomodulatory changes such as a rise in eNO levels. Temporally, the changes appear to be accelerated in the RushIT group compared with the TradIT group, with return to baseline as maintenance IT levels are achieved.
Dinakar
Chitra
C
Section of Allergy/Asthma/Immunology, Children's Mercy Hospital, Kansas City, Missouri 64108, USA. cdinakar@cmh.edu
Van Osdol
Thomas J
TJ
Barnes
Charles S
CS
Dowling
Paul J
PJ
Zeigler
Aubrey W
AW
D000293:Adolescent; D001944:Breath Tests; D002648:Child; D003888:Desensitization, Immunologic / Q000379:methods; D045853:Exhalation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism*; D012130:Respiratory Hypersensitivity / Q000378:metabolism* / Q000628:therapy; D012720:Severity of Illness Index; D013997:Time Factors
D009569:Nitric Oxide