Biochemical markers as a response guide for steroid therapy in asthma.
BACKGROUND
Exhaled breath condensate pH and hydrogen peroxide concentration is a non-invasive, simple and inexpensive assay that can be performed for monitoring in patients with asthma.


OBJECTIVE
To evaluate the possibility of usefulness of expired breath condensate pH and H(2)O(2) concentration as well as serum total antioxidant capacity and malondialdehyde as markers for steroid treatment response.


METHODS
A total of 153 patients were included in this study (age range 18 to 64 years). Asthmatic patients, regularly followed for at least 3 months, were randomly recruited for the study over a period of one month. All patients received inhaled beclomethasone dipropionate (1,000 microg daily in four divided doses) and salbutamol inhalers (800 microg daily in four divided doses) for 4 weeks. Expired breath condensate was collected at the end of the study to determine hydrogen peroxide concentration and pH. Venous blood samples were collected for determination of total antioxidant capacity and malondialdehyde as markers of peroxidation.


RESULTS
In asthmatic patients with poorly controlled asthma, expired breath condensate hydrogen peroxide concentration was higher and the pH was lower than stable asthma. Serum malondialdehyde concentration in poorly controlled asthma was higher (6.98 micromol/L), and total antioxidant capacity was lower (589 micromol/L) than in stable asthma.


CONCLUSIONS
Exhaled hydrogen peroxide concentration and pH can be used as predictors for monitoring of nonresponse to asthma treatment.
Al Obaidi
Amina Hamed
AH
Departments of Biochemistry and Medicine, College of Medicine, Tikrit University, Tikrit, Iraq.
Al Samarai
Abdulghani Mohamad
AM
D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D000420:Albuterol / Q000008:administration & dosage*; D001249:Asthma / Q000175:diagnosis / Q000188:drug therapy*; D001507:Beclomethasone / Q000008:administration & dosage*; D015415:Biomarkers / Q000032:analysis*; D001944:Breath Tests; D015331:Cohort Studies; D016001:Confidence Intervals; D004351:Drug Resistance; D005260:Female; D005500:Follow-Up Studies; D005938:Glucocorticoids / Q000008:administration & dosage*; D006801:Humans; D006861:Hydrogen Peroxide / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D008297:Male; D008315:Malondialdehyde / Q000032:analysis; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D011237:Predictive Value of Tests; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D016896:Treatment Outcome
D015415:Biomarkers; D005938:Glucocorticoids; D008315:Malondialdehyde; D006861:Hydrogen Peroxide; D001507:Beclomethasone; D000420:Albuterol