G. Lis et Jj. Pietrzyk, RESPONSE-DOSE RATIO AS AN INDEX OF BRONCHIAL RESPONSIVENESS TO HYPERTONIC SALINE CHALLENGE IN AN EPIDEMIOLOGIC SURVEY OF ASTHMA IN POLISH CHILDREN, Pediatric pulmonology, 25(6), 1998, pp. 375-382
This epidemiological survey was done to evaluate the bronchial respons
iveness (BHR) to a 4.5% hypertonic saline (HS) challenge in 13-14 year
-old schoolchildren. BHR was measured by the response-dose ratio in wh
ich the response was estimated by the decline of FEV, index of BHR (Ix
FEV(1)). Validity of the HS challenge test as a screening test for con
firmation of reported asthma symptoms and the diagnosis of asthma was
assessed. With a cutoff of 90th percentile of IxFEV, in controls, the
test sensitivity and specificity for asthma symptoms in the last 12 mo
nths was 44% and 90%, respectively. For the diagnosis of asthma the te
st sensitivity was 67% and specificity 90%. The mean log transform of
IxFEV, was significantly higher in children with more than three episo
des of wheezing in the last 12 months and a diagnosis of asthma than i
n controls. Moreover, in the group with more than three episodes of as
thma in the last 12 months the mean IxFEV, was higher in girls than in
boys. There was no gender difference in other groups of asthmatic chi
ldren and controls. In Polish schoolchildren the prevalence of BHR to
HS was 12.5% when adjusted to the prevalence of wheezing in the last 1
2 months. By multiple linear regression analysis, factors associated w
ith BHR were serum levels of total IgE in children and of maternal IgE
, as well as children's peripheral blood eosinophil counts. Also, the
size of skin reaction to mite and dog allergens correlated with BHR. (
C) 1998 Wiley-Liss, Inc.