Læknablaðið - 15.04.1997, Page 25

LÆKNABLAÐIÐ 1997; 83
217
Nýr doktor í læknisfræði
Þann 22. september 1995 varði Sigurður
Kristjánsson doktorsritgerð við Háskólann í
Gautaborg. Ritgerðin nefnist Inflammatory
mediators and treatment effects in childhood
asthma and wheezing bronchitis. Ágrip úr rit-
gerðinni fer hér á eftir.
Eosinophils have the ability to secrete highly
toxic proteins such as eosinophil cationic pro-
tein (ECP) and eosinophil protein X (EPX),
which may play important roles in airway in-
flammation. Eosinophil-derived proteins were
measured in urine and serum in children with
atopic asthma to clarify if these markers can be
used to monitor airway inflammation. The re-
sults showed that active atopic asthma was as-
sociated with increased levels of urinary EPX
and serum ECP. Declining levels of the sub-
stances after anti-inflammatory treatment
seem to reflect suppression of airway inflam-
mation.
The leukotrienes (LTs) LTC4 LTD4 and
LTE4 are strong bronchoconstrictors, while
LTB4 is a chemotactic agent for human granu-
locytes. In blood, eosinophils are the main
source of LTC4 and neutrophils of LTB4. It has
been reported that eosinophils from asthmatic
patients produce more LTC4 than eosinophils
from healthy controls. The ex vivo release of
LTs induced by stimulation of leukocytes in
children with atopic asthma was determined to
clarify whether changed release is due to
changed capacity to release LTs or to changed
numbers of LT-producing cells. Increased leu-
kotriene levels found after the stimulation of
peripheral white blood cells obtained from
children with atopic asthma seem to be the
result of increased numbers of LT-producing
cells rather than being due to increased ability
of the individual cell to produce LTs.
The inhibitory effect of theophylline, terbu-
taline and hydrocortisone, separately and in
different combinations, on leukotriene pro-
duction of human leukocytes in vitro was ex-
amined. It was found that all these drugs inhib-
ited LT generation from white blood cells and
that combinations of the drugs had additive
inhibitory effects.
p2-agonists have been claimed to lack bene-
ficial effects in young children with acute
symptoms of wheezing bronchitis. A combined
a- and P- agonist, e.g. racemic adrenaline
(RA), could offer an interesting treatment al-
ternative. The effect of inhaled nebulised RA
on acute symptoms of wheezing bronchitis in
infants and toddlers was examined. It was
shown that nebulised RA improved oxygena-
tion and clinical signs in hospitalised children
below the age of 18 months with wheezing
bronchitis. The treatment is safe and may be
used as an alternative for symptom relief in
small children with acute wheezing bronchitis.
The possible changes in terms of hospital-
isation of children with asthma and wheezing
bronchitis were determined at a time period
when treatment with inhaled steroids as well as
the prevalence of asthma has increased. A de-
crease in hospitalisation of children with asth-
ma, aged 2-18 years was found to have oc-
curred despite the fact that the prevalence of
the disease has increased. This is most likely
due to increasing use of anti-inflammatory
treatment, largely in the form of inhaled ste-
roids. The results suggest that this is a very
cost-effective therapeutic approach.