METHACHOLINE AND ADENOSINE 5’-MONOPHOSPHATE

CHALLENGES IN PRESCHOOL CHILDREN WITH

COUGH-VARIANT AND CLASSIC ASTHMA

Gazi University Faculty of MedicineDepartment of Pediatric Allergy and Asthma

ADENOSINE 5’-MONOPHOSPHATE (AMP)

Effector cell: mast cell

Indirect bronchoconstrictor

PC20Adenosine: related with airway inflammation in asthma More sensitive than methacholine in monitoring response to asthma treatment

PC20Methacholine: related with structural changes in asthma

JACI 2006;118(3): 551

BACKGROUND

In school children and adults CVA is not different fromclassic asthma concerning the methacholine responsiveness, airway inflammation and remodelling

No study has compared AMP responsiveness betweenCVA and classic asthma in any age group

Bronchial challenge with different stimuli provides

different information and may be used as an adjunct to

understand the pathophysiology of cough variant asthma

(CVA) in young children in whom the mechanism of

disease is still unresolved.

AIM

Coughvariant asthma

n=18

Classicasthma

n=31Control

n=10

Parental asthma, n (%) 5 (27.7) 8 (25.8) 0 (0)

Atopy (SPT) n (%) 7 (38.8) 16 (51.6) 0 (0)

IgE, ıu/ml 43.7 41.9 27.6

Eosinophil, /mm3 196.5 292 142

Methac. responsiveness, n (%) 18 (100) 31 (100) 1 (10)

PC15PtcO2 met (mg/ml ) 0.52 0.45 27.40

AMP responsiveness, n (%) 7 (38.9) 21 (67.7) 0 (0)

PC15PtcO2AMP (mg/ml ) 234.58 36.35 Hepsi >400

METHACHOLINEMETHACHOLINE

Calssic asthmaCoughVariant asthma

Control

PC15P

tcO

2Met

hach

olin

e (m

g/m

l)

AMPAMP

Control

PC15P

tcO

2AM

P (m

g/m

l)

CoughVariant asthma

Calssic asthma

CONCLUSION

Pre-school children with CVA were found to differ from

children with classic persistent asthma with regard to

response profiles to AMP challenge which may point to

different pathophysiologic mechanisms of CVA in the young

age group.

Ped Pulmonol 2007; 42: 973