Riseintotal IgEas an indicator ofallergic bronchopulmonary aspergillosis incystic fibrosis

Allergic bronchopulmonary aspergillosis isaserious complication of cystic fibrosis andmaybedifficult todia- gnose. Theaimofthisstudywastodefine theusefulness ofmeasuring total IgEcom- paredwithothermajorcriteria inthe diagnosis ofallergic bronchopulmonary aspergillosis inchildren withcystic fib- rosis. Methods- A retrospective analysis was carried outofthecaserecords of160chil- drenattending a tertiary referral pae- diatric cystic fibrosis clinic. Results -Sixteen children hadatotal IgE level above500IU/ml. Eleven children had sixormoreothermajorcriteria andwere considered to haveallergic broncho- pulmonary aspergillosis. These11children hadafourfold riseinIgEinassociation withclinical deterioration. Afurther child hadafourfold riseinIgEto341IU/1, and wasalsothought tohaveallergic broncho- pulmonary aspergillosis. Elevenhada fall inIgEwithsuccessful treatment; one patient diedwithuncontrolled disease. Onlyoneofthese 12children hadnegative precipitins toAspergillus fumigatus. The five children witharaised IgEnotthought tohavebronchopulmonary aspergillosis hadfourorfewermajorcriteria andwere nottreated; nonehadpositive precipitins. Conclusions -A fourfold rise intotal IgE, particularly toabove500IU/ml, isstrongly suggestive ofthediagnosis ofallergic bronchopulmonary aspergillosis inchil- drenwithcystic fibrosis. The meas- urementoftotal IgEhasthemeritofbeing simple toperform andobjective. Positive aspergillus precipitins provide useful con- firmatory evidence. Thesetwocriteria, takeninconjunction withclinical de- terioration andnew radiological shad- owing, allowsimplification ofthediagnosis of allergic bronchopulmonary asper- gillosis incystic fibrosis. (Thorax 1994;49:1002-1005)