Immunological studies in cystic fibrosis.

Evidence is presented to support the concept that much of the allergy 
in cystic fibrosis (CF) is IgE mediated. Total IgE levels were 
higher in allergic than in nonallergic CF patients. Levels were also 
higher in those patients who had had the greatest number of 
chest infections in the preceding 12 months. IgE antibody levels to 
Dermatophagoides pteronyssinus, Timothy grass pollen, and Aspergillus fumigatus were higher in 
those with positive results from skin tests to these allergens. The 
serum IgG, IgM, and IgA levels of allergic and nonallergic CF 
patients did not differ but the overall mean values for IgG 
and iGM were higher than those reported for healthy British children. 
The highest levels tended to be present in patients with the 
greatest number of recent major chest infections and the difference was 
significant for IgG. 16 patients had IgA levels >2 SD below 
the reported means for age-matched controls and 11 of these were 
nonallergic. IgA levels were also higher in patients who had recently 
experienced major chest infections. 45 of the patients were tissue types 
for HLA A and B antigens but no significant clinical associations 
with single antigens were observed. The antigen phenotype A1 + B8 
was more common in patients with multiple allergic symptoms than in 
those with a single allergy or merely a positive result from 
a skin test. Nonsignificant increases of W19 in patients with frequent 
infections and of A2 in patients presenting with meconium ileus were 
also noted. The data presented do not permit a choice to 
be made between the alternative concepts of allergy as a primary 
abnormality in CF, and allergy arising secondary to infection. 