THE INFLUENCE OF ALLOTYPES ON THE IGG SUBCLASS RESPONSE TO CHROMOSOMAL BETA-LACTAMASE OF PSEUDOMONAS-AERUGINOSA IN CYSTIC-FIBROSIS PATIENTS

Sera from 70 adult cystic fibrosis (CF) patients with chronic lung inf ection with Pseudomonas aeruginosa were typed for seven GM and two KM allotype determinants. IgG class and all four IgG subclasses of antibo dies against chromosomal beta-lactamase of Ps. aeruginosa (a beta ab) were measured in all 70 CF patients in a cross-sectional study. The a beta ab IgG subclass response in sera collected during the first 11 ye ars of chronic infection from 20 CF patients (10 patients with G3M5 G 1M3/G3M*5 G1M*3 genotype and 10 patients with G3M*21 G1M*1/G3M*21 G1M 1 genotype) was analysed in a longitudinal study. Increased levels of IgG2 were associated with the presence of GM 23 allotype. IgG3 a beta ab levels were the lowest for subjects with the GM 1,2,3,17 23 5,21 a nd GM 1,3,17 21 phenotypes and the highest in subjects with GM 3,23,5 and GM 3,5. No significant differences in IgG1 and IgG4 apab levels we re found between the different phenotypes. IgG1 apab levels were highe r in patients with KM3/KM*3 genotype compared with patients with KM*3 , 1 genotype. Patients with G3M*5 G1M*3/G3M*5 G1M*3 genotype had in b oth the cross-sectional and the longitudinal study higher IgG3 a beta ab, lower IgG4 a beta ab levels and poorer lung function than patients with G3M21 G1M*1/ G3M*21 G1M*1 genotype. An influence of the allotyp es on the clinical course of chronic lung infection with Ps. aeruginos a in patients with CF is suggested.