Background and aims The protein CC16 is secreted in airways by the nonciliated bronchiolar Clara cells and has an important role in inflammation and immune modulation. Our study aimed to investigate the association of the CC16 A38G polymorphism with asthma severity in Moldavian children.

Methods A case-control study was used to detect the genotypes of 38 A/G of CC16 gene of 90 patients with asthma and 90 controls from the Moldavian ethnic group by polymerase chain reaction-restriction fragment length polymorphism. All patients underwent complex clinical and functional examination.

Results No significant differences were observed in the frequencies of polymorphic genotypes in site 38 of CC16 gene between asthmatic children and control subjects (p > 0.05, genotype frequency: AA+AG: 61.1% vs. 58.9%). The frequency of A allele was remarkable increased in girls with asthma compared to healthy controls (0.49 ± 0.06% vs. 0.33 ± 0.05%; χ²=3.21; gl=1; p = 0.07). In children with moderate and severe asthma the functionally compromised genotypes AA+AG were identified significantly more frequent comparing to the homozygous normal genotype (GG): 76.9% vs. 23.1% (t=2.3; p < 0.05) and 63.6% vs. 36.4% (t=1.9; p = 0.07), accordingly. The frequency of A allele was significantly increased in severe asthma cases compared with mild ones (0.54 ± 0.1 vs. 0.30 ± 0.06; gl=1; χ²=3.5; p = 0.054).

Conclusions The study showed an association of the CC16 A38G polymorphism with more complex and severe forms of asthma. The studied gene was selected because of its important role in regulating inflammatory processes, but it is necessary to conduct further studies of extended range of genes in this ethnic group.