Abstract:OBJECTIVE: To investigate the frequency of heterozygous α 1 antichymotrypsin(α 1 ACT) deficiency and the types of gene mutation in childhood asthma. METHODS: The plasma level of α 1 ACT was detected using the rocket immunoelectrophoresis in 90 children with asthma (asthma group), 195 healthy children (normal children control group) and 198 healthy adults (normal adult control group). The frequency of heterozygous α 1 ACT deficiency was determined by studying the family history in the 3 groups. The clinic data of the children with or without heterozygous α 1 ACT deficiency were analyzed. Gene exon Ⅱ and exon Ⅲ were detected by PCR and restriction endonuclease mapping techniques in the 5 cases with heterozygous α 1 ACT deficiency. RESULTS: The frequency of heterozygous α 1 ACT deficiency in the asthma group ( 4.4% ) was markedly higher than that in the normal child control group (0) and the normal adult control group ( 0.5% ) (both P< 0.05 ). The age of the onset of asthma was smaller, the number of times of hospitalization for asthma were greater, and the positive rate of the radioactive allergen sensitive test was higher in the children with heterozygous α 1 ACT deficiency than those without deficiency (P< 0.05 or 0.01 ). No variants of Bonn 1 and Bochum 1 were found in the 5 cases with heterozygous α 1 ACT deficiency. CONCLUSIONS: There is a possible association between heterozygous α 1 ACT deficiency and childhood asthma; the variants of Bonn 1 and Bochum 1 are not correlated with childhood asthma.
