Association of interferon-γCA repeat sequence gene polymorphisms with Mycoplasma pneumoniae infection and recurrent respiratory tract infection among obese children

OBJECTIVE To analyze the association of interferon (IFN)-γCA repeat sequence gene polymorphisms with Mycoplasma pneumoniae (MP) infection and recurrent respiratory tract infection (RRI) among obese children. METHODS A total of 100 obese children with MP infection who were treated in Baotou Central Hospital from May 2017 to May 2020 were assigned as the MP group, meanwhile, 50 healthy children who received physical examination in the physical examination of the hospital were chosen as the control group. The IFN-γCA repeat sequence gene polymorphisms were detected for the two groups of research subjects. The IFN-γCA gene polymorphisms were compared between the MP group and the control group. The children of the MP group were divided into the MP+RRI group with 27 cases and the MP non-RRI group according to the status of RRI within 1 year, and the IFN-γCA gene polymorphisms were compared between the MP+RRI group and the MP non-RRI group. RESULTS There was no significant difference in the (CA12)+/(CA12)-genotype between the MP group and the control group, the frequency of (CA12)+/(CA12)+ genotypes of the MP group was lower than that of the control group (P<0.05), the frequency of (CA12)-/(CA12)-genotype of the MP group was higher than that of the control group (P<0.05). There were no significant differences in the frequencies of the IFN-γCA genotypes between the MP-RRI group and the MP non-RRI group. CONCLUSION The MP infection in the obese children is closely associated with the IFN-γCA repeat sequence gene polymorphisms. (CA12)+/(CA12)+ and (CA12)-/(CA12)- of the MP group may respectively play the resistance and promotion role in MP infection among the obese children, but RRI is not affected by the IFN-γCA repeat sequence gene polymorphisms.