Analysis on the relationship between the human EV71 associated HFMD children's clinical manifestation and the genetic polymorphism and serum concentration of mannan binding lectin / 中华微生物学和免疫学杂志

ABSTRACT

Objective To explore the relationship between the genetic polymorphism and serum concentration of mannan binding lectin (MBL)and the clinical manifestation of the hand-foot-mouth disease (HFMD) children infection by human enterovirus 71 (HEV71).Methods One hundred and thirty-eight children diagnosed as HFMD infected by HEV71 (including 80 mild cases and 58 severe cases) and 40 healthy,symptom-free children were investigated.The concentrations of serum MBL were measured in 40 healthy controls,80 mild HFMD cases and 56 severe HFMD cases at both acute and convalescent phases by a sandwich enzyme immunoassay with a human MBL ELISA kit.And the genomic DNA of all cases were extracted from blood according to standard phenol-chloroform procedure.Six SNPs in the MBL gene(-550G/C,-221G/C and +4C/T of the promoter,CGT52TGT,GGC54GAC,and GGA57GAA of the exon 1) were analyzed by a sequencing-based typing method.Results The MBL serum level of the severe HFMD circulatory respiratory failure group in acute phase was significantly increased compared with severe HFMD encephalitis group,the mild cases and the control,but in the convalescence phase it significantly decreased compared with them.The frequencis of type B/B mutation (+230 of the exon 1),type P/P mutation (+4C/T of the promoter),and type H/H mutation (-550G/C of the promoter) were a significant difference among mild group,severe group and the control(P=0.006,0.043,0.028,respectively).The frequencies of LYPB/LYPB genotype and HYPA/HYPA genotype were a significant difference among mild group,severe groupand the control (P=0.028,0.014,respectively).Conclusion Low MBL protein level as a result genetic polymorphism seems to be correlative with clinical manifestation of HFMD disease.The MBL gene mutation and low MBI.protein level may be used as one of the evaluation method of HFMD severeity.