健康成人抗百日咳毒素和抗百日咳丝状血凝素抗体检测与分析

Detection and analysis of antibodies against pertussis toxin and filamentous hemagglutinin among healthy adults

目的评估健康成人抗百日咳毒素(anti-PT)和抗百日咳丝状血凝素(anti-FHA)抗体水平。方法选择20-59岁健康成人,采用改良ELISA(mELISA)、改良硫氰酸铵-ELISA分别测定血清anti-PT和anti-FHA IgG抗体的浓度、亲和力,分析二者的相关性;采用CHO细胞簇集试验测定anti-PT中和抗体滴度,分析与anti-PT IgG抗体浓度的相关性。结果共纳入研究对象73名,anti-PT、anti-FHA IgG抗体几何平均浓度(GMC)分别为10.4 IU/mL、58.2 IU/mL,抗体亲和力中位数分别为34.8%、61.4%,anti-PT中和抗体几何平均滴度(GMT)为1:27.3。anti-PT、anti-FHA IgG抗体的浓度与亲和力均呈正相关(r=0.45,P<0.01;r=0.76,P<0.01);anti-PT中和抗体滴度与浓度呈正相关(r=0.77,P<0.01)。结论健康成人anti-PT抗体水平较低,建议制定成人百日咳疫苗免疫程序;mELISA可替代CHO细胞簇集试验用于百日咳血清学检测。

Objective To assess IgG antibody levels against pertussis toxin(PT)and filamentous hemagglutinin(FHA)in healthy adults.Methods We enrolled 20-59-year-old healthy adults and obtained blood samples from subjects.We tested sera for concentrations and avidities of anti-PT IgG and anti-FHA IgG using a modified enzymelinked immunosorbent assay(mELISA)and an adapted ammonium thiocyanate(NH4 SCN)-ELISA,respectively,for a correlation analysis.We used a CHO cell clustering assay to measure neutralizing antibody titers against PT to determine correlation with anti-PT IgG concentrations.Results A total of 73 subjects were enrolled into the study.Geometric mean concentrations(GMCs)for anti-PT IgG and anti-FHA IgG were 10.4 IU/mL and 58.2 IU/mL,respectively,with median antibody avidities of 34.8%and 61.4%.The geometric mean titer(GMT)for anti-PT neutralizing antibody was 1:27.3.Anti-PT IgG and anti-FHA IgG concentration were positively correlated with avidity(r=0.45,P<0.01;r=0.76,P<0.01);anti-PT neutralizing antibody titer was positively correlated with concentration of anti-PT IgG(r=0.77,P<0.01).Conclusions The level of anti-PT antibodies in healthy adults was low.We recommend developing pertussis immunization schedules for adults.Modified ELISA could replace the CHO cell clustering assay for pertussis serological testing.