登革热血清抗体反应的动态变化特征及在初次/二次感染判定中的意义

Discriminating the primary/secondary infection of dengue fever by the dynamic variation characteristic of antibody response

目的观察2014年登革热疫情中,登革病人特异性Ig M和Ig G抗体产生在病程中的动态变化特征,探讨其在初次感染及二次感染判定中的意义。方法收集38例住院登革热患者系列血清或血浆样品298份,至少包含发热期和极期中的3个时点。采用Panbio登革热Ig M/Ig G捕获ELISA法检测血清或血浆中特异性的抗体。每个样品做3个复孔,取平均值后使用试剂盒公式算出Panbio Units值。依据抗体的动态变化进行初次/二次感染判定,并与常用的依据Ig M/Ig G比值判定方法比较。结果观察到5种不同的登革病毒特异Ig M和Ig G抗体反应趋势。依据Ig G反应趋势可区分成2组。一组Ig G在病程的第4-5天可检测到,呈现快速上升。另一组在病程的第7天可检测到,一直维持在低的水平。依据Ig M和Ig G抗体反应趋势判定轻症样品中初次感染11例(29.7%);轻症样品中二次感染9例(24.4%);重症样品中初次感染7例(18.9%);重症样品中二次感染10例(27.0%),组间比较差异无统计学意义(P>0.05)。采用Ig M/Ig G一个时点比值法判定会出现将二次感染误判为初次感染的情况。结论依据Ig G反应趋势可以明确初次/二次感染的判定。2014年爆发的登革热疫情中,二次感染可能不是重症病例发生的危险因素。

Objective To observe the kinetic changes of dengue virus specific Ig M and Ig G antibodies during the course of disease and explore the meaning in discriminating the primary and secondary infection in 2014 outbreak. Methods The 208 samples of serum or plasma, at least three time points, were collected from 38 hospitalized patients on febrileand critical-phase. Anti-dengue Ig M and Ig G antibodies were measured with Panbio dengue Ig M / Ig G capture ELISA.Each sample was done in triplicate and panbio units value was calculated. Primary or secondary infection was determined according to the dynamic change of antibody and compared with the commonly used method of Ig G / Ig M ratio. Results Five patterns of dengue-specific antibody responses were observed and could be distinguished into two groups based on the production of Ig G. In one groups, Ig G was detected on the illness day 4 to 5 and then increased rapidly. But in the other group, Ig G was measurable on the illness day 7 and maintained at a low level. By the pattern of antibody response, 11（29.7%） primary and 9（24.4%） secondary infection were detected in the mild symptom patients, while 7（18.9%） primary and 10（27.0%） secondary infection were detected in the serious symptom patients. Only consider the ratio of Ig G / Ig M at one time point, one may misread the secondary as primary infection. Conclusion The primary and secondary infections in dengue fever can be discriminated by the trend of Ig G antibody response. Secondary infection may not be a risk factor for severe dengue in 2014 outbreak.