EB病毒感染患儿淋巴细胞亚群特征和EBV DNA载量分析

Characteristics of lymphocyte subsets and Epstein-Barr virus DNA load in children with Epstein-Barr virus infection

目的探讨儿童EB病毒(EBV)感染引起的外周血淋巴细胞亚群的变化特点,并检测EBV感染患儿血清EBV DNA的载量。方法选取17例传染性单核细胞增多症(IM)患儿(IM组)、18例慢性活动性EB病毒(CAEBV)感染患儿(CAEBV组)和15名健康儿童(健康对照组)。采用流式细胞术检测淋巴细胞亚群,荧光定量聚合酶链反应(PCR)检测血清EBV DNA载量,采用Kruskal-Wallis H和Mann-Whitney U检验进行统计分析,Spearman法进行相关分析。结果 IM组淋巴细胞比例和计数、CD4^+T细胞计数、CD8^+T细胞计数均明显高于健康对照组(P<0.05),其中CD8^+T细胞比例和计数的中位数分别高达61.5%和5 217个/μL,自然杀伤(NK)细胞、CD19^+细胞比例明显低于健康对照组(P<0.05)。CAEBV组淋巴细胞比例明显高于对照组(P<0.05),B、NK、CD4^+T、CD8^+T 4种细胞计数2个组之间差异无统计学意义(P>0.05),CD4^+T细胞、CD8^+T细胞计数明显低于IM组(P<0.05)。IM组和CAEBV组EBV DNA载量中位数分别为3.60×103和1.25×104拷贝/m L,2个组之间差异有统计学意义(P=0.027)。IM组和CAEBV组EBV DNA载量与淋巴细胞亚群数量无相关性(P>0.05)。结论 IM患儿与CAEBV感染患儿的淋巴细胞亚群特点有很大不同,IM患儿CD8^+T细胞大量增殖是淋巴细胞计数显著升高的主要原因。综合血清EBV DNA载量与淋巴细胞亚群检测有助于IM与CAEBV感染的鉴别诊断。

Objective To investigate the characteristics of lymphocyte subsets in children with Epstein-Barr virus(EBV)infection,and to study EBV DNA load.Methods A total of 17 infectious mononucleosis(IM)patients,18 chronic active Epstein-Barr virus(CAEBV)infection patients and 15 healthy children were enrolled.Lymphocyte subsets were determined by flow cytometry.EBV DNA load in peripheral blood was determined by fluorescence quantitation polymerase chain reaction(PCR).The results were analyzed statistically by Kruskal-Wallis H test and Mann-Whitney U test.The correlation analysis was performed by Spearman method.Results The lymphocyte count and proportion and CD4+T and CD8+T cell counts in IM group were higher than those in healthy control group(P<0.05),and the proportion and count median of CD8+T cell reached up to 61.5%and 5 217/μL.Natural killer(NK)cell and CD19+cell proportions in IM group were lower than those in healthy control group(P<0.05).The lymphocyte proportion in CAEBV group was higher than that in healthy control group(P<0.05),and there was no statistical significance in B,NK,CD4+T and CD8+T cell counts between the 2 groups(P>0.05).CD4+T and CD8+T cell counts in CAEBV group were lower than those in IM group(P<0.05).The medians of EBV DNA load in IM and CAEBV groups were 4.90×103 and 1.25×104 copies/mL,respectively.The EBV DNA loads between the 2 groups had statistical significance(P=0.027).No correlation was found between the number of lymphocyte subsets and EBV DNA load(P>0.05).Conclusions The characteristics of lymphocyte subsets between the 2 groups are different.The increasing of extensively activated CD8+T cells in IM group is a cause for lymphocyte count increasing.The combined determination of lymphocyte subsets and EBV DNA load is helpful for the differential diagnosis of IM infection and CAEBV infection.