抗EBV抗体结合VCA-IgG亲和力在儿童EBV感染IM诊断及病情评估中作用

Role of anti-EBV antibodies combined with VCA-IgG affinity in diagnosis of IM and disease severity assessment of EBV infection in children

目的研究抗EB病毒(EBV)抗体结合衣壳抗原免疫球蛋白(Ig)G抗体(VCA-IgG)亲和力在儿童EBV感染传染性单核细胞增多症(IM)诊断和病情评估中的作用。方法选取该院于2022年1月至2023年6月收治的EBV感染IM患儿100例作为IM组,另选取同期在该院体检健康、且既往无EB感染史的儿童100例作为NC组。检测并对比两组抗EBV抗体[衣壳抗原IgM(VCA-IgM)、VCA-IgG、EBV核抗原(EBNA)-IgG]、抗VCA-IgG亲和力,以及非特异性免疫(采用补体C3、C4水平进行评价)和特异性免疫[采用T淋巴细胞亚群(CD4+、CD8+)、IgA、IgG、IgM水平进行评价]相关指标水平。分析IM组不同性别、不同年龄段、不同EBV-DNA载量及不同病情严重程度患儿抗EBV抗体检测结果及抗VCA-IgG亲和力情况。使用诊断评价四格表计算抗EBV抗体、抗VCA-IgG亲和力对EBV感染IM患儿的诊断价值及病情评估价值。结果IM组VCA-IgM、VCA-IgG、EBNA-IgG阳性率及抗VCA-IgG低亲和力阳性率均明显高于NC组(P<0.05)。IM组CD4+T淋巴细胞比例低于NC组,CD8+T淋巴细胞比例及IgA、IgG水平高于NC组,差异均有统计学意义(P<0.05)。不同性别、不同年龄段EBV感染IM患儿的VCA-IgM、VCA-IgG、EBNA-IgG阳性率及抗VCA-IgG低亲和力阳性率比较,差异均无统计学意义(P>0.05)。EBV感染IM患儿的VCA-IgM、VCA-IgG、EBNA-IgG阳性率均为高载量组>中载量组>低载量组,且任意两组间比较,差异均有统计学意义(P<0.05);虽然EBV感染IM患儿的抗VCA-IgG低亲和力阳性率为EBV-DNA高载量组>中载量组>低载量组,但任意两组间比较,差异均无统计学意义(P>0.05)。重症EBV感染IM患儿VCA-IgM、VCA-IgG、EBNA-IgG阳性率及抗VCA-IgG低亲和力阳性率均高于轻症患儿(P<0.05)。VCA-IgM阳性、VCA-IgG阳性、EBNA-IgG阳性、抗VCA-IgG低亲和力阳性和4项联合检测IM的灵敏度分别为68.00%、41.00%、29.00%、95.00%、91.00%,准确度分别为84.00%、64.00%、63.50%、97.00%、85.50%。VCA-IgM阳性、VCA-IgG阳性、EBNA-IgG阳性、抗VCA-IgG低亲和力阳性和4项联合检测的灵敏度分别为86.36%、61.36%、45.45%、100.00%、90.91%,准确度分别为64.00%、69.00%、67.00%、49.00%、86.00%。结论抗EBV抗体、抗VCA-IgG亲和力与EBV感染IM患儿免疫状态、EBV-DNA载量有关,可作为诊断和评估EBV感染IM患儿病情的重要指标。

Objective To study the role of anti-EB virus(EBV)antibodies combined with capsid antigen immune globulin(Ig)G antibodies(VCA-IgG)affinity in the diagnosis and disease severity assessment of children with infectious mononucleosis(IM)caused by EBV infection.Methods A total of 100 children with EBV-infected IM admitted to the hospital from January 2022 to June 2023 were selected as the IM group,and another 100 children with healthy physical examination in the hospital during the same period and without previous history of EB infection were selected as the NC group.Anti-EBV antibodies[VCA-IgM,VCA-IgG,EBV nuclear antigen(EBNA)-IgG],and anti-VCA-IgG affinity,as well as non-specific immunity[evaluated by complement 3(C3)and C4]and specific immunity[evaluated using the levels of T-lymphocyte subpopulations(CD4+,CD8+),IgA,IgG,IgM]related indexes levels were detected and compared between the two groups.The status of the anti-EBV antibodies and anti-VCA-IgG affinity of children with different sexes,ages,EBV-DNA loads and disease severities in the IM group were analyzed.Diagnostic evaluation four-fold table was used to calculate the diagnostic value of anti-EBV antibody for children with EBV-infected IM and anti-VCA-IgG affinity,and the value for disease evaluation.Results The positive rates of VCA-IgM,VCA-IgG,EBNA-IgG,and anti-VCA-IgG low-affinity in the IM group were significantly higher than those in the NC group(P<0.05).The level of CD4+in the IM group was lower than that in the NC group,and the levels of CD8+,IgA and IgG were higher than those in the NC group,with statistically significant differences(P<0.05).The positive rates of VCA-IgM,VCA-IgG,EBNA-IgG and anti-VCA-IgG low-affinity in children with EBV-infected IM between/among different genders and ages showed no statistically significant differences(P>0.05).The positive rates of VCA-IgM,VCA-IgG and EBNA-IgG in children with EBV-infected IM in EBV-DNA high-load group>medium-load group>low-load group,and the comparison between any two groups showed statistically significant differences(P<0.05);however,the positive rate of anti-VCA-IgG low-affinity in children with EBV-infected IM in EBV-DNA high-load group>medium-load group>low-load group,the comparison between any two groups showed no statistically significant differences(P>0.05).The positive rates of VCA-IgM,VCA-IgG,EBNA-IgG and anti-VCA-IgG low-affinity in children with severe EBV-infected IM were higher than those in children with mild EBV-infected IM(P<0.05).The sensitivities of positive VCA-IgM,positive VCA-IgG,positive EBNA-IgG,positive anti-VCA-IgG low-affinity,alone or in combination of the four indicators,for diagnosis o IM,were 68.00%,41.00%,29.00%,95.00%and 91.00%,respectively,with the accuracies of 84.00%,64.00%,63.50%,97.00%and 85.50%.The sensitivities of positive VCA-IgM,positive VCA-IgG,positive EBNA-IgG,positive anti-VCA-IgG low-affinity,alone or in combination of the four indicators,were 86.36%,61.36%,45.45%,100.00%,and 90.91%,respectively,with accuracies of 64.00%,69.00%,67.00%,49.00%,and 86.00%,respectively.Conclusion Anti EBV antibodies and anti VCA IgG affinity are related to the immune status and EBV-DNA load of EBV-infected IM children,which can be used as important indicators for diagnosing and evaluating the condition of EBV-infected IM children.