儿童细小病毒B19感染的诊断方法

目的：评价巢式PCR，ELISA，间接免疫荧光法(IIF)诊断B19感染的价值．方法：用ELISA及巢式PCR对129例小儿血液病和结缔组织病患血清进行B19-IgM，DNA检测；用IIF及巢式PCR对50例血液病患骨髓进行B19抗原及DNA检测．结果：病例组129例，血清B19-DNA阳性41例，阳性率31．8％；IgM阳性28例，阳性率21．7％；B19-DNA及IgM同时阳性26例，仅IgM阳性2例，B19感染率为33．3％．对照组50例，B19-DNA阳性率2％，IgM阳性率0％，B19感染率为2％．血液病患50例骨髓B19-DNA阳性17例，阳性率34％；抗原阳性8例，阳性率16％．与巢式PCR相比，ELISA法的灵敏度为63．4％，特异度为97．7％，符合率为86．8％，阳性预告值为( PV)为92．8％，阴性预告值(-PV)为85．1％；IIF法的灵敏度为47．0％，特异度为100％，符合率为82．0％， PV为100％，-PV为78．6％．结论：ELISA及IIF敏感性低于巢式PCR，诊断B19感染时最好同时检测B19-DNA和IgM或抗原．

Diagnostic methods of children parvovirus B19 infection

AIM: To study the value of nested PCR,ELISA and indirect immunofluoscence (IIF) in diagnosing B19 infection. METHODS: ELISA and nested PCR were used to detect B19 IgM and DNA in the sera of 129 patients with hematonosis and connective tissue diseases and B19 antigen and DNA in the bone marrow samples of 50 patients with hematonosis were examined by IIF and nested PCR. RESULTS : Of the 129 children with hematonosis and connective tissue diseases, 41 patients were sera B19 DNA positive and 28 were IgM positive, with a positive rate of 31.8% (41/129)and 21.7% (28/129) respectively. The infection rate of the case group is 33.3%(43/129). Of the 50 healthy children in the control group, 2 were sera B19 DNA positive and none was IgM positive and the infection rate of the control group was 2%(1/50). The positive rates of B19 DNA and antigen in the bone marrow samples of the 50 patients with hematonosis were 34% (17/50) and 16%(8/50). Compared with nested PCR, the sensitivity, specificity, crude agreement, positive predictive value and negative predictive value of ELISA were 63.4%, 97.7%, 86.8% , 92.8% and 85.1%, respectively, while those of IIF were 47.0%, 100%, 82.0%, 100% and 78.6%, respectively. CONCLUSION: The sensitivity of ELISA and IIF for B19 infection is lower than that of nested PCR. Both B19 DNA and IgM or antigen should be detected in diagnosing B19 infection.