| Chickenpox and herpes zoster are all caused by varicella-zoster virus, the virus initially infects the children and causes chickenpox, the reactivation of latent virus in adults would cause shingles. The true incidence of chickenpox is very high in China (mainland), which is one of the main reasons for the public health emergencies. Herpes zoster is closely related to decreased varicella-zoster virus (VZV)-specific cell-mediated immunity, and when the CMI levels decline, VZV is activated and herpes zoster occurs. At present, the treatment of chickenpox and herpes zoster cannot completely eliminate the virus, and the vaccination can effectively prevent these two diseases. With the increase in the number of vaccinated and the application of herpes zoster vaccine in the future, it is urgent to establish a simple, rapid and accurate method to evaluate the CMI of the varicella vaccine, and the VZV specific CMI was evaluated to determine whether it is susceptible to the population, and whether it should be vaccinated to prevent herpes zoster.VZV specific CMI were mainly detected by the methods listed as follows, intracellular cytokine staining, skin test, IFN-γ Elispot and IFN-γ release assay, the first three were low sensitivity, impracticable operation in Lab and complex process respectively, and cannot be quantified. In recent years, the development of IFN-γ release assay is gradually recognized, which has been applied to the diagnosis of TB/LTB and the related commercial kits are approved for using. There are also many reports on the application of VZV and CMI HCMV detection. Based on the above, this study applied the novel IFN-γ release assay to evaluate the VZV specific CMI, and the changes of the CMI level in subjects after vaccination of varicella vaccine.In this study, firstly, we optimized the IFN-γ release assay, determined the treatment of virus stock, the optimal co-culture time of the whole blood&antigen, the amount of antigen, the stability of whole blood et al. Then we randomly selected 12 adults as the research subjects, whole blood from these subjects were collected before inoculation and incubated with VZV antigen, the IFN-γ production were detected by IFN-γ ELISA kit, to investigate the VZV specific CMI level of unknown population. Then inoculated these subjects with a live attenuated vaccine, collected their whole blood after 21 days vaccination for detection of IFN-γ level and compared with the IFN-γ production of them before vaccination.The results of this study showed that (1) the treatment of virus stock, the optimal co-culture time of the whole blood&antigen, the amount of antigen, the stability of whole blood had effect on the release of IFN-γ. The UV-inactivated VZV antigen is suitable, the optimal co-culture time is about 48h, and the whole blood samples should be tested as soon as possible. (2) IFN-γ level are different between these subjects before vaccination, and all increased in various degrees after vaccination, the GMT of IFN-γ were 6.13pg/ml and 234.75pg/ml before and after inoculation respectively. Because of different age, gender and physical condition, the growth rate varies greatly in the individuals. (3) Because of the limited samples, it is impossible to carry out statistical analysis, and difficult to determine the threshold of IFN-γ in high-risk population. We need a large number of whole blood samples from adults to determine the level of IFN-γ release in susceptible populations with VZV, and hope that we can apply the IFN-γ release assay to the screen the high risk population in clinical research of herpes zoster. |
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