Imbalance of IgG subclasses in preschool children with a different type of vaccine response to MMR

Abstract

Smilianska M. Introduction. The only way to protect children against measles, mups and rubella viruses (MMR) is vaccination. However, among vaccinated individuals there are always people who react poorly to vaccine preparations until they are completely insensitive due to their individual genetic or phenotypic characteristics. It is not always possible to achieve a full protective effect of vaccination. A comprehensive study of humoral immunity factors, such as total IgG, their subclasses, virus-specific antibodies, can predict the nature of the formation of a specific immune response to a vaccine, it is important when choosing a tactic for vaccination of preschool children. The aim of the work was to determine the subclasses of IgG (1, 2, 3, 4), their relationship and relationship with the type of vaccine immune response to the MMR vaccine in children of preschool age.  Material & methods. The content of serum IgG and subclasses was studied in children 6–7 years old with no specific response or a very strong vaccine response to one or more components of the MMR vaccine and it was 23% ARI, or 32 children and 31% HRI, or 44 children, respectively. The control group consisted of 19 children of the appropriate age without herpes virus load and with a normal vaccination response to the MMR.  Antibodies of the IgG class to the measles virus were determined using an enzyme immunoassay test system manufactured by IBL international GMBH - Meales virus IgG ELISA (Germany); rubella virus was determined using the enzyme immunoassay test system Rubella IgG-ELISA manufactured by Xema Co.Ltd. (Kiev, Ukraine); to the mumps virus was determined using an enzyme immunoassay test system manufactured by R-Biopharm AC (Germany) - RADASCREEN® Mumps Virus IgG (K5521). To determine the content in the serum of IgG subclasses (IgG1, IgG2, IgG3, IgG4), ELISA was used using the IgG subclasses test systems manufactured by Vector Best. The determination of the antigens of the Herpesviridae family was carried out by an immunofluorescence method using specific monoclonal mouse antibodies of Santa Cruz Biotechnologu, Inc. (USA).  Results. An imbalance of IgG subclasses in preschool children with a different type of specific response to the CCP vaccine has been established. Thus, in the group with hyperreactive response, the level of IgG4 was significantly elevated, and in the group of reactive children, an increased level of IgG1 and a decrease in IgG3 were determined. The imbalance of IgG subclasses in preschool children can be associated with herpes viral load and the presence of individual members of the Herpesvirus family, which together leads to the development of a different type of immune response to the CCP vaccine. The determination of total IgG and subclasses, specific antibodies, can allow to predict the nature of the formation of a specific immune response to the vaccine, it is important when choosing the tactics of vaccination of children of preschool age.  Conclusion. Quantitative determination of serum IgG in parallel with other classes of immunoglobulins is one of the mandatory tests in the study of the human immune status. Namely, an IgG imbalance of one or several subclasses can cause a partial imbalance in the system of regulation of the humoral immune response in children of preschool age (for example, a decrease in the level of cytokine production, or specific antibodies).