Agglutination of red blood cells in viral infections

Agglutination of red blood cells with viral infections detected either by direct interaction of the virus with the surface of red blood cells (reaction of haemagglutination - DSA), or as a result of interaction with antiviral immune serum and erythrocytes previously sensitized viral antigen (reaction indirect or passive haemagglutination - RNA, TPHA). Agglutination follows the adsorption of the virus or its antigen on the surface of native or formalisierung erythrocytes. DSA occurs directly in the mixture hemagglutinins of the virus with the cell. Stability agglutination depends on the presence or absence in the membership of the virion receptor-destroyuser enzyme, quickly destroying at temperature 37 deg viral receptors on the surface of red blood cells, resulting comes elution (exemption) of the virus and the putting up of red blood cells. Slow spontaneous elution comes to cold. After the elution erythrocytes not agglutinate viruses same serotype, but agglutinate similar viruses other serotypes that made it possible to locate mixa - and echo-viruses in a certain order (receptor gradient). DSA may be neutralized if you interact with the cell to hemagglutinins the virus to add specific immune serum (reaction braking delay of haemagglutination - RTG, RZGA).
DSA, rtga were first proposed for the detection of influenza virus and titration of influenza antibodies [Hurst (G. K. Hirst)]. Soon appeared reports hemagglutinins virus activity ospowiki, ectromelia, false plague chickens, mumps, smallpox, pneumonia mice, measles, Arbo-, adeno - and paragrapsh and enteric viruses. Myxovirus agglutinate erythrocytes many species of animals and birds, viruses virus and vaccine - erythrocytes Petukhov, arbovirus and the measles virus - erythrocytes monkeys and geese, most non-polio enteric viruses - human erythrocytes.
The ability to agglutinate erythrocytes monkeys and rats adenoviruses were divided into three groups. Viral hemagglutinin (HA) is a specific antigen. HA at myxoviruses (v-antigen) and viruses ECHO is part of the virion. The adenoviruses HA found in a free state. The vaccinia virus and arbovirus described as soluble or associated with the virion HA. Antigenic properties HA widely used for serological classification of viruses. With the help of immune serum in rtga installed 11 subtypes of influenza virus And pathogenic for humans, animals and birds, over 20 groups arboviruses pathogenic for humans and animals. HA different viruses have different resistance to heat, the action of formaldehyde and other physical and chemical factors.
Identification of the phenomenon of haemagglutination (see) is connected with the choice of optimum conditions of cultivation of viruses and the given reaction. The results of the RSA depend on the type of erythrocytes, pH, concentration of electrolytes, temperature, time of incubation mixture of the virus with the cell. To evaluate specificity of rtga great importance is the elimination of non-specific inhibitors of haemagglutination and nonspecific of hemagglutinin present in human sera and animals. Nonspecific inhibitors removed, programa serum temperature of 56 degrees for 30 minutes followed by treatment of CO2, KJO4, kaolin, or via receptor-destroyuser enzyme produced by Vibrio cholerae. Nonspecific hemagglutinin is removed by absorption sera of erythrocytes. Specificity of RTG is increased by adding to the mixture of the virus with immune serum cofactor (native normal serum). HA accumulates in allantoina fluid with the reproduction of virus in chicken embryo or in liquid phase environment when grown in tissue culture.
About reproduction hemagglutinins viruses in cells of a single layer of tissue culture can be judged by the presence of reaction haemadsorption (Lads). This response is based on the agglutination of red blood cells by the virus, found on the cell surface. Lads becomes positive even before HECTARES in the liquid phase culture and to the development of cytopathic changes in infected cells. The specificity of Lads determined by its inhibition by means of immune sera.
RNA using native red blood cells appeared to be specific when false plague chickens, mumps, some paragrapsh infections, however, flu have been received non-specific results. Erythrocytes treated with influenza virus, acquired the ability to agglutinated any and normal immune sera (Panagyurishte). Specific results were achieved when sensitization viral antigen of erythrocytes treated with tannin on Bogeno. Such "tehnizirovannye" erythrocytes adsorb protein antigens, native red blood cells is mainly polysaccharide antigens. Indirect hemagglutination at the expense change the properties (sensitization) the surface of red blood cells while adsorption of viral antigen; adding immune serum leads to adsorption of antibodies on sensitized red blood cells and the formation of flakes agglutinate. Sensitizing activity has particulate antigens (viruses of herpes simple, tick-borne encephalitis, tobacco mosaic), and soluble (adenovirus, influenza viruses, pathogens fever). Not clarified the nature of sensitizing antigen many viral agents, which received positive RNA (viruses fixed rabies, ospowiki, polio, chicken sarcoma, hepatitis dogs, Mycoplasma pneumonia, and others). The process of sensitization of erythrocytes and technology of the production rnga for each viral infection depend on the type of red blood cells, the concentration of antigen, pH, temperature, etc. For rnga not recommend the use of red blood cells that agglutinate this virus in the direct state administration. Rnga used in virologic practice for titration of antibodies. RNA is serological reaction that 100-1000 times more sensitive than rtga and a reaction of binding complement (RAC). In contrast, rtga that detects subtle antigenic differences among strains of the same virus type, rnga detects estipouy differences like the RJC.