[Inhibitory activity of blood group antigens M and N in inhibition of virus hemagglutination reactions of influenza viruses].

INTRODUCTION: M and N blood group antigens demonstrate inhibitory activity in inhibition reaction of viral hemagglutination with some influenza virus strains, with help of N-acetylneuraminic acid (sialic acid) which occurs in glycophorins on the red blood cells surface, and represent specific hemagglutunation receptors and substrate for action of influenza virus neuraminidase. MATERIAL AND METHODS: Reactivity of human O red blood cells with MM and NN phenotypes is established in inhibition reaction of viral hemagglutination by influenza virus A2 Singapore, with intention to fortify possibility of using human red blood cells in viral hemagglutination, to determine their reactivity in titration, retitration of hemagglutinins and inhibition reaction of hemagglutination. The aim of investigation was to describe destinations between different red blood cells in view of speed of reaction and receptor capacity. Material included 69 samples of sera from persons infected with influenza virus, among them 32 samples were positive with titres 1/80 and more. RESULTS: Reactivity of erythrocytes with MM and NN phenotypes in titration of hemagglutinins of influenza virus A2 Singapore in which base is viral hemagglutination is identical, because there are no statistically significant differences of average geomaterical levels of antibody titers. Enzymatically derived red cells by papain, which do not contain M and N blood group antigens, not cause viral hemagglutination phenomenon, because they sediment in all dilutions. Reactivity of red blood cells with MM and NN phenotypes in retitration of haemagglutinins and inhibition reaction of hemagglutination is identical, because there are no statistically significant differences in results with two kinds red blood cells. DISCUSSION: Results of investigation revealed that the reactivity of O human red blood cells different in MN phenotype is identical in regard to speed of reaction and receptor capacity in titration, retitration and inhibition reaction of viral hemagglutinatination and also showed that they demonstrate viral hemagglutination phenomenon in contrast with papainised red blood cells which do not contain M and N blood group antigens, which indirectly means that M and N blood group antigens contain receptors for influenza virus. CONCLUSIONS: Human red cells with MM and NN phenotypes cause viral hemagglutination phenomenon with influenza virus A2 Singapore, and could be used in routine virusological diagnostic procedures. O blood group red cells (MM and NN) in reaction of viral hemagglutination result identically in view of speed of reaction and receptor capacity, and have the same impact on result of this reaction. Enzymatically derived red cells by papain do not cause viral hemagglutination phenomenon, because they do not contain receptors for viral hemagglutinin on red cell membrane surface, which are hydrolazed by papain. Receptors for influenza virus on red cell membrane surface are a component part of M and N blood group antigens which are destroyed by papain.