Vol 63, No 4 (2018)

Human A (H3N2) influenza viruses are distinguished by a high rate of evolution and regularly cause epidemics around the world. Their ability to adapt and to escape from the host's immune response and to change their receptor specificity is very high. Over the past 20 years, these viruses have lost the ability to agglutinate red blood cells of chickens and turkeys and have practically ceased to propagate in chicken embryos - the main source of influenza vaccines. Isolation of viruses in the MDCK cell culture led to the selection of strains that lose one of the potential glycosylation sites. Many of the A (H3N2) strains have acquired mutations in neuraminidase, which distort the results of antigenic analysis in the hemagglutination inhibition test - the cornerstone method for the analysis of the match between viral isolates circulating in human population to strains selected for the influenza vaccines. In this regard, the characteristics of the antigenic properties of influenza A (H3N2) viruses by traditional methods become poorly informative, and the selection of vaccine strains of this subtype is erroneous, which is reflected in the discrepancy between vaccine and circulating A (H3N2) viruses in recent years (2013-2014, 2014 -2015, 2015-2016). The search, development and implementation of new algorithms for the isolation and antigen analysis of influenza A (H3N2) viruses are extremely urgent.

Introduction. Angioimmunoblastic T-cell lymphoma (AITL) is associated with the Epstein-Barr virus (EBV) in most cases. It is believed polyclonal hypergammaglobulinaemia observed in 53-80% of AITL patients has anti-herpes viral antibodies as its substrate. Aim. The aim of the study was to compare serological markers of herpes viruses and quantitative immunoglobulinopathies of classes M and G in primary patients with AITL. Materials and methods. 26 primary patients with newly diagnosed AITL treated at the National Research Center for Hematology from 2002 to 2017 were enrolled in the study. The male/female ratio was 16/10; median age was 62 (29-81) years. The levels of total immunoglobulins of classes M and G, serological markers of EBV, cytomegalovirus (CMV) and herpes simplex virus type 1 and type 2 (HSV 1, 2) were assessed in all patients. Results. Significant relationship was found between the presence of virus-specific IgM (IgM HSV 1, 2, IgM CMV, IgM VCA EBV) and an elevated level of total immunoglobulins of class M (p <0.0001). Studies of each virus separately showed that the greatest correlation was observed for IgM HSV 1, 2 (p <0,0001), whereas the association of IgM CMV and IgM VCA EBV with quantitative immunoglobulinopathies of class M was not confirmed (p = 0,15 and p = 0,36 respectively). There was no considerable relationship between polyclonal IgG hypergammaglobulinaemia and an increased level of antiviral IgG (IgG HSV 1, 2, IgG CMV, IgG EBNA-1 EBV, IgG EA EBV) (p> 0,37). Conclusion. We have shown that the presence of the anti-herpes viral IgM strictly correlates with polyclonal IgM hypergammaglobulinaemia, while an increased level of virus-specific IgG antibodies does not affect the formation of polyclonal IgG hypergammaglobulinaemia and can be observed in IgG hypogammaglobulinaemia.

The results of phylogenetic analysis of three species of bovine pestiviruses circulating in six regions of Siberia, as well as those detected in fetal embryonic serum (FBS) and continuous cell cultures, are presented. The typing was made based on comparison of sequences from the 5' untranslated region (5'-UTR) of the viral genome. Among the highly productive dairy cattle, circulation of five subtypes of the BVDV1 (a, b, d, f, r) and BVDV2 was established. The predominant subtype was 1b (48% positive samples). The number of subtypes of BVDV1 was as follows: BVDV1: 1а (8%), 1b (48%), 1d (8%), 1f (16%) и 1r (8%) and BVDV2 (12%). Cell cultures revealed BVDV1a. The distribution of types and subtypes of viruses had geographical differences. BVDV1b, BVDV1d, BVDV1f и BVDV1r were detected in cattle or persistently infected (PI) animals in farms with respiratory distress. BVDV 1a revealed in the serum of PI heifer without manifestation of clinical symptoms. BVDV2 were detected in cattle with pathology of reproduction. The presence of the BVDV3 (atypical pestivirus) of the Italian group was established in seven lots of FBS obtained from two manufacturers. No evidence has been found for circulating of the atypical virus among cattle of various breeds, including imported, reindeers and red deers. Studies on the molecular epizootology of pestiviruses can be used to select and optimize the control strategy and address the issue of vaccine use in a particular region.