[Development of experimental test-system on the basis of immunochip for syphilis serodiagnostics].

AIM: Development of test-system on the basis of immunochip for detection of IgG to Treponema pallidum. MATERIALS AND METHODS: Recombinant T. pallidum antigens Tp47, Tp17, Tp15, TmpA were separately immobilized on activated slides as individual spots. The specific antibodies to T. pallidum in human serum were detected by indirect immunofluorescent assay on the immunochip using antispecies antibodies to human IgG. Fluorescent scanner was used to read results of testing. For each antigen threshold level of fluorescent signal and positivity coefficient were calculated. Assessment of specificity and sensitivity of the immunochip was performed on 400 human serum samples containing or not-containing antibodies to T. pallidum. RESULTS: From 200 positive serum samples 5 were interpreted as inconclusive because positive results on antigen Tp17 only were registered that was comparable with the results of immunoblotting. For each other 195 serum samples, positive result on 2 or more antigens was obtained. Specificity of the immunochip-based test-system was 100%. CONCLUSION: Experimental immunochip-based test-system for differential serologic diagnostics of the syphilis was developed. Its sensitivity and specificity are comparable with that of ELISA-based test-system.

[The avidicity index of specific IgG in the diagnosis of diseases caused by west Nile and tickborne encephalitis viruses].

The significant antigenic crossovers between West Nile virus (WNV) and tick-borne encephalitis virus (TBEV) make the immunological diagnosis of these diseases difficult. The avidicity index of virus-specific class G immunoglobulins (IgG) was used as a criterion for the differentiation of an immune response to WNV or TBEV in patients and convalescents. The panels of the sera sampled from patients with tick-borne encephalitis and convalescents in the Novosibirsk and Tomsk Regions and in the Primorye Territory and from those with West Nile fever and convalescents in the Volgograd Region. The determination of the avidicity index could establish that in the convalescents' sera, the avidicity index of virus-specific IgG was much higher than that in the patients' sera in the acute phase of infection. In relation to heteroantigen, the avidicity index and the positivity coefficient were substantially less than those in the reaction with homoantigen. The findings have indicated that the determination of the value of the avidicity index of virus-specific IgG and the positivity coefficient makes it possible to differentiate West Nile fever and tick-borne encephalitis with confidence on the basis of solid-phase enzyme immunoassay in determining virus-specific IgG in the sera of patients and convalescents in different regions of Russia.

[Clinical and immunological characteristics of rubella in western Siberia].

Evaluations of immune system of 155 patients with rubella and 90 contacts with patients were examined. Detection of viral genetic material in blood, urine, and nasopharyngeal swabs has been performed using RT-PCR method. Clinical diagnosis has been confirmed by RT-PCR in 114 (73.5%) patients. Changes of laboratory tests for rubella without clinical signs of the infection were observed in 20% of contacts. Complex ELISA- and PCR-assisted examination of patients can help to determine the stage of disease and characteristics of immune response. For differential diagnostic of rubella and other infectious diseases with exanthema it is rational to perform complex examination of patients using immunologic and molecular biologic methods.

[Designing of the pp65 recombinant antigen of human cytomegalovirus and investigation of its immunochemical properties].

The primary and secondary structures of the pp65 phosphoprotein of human cytomegalovirus coded by the UL83 gene were studied by the methods of computer-aided analysis. An immunodominant protein fragment with 3 antigenic determinant was detected. The UL83 fragment coding the selected region was amplified and cloned in bacterial expressing vector. The recombinant protein was obtained and purified. On the basis of ELISA findings it was acknowledged as possible to use the pp65 recombinant protein jointly with pp150 and p52 in the diagnosis of antibodies specific to human cytomegalovirus.

[Immunological safety and sensitizing effect of an MB-7-based vaccine against hepatitis A]. / Immunologicheskaia bezopasnost' i sensibiliziruiushchee deistvie vaktsiny protiv gepatita A na osnove shtamma MB-7.

The influence of a vaccine based on the MB-7 strain of hepatitis A virus (VP-MB-7) designed at the "Vector" Center of Virology and Biotechnology was studied. VP-MB-7 was found to provoke no allergic response and to have an activating effect on the specific and non-specific responses of cell and humoral immunity similar to those evoked by hepatitis A vaccine "Hep-A-in Vac".

[Safety research of a vaccine preparation in hepatitis A derived from the MB-7 rapidly growing strain]. / Izuchenie bezvrednosti vaktsinnogo preparata protiv gepatita A iz bystrorastushchego shtamma MB-7.

A study was undertaken to prove that a vaccine drug based on the fast-growing MB-7 (MB-7 VD) of hepatitis A virus (HAV) is safe. It was established that MB-7 VD, when once injected to white outbred mice and when 4 times injected to Hartley guineas pigs, did not cause any hematological and biochemical changes in the peripheral blood or in the condition of the central nervous system of experimental animals, which shows that MB-7 VD is free of any toxic properties.

[Construction of reference panel of immune serum against hepatitis C virus with standard level of IgG antibodies]. / Konstruirovanie referens-panelei syvorotok k virusu gepatita C s normirovannym urovnem IgG-antitel.

A panel of anti-HCV sera (lot 03HC) was prepared from human sera obtained at blood transfusion centers and infectious hospitals. Donor sera and high-titer sera from patients infected with HCV were used. For positive samples, specific sera reactive with the core and/or NS proteins of HCV 1b and 2 were selected. Positive sera were standardized by the concentrations of IgG with a pool of negative sera containing no HBsAg and antibodies to HIV, HCV, and syphilis. The sera for the panel were selected and titered in screening and specific tests. The anti-HCV panel includes negative and positive sera with low and high titers. The panel sera are stabilized and can be stored for a short time at room temperature. The anti-HCV panel of sera, lot 02HC, was certified at L. A. Tarasevich Institute for Standardization and Control as anti-HCV reference panel intended for sensitivity, specificity, and stability control of diagnostic systems for detection of antibodies to HCV in Russia.