[Resistance to antiviral drugs in human viruses from the subfamily Betaherpesvirinae].

The review provides information on the mechanisms of the emergence of resistance to antiviral drugs in human viruses from the subfamily Betaherpesvirinae. Data on the principles of action of antiviral drugs and their characteristics are given. The occurrence rates of viral resistance in various groups of patients is described and information about the possible consequences of the emergence of resistance to antiviral drugs is given. Information is provided regarding the virus genes in which mutations occur that lead to viral resistance, and a list of such mutations that have described so far is given. The significance of the study of mutations leading to the resistance of the virus to antiviral drugs for medical practice is discussed.

[Mutations in the UL97 gene of cytomegalovirus (Herpesvirales: Herpesviridae: Cytomegalovirus: Human betaherpesvirus 5) associated with ganciclovir resistance in recipients of allogeneic hematopoietic stem cells].

INTRODUCTION: Infection caused by cytomegalovirus (CMV) is a serious problem for patients with weakened immunity, including patients with hematopoietic depression. The cases of complications associated with cytomegalovirus require antiviral therapy. However, during the natural mutation process, especially with prolonged use of drugs in suboptimal doses, CMV strains resistant to the action of antiviral drugs (such as ganciclovir, valganciclovir) may occur. Hypothetically, the emergence of resistance in the virus may cause a more aggressive course of infection, the ineffectiveness of antiviral therapy and, as a result, an increase in the number of deaths. In this regard, timely detection of mutations that can potentially lead to the resistance of the virus to antiviral drugs during hematopoietic stem cell transplantation (HSCT), as well as during organ and tissue transplantation, may be important when making a therapeutic decision. We describe three clinical cases for which the dynamics of the appearance of a mutant strain of CMV by the UL97 gene, which correlates with the viral load and clinical picture, is analyzed.The aim of the study was to determine the timing of the occurrence of mutations in CMV phosphotransferase UL97 gene associated with resistance to antiviral drugs in patients with hemoblastoses after allogeneic hematopoietic stem cell (allo-HSCs) transplantation. MATERIAL AND METHODS: The study included 48 samples of CMV DNA isolated from the peripheral blood of three allo-HSCs recipients with CMV infection who were treated in the clinics of the FSBI «National Medical Research Center for Hematology¼ of the Ministry of Health of Russia with oncohematological diseases during 2015-2017. Patients received conditional codes (PR, PD, and FS). Mutations associated with antiviral therapy (AVT) resistance were identified in all patients. Sanger sequencing was used for mutation detection. The obtained DNA sequences were analyzed using Nucleotide BLAST and Genome compiler software. Mutations were searched in MRA mutation resistance analyzer software. The nucleotide sequences were compared with the UL97 reference sequence of the Merlin CMV strain using this software environment. RESULTS AND DISCUSSION: For all patients in whom the virus strains containing C592G (PR), C607F (PD) and C603W (FS) mutations were detected, the timing of the mutation occurrence was determined at days 187, 124 and 1184, respectively. The emergence of mutations with a high resistance factor was shown to be accompanied by an increase in viral load (VL), the appearance of a clinical picture characteristic of CMV infection and a lack of an adequate response to therapy with ganciclovir and its derivatives. CONCLUSION: Using these results, it is proposed to develop the test system based on random polymerase chain reaction (rPCR) to detect mutations in the most frequently encountered codons: M460I/V, C592G, A591V, A594T/V, L595F/S, C603W. Given that the data on the prevalence of these mutations were obtained from foreign sources, it is advisable to conduct similar studies on the frequency of mutations in the UL97 gene among the population of the Russian Federation in order to improve the quality and accuracy of test systems.

[Identification by enzyme immunoassay of escape mutants S143L and G145R of hepatitis B virus (Hepadnaviridae: Orthohepadnavirus: Hepatitis B virus)].

INTRODUCTION: The achievement of the goal of the World Health Organization to eliminate viral hepatitis B by 2030 seems to be problematic partly due to the presence of escape mutants of its etiological agent, hepatitis B virus (HBV) (<i>Hepadnaviridae: Orthohepadnavirus: Hepatitis B virus</i>), that are spreading mainly in the risk groups. Specific routine diagnostic assays aimed at identification of HBV escape mutants do not exist.The study aimed the evaluation of the serological fingerprinting method adapted for routine detection of escape mutations in 143 and 145 aa positions of HBV surface antigen (HBsAg). MATERIAL AND METHODS: HBV DNA from 56 samples of HBsAg-positive blood sera obtained from donors, chronic HBsAg carriers and oncohematology patients has been sequenced. After the identification of mutations in HBsAg, the samples were tested in the enzyme-linked immunosorbent assay (ELISA) kit «Hepastrip-mutant-3K¼. RESULTS AND DISCUSSION: Escape mutations were detected mainly in patients with hematologic malignancies. Substitutions in 143 and 145 aa were found in 10.81% and in 8.11% of such patients, respectively. The G145R mutation was recognized using ELISA kit in almost all cases. The kit specifically recognized the S143L substitution in contrast to the S143T variant. The presence of neighbor mutation D144E can be assumed due to it special serological fingerprint. CONCLUSION: ELISA-based detection of escape mutations S143L, D144E and G145R can be used for routine diagnostics, especially in the risk groups. The diagnostic parameters of the kit can be refined in additional studies. This immunoassay and methodology are applicable for the development and quality control of vaccines against escape mutants.

[Herpesviruses in patients after renal transplantation].

AIM: To estimate graft function after kidney transplantation during active herpesviruses or superinfection Materials and methods. The study included 32 patients (men 21, women 11) with end-stage chronic kidney disease. The median age was 43 years. Cytomegalovirus (CMV), EpsteinBarr virus (EBV) and human herpes virus 6 (HHV-6) DNAs were screened by RT-PCR in the donor's transplant biopsy, and recipients peripheral blood and urine after kidney transplantation (KT) on 0, 1, 2, 4, 6, 12 months. Antiviral antibodies (IgM and IgG) were also screened by Enzyme-linked immunoassay analysis (ELISA) along with PCR. The 500 or less copies of viral DNA per 105 nuclear cells or 1 ml of urine was considered as low, more than 1000 copies high. RESULTS: On the first month after KT CMV DNA was detected in 50% of pts., EBV DNA in 40% and HHV-6 DNA in 33%. During first year after KT two or three viruses simultaneously were found in 12 recipients: CMV, EBV, and HHV-6 were detected in 5 recipients; CMV and EBV in 4 patients; CMV and HHV-6 in 2 pts; EBV and HHV-6 in 1 pt. Graft dysfunction was observed in 9 patients with a high concentration of viral DNA of one, two or three viruses simultaneously. An upraise of the concentration of virus DNA (CMV, EBV and HHV 6) was detected primarily in the urine, while in the blood its concentration was less than 500 cop or undetectable. Renal dysfunction was not observed on the background of low concentrations of viral DNA in urine and blood. However, with an increase of DNA concentration, an impaired graft function in 8 of 12 patients appeared. Low viral DNA level proved to be a background for another virus activation or bacterial/fungal superinfection. CONCLUSION: Graft dysfunction occurs at high viral DNA levels detection during mono-or superinfection. Low viral load can serve as a background for another virus activation and/or bacterial/fungal superinfection.

[Low concentrations of hepatitis C virus RNA in serologically mild infection.]

Occult HCV infection (OCI) provides significant interest recently. HCV RNA in this case can be detected not in plasma, but in blood cells and/or in liver tissue. In case of antibody genesis impairment anti-HCV detection may lead to negative or "uncertain" result. The aim of the study was to estimate infection type in blood donors and patients with hematological diseases by exploration of samples with uncertain anti-HCV detection results. Blood samples of 30 180 potential blood donors' and 4322 patients with hematological diseases were tested. Comparative analysis of wide pattern of HCV markers was performed. 33 blood donors and 42 patients were enrolled in follow-up examination. Uncertain results of Anti-HCV detection in donors' samples were in 0.18% of cases. Follow-up examination of 33 donors provided discordant results using immunochemiluminescence assay and ELISA. 15.2% donors' samples contained HCV RNA in low concentration. Follow-up observation of 42 patients with incomplete antiviral antibody pattern showed HCV RNA presence in 40.5% cases (21.4% high viremia and 19.0% low viremia). Samples with low RNA concentration contained low titers of anti-core antibodies. Samples with high titers of anti-core antibodies contained high HCV RNA level. Uncertain results of anti-HCV in 15.2% of potential blood donors' samples were confirmed by detection of HCV RNA in low concentration. It proved OCI presence in these individuals and called for testing for wide pattern of HCV markers in addition to routine screening. Patients with hematological diseases showed low level of HCV RNA along with low titers of antibodies against one or two viral antigens.

LABORATORY DIAGNOSTICS OF ACTIVE AND LATENT HHV 6-INFECTION IN PATIENTS WITH HEMATOLOGICAL MALIGNANCIES.

INTRODUCTION: Human herpes virus type 6 (HHV 6) can cause serious infectious complications in immunodeficient patients. It is also capable of integrating into the genome of the infected cell. Due to this, there can be a misdiagnosis between viral integration and active infection during laboratory diagnostics. Thus, determination of HHV 6 infection using proper laboratory tools is relevant. Also the data on viral interference of HHV 6 and other herpes viruses are very poor especially for patients with hematological malignancies. The aim of the study was to identify laboratory markers of HHV 6 and the form of infection in patients with hematological malignancies. MATERIALS AND METHODS: 98 patients with hematological malignancies positive for HHV 6 DNA during the infectious complication were enrolled in the study. Viral load in leukocytes and plasma of peripheral blood, antiviral M and G immunoglobulins and peripheral blood leukocytes count were evaluated. RESULTS: The majority of patients (66 out of 98, 67.3%) showed laboratory signs of latent HHV 6. Integrated HHV 6 was suspected in 2 patients due to high viral load (1.5x105 copies and 1.7x105 copies), but it was not confirmed subsequently. Additional testing of HCMV and EBV in patients with laboratory signs of active HHV 6 infection revealed the superiority of monoinfection over mixed infection (20 of 32, 62.5%). In cases of mixed infection, the most common co-infectant was HCMV observed in 9 out of 12 (75%) cases. Mild leukopenia accompanied HHV 6 active infection. CONCLUSION: Laboratory signs of latent HHV 6 tend to be prevalent in patients with hematological malignancies. In patients with laboratory markers of active HHV 6, the monoinfection demonstrated the superiority over mixed one. In cases of mixed infection, HCMV appeared to be the most commonly co-infectant. No cases of an integrated form of HHV 6 have been observed. The viral load of HHV 6 in leukocytes and blood plasma is almost 3 times lower in patients with a mixed infection than with a monoinfection. Active replication of HHV 6 was accompanied with mild leukopenia.

COMPARATIVE ANALYSIS OF SEROLOGICAL MARKERS OF HERPES VIRUSES AND QUANTITATIVE IMMUNOGLOBULINOPATHIES IN PRIMARY PATIENTS WITH ANGIOIMMUNOBLASTIC T-CELL LYMPHOMA.

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.

[Impact of current approaches to laboratory screening of donated blood and its components on hepatitis B virus infection in patients with blood system diseases]. / Vliianie sovremennykh podkhodov k laboratornomu obsledovaniiu donorov krovi i ee komponentov na infitsirovannost' virusom gepatita V u bol'nykh s zabolevaniiami sistemy krovi.

AIM: To evaluate the detection rate of markers for hepatitis B virus (HBV) in the blood samples taken from patients with blood system diseases, by applying the current approaches to examining donated blood and its components for markers of viral infections. MATERIAL AND METHODS: The investigation included blood samples from patients with blood system diseases (n=364) and donors (n=5,011). The results of laboratory screening of donated blood samples (n=13,081) were retrospectively analyzed. Commercial kits of reagents were used for immunochemical assay and polymerase chain reaction. RESULTS: Patients with blood system diseases were recorded to have markers of active HBV infection in 12.6% of cases, anti-HBc in 31.3%, and anti-HBs in 37.6%. A retrospective analysis of the results of screening donated blood samples showed the presence of markers for active HBV infection in 0.28% of cases. A prospective examination of blood donors revealed markers of HBV infection in 4.83% of cases, including those of active forms in 0.54% and anti-HBc in 4.79%. The markers of active HBV infection in donors were only anti-HBc IgM in 0.42% of cases. The blood samples from donors with an anti-HBs titer of >200 mIU/ml contained anti-HBc IgM in 10.5%. CONCLUSION: In the last 5-7 years, the detection rate of markers of HBV infection in the blood samples of patients with blood system diseases have remained at a high level. Screening for decreed markers fails to identify people with inapparent infections among the donors. Even high anti-HBs concentrations in the donated blood may be a risk for HBV transmission by transfusion to a recipient.

[The screening of donor blood on antibodies to nuclear antigen of hepatitis B virus as a tool of increasing of safety of transfusion for patients with diseases of blood system.]

Despite application of decreed modes of laboratory analysis of components of donors' blood, the risk of infection of recipients with hepatitis B virus continues to be actual. The isolated identification of HBsAg provides no control of all categories of persons infected with hepatitis B virus. The analysis of presence of antibodies to nuclear antigen of hepatitis B virus that are the first out of antiviral ones and are preserved for life, is an expedient technique of screening testing of donor's blood that permits implementing an additional selection of donors. During March 2014 - March 2015, cohort of regular anti-hepatitis B virus negative donors of blood and its components. The testing of blood samples for anti-hepatitis B virus can be recommended as a routine test increasing viral safety of blood transfusions for patients with diseases of blood system.

Hepatitis B and C viruses interference in coinfected multitransfused recipients.

Data on hepatitis B (HBV) and c (HCV) viruses interference in hematological patients are described. Patients with a hematological malignancy are at high risk of HBV and HCV infection as recipients of multiple transfusions. Results of the laboratory testing of 339 blood samples of patients treated at the National Research center for Hematology, Russian Federation, were studied. Among these patients, HBV/HCV coinfection markers were observed in 153 patients; HBV markers only, in 76 patients; HCV markers only, in 110 patients. The vast majority of coinfected patients had HBV DNA in blood (significantly more in HBsAg-negative patients: 100% vs. 82.8%, p = 0. 0005). HBsAg-negative coinfected patients had low HBV DNA levels (102-103ME/ml) and reduced (or completely absent) HCV RNA levels. The virus interference leads to a decrease in the viral nucleic acid concentrations. Thus, virus detection should include implementation of high sensitive molecular techniques (such as real-time PCR), and an enhanced set of serological HBV markers along with routine screening methods (HBsAg, anti-HCV).

[The laboratory diagnostic of herpes viral infections under nosocomial pneumonia in oncologic hematologic patients].

The study was organized to discover diagnostically valuable clinical material for detection of etiologic agent of pneumonia in oncological hematological patients, rate of association of nosocomial pneumonia with herpes viruses and evaluation of viral load in patients with depressed immunity. In oncological hematological patients, half of nosocomial pneumonia cases is associated with herpes virus. In every third patient DNA of Epstein-Barr virus and DNA of type I and II are detected. The most informative material in this case is broncho-alveolar lavage fluid and the most convenient diagnostic technique is polymerase chain reaction in real-time. The low viral load in broncho-alveolar lavage fluid is specfic for Epstein-Barr virus, cytomegalovirus and human herpes virus type VI. The concentration of DNA ofsimple herpes virus type I and type II is located in both high and low values. The paradox phenomena is established concerning more benevolent course of nosocomial pneumonia associated with simple herpes virus type I and II in patients with higher viral load in broncho-alveolar lavage fluid. The further research in this direction is needed.

[The alternative view on diagnostic of hyperlipoproteinemia, cholesterol lipoproteins of low density and effect of statins: a lecture].

The effect of statins occur in several stages: 1) inhibition in hepatocytes of synthesis of functionally specific pool of spirit cholesterol, polar mono-layer of lipoproteins of very low density; 2) activation of hydrolysis of triglycerides in lipoproteins of very low density, formation of apoE/B-100-ligand and absorption of lipoproteins of very low density by insulin-depended cells; 3) decreasing of content of and spirit cholesterol-lipoproteins of very low density in blood plasma; 4) activation of hydrolysis of triglycerides in lipoproteins of low density, formation of apoB-100-ligand and absorption of lipoproteins of low density by insulin-independent cells; 5) decreasing of level of and increasing of content of lipoproteins of high density. During first weeks of effect of statins occurs decreasing of concentration of triglycerides and unesterified spirit cholesterol-lipoproteins of very low density in blood plasma. Then, slower and more durational decreasing of level of spirit cholesterol-lipoproteins of low density occurs. The value of spirit cholesterol-lipoproteins of low density is primarily determined by content of palmitic saturated fatty acid in food, its endogenous synthesis from glucose and concentration of palmitic triglycerides and lipoproteins of very low density of the same name in blood plasma. The effect of preparations is biologically valid and corresponds to alternative hypolipidemic preparations. All these preparations have an effect following a common algorithm: they activate, using different mechanisms, receptor absorption of lipoproteins of very low density or lipoproteins of low density by cells. The level of spirit cholesterol-lipoproteins of low density in full measure depends on content of triglycerides in blood. The concentration of spirit cholesterol in blood plasma has a reliable diagnostic significance only under physiological content of triglycerides. The main criterion of diagnostic and control of hypolipidemic therapy biologically is content of triglycerides. The comprehension of differences in effect of hypolipidemic preparations within framework of common algorithm permits rationally combine them under treatment of both primary inheritable phenotypes of glucolipoproteins and secondary symptomatic types of glucolipoproteins under obligatory observation of strict dietary treatment.

[The PCR markers of viral infections under chronic gastritis in children].

The extended monitoring (up to 1 year 11 months) of PCR markers was implemented concerning viral infections: cytomegalovirus, Epstein-Barr virus, simple herpes virus type I and II, hepatitis B virus, hepatitis C virus and bacterial infection of Helicobacter pylori in bioassays (blood, biopsy material of mucous coat of stomach and inferior third of esophagus) from children with different types of chronic gastritis. In biological samples from patients with gastritis type A and type A + B DNA of hepatitis B virus (87% and 71% of patients correspondingly) and DNA of Epstein-Barr virus (63% and 67% of patients) were detected with high rate. Under gastritis type B and C these markers were detected significantly rarely (20-36%). Among patients with gastritis type A, B and A + B, the positive results on DNA of cytomegalovirus consisted 13-17%. In patients with gastritis type C DNA of cytomegalovirus was not detected. In any of analyzed samples no DNA of simple herpes virus type I and II was detected. The control of DNA of H. pylori demonstrated its presence in biological materials of 67% and 84% of patients with gastritis type B and A +B. This type of DNA was absent in patients with gastritis type A and C. Under gastritis type A, B and A+B, DNA of Epstein-Barr virus and DNA of hepatitis B virus detected more often in biological materials of mucous coat of stomach (71%-100%) and out of them simultaneously in blood in 33%-60% of examined patients and only in blood up to 29%. DNA of Epstein-Barr virus was detected in leukocytes of peripheral blood and DNA of hepatitis B virus both in plasma and leukocytes of peripheral blood. Under gastritis type C DNA of Epstein-Barr virus was always detected in leukocytes of peripheral blood (in 20% out of these patients simultaneously in biological material) and DNA of hepatitis B virus just as much in blood (plasma and/or leukocytes of peripheral blood) and biological materials. The lower concentrations (less than 700 copies/ml) DNA of hepatitis B virus in most samples were detected in absence of markers of hepatitis B virus. In patients with autoimmune gastritis and in absence of bacterial infection H. pylori (group I) or against its background (group III) PCR-markers of hepatitis B virus and Epstein-Barr virus were detected quite often. The evidence of persistence (in superior sections of digestive organs) of Epstein-Barr virus nad hepatitis B virus is detection of DNA of these viruses under their extended monitoring (up to 1 year 11 months) in biological samples from patients with autoimmune forms of gastritis type A and type A+B.

[Long-term results of HBV and HCV infection in patients with blood system diseases].

AIM: To specify trends in clinical and laboratory manifestations of virus hepatitis B and C (HBV and HCV) in patients with blood diseases from the moment of the first positive specific tests for HBV and HCV markers; to assess effects of HBV and HCV infection on efficacy of treatment of blood disease treatment, i.e. lifespan of patients with hematological diseases. MATERIAL AND METHODS: The study enrolled 257 patients: 205 with acute leukemia - AL, 40 with lymphoproliferative diseases, 4 - with CML and 8 - others; 8 healthy bone marrow donors. The patients were admitted to Russian Hematological Research Center in 2004-2006 Follow-up median was 253 days. A total of 7800 biological samples were studied, among them about 4000 tests for HBV DNA and HCV RNA. RESULTS: Positive tests for specific markers of HBV and HCV were absent only in 78 (29.4%) patients. Positive markers of coinfection were detected in 57 (32.8%) of 174 patients with HBV infection and in 81.4% of 70 patients with HCV infection. Probability of detection of HCV markers after positive tests for HBV markers and vice versa is about 3 times higher than probability of their isolated detection. Among patients infected with HBVsymptoms of hepatitis B are likely to appear in 56% patients to day 500 of follow-up from the date of the first positive specific test. Median of the interval between the first positive test for HBV markers and probable clinical signs of hepatitis was 30 days. Among patients with HCV infection, 85% develop hepatitis to follow-up day 300 since the date of the first specific positive test. Almost 100% patients infected with two viruses develop hepatitis to follow-up day 600. Median of the interval between the first positive test for HBV and HCV markers and probable hepatitis picture was 47 days. Overall 3-year survival of AL patients was 40%, of patients with lymphoproliferative diseases - 58%. Overall 7-month survival was 75% in AA patients. HBV infection in patients with blood disease is associated with high risk of death, especially in AA and AL. Association between HCV infection and survival is not proved. CONCLUSION: A high rate of clinical realization of viral hepatitis B and C, especially in coinfection, calls for virological and clinical monitoring of patients with any positive test for HBV and HCV markers.

[Laboratory diagnosis of herpesvirus infections in patients with acute leukemias].

The paper presents the results of monitoring the markers of herpes simplex viruses types 1 and 2, cytomegalovirus, Epstein-Barr virus, and human herpesvirus type 6 in the blood and bone marrow of patients with acute leukemias during induction multidrug therapy. Whether it is expedient to diagnose herpesvirus markers in patients with acute leukemias in the period of remission induction is discussed.

[Comparative analysis of hepatitis C virus core protein in the plasma and serum samples from HCV-infected blood donors and patients with hepatitis C].

The aim of the study was to develop a sensitive and specific method for revealing the direct marker of hepatitis C virus (HCV)--core protein in the serum and to test it in the laboratory setting. Experiments were made on plasma and serum samples from asymptomatic HCV-seropositive blood donors (n=65), patients with acute (AHC) and chronic (CHC) hepatitis C (n=295), and HCV-seronegative blood donors (n=20). The processing protocol for serum included their concentration by means of polyethylene glycol and subsequent treatments of pellets to detect core protein in free virions, nonenveloped nucleocapsids, and immune complexes. This allowed an assay to be developed for the detection of core protein, by using a sandwich ELISA. Inclusion of a combination of three original monoclonal antibodies into the sandwich could reveal in the samples core proteins of at least 3 genotypes of HCV (1, 2, and 3) with a sensitivity of 20 pg/ml in the majority of HCV-infected subjects. The results of determination of core protein and HCV RNA correlated with a high degree of sensitivity. To detect HCV in the blood of patients with AHC, it was shown to be sufficient to find freely circulating virions whereas an analysis of immune complexes should be included in cases of CHC to achieve more sensitivity. The findings are a basis for developing a test system for the diagnosis of hepatitis C, including its early stages before seroconversion and for determining a viral load during interferon therapy. Introduction of the method into practice increases the reliability of the diagnosis of hepatitis C and virus-free safety of blood transfusions.

[Type-specific antibodies to hepatitis C virus in sera from patients with various hematologic diseases]. / Tipospetsificheskie antitela k virusu gepatita C v syvorotkakh bol'nykh s razlichnymi zabolevaniiami krovi.

The reactivity of 100 sera taken from patients with different blood diseases and donors with respect to synthesized peptides in the variable area of protein NS4 of hepatitis C virus was studied. The presence of type-specific antibodies in the blood sera of patients with hepatitis C was shown. Two antigenic determinant corresponding to 1683-1705 and 1711-1732 amino acid residues in the protein area under study were detected. In hematological patients undergoing frequent blood transfusions mixed infection with different types of hepatitis C virus was registered; these types could be reliably determined with the use of synthetic peptides. The serotype determined with the use of peptides corresponded to the type of the circulating virus.

[Immunodiagnosis of HIV infection in the transfusion service]. / Immunodiagnostika VICh-infektsii v transfuziologicheskoi sluzhbe.

Enzyme immunoassay (EIA) is the basic method of the laboratory diagnosis of HIV-infection used as the first component of donors' screening. The possibility of nonspecific reactions presents a significant shortcoming of this method. An algorithm involving three stages has been elaborated to investigate donors for anti-HIV antibodies and to verify seropositive samples. The first-stage screening is conducted with the use of Soviet test-reagents. Positive samples are assayed again in the Soviet EI-systems based on varying types of sorbed antigens. In case of questionable or positive reactions the sample is assayed in commercial imported test-systems (the second stage). The positive sera are assayed in the immunoblotting test (the third stage). The algorithm suggested provides a reliable control and is worthwhile economically. The causes of nonspecific reactions in EIA have been described.

[Comparative evaluation of the immunoenzyme test systems for HIV-1 and HIV-2 infections]. / Sravnitel'naia otsenka immunofermentnykh test-sistem dlia infektsii VICh-1 i VICh-2.

Comparative investigations of enzyme immunoassay systems for the diagnosis of HIV-infection were conducted in panels with HIV-1 and HIV-2-positive and negative samples. It has been shown that immunodiagnostic reagents produced by the firms "Abbott" (USA) and "Behring" (FRG) possess the highest sensitivity and specificity. It has been established that the test-systems for HIV-1 cannot identify HIV-2-positive samples due to the absence of cross-reactivity. To decrease the risk of HIV transmission through the blood it is recommended that immunodiagnostic tests for both virus types should be conducted in blood donors' screening.

[Serological markers of viral infections and various indicators of immunity in patients with hemophilia]. / Serologicheskie markery virusnykh infektsii i nekotorye pokazateli immuniteta u bol'nykh gemofiliei.

The authors have studied the incidence rate for markers of viruses of AIDS (HIV), hepatitis B (HBV) and cytomegalia (CMV), as well as certain parameters of antiinfectious defense in hemophilia patients. A high incidence rate of HBV and CMV markers was established in the investigated patients, and among them no seropositive subjects, by antibodies to HIV, were detected. In the presence of a low incidence rate of chronic HBsAg-carriership in this category of patients, a significant number of immune subjects was observed, that correlated with a relative stability of such immunity parameters as concentration of serum immunoglobulin G and the level of circulating immune complexes.