Neonatal protection and preterm birth reduction following maternal group B streptococcus vaccination in a mouse model.

PURPOSE: Evaluate effects of maternal immunization in a mouse model of Group B Streptococcus (GBS) vaginal colonization using clinical isolates. MATERIALS AND METHODS: Female pregnant mice were immunized with heat-killed GBS 21 days before pregnancy and were inoculated intravaginally with GBS cultures (5 × 107 CFU twice a day for three days) from the 16th day of pregnancy. Gestation period and mice survival were monitored. Maternal anti-GBS IgG levels have been determined by ELISA analysis in vaccinated, unvaccinated mothers and newborns. RESULTS: Maternal immunization before pregnancy provided protection to newborns for three of the four GBS strains used. Evaluation of the immunogenicity showed that this vaccination induced higher levels of IgG in vaccinated compared to unvaccinated dams and the presence of antibodies in the offspring at embryonic and postnatal age, and a Th1 response and high levels of IgG2a subclass antibody and IFN-γ were detected. A significant reduction of preterm births was observed in vaccinated mothers (p< 0.05). CONCLUSIONS: Our finding suggest that vaccinated mothers could protect their progeny from GBS infection and preterm birth through passive immunization. The proposed mouse model may represent a noninvasive and effective tool to investigate pathogenetic mechanisms of GBS ascending infection and for vaccine protection studies.

Quantitative assessment of serum-specific IgE in the diagnosis of human cystic echinococcosis.

Anti-Echinococcus serum immunoglobulin (Ig)E was assessed by the ImmunoCAP system and compared with anti-Echinococcus serum IgG assessed by enzyme-linked immunosorbent assay (ELISA) and Western blot. The ImmunoCAP system revealed very high specificity (one false positive of 110 healthy individuals), low cross-reactivity (one false positive of 58 patients with other diseases) and decreased sensitivity (73.55%). Receiver operating characteristic analysis displayed a beneficial diagnostic value with high accuracy. Comparison of the ImmunoCAP system with ELISA and Western blot showed significantly higher specificity and significantly lower cross-reactivity compared with the ELISA. Examination of sera from 155 patients with cystic echinococcosis (CE) showed varying levels of anti-Echinococcus IgE (range, 0.01-118.33 kUA/L). However, most samples had moderately elevated IgE levels. Analysis of serum-specific IgE revealed significantly higher sensitivity of the ImmunoCAP system and significantly higher antibody levels in hepatic CE compared with pulmonary CE.

[Current directions of studies for development of methods for specific diagnostics of allergic diseases in vitro].

Results of studies as well as perspectives for development and use of modern in vitro methods of allergic diseases diagnostics are presented. High prevalence of allergic diseases dictates the need of high-quality etiologic diagnosis for conducting relevant etiopathogenetic treatment - allergen-specific immunotherapy and prophylactic measures. Interest to in vitro diagnostic methods due to their high specificity and commonality is rising. They are directed to identification of various elements of "material substrate" of allergic reaction - specific antibodies, cell elements, cytokines as well as genes, which encode them. Intensively developing methods based on immunoenzyme, immunofluorescent, and immunochemiluminescent reactions are widely used now. Methods based on the use of various monoclonal antibodies for identification of lymphocytic markers, cytokines, antigen-presenting cells by laser flowcytometry are also very promising. ELISPOT technology is also intensively used for diagnostics of allergic diseases. From immunogenetic methods great potential belongs to molecular biologic methods of assessment of genome specificity characterizing sensitization to given antigen.

Comparision of two-flow cytometry methods for basophil degranulation in patients sensitized to grass pollen.

BACKGROUND: Two-flow cytometry methods for quantification of degranulated basophil after allergen-specific activation were discussed. The methods are discerned by used membrane receptors--FcepsilonRI or IL-3Ralpha Our goal was to evaluate the diagnostic potential of the methods and to correlate them to allergen-specific IgE detection and skin prick test (SPT). METHODS: Patient's and control's groups were studied with Bulgarian grass pollen allergen B1 simultaneously by flow cytometry kits: Basotest and BD FastImmune test. Allergy diagnosis was based on clinical history and SPT. The determination of specific IgE was performed by ELISA--RIDASCREEN. RESULTS: There were no significant differences between the patient's results from Basotest and FastImmune (P>0.05). A significant correlation between values, analyzed by Basotest and by FastImmune was found (r=0.88). The sensitivity and specificity of the Basotest, FastImmune, specific IgE and SPT were 85%, 72%, 92% and 92% sensitivity and 100%, 92%, 100% and 85% specificity respectively. The efficiency was between 82% and 97%. There were a significant correlation between the specific IgE and flow cytometry tests: tau=0.92 (Basotest) and tau=0.71 (FastImmune) and a moderate significant correlation between the SPT and the in vitro tests: tau=0.26 (Basotest) and tau=0.31 (FastImmune). CONCLUSION: The successful use of the Bulgarian grass pollen allergen B1 and both flow cytometry tests was presented. These methods could be as specific tools for IgE-mediated diagnosis especially FastImmune in the case of low IgE receptor expression.

[Polybacterial immunostimulators in medical practice]. / Polibakterial'nye immunostimuliatory v meditsinskoi praktike.

During 20 years different oral immunostimulators have been developed and tested in the National Center of Infectious and Parasitic Diseases in Sofia, Bulgaria. Some of them are widely and quite successfully used in clinical practice for immunotherapy and immunoprophxis (Respivax, Urostim, Dentavax). Data on the immunostimulating activity of polybacterial immunostimulants are presented. Numerous clinical investigations, including double-blind studies, have convincingly demonstrated their high efficacy in the prevention and treatment of non-specific infections of the respiratory organs, the urogenital tract, the oral mucosa and periodontium, as well as in the complex therapy of AIDS. All these facts suggest that immunostimulators, in particular polybacterial ones, are a highly promising tool of modern immunotherapy and immunoprophylaxis aimed at the beneficial modulation of immune response in humans.

Immunostimulating and protective effects of an oral polybacterial immunomodulator 'Dentavax' in a rabbit experimental model.

The immunostimulating and protective effects of an oral polybacterial immunomodulator, Dentavax (D), composed of killed cells from Klebsiella pneumoniae, Streptococcus pyogenes, Staphylococcus aureus, Candida albicans and Lactobacillus acidophilus and their lysates, have been investigated on an experimental rabbit model. In this model, mixed suspensions of the above bacterial wild strains have been injected in six sides of oral mucosa. A long-lasting inflammation with the development of infiltrates and confluating abscesses has been observed. The influence of orally given Dentavax on the course of the model infection as well as on the dynamics of the immune response has been studied. A two-fold decrease in the duration and severity of inflammatory reaction, confirmed by the histological findings, has been registered. In immunised animals, an activation of polymorphonuclear phagocytosis, together with stimulation of humoral systemic and mucosal immunity with synthesis of specific serum (predominantly, IgG) and coproantibodies (predominantly, S-IgA) determined by ELISA, has been found. The results obtained proved the strong immunostimulating and protective effects of the preparation D, which is meant for the prophylaxis and treatment of inflammatory periodontal diseases.

Stimulating effect of an oral polybacterial immunomodulator on the proliferative activity of guinea pig lymphocytes.

A preparation for the prophylaxis and treatment of inflammations of oral mucosa and parodont Dentavax (D) was investigated in guinea pigs. Animals were given orally D for 5 consecutive days and a month later the procedure was repeated. On day 3, 10, 21, and 28 after immunization and reimmunization lymphoproliferative responses to PHA, rIL-2, LPS and D were measured by the radiometric blast transformation assay in peripheral blood, spleen, mesenteric lymph nodes (MLN) and Peyer's patches (PP). The percentage of cells entering S and G2/M-phases of cell cycle was assessed by the flow cytometric DNA analysis. A correlation in proliferative activity of cells after in vitro stimulation with PHA and LPS has been established by both methods. Peak values of lymphocyte stimulation were found on day 10, especially after the second administration of D in all organs tested, mainly in MLNs and spleen. Electron-microscopic studies demonstrated an extensive development of the endoplasmatic reticulum in plasmatic cells from spleen, PPs, mesenteric, bronchial and inguinal lymph nodes. The results obtained may be considered a proof of the immunostimulating effect of Dentavax.

[The isolation and characteristics of a chemically modified allergen (allergoid) from Dermatophagoides pteronyssinus mites]. / Poluchenie i kharakteristika khimicheski modifitsirovannogo allergena (allergoida) iz kleshchei Dermatophagoides pteronyssinus.

Chemically modified allergens (allergoids) were obtained from house dust mites (Dermatophagoides pteronyssinus). The allergenicity of allergoids in comparison with commercial mite allergen was determined by the skin prick test and by the in vitro test of degranulation of passively sensitized rat mast cells. Changes in allergoid molecules were determined with the use of gel filtration in a column packed with Sephadex G-75, isoelectric focusing in polyacrylamide gel, the determination of the concentration of end amino groups and the enzymatic activity of preparations, as well as HPLC. The possibility of using these methods for controlling the process of modification was studied. The results confirmed the fact that the modification on the allergenic preparation really occurred and the allergenic activity of allergoids was low.

[Clinico-allergological studies of workers in the manufacture of fodder yeasts]. / Kliniko-alergologichni izsledvaniia na rabotnitsi ot proizvodstvoto na furazhni drozhdi.

The authors have examined 161 persons from the production of fodder yeasts. On the background of detailed clinical examination are performed immunoallergological studies, including skin allergologic tests with series of standard allergens and antigens of the produced culture yeasts and determined immunoprecipitants in the blood serum. Increased sensibilization is established in 34.7% of the examined, as the prevailing cases are with monoallergy. More seldom--in 18.8% are established immunoprecipitations with the professional allergens. The changed general and specific immunoallergologic reactivity in part of the workers is due exclusively to the biological factors of the working environment.

The collaborative study of the international standard of dog, Canis domesticus, hair/dander extract.

A collaborative study was carried out to assess the suitability of a chosen preparation to serve as the international standard (IS) for dog (Canis domesticus) hair/dander extract. Sets of five coded preparations of dog extract, including the proposed IS, were delivered to each participating laboratory in glass-sealed ampules. Fifteen laboratories in nine different countries examined the preparations by RAST inhibition, crossed immunoelectrophoresis/crossed radioimmunoelectrophoresis, histamine release, and by other methods. In spite of the use of different versions of methods and different reagents, quite consistent results were obtained, and the proposed IS was found to have a satisfactory activity in all assays and to be useful as a calibrator when allergenic potency of similar dog allergenic extracts was estimated. Four laboratories estimated the specific content of allergens Ag 3, Ag 13, and albumin and found the proposed IS to be a suitable standard for these assays. On the basis of the results from this study, the World Health Organization established the preparation as the international standard for dog hair/dander extract with an assigned unitage of 100,000 IU per ampule. The units refer to both the total allergenic activity of the ampule and to that of individual allergens.

[Evaluation of the biological activity of allergens by different in vivo and in vitro immunological methods]. / Otsenka biologicheskoi aktivnosti allergenov razlichnymi immunologicheskimi metodami in vivo i in vitro.

The specific activity of different allergens has been studied in vivo and in vitro by certain immunological methods (complement inactivation, mastocyte degranulation, neutrophil damage index, lymphocyte blast transformation). The results obtained by the skin allergic tests have been found to correlate well with those obtained by the in vitro methods. This allows one to use these methods for a more complete characterization of allergens and their standardization.