Anti-hepatitis E virus markers in hemodialysis patients.
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Antibodies, Viral↗
Biomedical subjects
J Pillot
Publications and source records attributed to J Pillot.
[Prevalence of serum anti-hepatitis C virus antibodies and risk factors of contamination in the personnel of a hospital in the Paris region. A prospective survey].
OBJECTIVES: The aim of this prospective study was to estimate the prevalence of subjects with serum anti-HCV antibodies in a University Hospital in the Paris area, and to identify the risk factors associated with contamination. METHODS: Over an 18 month period, each person working in the hospital was systematically requested to fill out an anonymous questionnaire including 23 questions and to undergo a blood test for an anti-HCV assay during their annual medical visit. RESULTS: 557 (33%) of 1693 employees accepted to fill out the questionnaire and the anti-HCV assay. Serum anti-HCV antibodies were present in 9 subjects, which represents a prevalence of 1.6%, and serum RNA was positive by PCR, m 7. The prevalence was significantly higher in subjects working in clinical units (3.0%) compared to subjects working in non-clinical units (0.7%: P = 0.04) and in subjects with a history of acute hepatitis (5.5% vs 0.9%; P = 0.002%) Anti-HCV-positive subjects had more history of manipulating blood products than HCV-negative subjects (17.0 vs 8.8 years of exposure; P = 0.01), other human samples (17.0 vs 7.6 years; P = 0.01), and of having at risk contacts (16.7 vs 6.2 years; P = 0.0004). CONCLUSION: These results suggest the importance of systematic anti-HCV screening among health care workers particularly those in contact with patients.
Adult↗
Interplay between a new HNF3 and the HNF1 transcriptional factors in the duck hepatitis B virus enhancer.
We identified a new hepatocyte nuclear factor 3 (HNF3) binding site in the DHBV enhancer. This site is close to the hepatocyte nuclear factor 1 (HNF1) binding site, responsible for most of the enhancing activity. No differences in the migrating properties were found between this new site and the two other HNF3 sites recently described in this enhancer. Factor HNF1 strongly inhibits binding of the HNF3 factor in this newly characterized site. The two factors were never detected simultaneously on the DNA fragment, even when their respective concentrations were modified. Competition persisted after enlarging by 5 and 10 nucleotides the space between the two sites. On the contrary, when the HNF3 binding site was changed into the perfect consensus site, binding of the HNF3 factor was not inhibited any longer by HNF1 and a supershift, corresponding to the binding of both factors, was observed. Thus a limited mismatching appears to modulate the interaction between transcriptional proteins and DNA and allows a second transcriptional protein to interplay with the former one.
Base Sequence↗
[Prevalence of hepatitis E virus antibodies in pregnant women in the Paris region: serological considerations].
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Female↗
Antibodies to HTLV-I in Sjögren's syndrome.
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Adult↗
Detection of seminal antibodies to human immunodeficiency virus in vaginal secretions after sexual intercourse: possible means of preventing the risk of human immunodeficiency virus transmission in a rape victim.
Detection of semen anti-human immunodeficiency virus (HIV) antibodies within the cervicovaginal secretions from a non-HIV-infected woman who has had a recent sexual intercourse with an HIV-infected man is theoretically possible since the seminal fluid from all HIV-infected men contains a high titer of IgG antibodies to HIV. We report the case of an HIV-seronegative African woman whose cervico-vaginal secretions contained IgG antibodies to HIV, including antibodies to HIV-env-encoded glycoproteins. This woman had also detectable prostatic specific antigens and acid phosphatase in her cervico-vaginal secretions, establishing the persistence of semen. In order to confirm whether anti-HIV antibodies in seminal fluid could be detected in vitro when mixed with cervico-vaginal secretions, 10(-1) to 10(-6) 10-fold dilutions of seminal fluid from HIV-1-seropositive donors were realized with a pool of HIV-negative cervico-vaginal secretions as diluent. Six commercial enzyme immunoassays or rapid tests were compared for semen anti-HIV detection in the secretions. At a 10(-1) dilution of the mixture, all assays were markedly positive for all tested semens and the greatest dilutions of seminal fluid showing positivity ranged from 10(-3) to 10(-5). The IgG immunocapture assay appeared to be the most sensitive test. The rapid tests permitted the detection of semen IgG antibodies to HIV at dilutions ranging from 10(-1) to 10(-3) suggesting their potential value in emergency situations.
Coitus↗
Proinflammatory cytokine expression in cervicovaginal secretions of normal and HIV-infected women.
Proinflammatory cytokines may stimulate replication and spread of HIV. To evaluate to what extent the female genital tract represents a source of these cytokines, we determined TNF-alpha, IL-1 beta and IL-6 concentrations in paired serum and cervicovaginal washings from 45 HIV-negative and 50 HIV-positive women, and then we looked for the relevant mRNAs in cervicovaginal secretions by RT-PCR. Cytokines were detected by ELISA in cervicovaginal fluid from most healthy women. Cervicovaginal washing levels of TNF-alpha were increased above the control value +2 SD in 11/50 HIV-positive women, those of IL-1 beta in 13/50, and those of IL-6 in 14/50. The prevalences of TNF-alpha, IL-1 beta and IL-6 increase and their levels in cervicovaginal washings were significantly higher in the 20 patients at stage IV than in the 30 patients at earlier stages of the disease. In HIV-infected patients, serum and cervicovaginal washing levels correlated positively for TNF-alpha and IL-6, but not for IL-1 beta. Nine of 15 cytokine mRNAs determinations were positive in HIV-infected women versus 1 of 15 in controls (P < 0.01). These findings could be relevant to bidirectional heterosexual transmission of HIV.
Case-Control Studies↗
Are blotting tests (Riba, western-blot ...) still useful as markers of hepatitis C virus infection?
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Biomarkers↗
Weak immunogenicity of the preS2 sequence and lack of circumventing effect on the unresponsiveness to the hepatitis B virus vaccine.
The preS2 sequence is known to circumvent immunological unresponsiveness to the S protein and to induce a 'carrier' effect on the anti-S antibody production, in mice. In humans, an anti-S response was found in 100% and 97% of healthy subjects vaccinated with the S and S + preS2 preparations, respectively, whereas less than 50% of drinkers responded whatever the vaccine used. Anti-preS2 were found in 44% of healthy recipients of the S + preS2 vaccine, whereas there were no anti-preS2 responders in drinkers. Anti-preS2 remained undetectable in 32% of the blood donors hyperimmunized with the S + preS2 vaccine, whereas anti-S antibody boosted in all cases. In humans, in contrast to mice, immunogenicity of the preS2 sequence appears weak and the preS sequence does not circumvent the anti-S unresponsiveness.
Adult↗
Local synthesis of IgG antibodies to HIV within the female and male genital tracts during asymptomatic and pre-AIDS stages of HIV infection.
Paired sera and cervicovaginal secretions or seminal fluids, obtained from HIV-1-infected, clinically asymptomatic women (n = 41) and men (n = 12), were investigated in order to test the hypothesis of a local synthesis of IgG to HIV in the female and male reproductive tracts. Anti-gp41 + p24 IgG was evaluated by an IgG immunocapture assay, and anti-gp160 IgG by an indirect ELISA. Estimation of anti-HIV IgG-specific activities was carried out after ponderal determination of total IgG and evaluation of anti-HIV IgG activity. IgG to gp41 + p24, as well as IgG to gp160, were specifically detected in all sera, cervicovaginal secretions, and seminal fluid samples from all tested HIV-1-infected subjects. The mean specific activities of IgG to gp41 + p24 in cervicovaginal secretions and in seminal fluids were about 33-fold (in women) and 16-fold (in men) that of the corresponding sera; similarly, the mean specific activities of IgG to gp160 in genital secretions were about 17-fold (in women) and 10-fold (in men) that of the corresponding sera. IgGs to HIV are constantly detected in genital secretions from HIV-1-infected subjects, and appear to be largely synthesized in situ within the genital tract of both genders.
Adolescent↗
Human immunodeficiency virus type 1 p24 antigen in cervicovaginal secretions.
The failure to detect human immunodeficiency virus (HIV) antigen in cervicovaginal secretions (CVS) from HIV-infected women could be due in part to an in situ formation of immune complexes involving HIV antigens and cervicovaginal anti-HIV antibodies. CVS from 30 HIV-1-infected heterosexual women were assayed for p24 antigen detection by ELISA before and after acid disruption of immune complexes. Before acid treatment, free p24 antigen was detected in only 1 sample of CVS, whereas after acid dissociation, 4 (13.5%) of 30 samples had detectable and neutralizable p24 antigen. Adsorbent capacities of the CVS for recombinant p24 antigen, evaluated in an in vitro model, depended on both titer and avidity of cervicovaginal antibodies to HIV. In conclusion, local antibodies to HIV are able in vivo to bind HIV antigen within CVS and to participate in the immune exclusion of free virus particles or proteins.
Adolescent↗
Cervicovaginal overproduction of specific IgG to human immunodeficiency virus (HIV) contrasts with normal or impaired IgA local response in HIV infection.
Paired sera and cervicovaginal secretions (CVS) from 30 women infected with human immunodeficiency virus (HIV) type 1 (before AIDS) were analyzed for IgG and IgA antibodies to HIV and for IgG, IgA, and human serum albumin. Subjects were compared with 30 aged-matched healthy controls. In HIV-infected women, cervicovaginal immunoglobulins were markedly increased, and IgG predominated. An increased immunoglobulin transudation was implicated, since cervicovaginal albumin levels were 2.3-fold above those of normal controls. Furthermore, IgG excretion by reference to albumin was increased 1.9-fold, whereas the IgA secretion tended to decrease, suggesting a possible enhanced local IgG synthesis. Mean IgG and IgA anti-HIV antibody titers were, respectively, 30- and 12-fold higher in serum than in CVS, but their mean specific activities were higher in CVS than in serum, suggesting a local synthesis of both isotypes. The IgA antibody response to HIV remained poor compared with the strong IgG response.
Adolescent↗
Decreased cervicovaginal production of both IgA1 and IgA2 subclasses in women with AIDS.
Paired sera and cervicovaginal secretions from 35 HIV-1-infected women representing different CDC stages of HIV infection were evaluated for total IgA, IgA1 and IgA2, for IgA, IgA1 and IgA2 to gp160, and for albumin. Age-matched healthy women (n = 45) served as controls. The secretion rates of total IgA, IgA1 and IgA2 were evaluated by calculating their relative coefficients of excretion by reference to albumin. In HIV-infected women, total IgA1 and IgA2 in sera and in cervicovaginal secretions increased proportionately as early as stages II + III and more markedly at stage IV. By contrast, the secretion rates of total IgA IgA1 and IgA2 were markedly reduced in AIDS women, the IgA2 secretion rate decreasing significantly as early as stages II + III. This apparent discrepancy was probably the result of increased transudation of serum-borne immunoglobulins into the vaginal cavity, since albumin levels in cervicovaginal secretions increased significantly according to the stages of disease. HIV-reactive IgA antibodies in serum, as in cervicovaginal secretions, were principally found within the IgA1 subclass. In women at stage IV, a high local production of IgA1 to gp160 occurred in spite of the impairment of cervicovaginal IgA synthesis, probably because of marked genital HIV replication at advanced stages.
Acquired Immunodeficiency Syndrome↗
Systemic and secretory humoral immunity in the normal human vaginal tract.
The molecular status of Abs in the vaginal fluid is reconsidered as a basis for immunization strategies for women' vaccination against HIV. Analysis of separated immunoglobulins (Igs) shows a large proportion of uncleaved IgG, whereas the low amount of IgA includes SIgA, monomers and fragments. SIgM is at a very low level, while free SC molecules are abundant. In addition to the already documented local synthesis, vaginal IgG contains serum-derived tetanus antitoxins. The IgG could reach the lumen by diffusion, and/or be transported by an Fc receptor-associated mechanism as suggested by the subclass imbalance in favour of the IgG1 isotype. VAginal SIgA contains very low levels of antibodies o the cell-well carbohydrates from a dental caries-associated streptococcus confirming the participation of the secretory immune system. IN addition, the low percentage of IgA2 suggests tha a proportion of vaginal SIgA can also derive from actively transported serum polymers. In agreement with our previous studies showing induction of vaginal tetanus antitoxins by intramuscular immunization, these results are in favour of classical, parenteral vaccinations to induce protection of the human vagina.
Adult↗
Dilution assessment of cervicovaginal secretions obtained by vaginal washing for immunological assays.
Local immunological defense mechanisms in the cervicovaginal mucosa currently remain incompletely defined, especially from a quantitative point of view. Addition of an inert substance, lithium chloride (LiCl), into the washing buffer used to carry out the vaginal washing for collecting cervicovaginal secretions and measurement of its concentration with a flame absorption spectrophotometer, before and after the specimen is sampled, permits the quantification of the volume of cervicovaginal secretions collected and the approximation of the dilution factor of a soluble component introduced by the washing. Lithium, at a concentration of 10 mM, gives the best precision of measurement and has no effect on the results of the immunoassays. In a population of 27 nonpregnant women (age range, 18 to 45 years), the volume of cervicovaginal secretions collected by vaginal washing with 3 ml of LiCl-phosphate-buffered saline was 12% +/- 3.2% (mean +/- standard deviation) of the total volume and showed large interindividual variations (range, 5.6 to 18.8%); the mean dilution factor of a soluble component from the vaginal secretions was 9.9% +/- 2.8% (range, 6.3 to 18.8%). According to the date of the menstrual cycle, the mean volume of collected cervicovaginal secretions was significantly increased in the luteal phase in comparison with the follicular phase; conversely, the mean dilution factor of a soluble component was more important in the follicular than in the luteal phase. These features strengthen the need to quantify accurately the dilution factor introduced by vaginal washing when studying cervicovaginal immunity.
Adolescent↗
Fibronectin of human liver sinusoids binds hepatitis B virus: identification by an anti-idiotypic antibody bearing the internal image of the pre-S2 domain.
Anti-idiotypic antibodies (anti-Ids) have been successfully used to characterize and isolate receptors of several cell ligands. To prepare an immunological probe for identification of cellular components interacting with the hepatitis B virus (HBV), polyclonal antisera against a panel of five HBV-specific monoclonal antibodies (MAbs) were produced in syngeneic BALB/c mice. MAbs to HBV used for immunization (Ab1) recognized biologically important and potentially neutralizing epitopes, located in the pre-S1, pre-S2, or S region-encoded domains of HBV proteins. All the anti-Ids (Ab2) were specific to idiotopes of the homologous Ab1 and inhibited their interaction with the corresponding viral epitopes, suggesting that they recognized unique determinants on the paratope of each immunizing Ab1. Therefore, all five generated polyclonal anti-Ids were of the Ab2 beta type and could represent internal images of viral epitopes. Ab2 raised against the pre-S2 region-specific MAb F124 bound to the extracellular matrix fibronectin of human liver sinusoids. Immunohistochemical studies demonstrated the attachment of viral and recombinant (S, M) hepatitis B surface antigen particles with the pre-S2 region-encoded epitopes to the fibronectin of human liver sinusoids. In contrast, recombinant (S, L*) hepatitis B surface antigen particles, in which the epitope recognized by F124 MAb was not expressed, did not show any binding capacity. These findings suggest that human liver fibronectin may bind HBV in vivo by the pre-S2 region-encoded epitopes in a species-restricted manner. Furthermore, binding of the circulating virus to liver sinusoids could facilitate its subsequent uptake by hepatocytes.
Animals↗
Cross-reactive immunity against different strains of the hepatitis E virus transferable by simian and human sera.
Monkey infection with the hepatitis E virus induces protection. We confirm the humoral nature of this immunity and show that protection is effective against the homologous strain, as well as against heterologous strains isolated from Asian and African countries. However this immunity is incomplete since only the clinical disease seems to be prevented, while the virus is still excreted in stools and can even appear in blood as well after serotherapy as previous acute or occult infections. We obtained also a preliminary evidence that convalescent human sera are also efficient for the passive protection, indicating that seroprophylaxis of HEV hepatitis in pregnant women (20% of mortality during the 3rd trimester of pregnancy) should be attempted in the case of epidemics.
Animals↗