Detection of GB virus C/hepatitis G virus in semen and saliva of HIV type-1 infected men.

OBJECTIVE: To investigate the presence of the genome of GB virus C/hepatitis G virus (GBV-C/HGV) in semen and saliva from HIV-1-infected men. METHODS: Samples of blood from 33 men seropositive for HIV-1 were tested for the presence of GBV-C/HGV markers of infection, RNA by RT-PCR, and anti-E2 antibodies by ELISA, respectively. The cell-free fractions of seminal fluid and saliva samples of the patients with positive blood samples for GBV-C/HGV RNA or anti-E2 antibodies were then analyzed for the presence of the RNA of this virus. In addition, six semen samples and 11 saliva samples from GBV-C/HGV-negative men were tested. RESULTS: The GBV-C/HGV RNA tested by RT-PCR was recovered from blood in 11 patients of 33 (33.3%), and the antibodies to E2 envelope protein were detected in six patients (18.2%). Since no patient was positive for both markers, the overall prevalence of GBV-C/HGV infection was 51.5% in the studied population. Four-all belonging to the homosexual risk group-of the 17 men with markers to GBV-C/HGV in blood were found to be positive for GBV-C/HGV RNA in mucosal samples: two of them exhibited genomic RNA in both semen and saliva, and two others were positive for semen only. The absence of inhibitors of the PCR technique was confirmed in all mucosal fractions found negative for GBV-C/HGV RNA, except for one saliva sample and one seminal fluid sample. CONCLUSION: These results confirm the high prevalence of GBV-C/HGV infection in patients infected with HIV-1 by sexual exposure and the presence of GBV-C/HGV RNA in seminal fluid and saliva of men with markers of this virus in the blood, suggesting that mucosal fluids could be a potential source for the spread of the GBV-C/HGV infection.

Prevalence of GBV-C/hepatitis G virus RNA and E2 antibody among subjects infected with human immunodeficiency virus type 1 after parenteral or sexual exposure.

GB virus C (GBV-C) or hepatitis G virus (HGV) is transmitted by the parenteral route but the importance of sexual transmission needs to be ascertained. GBV-C/HGV infections were investigated using RNA and E2-antibody detection methods in 80 subjects infected by the human immunodeficiency virus type 1 (HIV-1) divided into 4 groups of 20 individuals each according to their main risk factor for HIV-1 infection: blood product recipients (group 1), intravenous drug users (group 2), homosexuals (group 3), or heterosexual exposure (group 4). The overall prevalence of GBV-C/HGV infection was 66.3%. No significant difference was observed in GBV-C/ HGV prevalence among the four groups: 75, 75, 55, and 60% in groups 1, 2, 3, and 4, respectively. Hepatitis C virus (HCV) antibodies, used as a control for parenteral exposure, were found in 70% and 90% of the subjects in groups 1 and 2 versus only 15% and 20% of the subjects in groups 3 and 4, respectively (P< .001). Similarly, coinfections with GBV-C/HGV and HCV were significantly associated with the parenteral route (P <.001). These data emphasized the usefulness of combining the detection of RNA and the E2 antibody to determine the actual prevalence of GBV-C/HGV infection. The high prevalence of the GBV-C/HGV markers among the HIV-1-infected subjects, especially those with sexual exposure, provides additional evidence that this route of transmission plays a key role in the epidemiology of GBV-C/HGV. The potential influence of GBV-C/HGV infection on the course of HIV-1 disease needs further evaluation.

Quantification of IgA and IgG and specificities of antibodies to viral proteins in parotid saliva at different stages of HIV-1 infection.

Paired sera and parotid saliva from 75 HIV-1-infected patients, divided in three equal groups with CD4+ cell counts > 500, 200-500 and < 200/mm3, respectively, were analysed for IgG, IgA and secretory IgA (sIgA) concentrations and for IgG and IgA antibody directed to HIV-1. Twenty-nine age-matched HIV-subjects were used as controls. In serum the concentrations of immunoglobulins were significantly increased in HIV-infected subjects compared with controls, and a progressive increase of IgA and sIgA was noticed while the CD4+ cell count decreased. In contrast, concentrations of IgA and sIgA were not different in parotid saliva between the four subject groups. By an ELISA test directed towards HIV-1 proteins, 73 of the 75 serum specimens from the HIV-infected subjects (97%) and 43 of the corresponding saliva (57%) were found positive for specific IgA antibodies to HIV-1, with an even distribution among the three groups of patients. By Western blotting multiple specificities of IgA to HIV-1 proteins were not frequently found in patients. By contrast, in spite of an IgG concentration in saliva about 100 times lower than that of IgA, reactivities were significantly higher for IgG than for IgA antibodies, especially to env and to pol HIV-1 products. Altogether, these data suggest that the regulation of IgA production in HIV-infected subjects is independent in serum and in parotid saliva. This imbalance of IgA/IgG antibodies to HIV-1 at the mucosal level appears to be a specific feature of HIV-1 infection, and may raise important issues in terms of local protection after immunization.

Prognostic value of serum immunoglobulin A antibodies to pol gene products during HIV-1 infection.

Serum specimens from 66 HIV-1-infected subjects were tested by ELISA for the presence of IgA antibodies to HIV-1: 44 samples were found positive and 37 were confirmed by immunoblot. In these subjects, the presence of anti-HIV IgA antibodies was studied in relation to the total count of circulating CD4+ lymphocytes and to the level of serum IgA. A significative correlation (P < 0.03) was found between the absence of IgA to the subunit p68 of the reverse transcriptase and a count of CD4+ cell < 400/mm3 or total IgA level over 4.25 g/l. The same pattern was observed for the IgA antibodies to the p52 subunit but the association was just not significant (P < 0.07). No significant decrease was noted for the IgA directed towards the other proteins of HIV-1, especially the products of the gag gene.

Detection of immunoglobulin G, M, and A antibodies to enterovirus structural proteins by immunoblot technique in echovirus type 4-infected patients.

Paired serum specimens from 24 patients with echovirus (EV) type 4 infection by virus isolation were tested by the immunoblot technique for the presence of IgG, IgM, and IgA antibodies to EV4 structural proteins. Single sera from 20 patients without neutralizing enterovirus IgM were used as controls. All the sera from EV4-infected patients had IgG antibodies to VP1 of EV4 but also 13 out of the 20 controls. 23 out of 24 EV4-infected patients elicited IgM and IgA specific antibodies to VP1, a pattern highly significant as compared with controls (3/20 for IgM and 8/20 for IgA). In 16 out of the 24 EV4-infected patients, the IgM antibodies were also directed against VP2 (versus 2 out of 20 in the control group). Anti-VP2 IgA were detected in 4 out of the 24 EV4 patients (versus 0 in controls). The 24 paired sera from EV4-infected subjects were also tested by immunoblot technique against three other enteroviruses: EV21, coxsackievirus A9 and poliovirus 1. Cross-reactivities were observed to a large extent against VP1 and VP2 proteins with the three classes of antibodies. These results confirm the data of previous studies on the reactivity of IgM antibodies to various structural proteins that IgG antibodies react exclusively to VP1. Furthermore, this study demonstrates the occurrence of circulating IgA antibodies directed to VP1 and sometimes VP2 in the course of enterovirus infection. The potential interest of this latter finding for diagnosis requires further investigation.