RESUMEN
OBJECTIVES: Individuals with HIV infection often have early waning of protective antibody following hepatitis B virus (HBV) vaccination. HIV viraemia at the time of vaccination may limit the durability of serum anti-HBV surface antibody (HBsAb) levels. We investigated the relationship of HIV plasma viral load (VL) and duration of HBsAb among vaccinees enrolled in the US Military HIV Natural History Study. METHODS: We included in the study participants who had no history of prior HBV infection, who had received all HBV vaccine doses after HIV diagnosis, and who had demonstrated an initial vaccine response, defined as HBsAb ≥ 10 IU/L. Responders were retrospectively followed with serial HBV serology from the time of the last vaccine dose until the development of waning (HBsAb < 10 IU/L) or the last HBsAb measurement. Time to and risk for waning were evaluated with Kaplan-Meier survival methods and Cox proportional hazards models, respectively. RESULTS: A total of 186 initial vaccine responders were identified. During 570 person-years of observation, HBsAb waned in 52 of 186 participants (28%). The cumulative proportion maintaining HBsAb ≥ 10 IU/L was 83% at 2 years and 56% at 5 years. Participants with an undetectable VL [hazard ratio (HR) 0.37; 95% confidence interval (CI) 0.18-0.76] or with detectable VL of ≤ 10 000 copies/mL (HR 0.46; 95% CI 0.21-1.00) had reduced risk of waning. Other factors including age, number of vaccine doses, CD4 count, and receipt of highly active antiretroviral therapy (HAART) were not significantly associated with risk of waning HBsAb. CONCLUSIONS: Undetectable or low HIV VL at the time of HBV vaccination is associated with greater durability of vaccine response in patients with HIV infection.
Asunto(s)
Infecciones por VIH/inmunología , Anticuerpos contra la Hepatitis B/inmunología , Vacunas contra Hepatitis B/administración & dosificación , Virus de la Hepatitis B/inmunología , Hepatitis B/prevención & control , Huésped Inmunocomprometido/inmunología , Personal Militar , Viremia/inmunología , Adulto , Recuento de Linfocito CD4 , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Infecciones por VIH/complicaciones , Infecciones por VIH/virología , Hepatitis B/inmunología , Hepatitis B/virología , Antígenos de Superficie de la Hepatitis B/inmunología , Vacunas contra Hepatitis B/inmunología , Humanos , Incidencia , Estimación de Kaplan-Meier , Masculino , Modelos de Riesgos Proporcionales , ARN Viral/sangre , Factores de Riesgo , Factores de Tiempo , Estados Unidos/epidemiología , Vacunación , Carga Viral , Viremia/virologíaRESUMEN
Exposure to certain environmental factors during childhood may influence the developing immune system, causing predisposing or protective effects toward development of autoimmune disorders. This study examines the hypothesis that past infection with parvovirus B19, a common childhood infection, is associated with altered levels of subclinical inflammatory activity in presumably healthy adults. Qualitative anti-parvovirus B19 IgG antibody and high-sensitivity C-reactive protein were determined in serum samples from adult blood bank donors. C-reactive protein values of B19 IgG-positive and B19 IgG-negative groups were compared. Analysis was performed on 282 blood bank donor serum samples. Among donors aged 17-49 years (n = 152), B19 IgG-positive samples (57.9%) were associated with significantly lower C-reactive protein levels compared with B19 IgG-negative samples (median C-reactive protein: 1.30 mg/l vs. 2.65 mg/l; p = 0.012 unadjusted (Mann-Whitney U-test); p = 0.014 adjusted for gender and age (logistic regression)). Among donors aged >49 years, median C-reactive protein levels were identical by B19 IgG status. The association of B19 IgG antibody with lower C-reactive protein levels in the serum of younger adults supports the hypothesis that infection in childhood may contribute long-term beneficial adaptive immune responses.
Asunto(s)
Donantes de Sangre , Proteína C-Reactiva/análisis , Inmunoglobulina G/sangre , Parvovirus B19 Humano/inmunología , Adolescente , Adulto , Factores de Edad , Anciano , Anticuerpos Antivirales/sangre , Exposición a Riesgos Ambientales , Femenino , Humanos , Higiene , Modelos Logísticos , Masculino , Persona de Mediana Edad , Infecciones por Parvoviridae/inmunología , Adulto JovenRESUMEN
Persistent infection with the Edmonston strain of measles virus (MV) has been established in IC-21 cells, an immortalized murine macrophage cell line. Persistence was established immediately without syncytia formation or cytopathic effects. MV was expressed in the majority of the cells as evidenced by immunofluorescence microscopy, flow cytometry, infectious centers assays, and limiting dilution analysis. Hemagglutinin (H) and phosphoprotein expressed in persistently infected IC-21 cells had retarded migration in SDS-PAGE gels when compared to these proteins expressed in Vero cells. H protein differences were also found between freshly infected IC-21 cells and persistently infected IC-21 cells passaged for over 2 years. Six sublines of IC-21 cells, infected at different times, have maintained these characteristics for 2 years of passage. During this time period the intensity of immunofluorescence and the number of infectious virus particles recoverable fluctuated in five of the six cell lines. In one cell line virus expression remained at a consistent high level. The ability to establish a persistent MV infection in murine macrophages allows studies using a cell important in disseminating the infection. It facilitates experiments on immunological aspects of viral immunity by enabling cell mixing experiments with histocompatible cell populations and by making available the wide array of cellular and humoral reagents in the mouse.
Asunto(s)
Macrófagos/virología , Virus del Sarampión/crecimiento & desarrollo , Animales , División Celular , Línea Celular Transformada , Chlorocebus aethiops , Citoplasma/virología , Cinética , Ratones , Células Tumorales Cultivadas , Células Vero/virología , Ensayo de Placa Viral , Proteínas Virales/biosíntesisRESUMEN
Immune regulation of measles virus (MV) expression was studied in a persistently infected mouse macrophage cell line. Synthesis of both membrane-associated and internal MV antigens was suppressed when infected macrophages were treated with polyclonal rabbit anti-MV antibody that was specific for MV proteins. Persistently infected macrophages were treated for 3, 5, or 7 days with increasing doses of anti-MV antibody. All MV proteins were down-regulated 2 days after treatment was terminated. One week after treatment was terminated, down-regulation was still evident but to a lesser degree. MV protein synthesis was suppressed whether or not complement components were inactivated by heating all serum supplements and antibodies. However, when complement was active, cell lysis accounted for some of the reduced MV protein synthesis. When lytic destruction of infected cells by antibody and complement was prevented by inactivation of complement, antibody alone reduced the cellular synthesis of viral proteins by noncytolytic mechanisms. The absence of cell death in the absence of complement was confirmed by the lack of 51Cr release from labeled cells, the lack of reduction in cell number, and the lack of a decrease in total protein synthesis when radiolabeled infected cells were treated with antibody. It is noteworthy that low doses of antibody were optimal for suppression in the longer-term experiments and did not cause lysis, even in the presence of active complement. Since infected macrophages disseminate virus in measles infection, noncytolytic regulation of these cells by antibody may supplement viral clearance by cytolytic T cells and other immune mechanisms.
Asunto(s)
Anticuerpos Antivirales/inmunología , Macrófagos/virología , Virus del Sarampión/inmunología , Animales , Línea Celular , Transformación Celular Viral , Citotoxicidad Inmunológica , Virus del Sarampión/metabolismo , Ratones , Conejos , Proteínas Virales/biosíntesisRESUMEN
Haemophilus species are rarely associated with hepatobiliary infections. We report a case of hepatic abscess caused by Haemophilus paraphrophilus and review the English-language literature for reports of infections of the liver and biliary system caused by Haemophilus species. Most patients identified had predisposing conditions. The pathogenesis of hepatobiliary infections due to Haemophilus species may involve ascending spread from the gastrointestinal tract or hematogenous seeding following oropharyngeal colonization.