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1.
Eur J Clin Microbiol Infect Dis ; 32(1): 43-9, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22903166

RESUMEN

The acquisition of specific antibodies is paramount to protect children against pneumococcal diseases, and a better understanding of how age, ethnicity and/or Streptococcus pneumoniae (Spn) nasopharyngeal carriage influence the acquisition of antibodies to pneumococcal surface proteins (PSP) is important for the development of novel serodiagnostic and immunisation strategies. IgG antibody titres against three conserved PSP (PhtD, PcpA and PrtA) in the sera of 451 healthy children aged 1 to 24 months from Israel [Jewish (50.1 %) and Bedouin (49.9 %)] were measured by enzyme-linked immunosorbent assay (ELISA), while nasopharyngeal swabs from these children were assessed for the presence of Spn. Globally, anti-PhtD and anti-PrtA geometric mean concentrations (GMC; EU/ml) were high at <2.5 months of age [PhtD: 35.3, 95 % confidence interval (CI) 30.6-40.6; PrtA: 71.2, 95 % CI 60-84.5], was lower at 5-7 months of age (PhtD: 10, 95 % CI 8-12.4; PrtA: 17.9, 95 % CI 14.4-22.1) and only increased after 11 months of age. In contrast, an increase in anti-PcpA was observed at 5-7 months of age. Anti-PcpA and anti-PrtA, but not anti-PhtD, were significantly higher in Bedouin children (PcpA: 361.6 vs. 226.3, p = 0.02; PrtA: 67.2 vs. 29.5, p < 0.001) in whom Spn nasopharyngeal carriage was identified earlier (60 % vs. 38 % of carriers <6 months of age, p = 0.002). Spn carriage was associated with significantly higher anti-PSP concentrations in carriers than in non-carriers (p < 0.001 for each PSP). Thus, age, ethnicity and, essentially, nasopharyngeal carriage exert distinct cumulative influences on infant responses to PSP. These specific characteristics are worthwhile to include in the evaluation of pneumococcal seroresponses and the development of new PSP-based vaccines.


Asunto(s)
Anticuerpos Antibacterianos/sangre , Antígenos Bacterianos/inmunología , Proteínas Bacterianas/inmunología , Proteínas Portadoras/inmunología , Portador Sano/epidemiología , Proteínas de la Membrana/inmunología , Infecciones Neumocócicas/epidemiología , Streptococcus pneumoniae/inmunología , Factores de Edad , Preescolar , Ensayo de Inmunoadsorción Enzimática , Etnicidad , Humanos , Inmunoglobulina G/sangre , Lactante , Péptidos y Proteínas de Señalización Intracelular , Israel/epidemiología , Masculino , Nasofaringe/microbiología , Red Social
2.
Am J Transplant ; 12(11): 2974-85, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22994936

RESUMEN

Varicella can have a severe course in immunosuppressed patients. Although prevention is fundamental, live-attenuated varicella-zoster (VZV) vaccine is not currently recommended in transplant recipients. Our aims were to (1) evaluate VZV immunity in pediatric liver transplant (LT) recipients; (2) immunize (two doses) seronegative patients post-LT; (3) monitor vaccine safety, (4) assess B and T cell vaccine responses. All patients followed at the Swiss National Pediatric LT Center were approached and 77/79 (97.5%) were enrolled (median age 7.8 years). Vaccine safety was monitored by standardized diary cards and phone calls. VZV-specific serology and CD4(+) T cells were assessed before and after immunization. Thirty-nine patients (51.1%) were seronegative including 14 children immunized pre-LT. Thirty-six of 39 seronegative patients were immunized post-LT (median 3.0 years post LT). Local (54.8%) and systemic (64.5%) reactions were mild and transient. The frequency of VZV-specific CD4(+) T cells and antibody titers increased significantly (respectively from 0.085% to 0.16%, p = 0.04 and 21.0 to 1134.5 IU/L, p < 0.001). All children reached seroprotective titers and 31/32 (97%) patients assessed remained seroprotected at follow-up (median 1.7 years). No breakthrough disease was reported during follow-up (median 4.1 years). Thereby, VZV vaccine appears to be safe, immunogenic and provide protection against disease in pediatric LT patients.


Asunto(s)
Anticuerpos Antivirales/inmunología , Varicela/prevención & control , Herpes Zóster/prevención & control , Huésped Inmunocomprometido/inmunología , Trasplante de Hígado/métodos , Varicela/inmunología , Vacuna contra la Varicela/administración & dosificación , Niño , Preescolar , Femenino , Estudios de Seguimiento , Rechazo de Injerto/prevención & control , Supervivencia de Injerto , Herpes Zóster/inmunología , Vacuna contra el Herpes Zóster/administración & dosificación , Humanos , Inmunización/métodos , Lactante , Trasplante de Hígado/efectos adversos , Masculino , Estudios Retrospectivos , Medición de Riesgo , Administración de la Seguridad , Inmunología del Trasplante , Resultado del Tratamiento
3.
HIV Med ; 13(4): 207-18, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22093373

RESUMEN

INTRODUCTION: We aimed to determine the antibody responses and effect on viral load of the AS03-adjuvanted pandemic H1N1 vaccine in HIV-infected patients. METHOD: A total of 121 HIV-infected patients and 138 healthy subjects were enrolled in a prospective, open-label study. Healthy subjects received one dose and HIV-infected patients two doses of the AS03-adjuvanted split influenza A/09/H1N1 vaccine (Pandemrix®; GlaxoSmithKline, Brentford, United Kingdom.) at an interval of 3-4 weeks. The study was extended in 2010/2011 for 66 patients. Geometric mean titres (GMTs), seroprotection rates (post-vaccination titre ≥ 1:40) and HIV-1 RNA levels were measured before and 4 weeks after immunization. RESULTS: After two immunizations, the seroprotection rate (94.2 vs. 87%, respectively) and GMT (376 vs. 340, respectively) in HIV-infected patients were as high as in healthy subjects after one dose, regardless of CD4 cell count. Four weeks after immunization, HIV RNA was detected in plasma samples from 40 of 68 (58.0%) previously aviraemic patients [median 152 HIV-1 RNA copies/mL; interquartile range (IQR) 87-509 copies/mL]. Subsequent measures indicated that HIV RNA levels had again declined to <20 copies/mL in most patients (27 of 34; 79.4%). Following (nonadjuvanted) influenza immunization in 2010/2011, HIV RNA levels only slightly increased (median final level 28 copies/mL) in three of 66 (4.5%) previously aviraemic patients, including two of 25 (8%) patients in whom an increase had been elicited by AS03-adjuvanted vaccine the year before. CONCLUSION: Most HIV-infected patients developed seroprotection after two doses of AS03-adjuvanted pandemic vaccine. A transient effect on HIV RNA levels was observed in previously aviraemic patients. A booster dose of the nonadjuvanted influenza vaccine containing the A/09/H1N1 strain the following year did not reproduce this finding, indicating a non-antigen-specific adjuvant effect.


Asunto(s)
Infecciones por VIH/inmunología , Vacunas contra la Influenza/inmunología , ARN Viral/sangre , Escualeno/inmunología , alfa-Tocoferol/inmunología , Adulto , Anticuerpos Antivirales/sangre , Combinación de Medicamentos , Femenino , Infecciones por VIH/virología , VIH-1/aislamiento & purificación , Pruebas de Inhibición de Hemaglutinación , Humanos , Vacunas contra la Influenza/administración & dosificación , Masculino , Persona de Mediana Edad , Polisorbatos/administración & dosificación , Estudios Prospectivos , Escualeno/administración & dosificación , Carga Viral , alfa-Tocoferol/administración & dosificación
4.
HIV Med ; 13(1): 54-61, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21722287

RESUMEN

OBJECTIVE: HIV-infected children have impaired antibody responses after exposure to certain antigens. Our aim was to determine whether HIV-infected children had lower varicella zoster virus (VZV) antibody levels compared with HIV-infected adults or healthy children and, if so, whether this was attributable to an impaired primary response, accelerated antibody loss, or failure to reactivate the memory VZV response. METHODS: In a prospective, cross-sectional and retrospective longitudinal study, we compared antibody responses, measured by enzyme-linked immunosorbent assay (ELISA), elicited by VZV infection in 97 HIV-infected children and 78 HIV-infected adults treated with antiretroviral therapy, followed over 10 years, and 97 age-matched healthy children. We also tested antibody avidity in HIV-infected and healthy children. RESULTS: Median anti-VZV immunoglobulin G (IgG) levels were lower in HIV-infected children than in adults (264 vs. 1535 IU/L; P<0.001) and levels became more frequently unprotective over time in the children [odds ratio (OR) 17.74; 95% confidence interval (CI) 4.36-72.25; P<0.001]. High HIV viral load was predictive of VZV antibody waning in HIV-infected children. Anti-VZV antibodies did not decline more rapidly in HIV-infected children than in adults. Antibody levels increased with age in healthy (P=0.004) but not in HIV-infected children. Thus, antibody levels were lower in HIV-infected than in healthy children (median 1151 IU/L; P<0.001). Antibody avidity was lower in HIV-infected than healthy children (P<0.001). A direct correlation between anti-VZV IgG level and avidity was present in HIV-infected children (P=0.001), but not in healthy children. CONCLUSION: Failure to maintain anti-VZV IgG levels in HIV-infected children results from failure to reactivate memory responses. Further studies are required to investigate long-term protection and the potential benefits of immunization.


Asunto(s)
Anticuerpos Antivirales/inmunología , Afinidad de Anticuerpos/inmunología , Infecciones por VIH/inmunología , Herpesvirus Humano 3/inmunología , Memoria Inmunológica/inmunología , Adolescente , Anticuerpos Antivirales/sangre , Niño , Preescolar , Ensayo de Inmunoadsorción Enzimática , Métodos Epidemiológicos , Femenino , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Masculino , Suiza
5.
Pediatr Transplant ; 16(1): 50-7, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22093802

RESUMEN

As children referred for OLT in Switzerland were not vaccinated optimally, new guidelines were developed and recommended to base catch-up immunization on serum antibody titers against vaccine-preventable diseases, before and after OLT. We measure the results of this serology-based intervention by comparing vaccine coverage and antibody titers in the pre- (1990-2002, P1) and post-intervention (2003-2008, P2) cohorts in a quality control project. Forty-four P1 and 30 P2 children were evaluated. At pre-OLT visit, D, T, SPn, and MMR serologies were checked more frequently in P2 than P1 (p < 0.05). More P2 children were up-to-date for DTaP and MMR (p < 0.05) or had received ≥1 dose of HBV, HAV, SPn, and VZV vaccines (p < 0.05). One yr post-OLT, DT, SPn, MMR, and VZV serologies were more frequently checked (p < 0.05), and antibody titers were higher for DT and HAV (p < 0.05) in P2. Gender, age, or diagnosis did not explain these differences. Among P2 patients, pre- and post-OLT titers for D, T, Hib, HBV, SPn14, and SPn19 were correlated (p < 0.05 for all). Protection against vaccine-preventable diseases of high-risk children like OLT patients can be significantly improved by serology-based intervention for vaccine-preventable diseases.


Asunto(s)
Esquemas de Inmunización , Fallo Hepático/complicaciones , Trasplante de Hígado/métodos , Vacunas/uso terapéutico , Virosis/prevención & control , Niño , Preescolar , Estudios de Cohortes , Control de Enfermedades Transmisibles , Femenino , Humanos , Lactante , Fallo Hepático/sangre , Fallo Hepático/virología , Masculino , Control de Calidad , Sistema de Registros , Serología/métodos , Suiza , Resultado del Tratamiento , Vacunación/métodos , Virosis/complicaciones
6.
Rev Epidemiol Sante Publique ; 60(6): 447-53, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23141298

RESUMEN

BACKGROUND: The recommendation for seasonal flu immunization from the second trimester of pregnancy, adopted in summer 2010 in Switzerland, is situated within a social context characterized by reluctance toward some vaccinations, a relatively low vaccination coverage against flu in the general population, and still heated debates fuelled by vaccination campaigns organized around the A(H1N1)pdm09 flu pandemic in winter 2009 to 2010. This study examines Swiss pregnant women's representations of the risks associated with seasonal flu and its vaccination. METHODS: Semi-structured interviews were conducted with 29 women, while in the maternity unit in March 2011, 3 to 5 days after giving birth. The interviews addressed the risks associated with flu, modes of protection, motivations for, and obstacles to vaccination. RESULTS: The interviewees did not show major preoccupations regarding seasonal flu and they tended to distance themselves from the at-risk status. They did not directly challenge seasonal flu immunization; however, they were reluctant to do it. Their attitudes were supported by their personal experience and the experience of their social networks. Healthcare professionals, particularly medical doctors, gave very little direction, or even did not raise the issue with them. CONCLUSIONS: Between the rather moderate positions of those who are against vaccination and those who support it, an intermediate grey zone, characterized by hesitation, was observed. Furthermore, the indecision of pregnant women is reinforced by doubts among the persons they are close to and also among the professionals they met during their pregnancy.


Asunto(s)
Conductas Relacionadas con la Salud , Vacunas contra la Influenza/administración & dosificación , Gripe Humana/prevención & control , Complicaciones Infecciosas del Embarazo/prevención & control , Adulto , Femenino , Personal de Salud , Humanos , Gripe Humana/epidemiología , Gripe Humana/inmunología , Embarazo , Complicaciones Infecciosas del Embarazo/epidemiología , Riesgo , Suiza , Adulto Joven
7.
Rev Med Suisse ; 8(324): 125-8, 2012 Jan 18.
Artículo en Francés | MEDLINE | ID: mdl-23185823

RESUMEN

Pertussis remains frequent in Switzerland (4000 yearly cases), where 80% of infants are infected by their family. To better protect parents and infants, a diphtheria-tetanus-pertussis (dTpa) booster is thus recommended at 25 years (catch-up 26-29 years), and to adults of any age in personal or professional contacts with infants < or = 6 months. In contrast, diphtheria-tetanus boosters may be spaced every 20 years (dTpa at 25, dT at 45 and 65 years), avoiding useless immunizations. A 10-year interval remains recommended after the age of 65. The Swiss immunization plan thus adapts to recent evidence, to the risk of pushing the habits! Fortunately, a Swiss electronic immunization record allowing a vaccine check (www.myvaccines.ch) is now available for free to both the public and the professio-


Asunto(s)
Vacuna contra Difteria, Tétanos y Tos Ferina/administración & dosificación , Difteria/prevención & control , Inmunización Secundaria , Tétanos/prevención & control , Tos Ferina/prevención & control , Adulto , Anciano , Difteria/epidemiología , Difteria/inmunología , Medicina Basada en la Evidencia , Humanos , Esquemas de Inmunización , Inmunización Secundaria/métodos , Inmunización Secundaria/normas , Guías de Práctica Clínica como Asunto , Suiza/epidemiología , Tétanos/epidemiología , Tétanos/inmunología , Toxoide Tetánico/administración & dosificación , Tos Ferina/epidemiología , Tos Ferina/inmunología
8.
Am J Transplant ; 11(8): 1727-33, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21672157

RESUMEN

In solid organ transplanted patients, annual influenza immunization is strongly recommended because of morbidity and mortality of influenza infections. In 2009, the rapid spread of a novel H1N1 influenza A virus led to the accelerated development of novel pandemic influenza vaccines. In Switzerland, the recipients received one dose of seasonal influenza and two doses of AS03-adjuvanted H1N1 vaccines. This situation provided a unique opportunity to analyze the influence of novel adjuvanted influenza vaccines on the production of de novo anti-HLA antibodies. We prospectively followed two independent cohorts including 92 and 59 kidney-transplanted patients, assessing their anti-HLA antibodies before, 6 weeks and 6 months after vaccination. Sixteen of 92 (17.3%) and 7 of 59 (11.9%) patients developed anti-HLA antibodies. These antibodies, detected using the single antigen beads technology, were mostly at low levels and included both donor-specific and non-donor-specific antibodies. In 2 of the 20 patients who were followed at 6 months, clinical events possibly related to de novo anti-HLA antibodies were observed. In conclusion, multiple doses of influenza vaccine may lead to the production of anti-HLA antibodies in a significant proportion of kidney transplant recipients. The long-term clinical significance of these results remains to be addressed.


Asunto(s)
Autoanticuerpos/inmunología , Antígenos HLA/inmunología , Subtipo H1N1 del Virus de la Influenza A/inmunología , Vacunas contra la Influenza/administración & dosificación , Trasplante de Riñón , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Femenino , Humanos , Vacunas contra la Influenza/inmunología , Masculino , Persona de Mediana Edad , Estaciones del Año
9.
Vaccine ; 39(26): 3459-3466, 2021 06 11.
Artículo en Inglés | MEDLINE | ID: mdl-34023135

RESUMEN

BACKGROUND: Solid organ transplantation (SOT) candidates and recipients are highly vulnerable to invasive pneumococcal diseases (IPD). Data on which to base optimal immunization recommendations for this population is scant. The national distribution of IPD serotypes led the Swiss Health Authorities to recommend in 2014 one dose of pneumococcal-13-valent-conjugate-vaccine (PCV13), without any subsequent dose of the 23-valent-polysaccharide-pneumococcal-vaccine (PPV23). METHODS: This is a retrospective analysis of pneumococcal immunity using a multiplex binding assay, to assess seroprotection rates against a selection of seven PCV13- and seven PPV23-serotypes in SOT-candidates and recipients evaluated and/or transplanted in 2014/2015 in the University Hospitals of Geneva. Seroprotection was defined as serotype-specific antibody concentration greater than 0.5 mg/l and overall seroprotection when this was achieved for ≥ 6/7 serotypes. RESULTS: Pre-vaccination and at time of transplant sera were available for 35/43 (81%), and 43/43 (100%) SOT-candidates respectively. At listing, 17/35 (49%) SOT-candidates were seroprotected against PCV13 and 21/35 (60%) against PPV23 serotypes. Following one systematic dose of PCV13 at listing, 35/43 (81%) SOT-recipients were seroprotected at day of transplant against PCV13-serotypes and 34/43 (79%) against PPV23 serotypes, compared to 21/41 (51%) and 28/41 (68%) respectively in the controls transplanted in 2013, before the systematic PCV13-vaccination. CONCLUSIONS: The systematic vaccination with PCV13 of all SOT candidates without additional PPV23 is a good strategy as it confers seroprotection against a wide range of pneumococcal serotypes. Indeed, one of five PCV13-vaccinated SOT-candidates was nevertheless not seroprotected at time of transplant, reflecting their partial immune competence, and indicating the need for additional dose of pneumococcal vaccines before transplant.


Asunto(s)
Trasplante de Órganos , Infecciones Neumocócicas , Humanos , Infecciones Neumocócicas/prevención & control , Vacunas Neumococicas , Estudios Retrospectivos , Streptococcus pneumoniae , Vacunas Conjugadas
10.
Clin Microbiol Infect ; 27(6): 878-885, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32896653

RESUMEN

OBJECTIVES: Protection induced by acellular vaccines can be short, requiring novel immunization strategies. Objectives of this study were to evaluate safety and capacity of a recombinant pertussis toxin (PTgen) -coated Viaskin® epicutaneous patch to recall memory responses in healthy adults. METHODS: This double-blind, placebo-controlled randomized trial (Phase I) assessed the safety and immunogenicity of PTgen administered on days 0 and 14 to healthy adults using Viaskin® patches applied directly or after epidermal laser-based skin preparation. Patch administration was followed by Boostrix®dTpa on day 42. Antibodies were assessed at days 0, 14, 28, 42 and 70. RESULTS: Among 102 volunteers enrolled, 80 received Viaskin-PT (Viaskin-PT 25 µg (n = 25), Viaskin-PT 50 µg (n = 25), laser + Viaskin-PT 25 µg (n = 5), laser + Viaskin-PT 50 µg (n = 25)), Viaskin-placebo (n = 10) or laser + Viaskin-placebo (n = 2). Incidence of adverse events was similar across groups (any local event: 21/25 (84.0%), 24/25 (96.0%), 4/5 (80.0%), 24/25 (96.0%), 8/10 (80.0%), 10/12 (83.0%), respectively). Direct application induced no detectable response. On day 42, PT-IgG geometric mean concentrations were significantly higher following laser + Viaskin-PT 25 µg and 50 µg (139.87 (95% CI 87.30-224.10) and 121.76 (95% CI 95.04-156.00), respectively), than laser + Viaskin-placebo (59.49, 95% CI 39.37-89.90). Seroresponse rates were higher following laser + Viaskin-PT 25 µg (4/5 (80.0%), 95% CI 28.4-99.5) and 50 µg (22/25 (88.0%), 95% CI 68.8-97.5) than laser + Viaskin-placebo (0/12 (0.0%), 95% CI 0.0-26.5). CONCLUSIONS: Viaskin-PT applied after laser-based epidermal skin preparation showed encouraging safety and immunogenicity results: anti-PT booster responses were not inferior to those elicited by Boostrix®dTpa. This study is registered at ClinicalTrials.gov (NCT03035370) and was funded by DBV Technologies.


Asunto(s)
Toxina del Pertussis/inmunología , Administración Cutánea , Adolescente , Adulto , Anticuerpos Antibacterianos/sangre , Anticuerpos Antibacterianos/inmunología , Método Doble Ciego , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Masculino , Toxina del Pertussis/administración & dosificación , Adulto Joven
11.
J Exp Med ; 182(6): 1793-9, 1995 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-7500024

RESUMEN

Presentation of exogenous protein antigens to T lymphocytes is based on the intersection of two complex pathways: (a) synthesis, assembly, and transport of major histocompatibility complex (MHC) class II-invariant chain complexes from the endoplasmic reticulum to a specialized endosomal compartment, and (b) endocytosis, denaturation, and proteolysis of antigens followed by loading of antigenic peptides onto newly synthesized MHC class II molecules. It is believed that expression of MHC class II heterodimers, invariant chain and human leukocyte antigen-DM is both necessary and sufficient to reconstitute a functional MHC class II loading compartment in antigen-presenting cells. Expression of each of these essential molecules is under the control of the MHC class II transactivator CIITA. Unexpectedly, however, whereas interferon gamma stimulation does confer effective antigen-processing function to nonprofessional antigen presenting cells, such as melanoma cells, expression of the CIITA transactivator alone is not sufficient. Activation of antigen-specific T cells thus requires additional CIITA-independent factor(s), and such factor(s) can be induced by interferon gamma.


Asunto(s)
Células Presentadoras de Antígenos/inmunología , Antígenos HLA-D/fisiología , Interferón gamma/fisiología , Proteínas Nucleares , Proteínas/inmunología , Transactivadores/fisiología , Antígenos de Diferenciación de Linfocitos B/fisiología , Células Cultivadas , Genes MHC Clase II , Antígenos HLA-D/química , Antígenos HLA-D/genética , Antígenos de Histocompatibilidad Clase II/fisiología , Humanos , Melanoma , Conformación Proteica , Toxina Tetánica/inmunología , Transfección
12.
Clin Microbiol Infect ; 26(10): 1386-1394, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32603801

RESUMEN

OBJECTIVES: To validate the diagnostic accuracy of a Euroimmun SARS-CoV-2 IgG and IgA immunoassay for COVID-19. METHODS: In this unmatched (1:2) case-control validation study, we used sera of 181 laboratory-confirmed SARS-CoV-2 cases and 326 controls collected before SARS-CoV-2 emergence. Diagnostic accuracy of the immunoassay was assessed against a whole spike protein-based recombinant immunofluorescence assay (rIFA) by receiver operating characteristic (ROC) analyses. Discrepant cases between ELISA and rIFA were further tested by pseudo-neutralization assay. RESULTS: COVID-19 patients were more likely to be male and older than controls, and 50.3% were hospitalized. ROC curve analyses indicated that IgG and IgA had high diagnostic accuracies with AUCs of 0.990 (95% Confidence Interval [95%CI]: 0.983-0.996) and 0.978 (95%CI: 0.967-0.989), respectively. IgG assays outperformed IgA assays (p=0.01). Taking an assessed 15% inter-assay imprecision into account, an optimized IgG ratio cut-off > 2.5 displayed a 100% specificity (95%CI: 99-100) and a 100% positive predictive value (95%CI: 96-100). A 0.8 cut-off displayed a 94% sensitivity (95%CI: 88-97) and a 97% negative predictive value (95%CI: 95-99). Substituting the upper threshold for the manufacturer's, improved assay performance, leaving 8.9% of IgG ratios indeterminate between 0.8-2.5. CONCLUSIONS: The Euroimmun assay displays a nearly optimal diagnostic accuracy using IgG against SARS-CoV-2 in patient samples, with no obvious gains from IgA serology. The optimized cut-offs are fit for rule-in and rule-out purposes, allowing determination of whether individuals in our study population have been exposed to SARS-CoV-2 or not. IgG serology should however not be considered as a surrogate of protection at this stage.


Asunto(s)
Anticuerpos Antivirales/sangre , Betacoronavirus/inmunología , Técnicas de Laboratorio Clínico/métodos , Infecciones por Coronavirus/diagnóstico , Inmunoensayo/normas , Inmunoglobulina A/sangre , Inmunoglobulina G/sangre , Neumonía Viral/diagnóstico , Adulto , Área Bajo la Curva , COVID-19 , Prueba de COVID-19 , Estudios de Casos y Controles , Niño , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/fisiopatología , Infecciones por Coronavirus/virología , Femenino , Humanos , Sueros Inmunes/química , Masculino , Pandemias , Neumonía Viral/inmunología , Neumonía Viral/fisiopatología , Neumonía Viral/virología , Curva ROC , SARS-CoV-2 , Sensibilidad y Especificidad , Índice de Severidad de la Enfermedad
13.
Science ; 265(5168): 106-9, 1994 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-8016643

RESUMEN

Major histocompatibility complex (MHC) class II genes are expressed constitutively in only a few cell types, but they can be induced in the majority of them, in particular by interferon-gamma (IFN-gamma). The MHC class II transactivator gene CIITA is defective in a form of primary MHC class II deficiency. Here it is shown that CIITA expression is controlled and induced by IFN-gamma. A functional CIITA gene is necessary for class II induction, and transfection of CIITA is sufficient to activate expression of MHC class II genes in class II-negative cells in the absence of IFN-gamma. CIITA is therefore a general regulator of both inducible and constitutive MHC class II expression.


Asunto(s)
Regulación de la Expresión Génica , Genes MHC Clase II , Antígenos de Histocompatibilidad Clase II/genética , Interferón gamma/farmacología , Proteínas Nucleares , Transactivadores/genética , Línea Celular , Mapeo Cromosómico , Cromosomas Humanos Par 16 , Fibroblastos , Antígenos de Histocompatibilidad Clase II/biosíntesis , Humanos , Modelos Genéticos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Transactivadores/biosíntesis , Transfección , Células Tumorales Cultivadas
14.
Rev Med Suisse ; 5(191): 416-9, 2009 Feb 18.
Artículo en Francés | MEDLINE | ID: mdl-19331098

RESUMEN

Similarly to other medications, vaccines may be responsible of allergic reactions. However, IgE-mediated allergies are extremely rare. The diagnosis of allergies to a vaccine is complex and these allergies are often over-diagnosis due to fear of severe anaphylaxis. Indeed, most of the patients labelled as allergic to a vaccine may tolerate a subsequent injection of the vaccine without clinical reaction. The economic impact and the impact on health, both from an individual point of view but also in terms of public health, are very important. Before this diagnosis can accurately be made, a complete work up is essential. If an allergy workup is necessary, it will be primarily based on skin tests.


Asunto(s)
Hipersensibilidad/diagnóstico , Hipersensibilidad/etiología , Vacunas/efectos adversos , Humanos , Vacunación/efectos adversos
15.
Rev Med Suisse ; 4(139): 72-5, 2008 Jan 09.
Artículo en Francés | MEDLINE | ID: mdl-18251220

RESUMEN

Immunization against HPV is now both recommended and reimbursed within the base medical insurance. The epidemiological data and the behavior of adolescents indicate that HPV immunization should be completed by the 15th birthday, catch-up being transiently recommended until the 20th birthday. The immunization against chickenpox of healthy children < 11 years remains non recommended, 2 vaccine doses being however recommended for high-risks children and adults. Hepatitis A vaccination is finally also reimbursed for high-risk patients - except for travelers. Finally, the WHO certified www.infovac.ch website now displays in French and German all information related to vaccine-preventable diseases and immunizations recommended in Switzerland, for both the professionals and the public. A source of information to be recommended without hesitation!


Asunto(s)
Vacunación , Adolescente , Varicela/prevención & control , Vacuna contra la Varicela , Niño , Femenino , Humanos , Infecciones por Papillomavirus , Vacunas contra Papillomavirus , Suiza , Neoplasias del Cuello Uterino/prevención & control , Neoplasias del Cuello Uterino/virología
16.
Rev Med Suisse ; 4(152): 920-4, 2008 Apr 09.
Artículo en Francés | MEDLINE | ID: mdl-18578433

RESUMEN

Measles is a highly contagious disease characterized by respiratory symptoms, rash and fever. Complications are common. Despite national recommendations concerning the need to vaccinate children with 2 doses of MMR vaccine (at age 12 months and between 15 and 24 months), epidemic outbursts still happen. The treatment of infected children is purely supportive, whereas susceptible household contacts may benefit from IVIG or catch up with vaccination depending on their age and the time spent since the contact. This paper defines a practical approach for measles infected cases and contact patients.


Asunto(s)
Vacuna contra el Sarampión-Parotiditis-Rubéola/uso terapéutico , Sarampión , Brotes de Enfermedades/prevención & control , Humanos , Inmunoglobulinas Intravenosas/uso terapéutico , Sarampión/diagnóstico , Sarampión/epidemiología , Sarampión/prevención & control , Sarampión/terapia
17.
Mol Cell Biol ; 13(10): 6375-84, 1993 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8413236

RESUMEN

Hepatitis B virus gene expression is to a large extent under the control of enhancer I (EnhI). The activity of EnhI is strictly dependent on the enhancer factor C (EF-C) site, an inverted repeat that is bound by a ubiquitous nuclear protein known as EF-C. Here we report the unexpected finding that EF-C is in fact identical to RFX1, a novel transcription factor previously cloned by virtue of its affinity for the HLA class II X-box promoter element. This finding has allowed us to provide direct evidence that RFX1 (EF-C) is crucial for EnhI function in HepG2 hepatoma cells; RFX1-specific antisense oligonucleotides appear to inhibit EnhI-driven expression of the hepatitis B virus major surface antigen gene, and in transfection assays, RFX1 behaves as a potent transactivator of EnhI. Interestingly, transactivation of EnhI by RFX1 (EF-C) is not observed in cell lines that are not of liver origin, suggesting that the ubiquitous RFX1 protein cooperates with liver-specific factors.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Elementos de Facilitación Genéticos , Virus de la Hepatitis B/genética , Transactivadores/metabolismo , Factores de Transcripción/metabolismo , Animales , Secuencia de Bases , Sitios de Unión , ADN Viral , Proteínas de Unión al ADN/genética , Humanos , Hígado/metabolismo , Ratones , Datos de Secuencia Molecular , Oligonucleótidos Antisentido/farmacología , Especificidad de Órganos/genética , Factores de Transcripción del Factor Regulador X , Factor Regulador X1 , Secuencias Repetitivas de Ácidos Nucleicos , Transactivadores/genética , Factores de Transcripción/genética , Proteínas del Envoltorio Viral/metabolismo
18.
J Comp Pathol ; 137 Suppl 1: S4-9, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17559867

RESUMEN

One of the major challenges in vaccinology is the development of products that are able to induce protective immunity in the early life period. There are clear differences between adult and neonatal immune responses in both mice and humans with respect to both humoral and cell-mediated immunity. As a rule, neonates respond poorly to T-independent polysaccharide antigens and make lower and less persistent antibody responses to T-dependent protein antigens. Nevertheless, B-cell priming in neonates may lead to the generation of memory B cells. Similarly, neonatal cell-mediated immune responses are of lower potency than those generated in adults, and a key factor underlying this phenomenon may be a less effective interaction between antigen and neonatal dendritic cells. In addition to immunological immaturity in the neonate, the presence of inhibitory concentrations of maternally derived antibody imposes a further barrier to effective early life vaccination. Novel vaccination strategies including early priming and subsequent boosting are most likely to counteract these effects and provide protection from exposure to infectious disease in early life.


Asunto(s)
Animales Recién Nacidos/inmunología , Recién Nacido/inmunología , Vacunación , Animales , Formación de Anticuerpos/fisiología , Linfocitos B/inmunología , Humanos , Sistema Inmunológico/crecimiento & desarrollo , Sistema Inmunológico/fisiología , Inmunidad Materno-Adquirida/inmunología , Ratones , Linfocitos T/inmunología
19.
J Comp Pathol ; 137 Suppl 1: S46-50, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17559869

RESUMEN

A broad spectrum of adverse events is reported following human vaccination but such reactions are considered to be relatively rare. A variety of mechanisms has been proposed to account for such adverse events. These most commonly relate to the actual process of vaccination and range from the vagal reaction associated with anxiety about needle injection, to use of an inappropriate site of administration, or infection of the healthcare worker by accidental injection during needle-capping. Other adverse events directly associated with the vaccine include reversion to virulence of attenuated vaccine strains of organisms, or contamination of the vaccine product. Adverse events may involve immune-mediated phenomena triggered by exposure to the microbial or other components of vaccines. These include: classical IgE-mediated type I hypersensitivity reactions, and immune-complex type III hypersensitivity (Arthus) reactions. Such reactions may be localized or systemic in nature. A variety of autoimmune reactions has been suggested to be triggered by vaccination, but in general the evidence for such associations remains largely anecdotal. Finally, many reported adverse events are simply chance instances of infection or disease onset around the time of vaccination and are not causally associated with administration of vaccine.


Asunto(s)
Vacunación/efectos adversos , Vacunas/efectos adversos , Formación de Anticuerpos/inmunología , Formación de Anticuerpos/fisiología , Autoinmunidad/inmunología , Preescolar , Contaminación de Medicamentos , Humanos , Hipersensibilidad/inmunología , Lactante , Recién Nacido , Infecciones , Inyecciones/efectos adversos , Vacunación/métodos , Vacunas/administración & dosificación , Vacunas/inmunología
20.
Rev Med Suisse ; 3(93): 63-7, 2007 Jan 10.
Artículo en Francés | MEDLINE | ID: mdl-17354664

RESUMEN

The essential modifications of practices to be applied in 2007 concern the immunization of young children and adolescents against pneumococcus and group C meningococcus, the vaccine catch-up of young adults (including future mothers) and the protection of those likely to be exposed to tick-borne encephalitis. New fact-sheets on immunizations, duly validated, have been introduced to guarantee patients' right to information and support physicians in their daily activities. Recommendations about new vaccines, such as against cervical cancer, will be communicated in real time to all the physicians registered at InfoVac.


Asunto(s)
Programas de Inmunización , Vacunación , Vacunas , Adolescente , Adulto , Niño , Humanos , Suiza
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