Segurança, imunogenicidade e eficácia protetora de duas doses da vacina RIX4414 contendo rotavírus atenuado de origem humana

OBJETIVO: Determinar a segurança, imunogenicidade e eficácia de duas doses da vacina contra o rotavírus em lactentes brasileiros saudáveis. MÉTODOS: Foi realizado um estudo randomizado, multicêntrico, duplo-cego e controlado por placebo no Brasil, México e Venezuela. Os lactentes receberam duas doses orais de vacina ou placebo aos 2 e 4 meses de idade, juntamente com as imunizações de rotina, exceto a vacina oral contra poliomielite (VOP). O presente estudo relata apenas os resultados obtidos em Belém, Brasil, onde o número de indivíduos por grupo e os títulos da vacina viral foram os seguintes: 194 (10^4,7 unidades formadoras de focos - UFF), 196 (10^5,2 UFF), 194 (10^5,8UFF) e 194 (placebo). A resposta de anticorpos anti-rotavírus (anti-RV) foi avaliada em 307 indivíduos. A gravidade clínica dos episódios de gastroenterite (GE) foi determinada através de um escore com 20 pontos, onde um valor ≥ 11 foi considerado como GE grave. RESULTADOS: As taxas de sintomas gerais solicitados foram semelhantes tanto nos indivíduos que receberam a vacina como naqueles a quem se administrou placebo. Aos 2 meses após a segunda dose, ocorreu resposta em termos de IgA sérica para RV em 54,7 a 74,4% dos vacinados. Não houve interferência na imunogenicidade das vacinas de rotina. A eficácia da vacina contra qualquer gastroenterite por rotavírus (GERV) foi de 63,5% (IC95% 20,8-84,4) para a maior concentração (10^5,8 UFF). A eficácia foi de 81,5% (IC95% 44,5-95,4) contra GERV grave. Em sua maior concentração (10^5,8 UFF), a RIX4414 conferiu uma proteção de 79,8% (IC95% 26,4-96,3) contra GERV grave causada pela amostra G9. CONCLUSÕES: A RIX4414 foi altamente imunogênica com baixa reatogenicidade, e não interferiu na resposta sérica à difteria, tétano, coqueluche, hepatite B e antígenos Hib. Duas doses da RIX4414 conferiram proteção significativa contra a GE grave causada pelo RV.

Análise da prevalência e de fatores de risco para as hepatites virais crônicas B e C em idosos residentes no município de Botucatu-SP

Pós-graduação em Fisiopatologia em Clínica Médica - FMB

Perfil de mutações de resistência e polimorfismos genéticos em variantes do vírus da hepatite B circulantes na região de Botucatu

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

Um Modelo Espacial para a Resposta Imunológica Adaptativa da Hepatite B

This paper proposed a two-dimensional spatial model to describe the adaptive immune response for viral hepatitis B. This model considered six populations: healthy hepatocytes T, infected hepatocytes Y , hepatitis B virus V , innate immune system I, active immune system X and memory cells, X. First, a compartmental model was constructed and its equilibrium solutions and also the threshold values related to the stability of each solution were obtained. Using this model, we was able to reproduce the different trends observed for the disease, which are: individuals that eliminate the infection without forming immune response, patients with acute and chronic carriers. By including dispersion of defense cells of the immune system and virus (spatial model), we analyze two situations: homogeneous model, in which the model parameters are the same at all points of the network, and heterogeneous model, which characterizes cells more permeable and less permeable to virus invasion. For the two spatial models (homogeneous and heterogeneous) the times relatead to the viral erradication and/or virus invasion and persistence becoming smaller in relation to the compartmental model. The results also showed that for the set of values used in the simulations and if the two diffusion rates are different from zero, the model is sensitive to variations in the rate of viral spread and not dependent on the dispersion of memory cells. Finally, the heterogeneous model when compared to the homogeneous model shows that the infection can be spatially limited depending on the type of the cell involved in the infection process

Interleukin-18 and interferon-gamma polymorphisms are implicated on proviral load and susceptibility to human T-lymphotropic virus type 1 infection

Interleukin-18 (IL-18) and interferon-gamma (IFN-?) exert important functions in both innate and adaptive immune responses against intracellular pathogens and viruses. Previous studies suggested that host genetic factors, including cytokines gene polymorphisms, could be involved in the pathogenesis of human T-cell leukemia virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Thus, we analyzed -137C/G and -607A/C of the IL-18 promoter and +874T/A of the IFN-? in DNA samples from 98 HTLV-1-infected individuals exhibiting or not clinical symptoms and 150 healthy control individuals. The IL-18 promoter -607CC genotype was significantly lower in HTLV-1 asymptomatic carriers (HAC) and HTLV-1-infected individuals (HAC + HAM/TSP) than healthy control group. In contrast, the -607AC genotype was significantly higher in HAC and HTLV-1-infected individuals group compared to the healthy control group. The -137G/-607A IL-18 haplotype was higher in infected group than healthy control group, and the -137C/-607C IL-18 haplotype was increased in the healthy control group compared to the others. Finally, the IFN-? polymorphism analysis showed that the HTLV-1-infected individuals with +874AT genotype presented higher proviral load than +874AA genotype. These data indicate that the IL-18-607AC genotype and -137G/-607A haplotype could be a risk factor for HTLV-1 infection, whereas the protective effect could be conferred by -607CC genotype and -137C/-607C haplotype. Also, the IFN-? could be implicated on the proviral load levels.

Imunogenicidade da vacina brasileira contra hepatite B em adultos.

OBJETIVO: Avaliar a imunogenicidade e segurança da vacina contra hepatite B, após o aumento na concentração do antígeno HBsAg para 25 μg, em comparação à vacina de referência. MÉTODOS: Ensaio com alocação aleatória e mascaramento simples, comparando a VrHB-IB (Instituto Butantan) com a vacina de referência (Engerix B®, Glaxo Smith Kline). Os voluntários, entre 31 e 40 anos de idade (n=419), foram alocados aleatoriamente ao grupo experimental (n=216) ou ao grupo controle (n=203), e receberam três doses de vacina. A primeira dose foi administrada no momento do recrutamento, a segunda e terceira 30 e 180 dias depois respectivamente, entre 2004 e 2005. Amostras de sangue foram colhidas para análise sorológica antes da randomização, e após a segunda e terceira doses. Foi realizada a vigilância ativa de eventos adversos durante os cinco primeiros dias após a vacinação. As diferenças foram avaliadas pelos testes do qui-quadrado e exato de Fisher, com nível de significância de 5%. RESULTADOS: Não se observaram eventos adversos graves. A soroporteção foi confirmada em 98,6% (213/216) dos voluntários do grupo experimental, em comparação a 95,6% (194/203) do grupo controle. Os títulos geométricos médios foram de 12.557 e 11.673, respectivamente. CONCLUSÕES: A vacina brasileira foi considerada equivalente à vacina de referência e seu uso recomendado para adultos.

Eficácia e segurança da vacina brasileira contra hepatite B em recém-nascidos

OBJETIVO: Analisar a efi cácia e segurança de vacina recombinante contra hepatite B em recém-nascidos. MÉTODOS: O estudo foi conduzido em hospital geral do município de Guarulhos, SP, entre 2002 e 2005. A vacina recombinante contra hepatite B do Instituto Butantan (VrHB-IB) foi analisada em dois ensaios clínicos. Em ambos os ensaios, os recém-nascidos foram alocados aleatoriamente ao grupo experimental ou controle (vacina de referência). Os recém-nascidos receberam três doses das vacinas, uma em até 24 h após o nascimento e as subseqüentes 30 e 180 dias após. No primeiro ensaio 538 recém-nascidos completaram o protocolo e no segundo ensaio, 486. Considerou-se critério de equivalência a diferença na soroproteção inferior a 5%. RESULTADOS: A soroproteção no primeiro ensaio (anti HBs ≥ 10mUI/ml) foi de 92,5% (247/267) no grupo experimental, comparada a 98,5% (267/271) no grupo controle (p = 0,001). Com este resultado, a VrHB-IB não atingiu o critério de equivalência estabelecido. Após o aumento da concentração de antígeno na vacina para 25μg, a soroproteção no segundo ensaio foi de 100% no grupo experimental e 99,2% no grupo controle. Nenhum evento adverso grave foi registrado. CONCLUSÕES: A vacina VrHB-IB modifi cada foi considerada equivalente à vacina de referência e seu uso recomendado à vacinação de recém-nascidos.

Mechanismen der Aktivierung und Detoxifizierung von Aflatoxin B 1 in verschiedenen Leberzelltypen von Ratten, Mäusen und Waldmurmeltieren

Zusammenfassung: Die Applikation des Mykotoxins Aflatoxin B1 (AFB1) führt in der Ratte zu Lebertumoren hepatozellulären Ursprungs, während bisher keine transformierende Wirkung dieses Mykotoxins auf Kupffer- und Endothelzellen (Nichtparenchymzellen, NPC) nachgewiesen werden konnte. Diese Resistenzmechanismen der NPC gegenüber AFB1 wurden im ersten Teil dieser Arbeit untersucht. AFB1 ist per se inaktiv, wird jedoch durch Verstoffwechselung in den chemisch reaktiven, an DNA bindenden Metaboliten AFB1-8,9-Epoxid überführt. Daneben stellt die enzymatische Hydroxylierung von AFB1 am Kohlenstoff-9a zum Aflatoxin M1 eine Detoxifizierung dar. Durch HPLC-Analyse der AFB1-Metabolite konnte gezeigt werden, daß in Nichtparenchymzellen (NPC) das Verhältnis von 9a-Hydroxylierung zu 8,9-Epoxidierung höher als in Parenchymzellen (PC) ist. Die AFB1-9a-hydroxylase fördert insbesondere in den NPC der Leber die Bildung des weniger gentoxischen Metaboliten AFM1 und konkurriert daher um die Aktivierung von AFB1 zum mutagenen und kanzerogenen 8,9-Epoxid. Dieser metabolische Unterschied scheint also einen Beitrag zur Resistenz der NPC der Leber gegenüber der hepatokanzerogenen Wirkung von AFB1 zu leisten. Da ein Synergismus zwischen der AFB1-Exposition und einer Infektion mit dem Hepatitis B-Virus (HBV) beim Menschen bezüglich des Auftretens von hepatozellulären Karzinomen zu bestehen scheint, wurde im zweiten Teil dieser Arbeit untersucht, ob die metabolische Aktivierung von AFB1 durch eine HBV-Infektion verstärkt wird. In einem Vergleich der Biotransformation von AFB1 mit mikrosomalen Leberfraktionen von transgenen HBV-Mäusen und Kontrollmäusen wurde keine signifikanten Unterschiede festgestellt. Dagegen wurde bei Virus-infizierten Waldmurmeltieren eine deutlich reduzierte Bildung des AFB1-8,9-Epoxids beobachtet. Es konnte z.T. ein Zusammenhang zwischen den verschiedenen Stadien der Leberschädigung und den Metabolismusraten festgestellt werden, wobei die metabolische Aktivierung mit zunehmender Leberschädigung abzunehmen scheint. Auch hinsichtlich der Aktivitäten verschiedener Cytochrom P450 abhängiger Monooxygenasen wurde eine weitgehende Übereinstimmung mit den durch HPLC ermittelten Metabolitenprofilen des AFB1 beobachtet. Diese Studien mit subzellulären Leberfraktion der transgenen HBV-Mäusen und der Waldmurmeltieren zeigen, daß die Interaktion zwischen Hepatitis und AFB1 nicht mit der verstärkten metabolischer Aktivierung von AFB1 zu erklären ist. TGF-ß1, aus der Gruppe der Cytokine, wird als Mediator bei Entzündungsprozessen in der Leber so z.B. im Verlauf einer Virushepatitis freigesetzt. Aufgrund der besonderen Bedeutung des murinen CYP2A5 (ortholog zum humanen CYP2A6) bei der Aktivierung von AFB1 wurde der Einfluß von TGF-ß1 auf CYP2A5 in Primärkulturen von Maushepatozyten untersucht. Durch Messung der Aktivität der Cumarin-7-hydroxylase sowie durch Bestimmung der Proteinmenge von CYP2A5 mittels Western Blotting konnte zunächst die Induzierbarkeit des CYP2A5-Isoenzyms durch Phenobarbital in kultivierten Hepatozyten der Maus gezeigt werden. Nur bei einer niedrigen TGF-ß1-Konzentration wurde eine leicht erhöhte Expression von CYP2A5 festgestellt, ansonsten führte die Behandlung der kultivierten Maushepatozyten mit TGF-ß1 zu einer dosisabhängigen Verminderung der Expression von CYP2A5.

Risposta Immunitaria Epatite B specifica in pazienti affetti da Epatocarcinoma

Hepatitis B x protein (HBx) is a non structural, multifunctional protein of hepatitis B virus (HBV) that modulates a variety of host processes.Due to its transcriptional activity,able to alter the expression of growth-control genes,it has been implicated in hepatocarcinogenesis.Increased expression of HBx has been reported on the liver tissue samples of hepatocellular carcinoma (HCC),and a specific anti-HBx immune response can be detected in the peripheral blood of patients with chronic HBV.However,its role and entity has not been yet clarified.Thus,we performed a cross-sectional analysis of anti-HBx specific T cell response in HBV-infected patients in different stage of disease.A total of 70 HBV-infected subjects were evaluated:15 affected by chronic hepatitis (CH-median age 45 yrs),14 by cirrhosis (median age 55 yrs),11 with dysplastic nodules (median age 64 yrs),15 with HCC (median age 60 yrs),15 with IC(median age 53 yrs).All patients were infected by virus genotype D with different levels of HBV viremia and most of them (91%) were HBeAb positive.The HBx-specific T cell response was evaluated by anti-Interferon (IFN)-gamma Elispot assay after in vitro stimulation of peripheral blood mononuclear cells,using 20 overlapping synthetic peptides covering all HBx protein sequence.HBx-specific IFN-gamma-secreting T cells were found in 6 out of 15 patients with chronic hepatitis (40%), 3 out of 14 cirrhosis (21%), in 5 out of 11 cirrhosis with macronodules (54%), and in 10 out of 15 HCC patients (67%). The number of responding patients resulted significantly higher in HCC than IC (p=0.02) and cirrhosis (p=0.02). Central specific region of the protein x was preferentially recognize,between 86-88 peptides. HBx response does not correlate with clinical feature disease(AFP,MELD).The HBx specific T-cell response seems to increase accordingly to progression of the disease, being increased in subjects with dysplastic or neoplastic lesions and can represent an additional tool to monitor the patients at high risk to develop HCC

Destruction of lymphoid organ architecture and hepatitis caused by CD4+ T cells

Immune responses have the important function of host defense and protection against pathogens. However, the immune response also causes inflammation and host tissue injury, termed immunopathology. For example, hepatitis B and C virus infection in humans cause immunopathological sequel with destruction of liver cells by the host's own immune response. Similarly, after infection with lymphocytic choriomeningitis virus (LCMV) in mice, the adaptive immune response causes liver cell damage, choriomeningitis and destruction of lymphoid organ architecture. The immunopathological sequel during LCMV infection has been attributed to cytotoxic CD8(+) T cells. However, we now show that during LCMV infection CD4(+) T cells selectively induced the destruction of splenic marginal zone and caused liver cell damage with elevated serum alanin-transferase (ALT) levels. The destruction of the splenic marginal zone by CD4(+) T cells included the reduction of marginal zone B cells, marginal zone macrophages and marginal zone metallophilic macrophages. Functionally, this resulted in an impaired production of neutralizing antibodies against LCMV. Furthermore, CD4(+) T cells reduced B cells with an IgM(high)IgD(low) phenotype (transitional stage 1 and 2, marginal zone B cells), whereas other B cell subtypes such as follicular type 1 and 2 and germinal center/memory B cells were not affected. Adoptive transfer of CD4(+) T cells lacking different important effector cytokines and cytolytic pathways such as IFNγ, TNFα, perforin and Fas-FasL interaction did reveal that these cytolytic pathways are redundant in the induction of immunopathological sequel in spleen. In conclusion, our results define an important role of CD4(+) T cells in the induction of immunopathology in liver and spleen. This includes the CD4(+) T cell mediated destruction of the splenic marginal zone with consecutively impaired protective neutralizing antibody responses.

Hepatitis C virus and non-Hodgkin's lymphoma: Findings from the Swiss HIV Cohort Study

Infections with hepatitis C virus (HCV) and, possibly, hepatitis B virus (HBV) are associated with an increased risk of non-Hodgkin's lymphoma (NHL) in the general population, but little information is available on the relationship between hepatitis viruses and NHL among people with HIV (PHIV). We conducted a matched case-control study nested in the Swiss HIV Cohort Study (SHCS). Two hundred and ninety-eight NHL cases and 889 control subjects were matched by SHCS centre, gender, age group, CD4+ count at enrollment, and length of follow-up. Odds ratios (OR) and corresponding 95% confidence intervals (CI) were computed using logistic regression to evaluate the association between NHL and seropositivity for antibodies against HCV (anti-HCV) and hepatitis B core antigen (anti-HBc), and for hepatitis B surface antigen (HBsAg). Anti-HCV was not associated with increased NHL risk overall (OR = 1.05; 95% CI: 0.63-1.75), or in different strata of CD4+ count, age or gender. Only among men having sex with men was an association with anti-HCV found (OR = 2.37; 95% CI: 1.03-5.43). No relationships between NHL risk and anti-HBc or HBsAg emerged. Coinfection with HIV and HCV or HBV did not increase NHL risk compared to HIV alone in the SHCS.

Hepatitis C in a sample of pregnant women in Switzerland: seroprevalence and socio-demographic factors

PRINCIPLES: The aim of this study was to determine the prevalence of hepatitis C (HCV) infection in a sample of pregnant women living in Switzerland in 1990-1991, in order to complement existing data in various populations. METHODS: Blood samples were collected from women from consecutive births in obstetric wards in public hospitals of 23 Swiss cantons over a one-year period. They were tested, among other things, for the presence of hepatitis C virus antibodies (anti-HCV). Statistical analyses were done to explore the association of demographic variables with anti-HCV. RESULTS: The study included a total of 9,057 women of whom 64 tested positive for anti-HCV, resulting in a crude prevalence of 0.71%. Prevalence varied by age and was highest in the 25-29-year age-group (0.90%). 43/5,685 Swiss women were HCV seropositive (0.76%) compared with 21/3,372 non-Swiss women (0.62%). Stratified analysis showed a significant association between anti-HCV and anti-HBc antibody positivity in Swiss (adjusted OR [aOR] 23, 95% CI 12-43) and non-Swiss nationals (aOR 3.3, 95% CI 1.3-8.3). CONCLUSIONS: The prevalence of anti-HCV antibodies in the early 1990s was <1% in this sample of pregnant women in Switzerland and was associated with age, nationality and the presence of anti-HBc antibodies, a marker of exposure to hepatitis B virus. These results are in accordance with those from other published European studies. If an effective intervention to prevent vertical transmission becomes available, information on the current prevalence of HCV in pregnant women would be needed in order to assess how screening recommendations should be modified.

Prevalence and associated factors of viral hepatitis and transferrin elevations in 5036 patients admitted to the emergency room of a Swiss university hospital: cross-sectional study

BACKGROUND: The epidemiology of liver disease in patients admitted to emergency rooms is largely unknown. The current study aimed to measure the prevalence of viral hepatitis B and C infection and pathological laboratory values of liver disease in such a population, and to study factors associated with these measurements. METHODS: Cross-sectional study in patients admitted to the emergency room of a university hospital. No formal exclusion criteria. Determination of anti-HBs, anti-HCV, transferrin saturation, alanine aminotransferase, and obtaining answers from a study-specific questionnaire. RESULTS: The study included 5'036 patients, representing a 14.9% sample of the target population during the study period. Prevalence of anti-HBc and anti-HCV was 6.7% (95%CI 6.0% to 7.4%) and 2.7% (2.3% to 3.2%), respectively. Factors independently associated with positive anti-HBc were intravenous drug abuse (OR 18.3; 11.3 to 29.7), foreign country of birth (3.4; 2.6 to 4.4), non-white ethnicity (2.7; 1.9 to 3.8) and age > or =60 (2.0; 1.5 to 2.8). Positive anti-HCV was associated with intravenous drug abuse (78.9; 43.4 to 143.6), blood transfusion (1.7; 1.1 to 2.8) and abdominal pain (2.7; 1.5 to 4.8). 75% of all participants were not vaccinated against hepatitis B or did not know their vaccination status. Among anti-HCV positive patients only 49% knew about their infection and 51% reported regular alcohol consumption. Transferrin saturation was elevated in 3.3% and was associated with fatigue (prevalence ratio 1.9; 1.2 to 2.8). CONCLUSION: Emergency rooms should be considered as targets for public health programs that encourage vaccination, patient education and screening of high-risk patients for liver disease with subsequent referral for treatment if indicated.

Little evidence that hepatitis C virus leads to a higher risk of mortality in the absence of cirrhosis and excess alcohol intake: the Swiss Hepatitis C Cohort Study

The objective of this study was to describe the all-cause mortality of participants in the Swiss Hepatitis C Cohort compared to the Swiss general population. Patients with hepatitis C virus (HCV) infection attending secondary and tertiary care centres in Switzerland. One thousand six hundred and forty-five patients with HCV infection were followed up for a mean of over 2 years. We calculated all-cause standardized mortality ratios (SMR) and 95% confidence intervals (CI) using age, sex and calendar year-specific Swiss all-cause mortality rates. Multivariable Poisson regression was used to model the variability of SMR by cirrhotic status, HCV genotype, infection with hepatitis B virus or HIV, injection drug use and alcohol intake. Sixty-one deaths were recorded out of 1645 participants. The crude all-cause SMR was 4.5 (95% CI: 3.5-5.8). Patients co-infected with HIV had a crude SMR of 20 (95% CI: 11.1-36.1). The SMR of 1.1 (95% CI: 0.63-2.03) for patients who were not cirrhotic, not infected with HBV or HIV, did not inject drugs, were not heavy alcohol consumers (ere not genotype 3, indicated no strong evidence of excess mortality. We found little evidence of excess mortality in hepatitis C infected patients who were not cirrhotic, in the absence of selected risk factors. Our findings emphasize the importance of providing appropriate preventive advice, such as counselling to avoid alcohol intake, in those infected with HCV.

Absence of Hepatitis Delta Infection in a Large Rural HIV Cohort in Tanzania

OBJECTIVES The epidemiological and clinical determinants of hepatitis delta virus (HDV) infection in sub-Saharan Africa are ill-defined. We determined the prevalence of HDV infection in HIV/hepatitis B virus (HBV)-co-infected individuals in rural Tanzania. DESIGN AND METHODS We screened all hepatitis B virus (HBV)-infected adults under active follow-up in the Kilombero and Ulanga Antiretroviral Cohort (KIULARCO) for anti-HDV antibodies. In positive samples, we performed a second serological test and nucleic acid amplification. Demographic and clinical characteristics at initiation of antiretroviral therapy (ART) were compared between anti-HDV-negative and positive patients. RESULTS Among 222 HIV/HBV-coinfected patients on ART, 219 (98.6%) had a stored serum sample available and were included. Median age was 37 years, 55% were female, 46% had WHO stage III/IV HIV disease and median CD4 count was 179 cells/μL. The prevalence of anti-HDV positivity was 5.0% (95% confidence interval 2.8%-8.9%). There was no significant predictor of anti-HDV positivity. HDV could not be amplified in any of the anti-HDV-positive patients and the second serological test was negative in all of them. CONCLUSIONS We found no confirmed case of HDV infection among over 200 HIV/HBV-co-infected patients in Tanzania. As false-positive serology results are common, screening results should be confirmed with a second test.