Polymorphisms in Plasmodium vivax Circumsporozoite Protein (CSP) Influence Parasite Burden and Cytokine Balance in a Pre-Amazon Endemic Area from Brazil.

Mechanisms involved in severe P. vivax malaria remain unclear. Parasite polymorphisms, parasite load and host cytokine profile may influence the course of infection. In this study, we investigated the influence of circumsporozoite protein (CSP) polymorphisms on parasite load and cytokine profile in patients with vivax malaria. A cross-sectional study was carried out in three cities: São Luís, Cedral and Buriticupu, Maranhão state, Brazil, areas of high prevalence of P. vivax. Interleukin (IL)-2, IL-4, IL-10, IL-6, IL-17, tumor necrosis factor alpha (TNF-α, interferon gamma (IFN-γ and transforming growth factor beta (TGF-ß were quantified in blood plasma of patients and in supernatants from peripheral blood mononuclear cell (PBMC) cultures. Furthermore, the levels of cytokines and parasite load were correlated with VK210, VK247 and P. vivax-like CSP variants. Patients infected with P. vivax showed increased IL-10 and IL-6 levels, which correlated with the parasite load, however, in multiple comparisons, only IL-10 kept this association. A regulatory cytokine profile prevailed in plasma, while an inflammatory profile prevailed in PBMC culture supernatants and these patterns were related to CSP polymorphisms. VK247 infected patients showed higher parasitaemia and IL-6 concentrations, which were not associated to IL-10 anti-inflammatory effect. By contrast, in VK210 patients, these two cytokines showed a strong positive correlation and the parasite load was lower. Patients with the VK210 variant showed a regulatory cytokine profile in plasma, while those infected with the VK247 variant have a predominantly inflammatory cytokine profile and higher parasite loads, which altogether may result in more complications in infection. In conclusion, we propose that CSP polymorphisms is associated to the increase of non-regulated inflammatory immune responses, which in turn may be associated with the outcome of infection.

Perfil epidemiológico dos marcadores sorológicos para vírus da hepatite B dos pacientes atendidos em um laboratório público / Epidemiological profile of serological markers for hepatitis B patients treated in a public laboratory

JUSTIFICATIVA E OBJETIVOS: A hepatite B é uma doença de distribuição universal que afeta ambos os sexos, podendo ser adquirida por meio de contato sexual, compartilhamento de seringas, exposição ocupacional e transfusão de sangue contaminado. O padrão de transmissão do vírus da hepatite B (VHB) está relacionado com a taxa de prevalência. O objetivo deste estudo foi determinar a prevalência de marcadores do VHB, de acordo com o índice de proteção vacinal. MÉTODO: A partir dos registros dos exames realizados em um laboratório público do município de São Luís, no ano de 2008, foram pesquisados os resultados para os marcadores de infecção com VHB: o anti-antígeno de superfície do VHB (HBsAg), os anticorpos anti-antígeno do core (anti-HBc) e anti-antígeno de superfície (anti-HBs).RESULTADOS: Dos 894 pacientes com sorologia positiva para VHB, 5,6% apresentaram marcador sorológico para fase aguda (HBsAg) prevalente em mulheres e pessoas com idade acima de 40 anos. Os anticorpos anti-HBc foram divididos em três tipos: anti-HBc (total), anti-HBc (IgG) e anti-HBc (IgM). Os índices de fase aguda e crônica utilizando estes marcadores foram similares (1,9% e 1,5%, respectivamente), com prevalência em mulheres e em pessoas com mais de 20 anos. O anti-antígeno de superfície anti-HBs foi detectado em 47,3% dos pacientes quando analisado isoladamente, indicando boa cobertura vacinal. CONCLUSÃO: Os dados do presente estudo indicam baixa prevalênciado VHB na população estudada.

BACKGROUND AND OBJECTIVES: Hepatitis B is a disease of worldwide distribution that affects both genders and can be acquired through sexual contact, needle sharing, occupational exposure and transfusion of contaminated blood. The pattern of transmission of hepatitis B virus (HBV) is related to the prevalence rate. The aim of this study was to determine the prevalence of HBV markers according to the rate of vaccine protection. METHOD: From the patient's records of a public laboratory of the city of São Luis (2008) the prevalence of three HBV infection markers, i.e., hepatitis B virus surface antigen (HBsAg), core anti-antigen (anti-HBc), and surface antigen antibody (anti-HBs) were studied. RESULTS: Of the 894 patients with positive serology for hepatitis B, 5.6% had prevalence of serologic marker for acute HBsAg in women and people over 40 years of age. The anti-HBc antibodies were divided into three types: anti-HBc (total), anti-HBc (IgG) and anti-HBc (IgM). The rates of acute and chronic use of these markers were similar (1.9% and 1.5% respectively) with the prevalence in women and in people over 20 years. The surface antigens anti-HBs were detected in 47.3% of patients when analyzed alone, indicating good vaccine coverage. CONCLUSION: The data from this study indicate low prevalence of hepatitis B virus among the studied population.