Brief Report: HIV-1 gp120 T-Cell Responses Correspond to Infection Outcomes in the Global iPrEx Chemoprophylaxis Trial.

Association of HIV-1-specific T-cell responses to infection risk in seronegative individuals is controversial. We quantified and phenotypically characterized gp120-specific T-cell responses in HIV-1 exposed, but uninfected subjects enrolled in the global Pre-exposure Prophylaxis Initiative (iPrEx) chemoprophylaxis trial. IFNγ ELISpot responses were detected in 24% of subjects irrespective of infection outcome. HIV-1 gp120 envelope-specific T-cell responses were more uniformly IFN-γ+TNF-α+Mip-1β+ in persistently seronegative subjects relative to subjects who later seroconverted (median frequency of 76.5% and 66.5%, respectively). IFNγ responses targeted the V2 loop for subjects who remained seronegative. HIV-1 gp120 envelope V2 loop-specific CD8 T-cell responses may help to protect against HIV-1 acquisition

High Prevalence of Hepatitis C Infection in a Brazilian Prison: Identification of Risk Factors for Infection

Hepatitis C virus (HCV) causes infectious hepatitis worldwide. It is transmitted mainly by blood products and sharing of intravenous paraphernalia during illicit drug use. High prevalence rates have been described among specific groups considered to be at higher risk for HCV infection, including prison inmates. The objectives of this study were: to determine the HCV seroprevalence among inmates of Cas

Prediction of intensive care admission and hospital mortality in COVID-19 patients using demographics and baseline laboratory data

Introduction: Optimized allocation of medical resources to patients with COVID-19 has been a critical concern since the onset of the pandemic. Methods: In this retrospective cohort study, the authors used data from a Brazilian tertiary university hospital to explore predictors of Intensive Care Unit (ICU) admission and hospital mortality in patients admitted for COVID-19. Our primary aim was to create and validate prediction scores for use in hospitals and emergency departments to aid clinical decisions and resource allocation. Results: The study cohort included 3,022 participants, of whom 2,485 were admitted to the ICU; 1968 survived, and 1054 died in the hospital. From the complete cohort, 1,496 patients were randomly assigned to the derivation sample and 1,526 to the validation sample. The final scores included age, comorbidities, and baseline laboratory data. The areas under the receiver operating characteristic curves were very similar for the derivation and validation samples. Scores for ICU admission had a 75% accuracy in the validation sample, whereas scores for death had a 77% accuracy in the validation sample. The authors found that including baseline flu-like symptoms in the scores added no significant benefit to their accuracy. Furthermore, our scores were more accurate than the previously published NEWS-2 and 4C Mortality Scores. Discussion and conclusions: The authors developed and validated prognostic scores that use readily available clinical and laboratory information to predict ICU admission and mortality in COVID-19. These scores can become valuable tools to support clinical decisions and improve the allocation of limited health resources

Proteins of Leishmania (Viannia) shawi confer protection associated with Th1 immune response and memory generation

<p>Abstract</p> <p>Background</p> <p><it>Leishmania (Viannia) shawi </it>parasite was first characterized in 1989. Recently the protective effects of soluble leishmanial antigen (SLA) from <it>L. (V.) shawi </it>promastigotes were demonstrated using BALB/c mice, the susceptibility model for this parasite. In order to identify protective fractions, SLA was fractionated by reverse phase HPLC and five antigenic fractions were obtained.</p> <p>Methods</p> <p>F1 fraction was purified from L. (V.) shawi parasite extract by reverse phase HPLC. BALB/c mice were immunized once a week for two consecutive weeks by subcutaneous routes in the rump, using 25 μg of F1. After 1 and 16 weeks of last immunization, groups were challenged in the footpad with L. (V.) shawi promastigotes. After 2 months, those same mice were sacrificed and parasite burden, cellular and humoral immune responses were evaluated.</p> <p>Results</p> <p>The F1 fraction induced a high degree of protection associated with an increase in IFN-γ, a decrease in IL-4, increased cell proliferation and activation of CD8⁺T lymphocytes. Long-term protection was acquired in F1-immunized mice, associated with increased CD4⁺central memory T lymphocytes and activation of both CD4⁺and CD8⁺T cells. In addition, F1-immunized groups showed an increase in IgG2a levels.</p> <p>Conclusions</p> <p>The inductor capability of antigens to generate memory lymphocytes that can proliferate and secrete beneficial cytokines upon infection could be an important factor in the development of vaccine candidates against American Tegumentary Leishmaniasis.</p

High prevalence of hepatitis C infection in a Brazilian prison: identification of risk factors for infection

Hepatitis C virus (HCV) causes infectious hepatitis worldwide. It is transmitted mainly by blood products and sharing of intravenous paraphernalia during illicit drug use. High prevalence rates have been described among specific groups considered to be at higher risk for HCV infection, including prison inmates. The objectives of this study were: to determine the HCV seroprevalence among inmates of Casa de Detenção de São Paulo; to identify risk factors for HCV infection; and to compare the seroprevalence of HCV to other blood borne or sexually transmitted diseases. From December, 1993, to January, 1994, a total of 779 inmates were interviewed to collect information on sociodemographic status, sexual behavior, and past experience with illicit drugs. Blood samples were obtained from 756 inmates for serological tests. 310 (41%) blood samples were positive for anti-HCV, 425 (56.2%) were negative, and 21 (2.8%) showed indeterminate results. In this population, we found a seroprevalence of 13.7% for HIV, 3.3% for syphilis (VDRL), and 68.1% for hepatitis B virus previous infection. Four variables were each identified as associated with a positive anti-HCV serologic test: a positive VDRL (OR = 2.63 IC 95% 1.08 to 6.36); a time of current imprisonment longer than 130 months (OR = 2.44 IC 95% 1.04 to 5.71); previous incarceration at Casa de Detenção de São Paulo (OR = 1.73 IC 95% 1.19 to 2.52) and; illicit drug use before admission to the Casa de Detenção de São Paulo (OR = 1.64 IC 95% 1.15 to 2.33). The seroprevalence of HCV antibodies among the study population was high (41%), indeed, one of the highest clusters of HCV infection recorded until now. Four variables were each shown to be associated with HCV infection. The simultaneous presence of these 4 variables is associated with an 82% probability of being anti-HCV positive. Although risk factor analysis indicates most HCV infections occur prior to inprisonment, initiation of control measures to prevent continued transmission after incarceration should be done

Brief Report: HIV-1 gp120 T-Cell Responses Correspond to Infection Outcomes in the Global iPrEx Chemoprophylaxis Trial.

Association of HIV-1-specific T-cell responses to infection risk in seronegative individuals is controversial. We quantified and phenotypically characterized gp120-specific T-cell responses in HIV-1 exposed, but uninfected subjects enrolled in the global Pre-exposure Prophylaxis Initiative (iPrEx) chemoprophylaxis trial. IFNγ ELISpot responses were detected in 24% of subjects irrespective of infection outcome. HIV-1 gp120 envelope-specific T-cell responses were more uniformly IFN-γ+TNF-α+Mip-1β+ in persistently seronegative subjects relative to subjects who later seroconverted (median frequency of 76.5% and 66.5%, respectively). IFNγ responses targeted the V2 loop for subjects who remained seronegative. HIV-1 gp120 envelope V2 loop-specific CD8 T-cell responses may help to protect against HIV-1 acquisition