[Immune evasion mechanisms of hepatitis C virus. Review]. / Mecanismos de evasión inmunitaria del virus de hepatitis C. Revisión.

Hepatitis Virus C (HCV) is a major worldwide health care problem. HCV infection usually tends to become chronic and can generate long-term hepatic cirrhosis and hepatocellular carcinoma. These affections frequently require a liver transplant to prolong the patients life. Maintenance of the chronic infection implies evasion of the host immune responses. Viral mechanisms involved in this evasion are being profusely studied in order to develop new and effective therapies and vaccines against HCV. An important HCV characteristic, its high genetic variability, has been proposed to contribute to immune evasion by means of antigenic change and variation. On the other hand, some studies suggest that genetic variability is not necessary to establish a chronic infection. Other studies related to immune responses in patients with spontaneous virus clearance and patients with chronic infection show a possible immunosuppression caused by some viral proteins, that may be essential to persist in the host. Specifically, it is believed that viral proteins NS5A, E2 and Core modulate some innate and specific immune mechanisms. The analysis of all data related to this topic suggests the existence of synergistic cooperation between viral variation and immunosuppression to overcome the immune defenses of the host.

Nuevo coronavirus (SARS-COV-2): una amenaza global / New Coronavirus (SARS-COV-2): a global threat

El nuevo coronavirus (SARS-CoV-2) identificado en Wuhan, China a principios de enero de 2020, es el agente infeccioso causante de la pandemia COVID -19, la cual ha sido declarada por la Organización Mundial de la Salud (OMS) el 11 de marzo de 2020 y es una amenaza global por el número de casos y muertes así como el importan- te impacto en los sistemas de salud. La enferme- dad se transmite de persona a persona a través de las gotas de saliva al hablar, toser o estornudar o al tocar las mucosas oral, conjuntival y nasal con las manos, después de tocar superficies contami- nadas por el virus. La infección puede ser asinto- mática, la gran mayoría de los pacientes presentan una enfermedad leve o moderada, el 14 % puede presentar neumonía y enfermedad grave, un 5 % o más. El órgano principalmente afectado es el pulmón, sin embargo, es una enfermedad sistémica. La fisiopatología de la enfermedad aún no está bien comprendida, no hay untratamiento específi- co, aunque se están ensayando experimentalmente numerosos fármacos. La vacuna, según los exper- tos, tardará en desarrollarse. Los profesionales sanitarios deben estar familiarizados con los aspectos de la enfermedad, así como con el diagnóstico y las medidas de control, entre otros(AU)

The new coronavirus (SARS-CoV-2) identified in Wuhan, China in early January 2020, is the infectious agent causing the COVID -19 pandemic, declared by the World Health Organization (WHO) on March 11, 2020. It has become a global threat due to the number of cases and deaths and its sig- nificant impact on health systems. The disease is transmitted from person to person by respiratory route through saliva droplets while speaking, coug- hing, or sneezing, or by touching the oral, conjunc- tival, and nasal mucosa with the hands after having touched surfaces contaminated by the virus. The infection may be asymptomatic, the vast majority of patients have mild or moderate disease, 14% may have pneumonia, and 5% or more can suffer severe disease. The main affected organs are the lungs but, it is a systemic disease. The pathophysiology of the disease is still not well understood, there is no specific treatment, although numerous drugs are being experimentally tested and the vaccine, according to experts, could take take some time to be ready. Healthcare profes- sionals should be familiar with all aspects of the disease, as well as diagnosis and control measures(AU)

[Viral loads in pediatric HIV patients with antiretroviral treatment]. / Carga viral en pacientes pediátricos VIH positivos con terapia antiretroviral.

BACKGROUND: Viral load in pediatric patients with HIV infections can help to make therapeutic decisions to modify the evolution of the disease. AIM: To evaluate viral load in positive HIV children with antiretroviral treatment. MATERIAL AND METHODS: Viral load was measured every six months during three years in fifty pediatric patients chosen randomly in aged 1 to 12 years, using the Test Monitor HIV-1 AMPLICOR, version 1.5. RESULTS: During the three years follow up, there was an increase in CD4 and CD8 lymphocyte count and decrease in the viral load. However, there was no significant relationship between lymphocyte subpopulation counts and viral loads. CONCLUSIONS: Viral load demonstrated to be an appropriate method to quantify plasma HIV-RNA. This tool can help to define the condition of a particular patient to predict clinical course of the disease and to assess the response to the treatment.

[Determination of HCV infection stage in a group of seropositive patients from Maracaibo, Venezuela by measurement the antibody avidity index of anti-HCV IgG]. / Determinación del estadío de la infección por el virus de Hepatitis C (VHC) utilizando la ténica de cuantificación de la avidez de las IgG.

OBJECTIVE: To identify HCV infection stage in a group of seropositive patients from Maracaibo, Venezuela, using the measurement of IgG antibody avidity technique. MATERIAL AND METHODS: We used a modification suggest by Leon et. al.(1997) of the normal protocol of ELISA Ortho HCV 3.0 Kit. This protocol modification was make two parallel assays for each sample adding new wash step using 6M Urea for one of parallel assays. RESULTS: The average AI (Avidity index) of 19 HCV seropositive patients found was 55 +/- 23,8%. Also, it was found that three (15,79%) of these patients were in primoinfection stage by HCV, seven (36,84%) were in past o chronic stage and nine (47,36%) were in chronic stage. The new cases ratio calculated for the investigation period was 1/5, this mean that for each five patients diagnosed with HCV, only one was in the acute phase of infection. CONCLUSION: Data from this study provides new information about epidemiology of HCV in the area.

[Seroprevalence of Hepatitis C Virus (HCV) in patients of the Regional Viral Reference Laboratory (Maracaibo, Venezuela)]. / Seroprevalencia del Virus de Hepatitis C (VHC) en pacientes del Laboratorio Regional de Referencia Virológica (Maracaibo, Venezuela).

PURPOSE: Collect and analyze information regarding seroprevalence of Hepatitis C Virus (HCV) in a population of 722 patients that visited the Regional Viral Reference Laboratory (Maracaibo, Venezuela) during the years 2000-2003. MATERIAL AND METHODS: An immunoenzymatic test INNOTEST HCV Ab IV of Innogenetics was used to evaluate the presence of IgG type antibodies against the Hepatitis C Virus (HCV) in the serum of the patients studied. Results obtained with respect to seroprevalence and other epidemiological variables, were organized and analyzed using SPSS 10.0 (Chicago, USA) and Origin Pro 7.5 (Northampton, USA) software. RESULTS: A seroprevalence of 2.63% (19,322) was found, higher than that reported in Venezuela for the general population (0.9%) and other groups. The infection was more frequent in men than in women. The most common symptoms in the infected patients were jaundice and cephalalgia (31.58%). CONCLUSION: The data reported shall update previous research in the zone and indicates the need to develop epidemiological control for Hepatitis C Virus (HCV) in the State of Zulia.

Carga viral en pacientes pediátricos VIH positivos con terapia antirretroviral / Viral loads in pediatric HIV patients with antirretroviral treatment

Background: Viral load in pediatric patients with HIV infections can help to make therapeutic decisions to modify the evolution of the disease. Aim: To evaluate viral load in positive HIV children with antiretroviral treatment. Material and methods: Viral load was measured every six months during three years in fifty pediatric patients chosen randomly in aged 1 to 12 years, using the Test Monitor HIV-1 AMPLICOR, versión 1.5. Results: During the three years follow up, there was an increase in CD4 and CD8 lymphocyte count and decrease in the viral load. However, there was no significant relationship between lymphocyte subpopulation counts and viral loads. Conclusions: Viral load demonstrated to be an appropriate method to quantify plasma HIV-RNA. This tool can help to define the condition of a particular patient to predict clinical course of the disease and to assess the response to the treatment.

Mecanismos de evasión inmunitaria del virus de hepatitis C: revisión / Inmune evasion mechanisms of hepatitis C virus: review

El virus de Hepatitis C (VHC) constituye un problema de salud pública mundial. La mayoría de las infecciones se tornan crónicas, ocasionando con frecuencia cirrosis hepática y carcinoma hepatocelular a largo plazo, precisándose no pocas veces de transplantes hepáticos para prolongar la vida del individuo. El mantenimiento de una infección crónica implica la evasión al sistema inmunitario del hospedero. Los mecanismos virales involucrados en dicha evasión están siendo estudiados arduamente con el fin de desarrollar nuevas terapias preventivas y curativas efectivas contra el virus. Una característica importante, la extrema variabilidad genética del virus, se cree que contribuya al escape inmunitario al cambiar continuamente los epítopos expuestos a la detección; sin embargo, algunos trabajos sugieren que no es necesaria para el establecimiento de la cronicidad de la infección. Por otra parte, el estudio comparativo de la respuesta inmunitaria de los pacientes que se recuperan espontáneamente con la de aquellos infectados de manera crónica, señala que algunas proteínas virales podrían inducir cierta inmunosupresión indispensable para la persistencia en el hospedero. Concretamente, se cree que las proteínas NS5A, E2 y core modulan ciertos mecanismos de las respuestas innata y específica. El análisis de los hallazgos relacionados con el tópico permite sugerir la existencia de una sinergia entre la variación genética y la inmunosupresión para evadir de manera continua la detección y destrucción por parte del sistema de defensas del individuo