A Synopsis of Hepatitis C Virus Treatments and Future Perspectives.

Hepatitis C virus (HCV) infection is a worldwide public health problem. Chronic infection with HCV can lead to liver cirrhosis or cancer. Although some immune-competent individuals can clear the virus, others develop chronic HCV disease due to viral mutations or an impaired immune response. IFNs type I and III and the signal transduction induced by them are essential for a proper antiviral effect. Research on the viral cycle and immune escape mechanisms has formed the basis of therapeutic strategies to achieve a sustained virological response (SVR). The first therapies were based on IFNα; then, IFNα plus ribavirin (IFN-RBV); and then, pegylated-IFNα-RBV (PEGIFNα-RIV) to improve cytokine pharmacokinetics. However, the maximum SVR was 60%, and several significant side effects were observed, decreasing patients' treatment adherence. The development of direct-acting antivirals (DAAs) significantly enhanced the SVR (>90%), and the compounds were able to inhibit HCV replication without significant side effects, even in paediatric populations. The management of coinfected HBV-HCV and HCV-HIV patients has also improved based on DAA and PEG-IFNα-RBV (HBV-HCV). CD4 cells are crucial for an effective antiviral response. The IFNλ3, IL28B, TNF-α, IL-10, TLR-3, and TLR-9 gene polymorphisms are involved in viral clearance, therapeutic responses, and hepatic pathologies. Future research should focus on searching for strategies to circumvent resistance-associated substitution (RAS) to DAAs, develop new therapeutic schemes for different medical conditions, including organ transplant, and develop vaccines for long-lasting cellular and humoral responses with cross-protection against different HCV genotypes. The goal is to minimise the probability of HCV infection, HCV chronicity and hepatic carcinoma.

Autoimmunity and Immunodeficiency in Severe SARS-CoV-2 Infection and Prolonged COVID-19.

SARS-CoV-2 causes the complex and heterogeneous illness known as COVID-19. The disease primarily affects the respiratory system but can quickly become systemic, harming multiple organs and leading to long-lasting sequelae in some patients. Most infected individuals are asymptomatic or present mild symptoms. Antibodies, complement, and immune cells can efficiently eliminate the virus. However, 20% of individuals develop severe respiratory illness and multiple organ failure. Virus replication has been described in several organs in patients who died from COVID-19, suggesting a compromised immune response. Immunodeficiency and autoimmunity are responsible for this impairment and facilitate viral escape. Mutations in IFN signal transduction and T cell activation are responsible for the inadequate response in young individuals. Autoantibodies are accountable for secondary immunodeficiency in patients with severe infection or prolonged COVID-19. Antibodies against cytokines (interferons α, γ and ω, IL1ß, IL6, IL10, IL-17, IL21), chemokines, complement, nuclear proteins and DNA, anticardiolipin, and several extracellular proteins have been reported. The type and titer of autoantibodies depend on age and gender. Organ-specific autoantibodies have been described in prolonged COVID-19. Their role in the disease is under study. Autoimmunity and immunodeficiency should be screened as risk factors for severe or prolonged COVID-19.

Coronavirus infection: An immunologists' perspective.

Coronavirus infections are frequent viral infections in several species. As soon as the severe acute respiratory syndrome (SARS) appeared in the early 2000s, most of the research focused on pulmonary disease. However, disorders in immune response and organ dysfunctions have been documented. Elderly individuals with comorbidities exhibit worse outcomes in all the coronavirus that cause SARS. Disease severity in SARS-CoV-2 infection is related to severe inflammation and tissue injury, and effective immune response against the virus is still under analysis. ACE2 receptor expression and polymorphism, age, gender and immune genetics are factors that also play an essential role in patients' clinical features and immune responses and have been partially discussed. The present report aims to review the physiopathology of SARS-CoV-2 infection and propose new research topics to understand the complex mechanisms of viral infection and viral clearance.

SARS-CoV-2 Infection in Venezuelan Pediatric Patients-A Single Center Prospective Observational Study.

Several studies suggest that children infected with SARS-CoV-2 have fewer clinical manifestations than adults; when they develop symptoms, they rarely progress to severe disease. Different immunological theories have been proposed to explain this phenomenon. In September 2020, 16% of the active COVID-19 cases in Venezuela were children under 19 years. We conducted a cross-sectional study of pediatric patients' immune response and clinical conditions with SARS-CoV-2 infection. The patients were admitted to the COVID-19 area of the emergency department of Dr José Manuel de los Ríos Children's Hospital (2021-2022). The lymphocyte subpopulations were analyzed by flow cytometry, and IFNγ, IL-6, and IL-10 serum concentrations were quantified using commercial ELISA assays. The analysis was conducted on 72 patients aged one month to 18 years. The majority, 52.8%, had mild disease, and 30.6% of the patients were diagnosed with MIS-C. The main symptoms reported were fever, cough, and diarrhea. A correlation was found between IL-10 and IL-6 concentrations and age group, lymphocyte subpopulations and nutritional status and steroid use, and IL-6 concentrations and clinical severity. The results suggest a different immune response depending on age and nutritional status that should be considered for treating pediatric COVID-19 patients.

Polimorfismos de número variable de repeticiones en tándem del intrón 2 de 5-htt y MUC 7 en pacientes venezolanos con asma o EPOC / 5-HTT intron 2 and MUC7 variable number of tandem repeats polymorphisms in a Venezuelan population with asthma or COPD

El asma y la enfermedad pulmonar obstructiva crónica (EPOC) son enfermedades inflamatorias crónicas. En ambas patologías existe broncoconstricción, producción de mediadores inflamatorios, hipersecreción de moco y migración de células inflamatorias. La serotonina tiene propiedades inmunomoduladoras que facilitan la broncoconstricción y su transportador (5-HTT) es el principal determinante de su concentración plasmática. Las mucinas (MUC) son glicoproteínas involucradas en la inmunidad innata local. El objetivo del presente trabajo fue estudiar la asociación entre polimorfismos de número variable de repeticiones en tándem (VNTR) del intrón 2 de 5-HTT (STin2) y MUC7 en pacientes venezolanos con asma o EPOC. El grupo de estudio consistió en 301 individuos (102 asmáticos, 99 EPOC, y 100 controles). No se observaron diferencias en las frecuencias de polimorfismos de MUC7 entre los grupos. Sin embargo, se encontró asociación entre alelos y genotipos de STin2 con presencia de asma o EPOC (p <0,001). El alelo STin2.9 tuvo un odds ratio (OR) de 0,15 (p=0,16) en los pacientes con asma, mientras que en los pacientes con EPOC los genotipos STin2.10/10 y 10/12 presentaron un OR de 0,33 (p=0,002) y 3,64 (p=0,002), respectivamente. Con relación a los haplotipos, el STin2/MUC7 10/10-6/6 se relacionó con riesgo en asma (OR=1,6, p=0,02) y protección en EPOC (OR=0,3, p=0,006) y el 10/12-6/6 (OR=3,7, p=0,002) fue un factor de riesgo para EPOC. En conclusión, en la población venezolana los polimorfismos de STin2 son importantes para definir factor de riesgo de enfermedad y, en consecuencia, el transportador de serotonina es relevante en ambas patologías.

Asthma and Chronic Obstructive Pulmonary Disease (COPD) are chronic inflammatory diseases. Both entities are characterized by bronchoconstriction, production of inflammatory mediators, mucus hypersecretion and inflammatory cell migration. Serotonin has immunomodulatory properties facilitating bronchoconstriction and its plasma concentration is transporter dependent (5-HTT). Mucins are glycoproteins involved in local innate immunity. The aim of this study was to assess the association between the variable number of tandem repeat polymorphisms (VNTR) of intron 2 of the serotonin ransporter (5-HTT) (STin2) and MUC7 in Venezuelan asthmatic or COPD patients. The group consisted of 301 individuals (102 asthmatics, 99 with COPD and 100 controls). There were no differences in the frequencies of MUC7 polymorphisms among the groups. However, there is a significant association between some alleles and genotypes with the presence of asthma or COPD (p <0.001). The STin2.9 allele had an odds ratio (OR) of 0.15 (p=0.16) in patients with asthma, while in patients with COPD, the STin2.10/10 and 10/12 genotypes had 0.33 (p=0,002) and 3.64 (p=0,002) OR, respectively. Regarding haplotypes, the STin2/ MUC7 10/10-6/6 is related to asthma risk (OR = 1.6, p=0.02) and COPD protection (OR=0.3, p=0.006) and 10/12-6/6 (OR=3.7, p=0.002), is a risk factor for COPD. In conclusion, in the Venezuelan population STin2 polymorphisms are important to define disease risk factor and consequently, the serotonin transporter is relevant to both pathologies.

Polimorfismos de nucleótidos simples V4 y T1 del gen ADAM33 en pacientes venezolanos con asma o enfermedad pulmonar obstructiva crónica / Single nucleotide polymorphisms V4 and T1 of the ADAM33 gene in Venezuelan patients with asthma or chronic obstructive pulmonary disease

ADAM33 es una metaloproteinasa de la matriz extracelular involucrada en la remodelación tisular y, por ello, en el asma y la enfermedad pulmonar obstructiva crónica (EPOC). Se han reportado varios polimorfismos del gen de ADAM33 asociados a la actividad enzimática. Los polimorfismos más estudiados son el V4, citosina por una guanina en la región 3’ UTR, y el T1, adenina por una guanina en el exón 19 del gen. El objetivo del presente trabajo fue determinar la posible asociación de los polimorfismos de nucleótido simple de ADAM33, V4 y T1, con la presencia de asma o EPOC en pacientes venezolanos. Los polimorfismos V4 y T1 fueron analizados en 303 individuos (103 asmáticos, 100 EPOC, y 100 controles) mediante PCR-RFLP (reacción en cadena de la polimerasa y análisis de polimorfismos por longitud de fragmentos de restricción enzimática). La frecuencia genotípica del polimorfismo V4 fue significativamente mayor (p<0,05) en ambos grupos de pacientes, asmáticos y EPOC, con respecto al control. No se encontraron diferencias significativas (P=0,4) en el polimorfismo T1. Sin embargo, se evidenció una diferencia significativa (p<0,05) cuando los haplotipos y diplotipos de ADAM33 V4/T1 se compararon entre los tres grupos. Se concluye que el polimorfismo ADAM33 V4 está asociado con la presencia de asma o EPOC en pacientes venezolanos.

ADAM33 is a metalloproteinase important in the extracellular matrix for tissue remodeling, and, consequently, in asthma and chronic obstructive pulmonary disease (COPD). Several polymorphisms of the ADAM33 gene have been associated with enzyme activity. One of the most studied polymorphisms is V4, cytosine for guanine in the 3’UTR region, and T1, adenine for guanine in the exon 19 of the gen. The aim of this study was to ascertain the possible association among single polymorphisms of ADAM33, V4 and T1, in Venezuelan patients with asthma or COPD. The polymorphisms V4 and T1 were analyzed in 303 individuals (103 asthmatic, 100 COPD and 100 controls) by PCR-RFLP (polymerase chain reaction and restriction fragment length polymorphisms). There was a significant difference (P<0.05) in the frequency of ADAM33 V4 polymorphism in both, asthmatic and COPD patients groups, as compared to controls. No significant differences (P=0.4) were found for T1 polymorphism. However, there were significant differences (P<0.05) when haplotypes and diplotypes of ADAM33 V4/T1 were compared in all three groups. It can be concluded that the polymorphism V4 of ADAM33 is associated with asthma or COPD in Venezuelan patients.