ABSTRACT Introduction. SARS-CoV-2, is causal agent of COVID-19. This virus causes infections that range from asymptomatic to symptomatic infection, with variable grade of severity. Cytokine storm, characterized for uncontrolled releasing of inflammatory mediators, has effect in the immunopathology of COVID-19. The aim was to evaluate if viral titers and unbalance of early immune response determined the clinical presentation of SARS-CoV-2 infection. Methods. Real time PCR was used to identify the level of SARS-CoV-2 replication in nasopharyngeal swabs (NPS). Expression of pro- inflammatory mediators with antiviral (IFN-γ) and chemokine (RANTES) functions were evaluated. TGFβ-1 anti-inflammatory cytokine was also determined. In cells collected from NPS. It was studied SARS-CoV-2 asymptomatic and symptomatic individuals; with 10 days or less of onset symptoms or contact with source of infection. A control group negative to virus was used to compare the results. Results. Level of viral replication was similar in individuals independently of their symptoms. It was identified a high expression of IFN-γ in SARS-CoV-2 infected subjects, which was significantly increased in symptomatic patients in comparison to controls (p = 0,0393). TGF-β1 and RANTES expression were lower in SARS-CoV-2 positive cases. It was observed a positive and significant correlation between IFN-γ and TGF-β1 in asymptomatic cases (r = +0,61, p = 0,0014). As a conclusion, the findings suggest an unbalance between pro-and anti-inflammatory mediators determinates the clinical presentation of SARS-CoV-2 infection.

RESUMEN Introducción. El SARS-CoV-2, es el agente causal de la COVID-19. Este virus produce infecciones que oscilan desde formas asintomáticas a sintomáticas, con grados de severidad variable. La tormenta de citoquinas, caracterizada por la liberación descontrolada de mediadores inflamatorios influye en la inmunopatología de la COVID-19. El objetivo fue evaluar si el título viral y el desbalance de la respuesta inmune temprana influían en la presentación clínica de la infección por SARS-CoV-2. Métodos. Se empleó el PCR en tiempo real, para determinar el nivel de replicación del SARS-CoV-2 en muestras de exudados nasofaríngeos (ENF). La expresión de mediadores pro-inflamatorios con función antiviral (IFN-γ), quimioquina (RANTES) y antiinflamatorio (TGFβ-1) fueron evaluados en células colectadas de los ENF. Se estudiaron individuos sintomáticos y sintomáticos infectados por SARS-CoV-2, en los primeros 10 días de diagnóstico o contacto con la fuente de contagio. Estos se compararon con un grupo control individuos negativos al virus. Resultados. El nivel de replicación viral fue similar en los individuos infectados por SARS-CoV-2, independientemente de la presencia de síntomas. Se identificó una expresión elevada de IFN-γ en los casos positivos al SARS-CoV-2, que fue significativamente mayor en los pacientes sintomáticos al compararla con los controles (p = 0,0393). La expresión de TGF-β1 y RANTES fue baja en los individuos infectados por SARS-CoV-2. Se observó una correlación positiva y significativa entre el IFN-γ y TGF-β1 en los individuos asintomáticos (r = + 0,61; p = 0,0014). Como conclusiones, los hallazgos sugieren que el desbalance entre los mediadores pro- y antiinflamatorios influyen en la presentación clínica de la infección por SARS-CoV-2.

ABSTRACT INTRODUCTION By the end of 2017, there were more than 28,000 individuals living with HIV in Cuba, over 80% receiving antiretroviral therapy, which dramatically reduces viral replication, improves immune status and decreases risk of transmission. These results could be jeopardized by emergence of HIV-1 drug resistance. In 2009, a test for HIV-1 genotypic resistance was introduced in routine clinical practice in Cuba. OBJECTIVE Investigate antiretroviral resistance and its relation to subtype distribution in HIV-1 treatment-naïve and previously treated patients in Cuba. METHODS Resistance and HIV-1 subtype distribution were determined in 342 antiretroviral treatment-naïve patients and 584 previously treated for HIV-1 whose blood specimens were sent to the Pedro Kourí Tropical Medicine Institute during 2009–2014. Transmitted drug resistance was determined using the Calibrated Population Resistance Tool v.6. Drug resistance analysis was conducted using the algorithm Rega v9.1.0. RESULTS Prevalence of transmitted drug resistance was 11.4%, and 41% of mutated viruses exhibited dual-class resistance to nucleoside reverse transcriptase inhibitor and non-nucleoside reverse transcriptase inhibitor. Overall, 84.9% of patients had ≥1 resistance mutation, 80% had ≥1 nucleoside reverse transcriptase inhibitor mutation, 71.4% had ≥1 non-nucleoside reverse transcriptase inhibitor mutation and 31.7% had ≥1 protease inhibitor mutation. K65R and K101E mutations were significantly more frequent in subtype C, L210W in CRF19_cpx, and M47V/I in CRF BGs (20, 23, 24). Full class resistance to nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, protease inhibitors and multidrug resistance were detected in 21.2%, 32.4%, 8% and 4.1% of patients, respectively. Average percentage resistance to nucleoside reverse transcriptase inhibitor, protease inhibitor, full class resistance to nucleoside reverse transcriptase inhibitor, protease inhibitor and multidrug resistance increased in patients failing two or more regimens. Nevertheless, after 2011, a declining trend was observed in the frequency of multidrug resistance and full class resistance to nucleoside reverse transcriptase inhibitors and protease inhibitors. CONCLUSIONS Detected levels of transmitted drug resistance highlight the need for a national surveillance study in treatment-naïve patients. Resistance prevalence is high in previously treated patients but appears to be decreasing over time. The frequency of resistance mutations in recombinant forms of HIV in Cuba needs further study.