Nucleoside and nucleotide analogues are essential antivirals in the treatment of infectious diseases such as human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), herpes simplex virus (HSV), varicella-zoster virus (VZV), and human cytomegalovirus (HCMV). To celebrate the 80th birthday of Prof. Dr. Erik De Clercq on 28 March 2021, this review provides an overview of his contributions to eight approved nucleos(t)ide drugs: (i) three adenosine nucleotide analogues, namely tenofovir disoproxil fumarate (Viread®) and tenofovir alafenamide (Vemlidy®) against HIV and HBV infections and adefovir dipivoxil (Hepsera®) against HBV infections; (ii) two thymidine nucleoside analogues, namely brivudine (Zostex®) against HSV-1 and VZV infections and stavudine (Zerit®) against HIV infections; (iii) two guanosine analogues, namely valacyclovir (Valtrex®, Zelitrex®) against HSV and VZV and rabacfosadine (Tanovea®-CA1) for the treatment of lymphoma in dogs; and (iv) one cytidine nucleotide analogue, namely cidofovir (Vistide®) for the treatment of HCMV retinitis in AIDS patients. Although adefovir dipivoxil, stavudine, and cidofovir are virtually discontinued for clinical use, tenofovir disoproxil fumarate and tenofovir alafenamide remain the most important antivirals against HIV and HBV infections worldwide. Overall, the broad-spectrum antiviral potential of nucleos(t)ide analogues supports their development to treat or prevent current and emerging infectious diseases worldwide.
Background
COVID-19 patients may experience “cytokine storm” when human immune system produces excessive cytokines/chemokines. However, it remains unclear whether early responses of inflammatory cytokines would lead to high or low titers of anti-SARS-CoV-2 antibodies.
Methods
This retrospective study enrolled a cohort of 272 hospitalized patients with laboratory-confirmed SARS-CoV-2. Laboratory assessments of serum cytokines (IL-2R, IL-6, IL-8, IL-10, TNF-α), anti-SARS-CoV-2 IgG/IgM antibodies, and peripheral blood biomarkers were conducted during hospitalization.
Results
At hospital admission, 36.4% patients were severely ill, 51.5% patients were ≥ 65 years, and 60.3% patients had comorbidities. Higher levels of IL-2R and IL-6 were observed in older patients (≥65 years). Significant differences of IL-2R (week 2 to week ≥5 from symptom onset), IL-6 (week 1 to week ≥5), IL-8 (week 2 to week ≥5), and IL-10 (week 1 to week 3) were observed between moderately-ill and severely ill patients. Anti-SARS-CoV-2 IgG titers were significantly higher in severely ill patients than in moderately ill patients, but such difference was not observed for IgM. High titers of early-stage IL-6, IL-8, and TNF-α (≤2 weeks after symptom onset) were positively correlated with high titers of late-stage IgG (≥5 weeks after symptom onset). Deaths were mostly observed in severely ill older patients (45.9%). Survival analyses revealed risk factors of patient age, baseline COVID-19 severity, and baseline IL-6 that affected survival time, especially in severely ill older patients.
Conclusion
Early responses of elevated cytokines such as IL-6 reflect the active immune responses, leading to high titers of IgG antibodies against COVID-19.
Under-five years of age is a critical period for children’s growth and development. Nutritional deficiency during this period is associated with wasting, underweight and stunting. We aimed to conduct an epidemiological study using data derived from the GBD2019 to found the global distribution and changing trends of nutritional deficiencies among children under 5 years old, as well as the correlation between social development status and nutritional deficiencies. Nutritional deficiencies in children under 5 years has been substantially improved in the past decade; however, the progress has been unevenly distributed globally. The incidence and DALY rate decreased with the increase of socio-demographic index. In 2019, the incidence (51,872.0 per 100,000) was highest in Central Sub-Saharan Africa and the DALY rate (5597.1 per 100,000) was the highest in Western Sub-Saharan Africa. Among five subcategories of nutritional deficiencies in children under 5 years, vitamin A deficiency accounted for the largest proportion of incident cases (100,511,850, 62.1% in 2019), while the proportion of DALYs caused by protein–energy malnutrition was the highest (9,925,276, 62.0%). Nutritional deficiency in some countries remains worrisome, for whom policies guarantees and sustained efforts to control nutritional deficiencies are urgently needed.
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