-
Global Heart 2023Dengue is a viral disease transmitted by the bite of a female arthropod, prevalent primarily in tropical and subtropical regions. Its manifestations include asymptomatic... (Review)
Review
Dengue is a viral disease transmitted by the bite of a female arthropod, prevalent primarily in tropical and subtropical regions. Its manifestations include asymptomatic infections, dengue fever, and a severe form called or . Atypical manifestations can also occur, called . We describe the case of a 43-year-old man with an unusual presentation of dengue, demonstrating a workup suggestive of myocardial and pericardial damage. Symptoms and markers indicative of cardiac compromise improved after five days on anti-inflammatory treatment. Dengue myocarditis is considered an uncommon complication of dengue, although its reported incidence is likely an underestimation. In general, most cases of dengue myocarditis are self-limited, with only a minority at risk of progressing to heart failure. In order to improve recognition and prevent progression, healthcare providers should maintain a high degree of suspicion regarding potential cardiac complications in patients with dengue.
Topics: Male; Humans; Female; Adult; Myocarditis; Dengue; Severe Dengue; Heart Diseases; Heart Failure
PubMed: 37547170
DOI: 10.5334/gh.1254 -
Nature Aug 2023Studies have demonstrated that at least 20% of individuals infected with SARS-CoV-2 remain asymptomatic. Although most global efforts have focused on severe illness in...
Studies have demonstrated that at least 20% of individuals infected with SARS-CoV-2 remain asymptomatic. Although most global efforts have focused on severe illness in COVID-19, examining asymptomatic infection provides a unique opportunity to consider early immunological features that promote rapid viral clearance. Here, postulating that variation in the human leukocyte antigen (HLA) loci may underly processes mediating asymptomatic infection, we enrolled 29,947 individuals, for whom high-resolution HLA genotyping data were available, in a smartphone-based study designed to track COVID-19 symptoms and outcomes. Our discovery cohort (n = 1,428) comprised unvaccinated individuals who reported a positive test result for SARS-CoV-2. We tested for association of five HLA loci with disease course and identified a strong association between HLA-B*15:01 and asymptomatic infection, observed in two independent cohorts. Suggesting that this genetic association is due to pre-existing T cell immunity, we show that T cells from pre-pandemic samples from individuals carrying HLA-B*15:01 were reactive to the immunodominant SARS-CoV-2 S-derived peptide NQKLIANQF. The majority of the reactive T cells displayed a memory phenotype, were highly polyfunctional and were cross-reactive to a peptide derived from seasonal coronaviruses. The crystal structure of HLA-B*15:01-peptide complexes demonstrates that the peptides NQKLIANQF and NQKLIANAF (from OC43-CoV and HKU1-CoV) share a similar ability to be stabilized and presented by HLA-B*15:01. Finally, we show that the structural similarity of the peptides underpins T cell cross-reactivity of high-affinity public T cell receptors, providing the molecular basis for HLA-B*15:01-mediated pre-existing immunity.
Topics: Humans; Alleles; Asymptomatic Infections; COVID-19; Epitopes, T-Lymphocyte; Peptides; SARS-CoV-2; HLA-B Antigens; Cohort Studies; T-Lymphocytes; Immunodominant Epitopes; Cross Reactions; Spike Glycoprotein, Coronavirus
PubMed: 37468623
DOI: 10.1038/s41586-023-06331-x