Pneumococcal disease in adult solid organ transplantation recipients

In solid organ transplant(SOT) recipients, Streptococcus pneumoniae can cause substantial morbidityand mortality ranging from non-invasive to invasive diseases, including pneumonia, bacteremia, and meningitis, with a risk of invasive pneumococcal disease 12 times higher than that observed in non-immunocompromised patients. Moreover, pneumococcal infection has been related to graft dysfunction. Several factors have been involved in the risk of pneumococcal disease in SOT recipients, such as type of transplant, time since transplantation, influenza activity, and nasopharyngeal colonization. Pneumococcal vaccination is recommended for all SOT recipients with 23-valent pneumococcal polysaccharides vaccine. Although immunological rate response is appropriate, it is lower than in the rest of the population, decreases with time, and its clinical efficacy is variable. Booster strategy with 7-valent pneumococcal conjugate vaccine has not shown benefit in this population. Despite its relevance, there are few studies focused on invasive pneumococcal disease in SOT recipients. Further studies addressing clinical, microbiological, and epidemiological data of pneumococcal disease in the transplant setting as well as new strategies for improving the protection of SOT recipients are warranted.

Dendritic cell deficiencies persist seven months after SARS-CoV-2 infection

Severe Acute Respiratory Syndrome Coronavirus(SARS-CoV)-2 infection induces an exacerbated inflammation driven by innate immunity components.Dendritic cells(DCs)play a key role in the defense against viral infections,for instance plasmacytoid DCs(pDCs),have the capacity to produce vast amounts of interferon-alpha(IFN-α).In COVID-19 there is a deficit in DC numbers and IFN-αproduction,which has been associated with disease severity.In this work,we described that in addition to the DC deficiency,several DC activation and homing markers were altered in acute COVID-19 patients,which were associated with multiple inflammatory markers.Remarkably,previously hospitalized and nonhospitalized patients remained with decreased numbers of CD1c+myeloid DCs and pDCs seven months after SARS-CoV-2 infection.Moreover,the expression of DC markers such as CD86 and CD4 were only restored in previously nonhospitalized patients,while no restoration of integrinβ7 and indoleamine 2,3-dyoxigenase(IDO)levels were observed.These findings contribute to a better understanding of the immunological sequelae of COVID-19.