Impact of COVID-19 Pandemic on the incidence and prevalence of postural orthostatic tachycardia syndrome.

Background: Individuals recovering from COVID-19 infection have reported experiencing symptoms of postural orthostatic tachycardia syndrome (POTS). These observations have raised concerns about COVID-19 as a significant precipitating factor in the development of post-viral POTS. Given the increasing number of POTS cases reported after COVID-19, we sought to examine the baseline characteristics of POTS patients before and after COVID-19.

Tackling of Immunorefractory Tumors by Targeting Alternative Immune Checkpoints.

Physiologically, well known or traditional immune checkpoints (ICs), such as CTLA-4 and PD-1, are in place to promote tolerance to self-antigens and prevent generation of autoimmunity. In cancer, the ICs are effectively engaged by the tumor cells or stromal ells from the tumor microenvironment through expression of cognate ligands for the ICs present on the cell surface of CD8 T lymphocytes. The ligation of ICs on CD8 T lymphocytes triggers inhibitory signaling pathways, leading to quiescence or an exhaustion of CD8 T lymphocytes.