A Focus on the Mechanisms of Alteration in Host Lymphocyte Level Following Severe Fever with Thrombocytopenia Syndrome Virus (SFTSV) Infection.

Nowadays, severe fever with thrombocytopenia syndrome (SFTS), featuring clinical manifestation of fever with leukopenia, thrombocytopenia and multiple organ function impairment, has been paid more and more attention. It has become the pandemic for a few years and a quantity of people died of it. Severe fever with thrombocytopenia syndrome virus (SFTSV) infection may lead to the development of SFTS, which is characterized by decreased counts of lymphocyte subsets, especially T cells, B cells and natural killer cells, and disruptive release of cytokines, chemokines and growth factors. However, the deeper mechanism of this disease remains unidentified. To excavate the mechanisms of lymphopenia in SFTSV infection and to introduce the potential therapeutics, this paper focuses on lymphopenia as well as reviews the mechanisms and effects of lymphopenia caused by SFTSV infection, mainly through making analogies with other similar viruses to explain the details of programmed cell death. Other factors such as IL-6,IL-10, TNF-α and some vital immunocytes also play significant roles in eliciting lymphopenia. Eventually, the probable clinical implications have been discussed, mentioning that lymphopenia induced by multiple pathways in SFTSV infection may be associated with the severity of viral disease and opportunistic infection.