Detection and evaluation of immunofunction of patients with severe fever with thrombocytopenia syndrome

Abstract

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by SFTS virus (SFTSV) with a high fatality rate. But the immunofunction was still unclear. The objective of our study was to assess the immunofunction in SFTS patients. Immunofunction test with flow cytometry which contains CD3+, CD4+ and CD8+ T lymphocytes, B cells and NK cells would be used for detecting serum samples collected from 34 SFTS cases and 20 healthy donors. We found that CD3+ and CD4+ T lymphocytes were significantly diminished in SFTS compared to normal control. In contrast, the percentage of NK cells was elevated. Further analysis revealed that the number of CD3+ and CD4+ T lymphocytes showed that there was a more robust pattern of depression in acute phase and severe SFTS infection compared to the patients in recovery phase and mild SFTS infection. But NK cells were significantly increased in acute phase and severe SFTS. They reverted to the near normal levels in convalescent phase. Additionally, the levels of CD3+ and CD4+ T lymphocytes progressively decreased in death group when compared with the survival group, but the level of B cells was higher. The damages of immune system were obvious, and the immune dysfunction might be partly responsible for disease progression of patients with SFTSV infection.

Severe fever with thrombocytopenia syndrome and its pathogen SFTSV

“…On the other hand, viruses would damage the immune system of hosts. Analysis of immune cells of SFTS patients revealed that the number of CD3þ and CD4þ T lymphocytes decreased in acute phase and severe SFTS infection compared to the patients in recovery phase and mild SFTS infection [27]. However, NK cells were significantly increased in acute phase and severe SFTS, and reverted to the near normal levels in convalescent phase.…”

“…No vaccines or effective drugs against SFTSV have yet been developed. Severity and clinical outcome of patients infected by SFTSV were associated with viral replication and host immune responses [27,56]. Therefore, the control strategies for SFTSV are blocking transmission and protecting susceptible populations, including protecting against tick bites, avoiding direct contact of infectious blood of patients, using personal protective equipments when treating patients and isolation of patients and suspected clinical SFTS patients.…”

Kinetics of viral load and cytokines in severe fever with thrombocytopenia syndrome

“…It has been hypothesized that the cytokine storm plays an important role in the pathophysiology of SFTS [6][7][8][9]. However, limited data have been published on the detailed kinetics of viral load and cytokine profiles concerning the course of disease [3,10,11].…”

Circulating regulatory T cells in patients with severe fever with thrombocytopenia syndrome

“…The relationship between SFTS and the immune system has been studied and debated for some time, and studies have confirmed that the host immune response is at least partly responsible for the pathogenesis of SFTSV infection [7,8]. Reports have shown that subpopulations of T cells were found to be changed at different phases of SFTSV-infected patients [16,19].…”

“…Studies have shown that the occurrence of MODS during initial hospitalization within 72 h is closely associated with mortality [6]. authors have found that SFTS is associated with host immune response, which plays a critical role in determining the severity and clinical outcome of patients who are infected by SFTSV [7,8].…”