The Preliminary Study On The Cellular Immune Function Of Fever With Thrombocytopenia Syndrome Patients In The Acute Phase And The Recovery Phase

Objective：The main purpose of this article is to detect peripheral blood T lymphocytesubsets and the serum levels of the peripheral blood IL-2, TNF-β, IFN-γ in severefever with thrombocytopenia syndrome (SFTS) patients, to preliminarily explore thecellular immune status of the patients infected with severe fever withthrombocytopenia syndrome bunyavirus (SFTSV).Methods：According to the diagnostic criteria of SFTS prevention guide (2010edition)issued by the Ministry of Health of the People’s Republic of China,30SFTShospitalized patients were observed in2012from April to August, Union Hospital inWuhan City. At the same time,8healthy control subjects were also collected. Theratio of CD3+, CD4+(Th) and CD8+(Tc) was detected in SFTS patients both in theacute phase and the recovery phase and the healthy control subjects by flow cytometry.In addition, the serum levels of the peripheral blood IL-2, TNF-β, IFN-γ were alsotested by enzyme-linked immunosorbent assay (ELISA) between the healthy controland the SFTS patients both in the acute phase and the recovery phase. Statistical analyses were performed to analyze the relationship between the changes of Tlymphocyte subsets and the serum levels of IL-2, TNF-β, IFN-γ and the cellularimmune status of SFTS patients.Results：The serum level of IL-2with SFTS patients in the acute phase (68.51±19.66)and the recovery phase (59.95±24.45), with no significant difference (P=0.518, P>0.05), but between the acute phase (68.51±9.66) with the control group(102.91±20.78), with a significant difference (P=0.000, P <0.05), the recovery phase(59.95±24.45) and the control group (102.91±20.78), there was a significantdifference (P=0.000, P <0.05). The serum level of TNF-β in the SFTS recoveryphase (73.68±28.78) compared with the control group (108.23±8.14) had a statisticalsignificance (P=0.006, P <0.05), neither the acute phase (76.87±49.38) and therecovery phase (73.68±28.78) nor the acute phase (76.87±49.38) and the controlgroup (108.23±8.14) had a significant difference (P=0.087,0.098, P>0.05). The levelof IFN-γ in the control group (104.35±28.14) and the acute phase (19.07±6.91), theacute phase (19.07±6.91) and the recovery phase (36.19±15.76), the control group(104.35±28.14) and the recovery phase (36.19±15.76), the differences weresignificant (P=0.013,0.000,0.000, respectively, P <0.05). CD3+T lymphocyte ratio ofSFTS patients in the acute phase (53.34±9.79)%was lower than the healthy controlgroup (79.77±2.61)%, CD3+T lymphocyte ratio of the recovery phase (63.08±5.56)was still lower than the healthy control group (79.77±2.61)%, CD3+T lymphocyteratio of the acute phase (53.34±9.79)%was lower than the recovery phase(63.08±5.56)%, the difference was statistically significant (P=0.000, P <0.05). CD3+CD4+T lymphocyte in the acute phase (28.46±6.72)%was significantly lower thanthe control group (55.95±3.21)%and the recovery phase (35.19±6.65)%patients, thedifference was statistically significant (P values were0.000,0.000and0.003, P <0.05).CD3+CD8+T lymphocytes in the acute phase (35.42±4.48)%and the control group(28.41±3.81)%, the recovery phase (37.82±2.82)%compared with the control group (28.41±3.81)%, there were statistically significant differences (P=0.001and0.000, P<0.05), but between the acute phase (35.42±4.48)%with the recovery phase(37.82±2.82)%, there was no significant difference (P=0.051, P>0.05). CD4+/CD8+ratio of SFTS patients with the acute phase (0.81±0.23) and the recovery phase(0.94±0.19), the difference was not statistically significant (P=0.076, P>0.05), thehealthy control group (2.11±0.49) compared with the acute phase (0.81±0.23), thedifference was statistically significant (P=0.000, P <0.05), the difference wasstatistically significant between the control group (2.11±0.49) and the recovery phase(0.94±0.19)(P=0.000, P <0.05).Conclusion：SFTSV infection resulted in the significant cellular immune injury. Inthe SFTS patients, CD4+T cells were obviously reduced, CD8+T cells were elevated,the CD4+/CD8+ratio was reversed and the serum levels of the peripheral bloodIL-2, TNF-β, IFN-γ were also significantly reduced both in the acute phase and therecovery phase.