ABSTRACT
Objective The aim of this study is to dynamically investigate peripheral blood lymphocyte subsets in fever with thrombocytopenia syndrome (SFTS) patients at different stages,to evaluate the influence of these changes in the infection process.Methods Case-control study was used in the research.Twelveconfirmedthrombocytopeniasyndromevirus ( SFTSV ) infectedpatientswere enrolled.According to SFTS prevention guide issued by Chinese Ministry of Health,these patients were divided into two groups,recovery group and death group.For each group,dynamic profiles of the CD3 + T cells,CD4 + helper T cells,CD8 + cytotoxic T cell and CD3 - CD16 + CD56 + natural killer cells were tested by flow cytometry.Meanwhile, the relationshipsbetween these dynamicchanges and liver function,leukocytes,and platelets were analyzed respectively.Two independent-samples t test was used to compare the difference of the peripheral blood lymphocyte subsets count between the SFTS patients and healthy control.Small sample was analyzed by Mann-Whitney U test.Results In the early stage of infection,Th cells in peripheral blood of recovery group were significantly reduced and Th/Tc ratio was reversed.On day 5,7,9 of post infection,Th cell counts in peripheral blood were (740.9 ± 6.4),(836.2 ± 272.3 ) and ( 1083.6 ± 319.7 ) cells/μl respectively,which were significantly lower than health control ( 1351.4 ± 295.1 ) cells/μl ( t value was -2.883,-4.235,-2.145 respectively,all P ＜0.05).Tc cell counts were significantly more than healthy controls (690.1 ± 194.8) cells/μl through the course,which were ( 1006.3 ±356.5),(1166.4±242.4),(1102.4±245.9),(991.3±205.1) and (886.5±154.5) cells/μl on day 7,9,11,13,15 of the course (t value was 3.312,5.661,4.574,3.874,2.382,all P＜0.05).NK cells were decreased significantly from the ninth day of the course.Associated with abnormal changes of cell subsets,WBC and PLT decreased significantly,and serum ALT,AST,LDH and CK etc.were higher than normal level.With the disease recovery,the abnormality above was gradually improved.In contrast,death cases showed significant decrease in T and Th cells compared with health control (P ＜ 0.05).On day 7,8,9 of the course,the counts of total T cell were (735.9 ± 359.9),(724.9 ± 125.9),(845.3 ± 389.3) cells/μl and the counts of Th cell were ( 533.2 ± 246.9 ),( 532.1 ± 105.7 ),( 551.7 ± 86.9 ) cells/μl,significantly lower than healthy control ( 1727.9 ± 230.2 ) cells/μl and ( 1351.4 ± 295.1 ) cells/μl,with statistically differences (z value was - 2.828, - 2.342,- 2.342 and - 2.828, - 2.342, - 2.342,all P ＜ 0.05 ).On day 7,8,9 of the course,the numbers of NK cell in death group were ( 1141.8 ± 415.5),( 1047.2 ±68.4),( 1276.3 ±545.3) cells/μl,which were significantly more than health group (470.7 ± 242.2) cells/μl,with statistically differences (z value was - 2.180,- 2.335,- 2.258,all P ＜0.05).Conclusions SFTSV infection can induce cell immunity damage.The changes of lymphocyte subsets are associated with clinical classification and prognosis.Significant reduction of T cell and CD4 +cell in peripheral blood are accompanied with significant increase of NK cell,which may be a pivotal indicator of poor prognosis and play an important role in making appropriate strategy in clinical treatment.( Chin J Lab Med,2012,35:826-831 )