发热伴血小板减少综合征患者外周血淋巴细胞亚群变化特点

摘要

目的 观察发热伴血小板减少综合征(SFTS)患者不同病程阶段外周血淋巴细胞亚群的动态变化特点,探讨其对疾病的发生、发展及预后的影响.方法 采用病例对照研究,收集江苏省人民医院2011年5-7月SFTS患者12例,诊断标准参照中华人民共和国卫生部发布的发热伴血小板减少综合征防治指南(2010版),按照临床预后分为痊愈组(9例)和死亡组(3例).32名健康对照者均为南京市中心血站健康献血者.采用流式细胞术动态定量检测健康对照者及SFTS患者在不同病程阶段外周血中CD3+即T细胞总数、CD4+即辅助性T细胞(Th细胞)、CD8+即细胞毒性T细胞(Te细胞)以及CD3 - CD16+ CD56+即自然杀伤细胞(NK细胞)表达水平,同时分析其与肝功能、血清酶学、WBC和PLT的关系.SFTS患者组与健康对照组间各淋巴细胞亚群计数的比较采用两独立样本t检验,5例以下小样本比较采用Mann-Whitney U检验.结果 SFTS痊愈组患者在病毒感染早期,Th/Tc比值倒置,外周血中Th细胞在病程第5天(d5)、d7、d9数量分别为(740.9±6.4)、(836.2±272.3)、(1083.6 ±319.7)个/μl,明显低于健康对照组的(1351.4±295.1)个/μl,差异有统计学意义(t值分别为-2.883、-4.235、-2.145,P均＜0.05)；外周血中Tc细胞在病程d7、d9、d11、d13、d15数量分别为( 1006.3±356.5)、(1166.4±242.4)、(1102.4±245.9)、(991.3 ±205.1)、(886.5±154.5)个/μl,明显高于健康对照组的(690.1±194.8)个/μl,差异有统计学意义(t值分别为3.312、5.661、4.574、3.874、2.382,P均＜0.05).至病程d9开始NK细胞明显下降；伴随细胞亚群的异常变化,患者外周血WBC和PLT计数显著下降,血清ALT、AST和LDH、CK等均明显高于正常范围,并随着CD4+细胞计数增加和淋巴细胞亚群恢复正常,大部分患者的WBC、PLT、ALT、AST、LDH、CK等指标也逐步恢复正常.SFTS死亡组患者则表现为T淋巴细胞总数和Th细胞显著减少,病程d7、d8、d9 T淋巴细胞总数分别为(735.9±359.9)、(724.9±125.9)、(845.3±389.3)个/μl;Th细胞计数分别为(533.2±246.9)、(532.1±105.7)、(551.7±86.9)个/μl,明显低于健康对照组的(1727.9±230.2)个/μl和(1351.4±295.1)个/μl,差异有统计学意义(Z值分别为- 2.828、-2.342、- 2.342和- 2.828、-2.342、- 2.342,P均＜0.05).NK细胞计数在病程d7、d8、d9分别为(1141.8±415.5)、(1047.2 ±68.4)、(1276.3 ±545.3)个/μl,显著高于健康对照组的(470.7±242.2)个/μl,差异有统计学意义(Z值分别为-2.180、-2.335、-2.258,P均＜0.05).结论 SFTS患者有明显的细胞免疫损伤,其淋巴细胞亚群的改变与临床分型及预后相关；外周血T淋巴细胞总数和CD4+细胞显著减少,同时伴有NK细胞显著增加,可能是SFTS患者预后不良的重要指标.%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.Twelve confirmed thrombocytopenia syndrome virus ( SFTSV ) infected patients were 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 relationships between these dynamic changes 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 )