尘螨变应性哮喘患儿外周血T淋巴细胞中协同刺激分子和细胞因子的异常表达及其意义

目的分析变应原刺激前后变应性哮喘患儿外周血T淋巴细胞表面协同刺激分子及胞内细胞因子表达的变化,探讨CD28家族不同协同刺激信号在变应性哮喘免疫病理机制中的作用。方法选取尘螨变应性哮喘患儿(哮喘组)和健康儿童(健康对照组)各30例,密度梯度离心法分离其外周血单个核细胞,应用免疫荧光标记和流式细胞术检测尘螨刺激前后体外培养的CD4+T淋巴细胞表面协同刺激分子CD28、可诱导共刺激分子(ICOS)和细胞毒T淋巴细胞相关抗原4(CTLA-4)的表达,运用细胞内染色技术检测CD4+T淋巴细胞内细胞因子γ干扰素(IFN-γ)、IL-4和IL-13的表达。并运用统计学方法比较哮喘组和健康对照组之间的差异。结果哮喘组患儿外周血CD4+T淋巴细胞表面CD28和ICOS的表达与健康对照组比较差异均无统计学意义(Pa>0.05),而CTLA-4的表达显著降低(P<0.01);细胞内IFN-γ表达水平显著升高(P<0.000 1),而IL-4和IL-13表达水平无明显变化(Pa>0.05)。经尘螨刺激后,体外培养的哮喘患儿外周血CD4+T淋巴细胞表面ICOS的表达较健康对照组儿童显著上调(P<0.000 1),CD28和CTLA-4的表达则无明显变化(Pa>0.05);细胞内细胞因子IL-4和IL-13的表达显著上调(Pa<0.000 1),而IFN-γ的表达则无明显差异(P>0.05)。结论变应性哮喘患儿外周血存在组成性的CTLA-4的表达下调和细胞因子IFN-γ的表达上调,介导Th1型细胞的异常活化;而变应原尘螨的刺激又介导了ICOS依赖的Th2型细胞的分化,导致Th1/Th2失衡。     

CD28表达与幼年特发性关节炎发病的相关性研究

目的 探讨CD28在幼年特发性关节炎(juvenile idiopathic arthritis,JIA)活动期及疾病静息期变化的意义.方法 利用流式细胞仪技术检测36例初发JIA患儿治疗前和疾病稳定后外周血CD4+、CD8+T细胞表面CD28的表达.结果 JIA患儿疾病活动期外周血CD4+T细胞CD28+表达显著低于正常对照组(P＜0.01),CD8+T细胞CD28+表达显著低于正常对照组(P ＜0.01);JIA患儿疾病活动期外周血CD28-表达的CD4+T细胞显著高于正常对照组(P ＜0.01);JIA患儿疾病活动期外周血CD4+T细胞数量显著高于正常对照组,CD8+T细胞显著减少(P ＜0.01);JIA患儿疾病静息期外周血CD4+T细胞和CD8+T细胞数量与正常对照组差异无统计学意义(P＞0.05);JIA患儿疾病静息期外周血CD4+T细胞CD28表达和CD8 +T细胞CD28表达与正常对照组差异无统计学意义(P＞0.05).结论 CD28-的表达水平可以作为JIA疾病活动期的指标之一;JIA患儿疾病活动期CD4+T细胞、CD4+ CD28-T细胞出现凋亡障碍.     

辅助性T淋巴细胞17/调节性T淋巴细胞偏倚在川崎病发病机制中的作用

目的 探讨辅助性T淋巴细胞17(Th17)和Foxp3+CD4+调节性T淋巴细胞在儿童川崎病(KD)免疫发病机制中的作用.方法 急性期KD患儿40例,同龄健康对照儿童30例.KD患儿在静脉丙种球蛋白(IVIG)治疗前直接取血备检.流式细胞术检测其外周血Th17细胞及Foxp3+CD4+T淋巴细胞比例;荧光定量PCR检测其CD4+T淋巴细胞转录因子ROR-γt、Foxp3 mRNA表达;ELISA法检测其血浆中IL-17、IL-6、转化生长因子-β(TGF-β)、IL-23水平.结果 急性期KD患儿外周血Th17细胞明显升高(P<0.01),而Foxp3+CD4+T淋巴细胞明显降低(P<0.01);急性期KD患儿Th17细胞转录因子ROR-γt转录水平明显高于健康对照组(P<0.01),Foxp3+CD4+T淋巴细胞转录因子Foxp3表达明显降低(P<0.01);血清IL-6、IL-23和IL-17水平明显升高(Pa<0.01),而TGF-β水平无明显变化(P>0.05).结论 Th17促炎性T淋巴细胞高表达和Foxp3+CD4+调节性T淋巴细胞数量减少导致免疫抑制效应不足是导致儿童KD免疫失衡的重要原因,体内相关细胞因子的变化是引起上述改变的原因.     

����������ԭ���������ۺ����Ի���CD4+CD25+������Tϸ����Ӱ�����

目的 观察原发性肾病综合征(PNS)患儿泼尼松治疗前后CD4+CD25+调节性T细胞(CD4+CD25+Tr)的变化,阐明肾上腺糖皮质激素治疗儿童PNS的免疫机制.方法 选择2004-2007年在深圳市儿童医院住院治疗的初发PNS患)L42例,其中激素敏感型32例,激素耐药型10例.同期25例健康体检儿童作为对照组.流式细胞术检测泼尼松治疗前后外周血CD3+CD4+CD8-、CD3+CD4-CD8+、CD4+CD25+Tr的比例,荧光定量聚合酶链反应(Real-time PCR)检测泼尼松治疗前后外周血单个核细胞(PBMC)叉头型基因P3(Foxp3)、细胞毒性T淋巴细胞相关抗原4(CTL-4)和糖皮质激素诱导的肿瘤坏死因子受体(GITR)基因mRNA的表达.结果 与对照组比较,PNS患儿外周血CD3+CD4+CD8-T细胞、CD3+CD4-CD8+T细胞、CD4+CD25+Tr比例无明显改变(P>0.05).激素敏感型PNS患儿CD4+CD25+Tr比例在泼尼松治疗后明显增高,差异有统计学意义(P<0.01);激素耐药型PNS患儿CD4+CD25+Tr比例在泼尼松治疗前后无明显改变(P>0.05).激素敏感型PNS患儿在泼尼松治疗后PBMC细胞Foxp3、CTLA-4和GITR基因mRNA的表达明显增高;而激素耐药型PNS患儿泼尼松治疗前后Foxp3、CTLA-4基因表达无明显改变,仅GITR表达明显增高.结论 泼尼松等肾上腺糖皮质激素类药物可通过上调激素敏感型PNS患儿CD4+CD25+调节性T细胞的表达发挥免疫治疗作用.     

幼年特发性关节炎患儿外周血Th细胞亚群变化

目的探讨幼年特发性关节炎(JIA)患儿外周血CD4 T淋巴细胞及其亚群CD4 CD45RA 、CD4 CD45RO 的表达及其临床意义。方法采用免疫荧光标记技术和流式细胞仪检测36例JIA患儿外周血CD4 T淋巴细胞及其亚群CD4 CD45RA 、CD4 CD45RO 的表达,同期检测20例年龄、性别无差异的健康儿童为对照。结果JIA患儿外周血CD4 T淋巴细胞明显低于对照组(t=2.099,P<0.05),CD4 CD45RA T淋巴细胞数与对照组比较明显降低(t=3.450,P<0.01),CD4 CD45RO T淋巴细胞数明显升高(t=3.913,P<0.01),CD4 CD45RA T/CD4 CD45RO T比值明显降低(t=4.904,P<0.01);与对照组比较,JIA各亚型(全身型、多关节型、少关节型)的CD4 CD45RO T淋巴细胞数均明显升高,CD4 CD45RA T/CD4 CD45RO T比值明显降低(P<0.01);CD4 CD45RA T淋巴细胞数与正常对照组比较在全身型中显著降低(t=4.192,P<0.01);在多关节型中明显降低(t=2.214,P<0.05);在少关节型中稍有降低,但与对照组比较差异无显著性(t=1.793,P>0.05)。结论JIA患儿的免疫功能紊乱主要表现为CD4 T淋巴细胞及其亚群CD4 CD45RA T/CD4 CD45RO T失衡,这可能在JIA发病机制中起着重要的作用。     

幼年类风湿关节炎患儿血清白介素-15变化与T_H细胞亚群表达的研究

目的：探讨幼年类风湿关节炎(JRA)患儿血清白介素15变化及其TH细胞亚群CD4+CD45RA+,CD4+CD45RO+的表达变化。方法：采用ELISA方法检测39例JRA患儿的血清IL15的水平,并同期选择26例年龄、性别无差异的健康儿童为对照。对其中24例JRA患儿采用免疫荧光标记技术和流式细胞仪检测外周血CD4+T淋巴细胞亚群CD4+CD45RA+,CD4+CD45RO+的表达。结果：JRA患儿组血清IL15水平显著高于正常对照组(P<0.05);JRA常见亚型中全身型患儿血清IL15水平明显升高,与对照组比较差异有显著性(P<0.01),而少关节型、多关节型患儿IL15水平与对照组比较差异无显著性(P>0.05);治疗后IL15水平较治疗前明显下降(P<0.01);JRA患儿血清IL15水平与外周血白细胞计数呈正相关(r=0.347,P<0.05),与血沉无相关(r=0.307,P>0.05),与C反应蛋白呈显著正相关(r=0.452,P<0.01);IL15高表达组患儿外周血CD4+CD45RO+T淋巴细胞数明显高于IL15低表达组患儿(P<0.05),CD4+CD45RA+T淋巴细胞数、CD4+CD45RA+T/CD4+CD45RO+T比值略低于IL15低表达组患儿,差异无显著性(P>0.05)。结论：JRA患儿血清IL15的水平显著升高;IL15升高使JRA患儿外周血CD4+T细胞表面CD45RA分子向CD45RO分子转换,促使T淋巴细胞大量激活,进而介导组织免疫病理损伤;在临床上可通过检测IL15以判断JRA的病情状况,为JRA治疗提供理论依据。     

难治性肺炎支原体肺炎患儿T细胞活化功能状态的变化

目的探讨难治性肺炎支原体肺炎(MPP)患儿T细胞活化功能状态。方法采用免疫荧光标记和流式细胞仪技术对26例难治性MPP患儿外周血T细胞亚群的表面标记和活化后表面分子的表达进行分析,并以18例健康儿童外周血作为对照。结果与对照组比较,难治性MPP患儿CD4 T细胞、CD4 /CD8 值、CD3 /HLA-DR 活化T细胞和T细胞活化后CD3 /CD25 细胞的表达率均显著降低(P均<0.01);难治性MPP患儿CD8 T细胞的表达率明显高于对照组(P<0.01);而CD3 T细胞的表达率在两组间无显著差异(P>0.05)。结论难治性MPP患儿存在T细胞免疫功能紊乱和T细胞活化功能障碍。     

卡介苗干预对哮喘小鼠T淋巴细胞活化/凋亡状态的影响

目的 探讨卡介苗(BCG)干预对哮喘小鼠共刺激分子B7-CD28/CD152的表达及T淋巴细胞凋亡的影响.方法 昆明小鼠27只随机分为哮喘组、BCG干预组和对照组,每组9只.用卵清蛋白(OVA)、100g/L氢氧化铝腹腔注射致敏哮喘组小鼠,OVA雾化吸入激发,复制哮喘模型.干预组在致敏前5、3、1 d采用BCG皮内注射,0.025 mg/只,共干预3次,余同哮喘组.对照组以9g/L盐水代替OVA及氢氧化铝致敏和激发.流式细胞术检测各组小鼠脾淋巴细胞悬液CD28、CD152、CD80、CD86的表达;采用Ficoll法分离各组小鼠外周血单个核细胞并培养出T淋巴细胞,采用Comet法检测各组小鼠T淋巴细胞凋亡率.采用SPSS10.0软件进行统计学分析.结果 哮喘和对照组小鼠比较CD28表达明显上调(t=3.94 P<0.01),CD152表达无变化(t=0.38 P>0.05),CD80表达无变化(t=0.40 P>0.05),CD86>达上升(t=2.68 P<0.05);BCG干预和哮喘组比较,CD28表达显著下调(t=4.21 P<0.01),CD152表达显著上调(t=3.21 P<0.01),CD80表达明显上调(t=2.50 P<0.05),CD86二组表达无差异(t=0.45 P>0.05).T淋巴细胞凋亡率BCG干预组明显高于哮喘组(t=3.15 P<0.01).哮喘与对照组T淋巴细胞凋亡率比较显著减少(t=5.83 P<0.01).结论 BCG通过抑制小鼠T淋巴细胞活化,促进T淋巴细胞凋亡,上调TH1反应,发挥其防治哮喘作用.     

儿童噬血细胞性淋巴组织细胞增生症淋巴细胞亚群变化及临床意义

目的探讨外周血淋巴细胞亚群对儿童噬血细胞性淋巴组织细胞增生症(HLH)诊断、治疗和预后判断的意义。方法 30例HLH患儿,采用HLH-2004诊断治疗方案,20例患儿获得完全缓解,10例死亡。30例同龄健康儿童作为正常对照。采用流式细胞术检测外周血淋巴细胞亚群。结果 20例缓解患儿和10例死亡患儿急性期与正常对照组比较,CD3+T和CD8+T细胞比例均增高,CD4+T和CD3-CDl6+CD56+NK细胞比例均下降,CD4+/CD8+比值减低,差异均有统计学意义(H=7.857~45.448,P均0.05);CD19+B细胞比例与对照组比较,差异无统计学意义(H=6.202,P0.05)。20例HLH缓解患儿缓解期与急性期淋巴细胞亚群比较,CD3-CD16+CD56+NK细胞比例的差异有统计学意义(Z=3.760,P0.05),CD3+T、CD8+T、CD4+T和CD4+/CD8+比值、CD19+B计数差异无统计学意义(Z=0.135~1.082,P均0.05)。结论 HLH患儿淋巴细胞亚群有明显变化,存在细胞免疫失衡;动态检测其变化可能有助于判断HLH的治疗效果及预后。     

外周血T淋巴细胞亚群比例对免疫抑制治疗急性再生障碍性贫血患儿预后预测的意义

目的探讨采用免疫抑制治疗急性再生障碍性贫血(AA)患儿的效果及与治疗前外周血T淋巴细胞亚群分类比例的关系。方法选取本科2000-2007年收治的43例接受免疫抑制治疗的急性AA患儿,依据治疗结果将患儿分为有效组和无效组。对2组患儿治疗前外周血T淋巴细胞亚群分类比例进行统计学分析。进一步将有效组患儿根据CD4+/CD8+比值分为3组:比例正常组,比例倒置组及比例超高组,分别将该3组CD4+/CD8+比值与治疗无效组进行比较,并进行统计学分析。结果免疫抑制治疗有效组与免疫抑制治疗无效组比较,有效组中CD4+/CD8+比例倒置及超高患儿与无效组比较差异有统计学意义;二组治疗前外周血T淋巴细胞亚群分类中CD8+CD28+及CD8+CD28-细胞比例差异有统计学意义,治疗有效组患儿CD8+CD28+/CD8+CD28-比值显著高于治疗无效组。结论急性AA患儿治疗前外周血T淋巴细胞亚群CD8+CD28+/CD8+CD28-细胞比例对预测免疫抑制治疗效果具有一定的临床意义。可有针对性的为急性AA患儿选择治疗方案提供参考依据。     

Pubertal growth and development and prenatal and lactational exposure to polychlorinated biphenyls and dichlorodiphenyl dichloroethene

OBJECTIVES: Polychlorinated biphenyls (PCBs) and dichlorodiphenyl dichloroethene (DDE) are ubiquitous toxic environmental contaminants. Prenatal and early life exposures affect pubertal events in experimental animals. We studied whether prenatal or lactational exposures to background levels of PCBs or DDE were associated with altered pubertal growth and development in humans.Study design: Follow-up of 594 children from an existing North Carolina cohort whose prenatal and lactational exposures had previously been measured. Height, weight, and stage of pubertal development were assessed through annual mail questionnaires. RESULTS: Height of boys at puberty increased with transplacental exposure to DDE, as did weight adjusted for height; adjusted means for those with the highest exposures (maternal concentration 4+ ppm fat) were 6.3 cm taller and 6.9 kg larger than those with the lowest (0 to 1 ppm). There was no effect on the ages at which pubertal stages were attained. Lactational exposures to DDE had no apparent effects; neither did transplacental or lactational exposure to PCBs. Girls with the highest transplacental PCB exposures were heavier for their heights than other girls by 5.4 kg, but differences were significant only if the analysis was restricted to white girls. CONCLUSIONS: Prenatal exposures at background levels may affect body size at puberty.     

Prevention and treatment of overweight and obesity in children and adolescents

Increasing numbers of obese children and adolescents all over the world demand an investment in the primary and secondary prevention of obesity and overweight in this age group. The goal of preventive measures in children is to avoid the negative short- and long-term health problems associated with obesity. Primary prevention aims at establishing a healthy, active lifestyle and keeping children and adolescents within a range of body weight which is considered to be healthy. Constant availability and affordability of palatable and energy-dense food in the affluent society of the western world demands preventive strategies. Universal or public health prevention seems to be the most suitable form because several other cofactors of morbidity and mortality of affluent societies can also be prevented. However, in most European countries there is a lack of awareness of the necessity of prevention programmes, not only among the general population but also among the medical society. More awareness and consciousness to the problem of obesity must be generated in order to lead to effective therapeutic programmes. For those children and adolescents who are already obese, secondary prevention is mandatory. Therapeutic intervention programmes for the obese aim at long-term weight maintenance and normalisation of body weight and body fat. They have to modify eating and exercise behaviour of the obese child and establish new, healthier behaviour and lifestyle. Treatments programmes must include behavioural components in order to permanently change nutrition and physical exercise of the obese children and adolescents. However, long-term results of treatment programmes in European countries are scarce and the reported results, even of multidisciplinary regimens, are not impressive. Conclusion In most European countries there is an urgent need not only for a growing awareness of the problem of obesity in children and adolescents but also for development of new comprehensive approaches in treating this group.     

Hypokalemia and Hyperkalemia in Infants and Children: Pathophysiology and Treatment

Potassium is the second most abundant cation in the body. About 98% of potassium is intracellular and that is particularly in the skeletal muscle. Electrical disturbances associated with disorders of potassium homeostasis are a function of both the extracellular and intracellular potassium concentrations. Clinical disorders of potassium homeostasis occur with some regularity, especially in hospitalized patients receiving many medications. This article will review the pathophysiology of potassium homeostasis, symptoms, causes, and treatment of hypo- and hyperkalemia.