感染性疾病患儿血浆甘露糖结合凝集素浓度分析

目的 分析常见感染性疾病患儿血浆甘露糖结合凝集素(MBL)的浓度.方法 应用ELISA法检测正常对照组(68例)、正常脐血组(48例)和感染性疾病组(124例)患儿血浆MBL浓度并加以比较.结果 正常脐血组MBL浓度(729.31±259.73)μg/L,明显低于正常对照组(898.34±284.58)μg/L(P=0.001);感染性疾病组支气管肺炎患儿、支气管炎患儿、肠炎患儿MBL浓度(分别为766.45±274.34 μg/L,774.82±273.34 μg/L,526.54±280.83 μg/L)与正常对照组比较均有显著性差异(P值分别为0.032,0.019和0.001).上呼吸道感染患儿MBL浓度(792.89±250.01 μg/L)与正常对照组比较无显著性差异(P=0.125).结论 患儿血浆MBL水平降低可能是儿童在免疫脆弱期易发生呼吸道和消化道感染性疾病的原因之一.     

儿科常见感染性疾病患儿血浆甘露糖结合凝集素浓度检测

目的 比较几种儿科常见感染性疾病患儿血浆甘露糖结合凝集素(MBL)浓度.方法 采用ELISA法检测血浆MBL浓度,组间比较采用SPSS软件11.0版的非参数检验.结果 健康组(105例)、反复呼吸道感染组(57例)、急性呼吸道感染组(21例)、急性阑尾炎组(17例)、体表局部脓肿组(13例)的血浆MBL浓度中位数分别为1 065、798、1 477、1 463和1 707 ng/ml,健康组MBL浓度低于急性呼吸道感染组(P=0.030)和体表局部脓肿组(P=0.021),但与反复呼吸道感染组(P=0.052)相比差异无统计学意义;反复呼吸道感染组与其他感染组相比,MBL浓度明显低于急性呼吸道感染组(P=0.011)和体表局部脓肿组(P=0.005).结论 低血浆MBL浓度可能是儿童反复呼吸道感染的影响因素之一.     

反复呼吸道感染患儿血浆甘露糖结合凝集素水平及其结构基因单核苷酸多态性分析

目的研究儿童甘露糖结合凝集素(MBL)结构基因外显子1区单核苷酸多态性(SNPs)、血浆MBL水平与反复呼吸道感染(RRTI)的关系。方法观察浙江大学医学院附属儿童医院2004-01—2005-10收治的反复呼吸道感染患儿60例,2005-05—2005-08入托体检儿童105名,其血浆MBL质量浓度的检测采用ELISA法,MBL基因SNPs分析采用序列特异性引物PCR法和序列分析法,统计分析采用SPSS软件11.0版。遗传学分析采用SHEsis软件。结果105名健康儿童血浆MBL质量浓度范围为3～6025ng/mL,中位数1065ng/mL;60例RRTI患儿MBL质量浓度范围为1～3633ng/mL,中位数822ng/mL;RRTI组中低血浆MBL的个体所占比例明显高于健康组(χ2=4.05,P<0.050)。健康组和RRTI组结构基因密码子54即 230位点的变异频率分别为0.167和0.283,两组该位点的等位基因分布均符合Hardy-Weinberg平衡,RRTI组的变异频率显著高于健康组(χ2=6.285,P=0.012);密码子52( 223位点)和57( 239位点)无突变,即无C和D型突变体发现。A/A、A/B和B/B型外显子表达的血浆MBL水平依次显著下降(χ2=80.028,P≈0.000)。结论中国汉族人中MBL结构基因C和D型外显子罕见,而54号密码子的变异与小儿反复呼吸道感染之间可能存在相关关系。     

甘露糖结合凝集素与感染性疾病

甘露糖结合凝集素（MBL）是一种钙调节依赖糖结合蛋白,属于凝集素家族,是一种血清C型凝集素,在固有免疫应答中发挥重要的免疫防御作用.MBL主要由肝细胞合成,少数来源于巨噬细胞、多形核白细胞、内皮细胞、成纤维细胞等.MBL与病原微生物如细菌、真菌、病毒、寄生虫等表面的糖类结构结合,并且通过MBL补体激活途径发挥调理作用,导致病原体裂解,亦可清除循环免疫复合物,在免疫监视和免疫防御中具有重要意义.鉴于血清MBL低下或缺失与临床感染性疾病密切相关,故有必要对MBL进行深入研究.     

甘露糖结合凝集素与感染性疾病

甘露糖结合凝集素(MBL)是一种钙调节依赖糖结合蛋白,属于凝集素家族,是一种血清C型凝集素,在固有免疫应答中发挥重要的免疫防御作用。MBL主要由肝细胞合成,少数来源于巨噬细胞、多形核白细胞、内皮细胞、成纤维细胞等。MBL与病原微生物如细菌、真菌、病毒、寄生虫等表面的糖类结构结合,并且通过MBL补体激活途径发挥调理作用,导致病原体裂解,亦可清除循环免疫复合物,在免疫监视和免疫防御中具有重要意义。鉴于血清MBL低下或缺失与临床感染性疾病密切相关,故有必要对MBL 进行深入研究。     

甘露糖结合凝集素基因多态性与川崎病

川崎病是一种儿童常见的自身免疫性疾病,以全身中小动脉炎症病变为主要特征,但其发病机制仍不完全清楚.近几年的研究显示川崎病与多种遗传基因片段的多态性有关,甘露糖结合凝集素基因与川崎病的关系也逐渐引起关注.该文就甘露糖结合凝集素结构和功能做一简述,并着重介绍甘露糖结合凝集索基因多态性与川崎病易患性和心血管损伤之间的关系.     

甘露糖结合凝集素基因多态性与幼年特发性关节炎的相关性

目的 探讨甘露糖结合凝集素（MBL）基因外显子1多态性与幼年特发性关节炎（JIA）易感性的关系。方法 采用聚合酶链反应．限制性片段长度多态性（PCR，RFLP）法分析93例JIA和48名正常健康儿童MBL基因外显子1第54和57位密码子的多态性。结果 1．JIA及健康儿童均未发现有57位密码子突变。2．JIA患儿第54位密码子野生型基因型频率为71．0％（66／93），杂合子型为25.8％（24／93），突变纯合子型为3．2％（3／93）；正常对照儿童野生型75．0％（36／48），杂合子型为25．0％（12／48），未发现突变纯合子基因型；各基因型与JIA组比较无差异（P〉0．05）。结论 MBL基因外显子1多态性与JIA无相关。     

甘露糖结合凝集素基因多态性与中国汉族儿童过敏性紫癜的相关性研究

目的：近来有研究认为某些自身免疫性疾病可能与甘露糖结合凝集素(MBL)缺陷有关。MBL基因多态性影响MBL水平。过敏性紫癜(Henoch-Schnlein purpura, HSP)是一种全身性血管炎综合征,其病因被认为可能与免疫损伤有关。该研究探讨MBL基因第54号密码子多态性与中国汉族儿童过敏性紫癜(HSP)的关系。方法：应用聚合酶链反应-限制性内切酶片段长度多态性分析,对160例健康中国汉族儿童及104例过敏性紫癜(HSP)患儿的MBL基因多态性进行检测。结果：①HSP患儿MBL基因GGC/GAC基因型频率明显高于健康对照组(51.9% vs 25.0%)(P<0.05),而GGC/GGC基因型频率显著低于健康对照组(46.2% vs 73.8%)(P<0.05)。HSP患儿GAC等位基因频率明显高于健康对照组(0.279 vs 0.138)(P<0.05),而GGC等位基因频率明显低于健康对照组(0.721 vs 0.862)(P<0.05);GAC等位基因与HSP的发病明显相关(OR=2.46,95% CI=1.32-4.48,P<0.05)。②在HSP患儿中,GAC型等位基因携带者中有前驱感染史者明显多于GGC纯合子(P<0.05)。结论：HSP发病受遗传背景影响,MBL第54号密码子基因多态性可能是HSP易感性标志。     

甘露糖结合凝集素基因54号密码子多态性与川崎病易感性的研究

目的　探讨甘露糖结合凝集素 (MBL)基因第 5 4号密码子多态性与中国汉族儿童川崎病的易感性和临床表型的关系。方法　应用聚合酶链反应 限制性内切酶片段长度多态性分析 ,对16 0例中国汉族健康儿童及 95例川崎病患儿的MBL基因多态性进行检测。结果　 ( 1)中国汉族健康儿童MBL基因多态性分布与文献报道的香港华人及高加索人种接近 ,无统计学差异。( 2 )川崎病患儿GAC等位基因频率高于健康对照组 ( 0 2 5 8vs 0 138,P <0 0 1) ,而GGC等位基因频率低于健康对照组 ( 0 74 2vs 0 86 2 ,P <0 0 1)。GAC型等位基因与中国汉族儿童川崎病密切相关 [OR =2 18,95 %CI(OR值的 95 %置信区间 )为 1 38～ 3 4 4 ,P <0 0 5 ]。 ( 3)在川崎病患儿中 ,GAC型等位基因携带者其病史有前驱感染史者多于GGC纯合子 (P <0 0 1)。结论　川崎病发病受遗传背景的影响 ,与MBL第 5 4号密码子基因多态性密切相关     

深圳地区学龄前儿童血清甘露聚糖结合凝集素分析

目的：甘露聚糖结合凝集素是机体天然免疫的关键组成成分,该研究探讨学龄前儿童血清甘露聚糖结合凝集素的水平及分布特征,为预防儿童感染提供指导依据。方法：随机留取深圳市三所幼儿园118名3～6岁儿童的血清标本,其中男性62例,女性56例,通过酶联免疫吸附法测定血清甘露聚糖结合凝集素的水平。结果：深圳地区学龄前儿童血清甘露聚糖结合凝集素的浓度为779.07±268.98 ng/mL,其中男性值为783.89±252.30 ng/mL,女性值为773.65±288.29 ng/mL,均值无性别差异（P>0.05）。血清甘露聚糖结合凝集素低于500 ng/mL的儿童有16名,占13.6%,其中50～500 ng/mL有14名,50 ng/mL以下2名。结论：深圳地区学龄前儿童血清甘露聚糖结合凝集素的分布范围为779.07±268.98 ng/mL,可为临床和科研工作者提供参考,对血清甘露聚糖结合凝集素低于正常值下限的儿童可以适当使用抗生素预防感染。     

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目的了解反复呼吸道感染(RRTI)儿童血清甘露聚糖凝集素(MBL)水平及第一外显子54密码子的突变率,探讨血清MBL水平与RRTI的关系。方法用ELISA方法检测2000～2003年在重庆医科大学附属儿童医院就诊的65例RRTI儿童和238名正常儿童血清MBL水平,测定其中11例低MBL血症的RRTI儿童的免疫学指标(IgG、IgA、IgM、C3、C4),并用聚合酶链反应(PCR)限制性内切酶片段长度多态性分析(RFLP)方法与55名正常儿童MBL第一外显子54密码子基因多态性进行分析。结果RRTI儿童出现低血清MBL水平频率明显多于正常儿童(χ2=6.96,P<0.05),其MBL54密码子突变率亦明显增高(P<0.05),低血清MBL血症导致RRTI主要在2岁以前,血清MBL水平越低,感染频率越高,其C3、C4水平也越高。结论儿童MBL54密码子突变导致低MBL血症在2岁以前有反复呼吸道感染的倾向,MBL水平越低,感染机率越高。     

Mannose-binding lectin levels in children with asthma

Mannose-binding lectin (mbl), one of the important components of innate immunity, can activate the lectin pathway of the complement system. After binding mannose containing carbohydrate structures of foreign antigen, mbl initiates and regulates the inflammatory responses. Asthma is a complex inflammatory disease of the lung involving many components of the immune system. Our objective was to investigate the serum mbl levels of asthmatic children in comparison with healthy controls. Serum mbl levels were determined by nephelometric assay in 72 asthmatic children (5-15 yr old) and 30 healthy age-matched controls. Mbl levels of asthmatic children were measured both during acute attack and after complete remission. There was no significant difference between the mbl levels during acute attack (median 4.1 mg/l) or quiescence of symptoms (median 3.6 mg/l). Serum mbl levels both during acute attack or quiescence of symptoms was significantly higher in asthmatic children than in the healthy controls (median 2.8 mg/l, p < 0.0001 for each). Furthermore, mbl levels of asthmatic children positively correlated with peripheral blood eosinophils (r = 0.377, p < 0.001), which is a systemic component of airway inflammation in asthma. Our findings indicate that mbl may be implicated in the pathogenesis of asthma by contributing to airway inflammation or by increasing the risk of developing asthma.     

Serum levels of mannose-binding lectin and the risk of infection in pediatric oncology patients with chemotherapy

Morbidity and mortality due to infections remain serious problems in pediatric oncology patients receiving chemotherapy. Association of mannose-binding lectin (MBL) levels with an increased risk for infection in previous studies was contradictory. The aim of this study was to determine whether MBL deficiency is associated with the risk of infections in pediatric oncology patients. Before the start of chemotherapy a blood sample was taken from 75 patients with acute lymphoblastic leukemia and MBL serum concentration was measured using a commercially enzyme-linked immunosorbent assay kit. Twenty patients had concentrations under 1000 μg/L, defining MBL deficiency and the remaining 55 patients had concentrations >1000 μg/L. Ten patients suffered from more than 1 episode of severe infection. Sixty-five percent of patients with MBL below 1000 μg/mL suffered from 2 or more episodes of infections (3 of 16 individuals with 1 severe infection; 10 of 16 with 2 and 3 of 16 with 3), in contrast to only 29 of 55 (52%) patients with MBL above 1000 μg/mL (19 of 27 individuals with 1 severe infection and 10 of 27 with 2). The difference between 2 groups was significant (P<0.001). The results of this study indicate that low MBL serum levels (<1000 μg/L) identify pediatric cancer patients at increased risk for infections.     

Serum levels of mannose-binding lectin and the risk of fever in neutropenia pediatric cancer patients

BACKGROUND: Fever in neutropenia (FN) is a frequent complication in pediatric oncology. Deficiency of mannose-binding lectin (MBL), an important component of innate immunity, is common due to genetic polymorphisms, but its impact on infections in oncologic patients is controversial. This study investigated whether MBL serum levels at cancer diagnosis are associated with the development of FN in pediatric cancer patients. PROCEDURE: Serum MBL was measured using ELISA. Frequency, duration, and cause of FN were assessed retrospectively. Association with MBL level was analyzed using uni- and multivariate Poisson regression taking into account both intensity and duration of chemotherapy. RESULTS: In 94 children, with a cumulative follow-up time of 81.7 years, 177 FN episodes were recorded. Patients with both very low MBL levels (<100 microg/L; risk ratio (RR), 1.93; 95% CI, 1.14-3.28; P = 0.014) and normal MBL levels (>or=1,000 microg/L; RR, P = 0.011) had significantly more frequent FN episodes than patients with low MBL levels (100-999 microg/L). Patients with very low MBL levels had significantly more episodes of FN with severe bacterial infection (bacteremia or pneumonia; RR, 4.49; 1.69 = 11.8; P = 0.003), while those with normal MBL levels had more FN episodes with no microbial etiology identified (RR, 1.85; 1.14 = 3.03; P = 0.014). CONCLUSIONS: Very low MBL levels are associated with more frequent FN episodes, mainly due to severe bacterial infections. The surprising finding that children with normal MBL levels had more frequent FN episodes than those with low MBL levels needs testing in prospective studies.     

Age-dependent association of human mannose-binding lectin mutations with susceptibility to invasive meningococcal disease in childhood

BACKGROUND: Mannose-binding lectin (MBL) is an important factor of the innate immune system, and MBL-initiated complement activation is an important early defense mechanism against various bacterial infections, including invasive meningococcal disease. METHODS: In a pediatric cohort (ages 2-215 months) with invasive meningococcal disease, we investigated the overall and age-stratified frequency of 3 MBL exon 1 variations (C154T, G161A, G170A), previously shown to result in markedly decreased MBL plasma concentrations, by allele specific fluorescent hybridization probe real-time PCR assays and direct sequencing. Healthy age-matched volunteers with the same ethnic background and no history of meningococcal disease served as a control group. RESULTS: The overall frequency of a MBL exon 1 variant genotype was significantly higher in patients than in controls (31.8% vs. 8.2%, P < 0.001). In the patient group with disease onset less than 24 months of age, the prevalence of MBL structural variant genotype was further increased (39.3%; P < 0.001) and most pronounced in children with disease onset less than 12 months of age (57.1%; P < 0.001) when compared with healthy controls. Analysis of clinical severity and outcome revealed no significant difference between patients with wild-type and mutant alleles. CONCLUSIONS: Our data suggest that MBL exon 1 structural variants are significantly associated with susceptibility to childhood meningococcal disease in an age-dependent manner.     

变态反应性疾病儿童血浆肥大细胞羧肽酶和类糜蛋白酶含量的检测

目的：测定变态反应性疾病患儿血浆中肥大细胞羧肽酶和类糜蛋白酶的含量,评价其在变态反应性疾病诊断中的意义。方法：采用ELISA法检测59例变态反应性疾病儿童和53例健康儿童血浆中肥大细胞羧肽酶和类糜蛋白酶水平。结果：变态反应性疾病患儿血浆羧肽酶和类糜蛋白酶含量分别为1.089±0.752 ng/mL、0.905(0.375~2.318)ng/mL,显著高于健康儿童［0.593±0.380 ng/mL、0.454(0.097~1.077) ng/mL］,差异有统计学意义（P<0.05)。变态反应性疾病患儿血浆羧肽酶水平与类糜蛋白酶水平呈显著正相关(r=0.684,P<0.01)。结论：变态反应性疾病儿童血浆中肥大细胞羧肽酶和类糜蛋白酶水平增高,提示二者可作为变态反应性疾病的诊断的有意义的指标。