肺炎支原体IgA对肺炎支原体肺炎感染期的诊断价值

目的　探讨肺炎支原体 (MP)特异性IgA在MP感染中的诊断价值。方法　 336份呼吸道感染血清标本用SerodiaMycoII试剂盒检测特异性IgM、ELISA方法检测特异性IgA ,同时检测正常对照 30例血清特异性IgM、IgA、IgG抗体 ;对不同病程的 96例MP肺炎住院患儿血清特异性IgM、IgA阳性结果进行比较。 结果　特异性IgM、IgA阳性率无明显差异 (P >0 0 5 ) ,两者存在一致性 ,与特异性IgG阳性率比较有显著差异。 结论　MP特异性抗体IgA与IgM阳性率类似 ,属于感染期抗体     

肾病综合征患儿免疫球蛋白检测与应用激素的探讨

目的检测原发性肾病患儿IgG、IgA、IgM、IgE、C3水平,探讨肾病患儿对肾上腺皮质激素(泼尼松)的敏感性,了解肾病的发病机制,指导临床治疗。方法分别采用散射比浊法检测血清IgG、IgA、IgM、C3及ELISA法检测血清IgE。结果原发性肾病患儿与正常对照组比较,血清IgA、C3无显著差异,肾病患儿血清IgG水平明显低于正常儿童,IgM、IgE明显高于正常儿童,单纯型与肾炎型肾病结果一致。单纯型与肾炎型肾病对激素治疗敏感性比较有非常显著性差异(x2=18.48 P< 0.005);原发性肾病患儿血清IgE升高组与IgE不升高组对激素治疗的敏感性比较有非常显著性差异(x2=12.46 P< 0.005)。结论原发性肾病综合征患儿存在免疫球蛋白合成异常,可能与患儿体液免疫紊乱有关。而激素治疗敏感性与肾病综合征临床分型及IgE水平高低有关。     

小儿包虫病特异性抗体的检测与观察

本文应用ELISA法对59例小儿包虫病人血清特异性IgG、IgM和IgE抗体进行检测。练果表明,小儿抗E.gIgG水平低于成人组(P<0.05),而抗E.gIgM略高于成人但无差异,提示小儿包虫病感染处于抗E.gIgM抗全水平下降,IgG抗体产主的急性未期。小儿包虫主要寄生于肝脏部位。实验表明,早期对小儿患者进行抗E.gIgG和IgM测定,临床诊断价值较高。     

应用抗μ链酶标记物ELISA法检测CMV-IgM抗体

本文报告采用过氧化物酶标记的抗人μ链抗体(抗μ—E)ELISA技术检测疑似HCMV感染患儿血清特异性IgM抗体,并与病毒分离、IgG抗体检测进行比较,结果前者阳性率较高。对18例双份血清IgM抗体检测,诊断符合率94.4％。抗原吸收2-ME阻断试验所测抗体均为特异性CMV-IgM抗体,与其他病毒感染患者阳性血清无交叉反应。不受RF、IgG影响。故本法具特异性强,敏感性高,快速简便等优点,可用于临床诊断。     

肺炎支原体感染4种特异性抗体检测的临床研究

目的：探讨肺炎支原体(MP)特异性IgM,IgA,IgG对肺炎支原体感染诊断价值,及MP IgE与支气管哮喘发病的关系。方法：采用酶联免疫吸附试验对临床高度怀疑肺炎支原体感染患儿测定特异性MP IgA,IgG,IgE,采用颗粒凝集法测定MP IgM,并对57例肺炎支原体感染患儿随访2~5. 5月。结果：在372例肺部感染患儿中,MP IgA阳性184人,占49. 5%;MP IgM阳性241人,占64. 8%; 2种抗体同时阳性140人,占37. 6%, 2种MP特异抗体测定结果的一致性非常显著。其中149例测定了MP IgG, 105例阳性,占70. 5%;而30例正常对照组中仅2例MP IgG阳性,占6. 7%,正常对照组MP IgA,MP IgM皆为阴性。MP IgA,MP IgM,MP IgG的阳性率,在发病第2周均达到80%以上,明显高于第1周,在随访的57例MP感染患儿中, 25例有反复呼吸道感染,MP IgA在随访时阳性率明显增高,MP IgM滴度居高不下;而在32例无呼吸道感染患儿中,MP IgA的阳性率变化不明显,MP IgM滴度则明显下降。MP感染组的MP IgE的阳性率达73. 3%,与哮喘合并MP感染组接近,但与哮喘合并非MP感染组及正常对照组比较差异有显著性。结论：4种特异性肺炎支原体抗体测定对于提高MP感染诊断的特异性、敏感性具有十分重要的临床价值,尤其对于MP再感染的发现及MP感染诱发支气管哮喘的发作机制研究及进一步治疗提供了     

77例格林—巴利综合征患儿免疫状态观察

我们观察分析了GBS患儿机体免疫状况,发现其血清APNAb阳性率为39.7％,CIC阳性率57.8％,84.4％IgM升高,近1/3 IgA降低,半数患儿的IgD升高和1/5患儿IgD降低,81.3％患儿的IgG处于正常范围;APNAb阳性者其血清IgM、IgA和IgD的改变趋势均高于APNAb阴性者,但Ig的含量均无显著性差异。     

婴幼儿急性呼吸道疾病和肺炎时体液及局部免疫特点

机体对抗原作用产生的特异性抗体,目前共有5种免疫球蛋白(IgG、IgA、IgM、IgD、IgE)。人体在发育过程中,免疫球蛋白的合成有一定的顺序。正常小儿出生时有从母体传给的抗体 IgG,新生儿在生后头几天能合成 IgM,第2周合成 IgA,3个月后能独自合成 IgG。血清抗体的主要部分为 IgG,     

腹泻患儿血清中食物过敏原特异性IgE、IgG抗体检测及其临床意义

目的 探讨血清中食物过敏原特异性IgE、IgG抗体与小儿腹泻的关系.方法 选取2006年3月至2007年5月经大便镜检和培养排除寄生虫和细茵感染的急性腹泻患儿组32例;慢性腹泻患儿组38例;正常对照组20例.分别检测其血清中食物特异性IgE、IgG抗体水平.结果 食物过敏原特异性IgE抗体检测,急性腹泻患儿组、慢性腹泻组、正常对照组阳性率分别为40.6%、5.6%、5.0%;食物过敏原特异性IgG抗体检测,慢性腹泻患儿组、急性腹泻组、正常对照组阳性率分别为97.2%、9.4%、5.0%.结论 检测食物特异性IgE、IgG抗体分别在小儿急、慢性腹泻诊治中有重要意义.     

严重呼吸综合征患儿及密切接触者血清SARS相关冠状病毒抗体的检测分析

目的　了解严重急性呼吸综合征(severeacuterespiratorysyndrome ,SARS)患儿SARS相关冠状病毒(SARS CoV)特异性抗体水平和与SARS患儿密切接触的成人有无隐性感染。方法　采用间接免疫荧光(IFA)和ELISA两种方法检测北京市2 4例恢复期儿童SARS患者和2 6名与其密切接触的家长血清SARS CoV特异抗体,其中IFA法检测IgM和IgG抗体,ELISA检测IgM和混合抗体;同时通过入户问卷收集流行病学资料。结果　( 1 )IFA法测定血清SARS CoV IgG的阳性者1 0例( 4 2 % ) ,SARS CoV IgM阳性2例( 8% ) ;经ELISA法测定SARS CoV混合抗体的阳性者9例( 3 8% )。( 2 )流行病学资料显示抗体阳性的1 0例患儿中有明确SARS接触史的患儿8例,而在抗体阴性的1 3例中仅1例阳性(P <0 . 0 5)。( 3 ) 1位受检家长(患儿的祖母)IFA法检测SARS CoV IgG和ELISA法检测混合抗体均为阳性,约占4% ( 1 / 2 6) ,该患儿的祖父亦为SARS患者。结论　( 1 )有SARS接触史的患儿在抗体阳性组的比例较之在抗体阴性组的比例明显增高,提示流行病学史在儿科SARS临床诊断中具有重要价值。( 2 )未能证实与儿童SARS患者接触的成人中存在隐性感染。     

肺炎支原体感染与儿童哮喘关系的研究

目的探讨肺炎支原体感染与儿童哮喘发病的关系。方法支气管哮喘患儿362例，肺炎患儿288例，正常对照组30例，分别采用颗粒凝集法检测血清肺炎支原体IgM（MP—IgM）抗体；同时采用同位素放射免疫法测定哮喘患儿血清总IgE。结果（1）支气管哮喘患儿MP-IgM阳性率49．45％，显著高于肺炎患儿MP—IgM阳性率39．24％，上述两组均显著高于正常对照组6．67％；（2）在各年龄组支气管哮喘患儿MP—IgM阳性率比较中，发现学龄期儿童MP-IgM阳性率最高；（3）MP—IgM阳性的支气管哮喘患儿血清总IgE水平明显高于MP-IgM阴性哮喘患儿的血清总IgE。结论儿童肺炎支原体感染与儿童哮喘发病密切相关。     

Immunoglobulin G subclasses in serum and circulating immune complexes in patients with Kawasaki syndrome

IgG subclass concentrations in sera of 17 patients with Kawasaki syndrome were determined. Significantly increased IgG1 (P less than 0.001) and IgG3 (P less than 0.001) were found in the patients compared with 22 age-matched healthy children, whereas IgG2 and IgG4 were normal or slightly decreased. IgG immune complexes were measured by protein A-enzyme-linked immunosorbent assay (ELISA) combined polyethylene glycol precipitations. Eight of 17 patients (47.1%) were found to have circulating immune complexes (CIC) values above the normal control range (geometric mean +2 SD). IgG subclass composition in CIC was analyzed. The subclasses in CIC were predominantly IgG1 and IgG3. Because the antibody responses to different antigens exhibit IgG subclass restriction, it would suggest that the change of serum and CIC IgG subclasses in Kawasaki syndrome may have relevance to the pathogenesis of the disease.     

Detection of IgA and IgG but not IgE antibody to respiratory syncytial virus in nasal washes and sera from infants with wheezing

BACKGROUND AND OBJECTIVE: The capacity of respiratory syncytial virus (RSV) to stimulate an IgE antibody response and enhance the development of atopy and asthma remains controversial. Nasal washes and sera from 40 infants (20 with wheezing, 9 with rhinitis, and 11 without respiratory tract symptoms) were obtained to measure IgE, IgA, and IgG antibody to the immunodominant, F and G, virion proteins from RSV. STUDY DESIGN: Children (aged 6 weeks to 2 years) were enrolled in the emergency department during the mid-winter months and seen at follow-up when they were asymptomatic. All nasal washes were tested for RSV antigen. Determinations of antibody isotypes (IgE, IgA, and IgG) to RSV antigens were done in nasal washes and sera by using an enzyme-linked immunosorbent assay. In a subset of nasal washes, IgE to RSV was also evaluated by using a monoclonal anti-F(c)E antibody-based assay. RESULTS: Fifteen patients with wheezing, two with rhinitis, and one control subject tested positive for RSV antigen at enrollment. Thirteen patients with wheezing were <6 months old, and most (77%) were experiencing their first attack. Among the children with positive test results for RSV antigen, an increase in both nasal wash and serum IgA antibody to RSV-F(a) and G(a) was observed at the follow-up visit. However, there was no evidence for an IgE antibody response to either antigen. CONCLUSION: Both IgA and IgG antibodies to the immunodominant RSV-F(a) and G(a) antigens were readily detected in the nasal washes and sera from patients in this study. We were unable to demonstrate specific IgE antibody to these antigens and conclude that the production of IgE as a manifestation of a T(H)2 lymphocyte response to RSV is unlikely.     

Serodiagnosis of Helicobacter pylori infection is not accurate for children aged below 10

BACKGROUND: In order to investigate the immune response to Helicobacter pylori in childhood, we compared anti-H. pylori IgG and IgA antibodies with H. pylori antigen in the stool and examined the clinical usefulness of the anti-H. pylori IgG and IgA antibodies. METHODS: This study included 157 children who were seen at our hospital. Serum and stool samples were obtained for these children. Antibodies to H. pylori were examined using an H. pylori IgG enzyme-linked immunosorbent assays (ELISA) and an H. pylori IgA ELISA. Analysis of stool samples was carried out by the H. pylori stool antigen (HpSA) enzyme immunoassay. RESULTS: Of the 157 children, 45 children were HpSA positive, 110 were negative and two were undetermined. Out of 45 HpSA positive patients, 25 children were both IgG and IgA positive and seven were negative for both IgG and IgA antibodies. Of the 110 patients who were HpSA negative, 97 were negative for both antibodies. All HpSA positive children older than 10 years were positive for IgG and IgA antibodies, but of the HpSA positive children under the age of 10, only 18 out of 35 (51.4%) were positive for IgG antibodies or IgA antibody. CONCLUSION: These facts suggested that an immature immune response or tolerance to H. pylori exists in childhood and serodiagnosis of H. pylori infection is less useful in children aged below 10.     

Immunoglobulin G subclass concentrations and infections in children and adolescents with severe asthma

It was the aim of this study to investigate possible dysfunctions of the humoral immune system in asthmatic children with frequent respiratory infections. Forty‐one severe asthmatics (7–15 years of age), classified according to the Second Brazilian Consensus in Asthma (1998), were divided into two groups: group I (n = 12) had recurrent respiratory infections; and group II (n = 29) were without recurrent respiratory infections. Immunoglobulin (Ig)G, IgA and IgM levels (nephelometry), and IgE (radioimmunoassay) and IgG subclasses (enzyme‐linked immunosorbent assay), were evaluated using standard methods. Asthmatics with recurrent infections presented with worse clinical evolution, an increased number of hospital admissions, and a higher need of medication than the children without recurrent infections. There were no significant differences between the mean values of IgG, IgA or IgM levels, or IgE or IgG subclasses, in patients of both groups. A complete IgA deficiency was detected in two patients of group I (one was associated with IgG subclass deficiency). Deficiency of one or more IgG subclasses was verified in eight of 12 (66%) children from group I and in 16/29 (55%) from group II. The following deficiencies were found in both groups: IgG₃ (10/41), IgG₄ (three of 41), IgG₂ (two of 41), IgG₁ (one of 41), IgG₃‐IgG₄ (four of 41), IgG₁‐IgG₃ (two of 41), and IgG₁‐IgG₃‐IgG₄ (one of 41). There were a higher proportion of children with low IgG₄ levels in group I than in group II (p = 0.01). To conclude, IgA and IgG subclass deficiencies were detected in both severely asthmatic groups, with a predominance of IgG₃ subclass deficiency. However, low IgG subclass levels appear not to be a suitable predictor of the development of infections in asthmatic children.     

Serum immunoglobulin (IgG, IgM, IgA) and IgG subclass concentrations in healthy children: a study using nephelometric technique

Immunoglobulin (Ig) G, IgM, IgA and IgG subclass (IgG1, IgG2, IgG3, IgG4) concentrations were determined in more than 500 healthy Turkish children using nephelometric technique. These parameters were thought to be highly varied for different ethnic groups because of environmental and genetic factors. Methodology used in previous studies has been reported to affect age-related normal values. Serum IgG, IgM, IgA and IgG1, IgG2, IgG3, IgG4 levels were measured in 510, 491, 486, 542, 511, 515, and 545 healthy children, respectively. According to their age, the patients were divided into 14 groups. In contrast to most of the previous studies, age-related normal values for IgG4 levels were also obtained. In conclusion, it has been suggested that our study as an example for Caucasians using nephelometric technique will supply useful information about age-related normal serum immunoglobulin and IgG subclass concentrations.     

Undetectable IgE responses after respiratory syncytial virus infection.

Sequential nasopharyngeal secretions were collected from 81 infants from one day to three months after admission to hospital with respiratory syncytial virus (RSV) infection. Samples from 21 infants were assayed for anti-RSV IgE in an antigen capture ELISA assay. No IgE antibodies were detected although an assay of IgA antibodies carried out in parallel by a similar technique detected IgA antibodies in the secretions of all patients tested. Neither prior absorption of IgA or IgG, concentration of the secretions by freeze drying, nor enzyme amplification of the assay revealed any virus specific IgE. Using an antibody capture ELISA with a sensitivity of 0.85 IU/ml, IgE could be detected in sequential secretions of only one of the 81 RSV infected infants studied. Further testing of the secretions from 12 of these patients and those of a further 15 using an enzyme amplified assay with a sensitivity of 0.1 IU/ml revealed no further positives. Low concentrations of IgE were found in the sera of the majority of infants with RSV infection but they did not differ from those of virus negative children of a similar age collected between RSV epidemics. No rise in mean serum IgE concentrations between acute and convalescent samples was observed. No virus specific IgE was detected in the sera of any infant using the enzyme amplified antigen capture ELISA.     

Undetectable IgE responses after respiratory syncytial virus infection

Sequential nasopharyngeal secretions were collected from 81 infants from one day to three months after admission to hospital with respiratory syncytial virus (RSV) infection. Samples from 21 infants were assayed for anti-RSV IgE in an antigen capture ELISA assay. No IgE antibodies were detected although an assay of IgA antibodies carried out in parallel by a similar technique detected IgA antibodies in the secretions of all patients tested. Neither prior absorption of IgA or IgG, concentration of the secretions by freeze drying, nor enzyme amplification of the assay revealed any virus specific IgE. Using an antibody capture ELISA with a sensitivity of 0.85 IU/ml, IgE could be detected in sequential secretions of only one of the 81 RSV infected infants studied. Further testing of the secretions from 12 of these patients and those of a further 15 using an enzyme amplified assay with a sensitivity of 0.1 IU/ml revealed no further positives. Low concentrations of IgE were found in the sera of the majority of infants with RSV infection but they did not differ from those of virus negative children of a similar age collected between RSV epidemics. No rise in mean serum IgE concentrations between acute and convalescent samples was observed. No virus specific IgE was detected in the sera of any infant using the enzyme amplified antigen capture ELISA.     

Disorders of immune function in children with selective IgA deficiency

Numerous additional alterations of immune function in patients with selective IgA deficiency (serum IgA less than 0.05 g/l) have been described. In this group of patients we have investigated the connection with allergic diseases and alterations of the other immunoglobulin isotypes. Sera of 44 children from 1 3/12 to 18 years were analysed. In all patients serum IgA was below the nephelometric detection limit of 0.05 g/l). Using a more sensitive ELISA, IgA could be detected in all sera in concentrations ranging from 10 micrograms/l to 0.04 g/l. 25 children (57%) revealed a profound elevation of IgG serum levels, in 27 (61%) IgM was elevated above the upper age related normal value. In 7 patients (16%) with normal IgG serum levels a combined IgG2-IgG4 deficiency was found. In most cases these patients had unusually frequent and severe infections. Total IgE serum levels were determined by a RIA technique. In addition, an IgE-mediated sensitization to the most common food and inhalation antigens was detected by a standardized procedure (Phadiatop, Pharmacia). In 9/44 children (20%) IgE was less than 2 U/ml (lowest detection limit), 27 patients (62%) revealed levels of 6-86 U/ml within the age-related normal range. In 8 patients (18%) total IgE was above 381 U/ml. Four patients demonstrated a sensitization to inhalants, specific IgE antibodies to nutritive antigens were detected in three children.(ABSTRACT TRUNCATED AT 250 WORDS)