Cow's milk protein-specific T-helper type I/II cytokine responses in infants with necrotizing enterocolitis

Enteral feeding, in particular with formula feeds, is associated with necrotizing enterocolitis (NEC). In this study, we have examined, in the systemic and mucosal immune compartments, for evidence of bovine milk antigen sensitization in infants with NEC. Eleven newborns with Bell's staging 2–3 NEC [median post-conceptional age 31 wk (range 27–41 wk)], 21 neonatal controls [33 (28–40) wk] and 15 infants undergoing intestinal resection or mucosal biopsy for non-inflammatory conditions [39 (34–42) wk] were studied. Spontaneous and antigen or mitogen elicited interferon-γ (IFN-γ) [T-helper type I (Th1)], interleukin (IL)-4 and IL-5 [T-helper type II (Th2)] responses were enumerated using single-cell enzyme-linked immunospot (ELISPOT) assay in peripheral blood (PBMC) or lamina propria mononuclear cells. NEC infants, compared with controls, showed a significant elevation in baseline PBMC cytokine secreting cells, vigorous mitogen responses (20- to 120-fold increase) for IFN-γ, IL-4 and IL-5 (p < 0.001), strong responses to beta-lactoglobulin (βlg) (IFN-γ > IL-4/IL-5, p ≤ 0.001), and somewhat smaller casein responses. Similarly, in the lamina propria, a small but significant increase in spontaneous cytokine-secreting cells was detected in NEC infants (p < 0.01), with an IFN-γ/IL-4 predominant phytohemagglutinin (PHA)/concanavalin-A (ConA) response. Three of nine NEC infants (but no controls) also showed a positive ELISPOT response to βlg (IFN-γ only) but none to casein. We have thus demonstrated significant cow's milk protein (CMP) sensitization in NEC, at least in the systemic compartment (mixed Th1/Th2), with minimal mucosal activation in some cases. These novel findings provide a potential mechanism for a direct contributory role of CMP in the pathogenesis of NEC.     

Probiotics during weaning reduce the incidence of eczema

A reduced microbial load early in life has been suggested to be linked to the increasing prevalence of allergic diseases in the industrialized world. Some studies have indicated that probiotics may be effective in the prevention of eczema. In vitro studies indicate that probiotics have immunomodulatory effects. In the present study, we evaluated the effects of feeding Lactobacillus F19 during weaning on the incidence of eczema and Th1/Th2 balance. In a double-blind, placebo-controlled randomized intervention trial, infants were fed cereals with (n = 89) or without Lactobacillus F19 (n = 90) from 4 to 13 months of age. We assessed the cumulative incidence of eczema at 13 months of age. The ratio of interferon-γ (IFN-γ) to interleukin 4 (IL4) mRNA expression levels in polyclonally stimulated peripheral blood T cells was used as a proxy for immune balance. Total and specific IgE serum levels were also assessed. The cumulative incidence of eczema at 13 months was 11% (4–17%, 95% CI) and 22% (13–31%, 95% CI) in the probiotic and placebo groups, respectively (p < 0.05). The number needed to treat was 9 (6.5–11.5, 95% CI). At 13 months of age, the IFN-γ/IL4 mRNA ratio was higher in the probiotic compared with the placebo group (p < 0.05). In contrast, there were no differences between groups in serum concentrations of IgE. In summary, feeding Lactobacillus F19 during weaning could be an effective tool in the prevention of early manifestation of allergy, e.g., eczema. The higher Th1/Th2 ratio in the probiotic compared with the placebo group suggests enhancing effects of Lactobacillus F19 on the T cell-mediated immune response.     

Ontogeny of T-helper 1 and T-helper 2 cytokine production in childhood

Compared to adults, infants and young children demonstrate differences in their immune response, indicating that there is maturation or change over time and it is probable that this may be reflected in cytokine production. Cytokine responses have been demonstrated to be different in atopic and non-atopic individuals. In this study, we examined T-helper 1 (Th1) (interferon-γ[IFN-γ]) and T-helper 2 (Th2) (interleukin [IL]-4, IL-5, and IL-13) cytokine release from atopic and non-atopic children in response to the staphylococcal superantigen, staphylococcal enterotoxin B (SEB). In non-atopic and atopic children, IFN-γ, IL-4, and IL-5 release was significantly related to age. Non-atopic children younger than 2 years of age were found to have significantly reduced Th2 (IL-4, IL-5, and IL-13) responses when compared with older, non-atopic children. Atopic children had a reduced IFN-γ response when compared with non-atopics in early childhood; however, the decreased IFN-γ response seen in early childhood did not persist after 10 years. These age-related changes in cytokine production provide further support for the concept that cytokine deviations may determine the natural history of atopic disease during early childhood. In addition, the present study indicates the necessity of age-matched controls when examining children for both Th1 (IFN-γ) and Th2 (IL-4) cytokine release.     

Interferon-γ production by cord-blood mononuclear cells is reduced in newborns with a family history of atopic disease and is independent from cord blood IgE-levels

For newborn children both elevated serum IgE levels in the cord blood and a positive family history of atopic disease have been shown to be risk factors for the manifestation of atopic diseases. In adult patients with atopic dermatitis, in vitro interferon-γ (IFN-γ) production is reduced and a negative correlation with serum IgE levels has been shown. We have now raised the question if newborn infants at risk for the development of atopic disease have similar abnormalities of cytokine production at birth. In vitro production of interleukin 2, interleukin 6 and interferon-γ by peripheral blood mononuclear cells was measured in 53 newborns: 21 had cord blood IgE levels above 0. 9 kU/1, 21 had a positive family history, 7 had both elevated IgE and a positive family history; 18 newborns with no identitiable risk for atopic disease served as controls. Umbilical cord blood mononuclear cells were stimulated with PHA or monoclonal antibody OKT3. In vitro production of interleukin 2 and 6 was comparable in all groups. Compared to controls IFN-γ production of peripheral mononuclear cells (PBMC) from newborns with elevated cord blood IgE was not different, but PMBC from newborns with a familial risk showed a significant decrease in PHA induced IFN-γ production (p < 0.005, U-test). No correlation between umbilical cord blood IgE and diminished IFN-γ production was found in newborns with or without a positive family history. We conclude that immunoregulatory abnormalities in newborns of atopic families are detectable already at birth and are unrelated to cord blood IgE.     

Allergen-induced cytokine secretion in atopic and non-atopic asthmatic children

Atopic asthma is characterized by excessive T helper 2 (Th2)-like immunity to allergens in the bronchial mucosa. The Th2-cytokine interleukin (IL)-4 induces IgE production, while the Th2-cytokine IL-5 promotes eosinophilic inflammation in the airways of asthmatics. Most asthmatics are atopic, but a subgroup is non-atopic. We hypothesize that allergen-induced Th2, particularly IL-5, responses can be observed in peripheral blood in both atopic and non-atopic asthmatic children but not in healthy control children. The aim of the present study was to determine IL-4, IL-5, IL-9, IL-10, IL-13 and IFN-γ secretion induced from peripheral blood mononuclear cells (PBMC) by a broad panel of inhalant allergens (timothy, cat, birch, dog and house dust mite) in asthmatic children with and without sensitization. The study included 13 atopic asthmatic, 5 non-atopic asthmatic, and 12 non-atopic non-asthmatic children. PBMC were stimulated with allergens and cytokine production was measured with enzyme-linked immunosorbent assay (ELISA). Higher levels of cat and dog antigen-induced IL-5 release were more commonly observed in both atopic and non-atopic asthmatics than in controls. Children with atopic, but not non-atopic, asthma produced higher levels of allergen-induced IL-4 and IL-9 than controls. Non-atopic asthmatics produced more IL-10 than atopic asthmatics after cat stimulation. High levels of eosinophilia-associated IL-5 responses are induced by cat and dog allergen in both atopic and non-atopic asthmatic children. The Th2 cytokines IL-4 and IL-9 were associated only with atopic asthma, probably due to their IgE-inducing properties.     

Interferon-gamma pretreatment of peripheral blood mononuclear cells partially restores defective cytokine production in children with atopic dermatitis

Interferon-gamma (IFN-γ) is considered an important determinant of the balance between T-helper type 1 and 2 cytokines and has been used experimentally for the treatment of atopic dermatitis. However, contrasting results have been reported relative to the Th-UTh-2 cytokine profile in atopic patients. In this study, we examined cytokine production by polyclonally activated peripheral blood mononuclear cells (PBMC) from children with atopic dermatitis, and assessed the influence of in vitro IFN-γ pretreatment on these cells. A fraction of PBMC isolated from children with severe atopic dermatitis, as well as from age-matched controls, was initially exposed to IFN-γ. After washing, both treated and untreated cells were then put into culture either alone or with the addition of phytohemagglutinin (PHA) or phorbol myristate acetate (PMA) plus ionomycin. IL-4, IL-5, IL-10 and IFN-γ production were measured in the supernatants using commercially available ELISAs. PBMC from atopic patients produced more IL-4 (P = 0.04) and IL-10 (P = 0.03) and less IFN-γ (P = 0.01) than controls, when stimulated with PHA. Interestingly, in PMA + ionomycin stimulated cultures, the atopic cytokine profile was different with more IL-5 (P = 0.0068) and less IFN-γ production (P = 0.00046) than the control group. When cells were pretreated with IFN-γ, there were no significant differences between patients and controls. PBMC from children with atopic dermatitis show alterations in cytokine production, compatible in general terms with the Th-l/ Th-2 model. Exposure of PBMC to IFN-γ before activation results in a reduction of these differences, so that cytokine production becomes similar in the atopic and normal groups.     

Method of birth alters interferon-gamma and interleukin-12 production by cord blood mononuclear cells

Many uncertainties exist regarding the capability of cord blood mononuclear cells (CBMC) to produce cytokines. A number of conflicting reports led us to examine the effects of method of birth on CBMC production of interferon-gamma (IFN-γ), interleukin-4 (IL-4) and interleukin-12 (IL-12). While constitutive production of IL-4 was found in both vaginally and cesarean-delivered infants, constitutive IFN-γ or IL-12 production was found in neither. CBMC from vaginally delivered infants responded to stimulation with concanavalin A/phorbol 12-myristate 13-acetate (Con A/PMA), phytohemagglutinin (PHA), and lipopolysaccharide (LPS) with significantly higher levels of IFN-γ than CBMC from unlabored cesarean section (CS) infants. Production of IL-12 was increased in the vaginally delivered group in response to LPS and PHA but not to ConA/PMA. In contrast, mode of delivery was not associated with differences in IL-4 production. These results indicate that mode of delivery significantly alters the capability of CBMC to produce some cytokines and therefore should be taken into account in interpreting fetal/neonatal mononuclear cell function studies.     

哮喘儿童细胞因子信号转导抑制因子mRNA表达与Th1/Th2的关系

目的：细胞因子信号转导抑制因子(SOCS)对JAK-STAT途径的细胞因子如白介素、干扰素等的调节起重要作用,目前SOCS与哮喘的关系仍在研究中。本研究观察SOCS1和SOCS3 mRNA在哮喘儿童外周血单个核细胞（PBMC）中的表达水平与CD4+ T细胞IFN-γ/IL-4平衡及特异性IgE（sIgE）的关系。方法：采集44例4~14岁过敏性哮喘患儿及30例健康儿童PBMC,分别用流式细胞仪分析CD4+ T细胞IFN-γ/IL-4比值,另提取总RNA,采用SYBR Green I逆转录荧光定量PCR的方法检测每组SOCS1和SOCS3 mRNA的表达。结果：哮喘组患儿外周血IFN-γ阳性的CD4+T细胞百分比［（15.7±2.0）%］及IFN-γ/IL-4比值（3.4±1.5）均低于对照组［分别为（19.1±2.7)%、4.8±2.9］;而SOCS1 mRNA（⊿Ct值11.1±1.9）表达显著高于对照组（⊿Ct值12.6±2.8）。两组儿童SOCS1 mRNA表达均与外周血分泌IFN-γ的CD4+ T细胞百分比呈负相关（P<0.05）。SOCS1和SOCS3与sIgE均无相关性。结论：SOCS1 mRNA在哮喘组患儿外周血中高表达,并与Th2占优势的免疫失衡有关。     

Effects of breast milk from allergic and non-allergic mothers on mitogen- and allergen-induced cytokine production

Breast milk contains several components that provide specific immunity and affect the maturation of the infant's immune system. The aim of this study was to analyze the effects of breast milk, on mitogen- and allergen-induced cytokine production from cord blood mononuclear cells (CBMC), and if those effects differ between allergic and non-allergic mothers. The cells were incubated for 96 h with phytohemagglutinin (PHA), ovalbumin or cat dander in the presence of various dilutions of colostrum. Colostrum inhibited both mitogen- and cat-induced IFN-γ and mitogen-induced interleukin-4 (IL-4) production. The inhibition on IFN-γ production was to some extent caused by TGF-β, as the effect was modified when an anti-TGF-β antibody was added to the cultures. In contrast, colostrum enhanced allergen-induced production of the Th2-like cytokines IL-5 and IL-13, and this was accompanied with increased production of IL-10. No differences were found between allergic and non-allergic mothers. The inhibitory effect of breast milk on IFN-γ production, which was partly due to the high levels of TGF-β, together with the enhancing effect on IL-10 secretion, confirm that breast milk is anti-inflammatory. Although the production of IL-5 and IL-13 was enhanced by colostrum, this was accompanied with an increased production of IL-10. Together with the high levels of TGF-β in breast milk and inhibitory effect of colostrum on IL-4 production, this suggests a possible mechanism whereby breast-feeding may protect against the development of allergy. Despite differences in the composition of breast milk between allergic and non-allergic mothers, the effects of breast milk on cytokine production from CBMC were independent of the atopic status of the mothers.     

特发性血小板减少性紫癜患儿Th亚群细胞因子的检测

目的探讨Th亚群细胞因子在儿童特发性血小板减少性紫癜(ITP)发病中的变化及作用。方法采用BioPlex系统和悬浮阵列技术通过荧光编码检测43例ITP患儿血清中的Th1型细胞因子TNFα、IFNγ、IL2、GMCSF和Th2相关细胞因子IL4、IL5、IL6、IL10的变化,并与20例正常儿童作对照。结果与正常健康儿童相比,ITP患儿Th1型细胞因子显著升高(P<0.01),而Th2型细胞因子显著降低(P<0.01)。结论儿童ITP发病中存在异常的淋巴细胞极化状态,是一种Th1优势的疾病。     

头孢呋辛对哮喘儿童外周血单个核细胞Th1/Th2平衡的影响

目的研究头孢呋辛对哮喘儿童外周血单个核细胞Th1/Th2平衡的影响。方法采用流式细胞术检测哮喘和健康儿童外周血单个核细胞IFN-γ和IL-4水平,以及哮喘儿童外周血单个核细胞经头孢呋辛体外干预后的IFN-γ和IL-4水平。结果与健康儿童相比,哮喘患儿外周血单个核细胞的IFN-γ和IFN-γ/IL-4比值降低,差异有统计学意义(P<0.05);哮喘患儿外周血单个核细胞在体外与头孢呋辛(100 mg/L)孵育48 h后,IL-4水平升高,差异有统计学意义(P<0.05),而IFN-γ的变化无统计学意义(P>0.05);IFN-γ/IL-4比值则降低,差异有统计学意义(P<0.01)。结论哮喘患儿外周血单个核细胞以Th2(IL-4)占优势,Th1/Th2比值平衡失调;而头孢呋辛更加剧这一倾斜,不利于哮喘治疗。     

Both allergen-specific CD4 and CD8 Type 2 T cells decreased in asthmatic children with immunotherapy

Allergen-specific immunotherapy (IT) has been used for the treatment of atopic diseases since the turn of this century. The precise working mechanisms, however, remain to be clarified. The aim of this study was to investigate the role of particular subsets of allergen-specific T cells in the non-atopic individuals, untreated asthmatic children and the asthmatic children receiving immunotherapy. We collected peripheral blood from 16 untreated asthmatic children and 17 asthmatic children receiving immunotherapy over one and half years. All the patients were sensitive to mite allergen. Peripheral blood mononuclear cells (PBMC) were isolated and, in vitro , stimulated with crude mite extract to enrich the mite-specific T-cell population. After 14 days, the enriched mite-specific T cells were stimulated with phorbol-12-myristate-13-acetate (PMA) and ionomycin for intracellular detection of cytokines such as IFN-γ, IL-4 in CD4⁺ and CD8⁺ T lymphocytes. The data here demonstrated that the levels of mite-specific IgG4 and IgA increased significantly in asthmatic children after immunotherapy. In addition, both IL-4 expressing CD4⁺ and CD8⁺ T cells were significantly lower in asthmatic children after immunotherapy compared with those of before treatment and the normal control (p < 0.05). In contrast, the frequency of IFN-γ expressing CD4⁺ and CD8⁺ T cells did not significantly differ between untreated and SIT-treated groups. All these data suggested that decreased Type 2 CD4⁺ and CD8⁺ T cells might be closely correlated with the regulatory mechanisms of immunotherapy.     

不同浓度地塞米松和甲泼尼龙对支气管哮喘患儿外周血单个核细胞免疫功能的影响

目的 观察不同浓度地塞米松(DEX)和甲泼尼龙(MP)对支气管哮喘患儿外周血单个核细胞(PBMC)中CD4+T淋巴细胞中2个功能性亚群(Th1/Th2)功能状态的影响.方法 选择2001年6月-2002年6月在重庆医科大学附属儿童医院就诊的15例哮喘患儿和14例健康体检儿童为研究对象.分为哮喘对照组、10-7mol·L-1DEX干预组、10-8mol·L-1DEX干预组、10-9mol·L-1DEX干预组、10-7mol·L-1MP干预组、10-8mol·L-1MP干预组、10-9mol·L-1MP干预组.清晨取其空腹静脉血5 mL,肝素抗凝,采用密度梯度离心法分离PBMC,加植物血凝素进行刺激培养,分别用10-7mol·L-1、10-8mol·L-1及10-9mol·L-1DEX或MP体外干预培养48 h.同期采集健康儿童空腹静脉血,同法分离培养.用ELISA法测定培养上清中γ干扰素(IFN-γ)、IL-4、IL-10及IL-12水平,并计算不同浓度DEX或MP对PBMC分泌细胞因子的抑制率.结果 1.哮喘对照组PBMC分泌IL-4水平显著高于健康对照组(P<0.05),IFN-γ/IL-4比值较健康对照组显著降低(P<0.05),2组间IFN-γ、IL-10及IL-12水平比较差异均无统计学意义(Pa>0.05).2.DEX和MP均可明显抑制哮喘患儿PBMC分泌IFN-γ、IL-4及IL-12,但对IL-10抑制作用差;与健康对照组比较,哮喘组DEX和MP抑制PBMC分泌IL-10的作用弱,差异有统计学意义(Pa<0.05).3.DEX和MP均以浓度依赖方式抑制哮喘患儿PBMC分泌IL-4,DEX在10-9mol·L-1时有促进IL-4分泌的效应,MP在10-9mol·L-1时可抑制IL-4的分泌,二组比较差异有统计学意义(P<0.05). 若以IFN-γ/IL-4表示Th1/Th2间的平衡,则MP可恢复Th1/Th2平衡(P<0.05).结论 DEX和MP均可抑制Th1/Th2类细胞因子分泌,但MP有助于恢复Th1/Th2平衡,提示临床选择MP治疗支气管哮喘更有利.     

Expansion of activated eosinophils in infants with severe atopic dermatitis

Abstract   Background : There is increasing concern in Japan over infants with atopic dermatitis (AD) who present with severe systemic complications, such as hypoproteinemia, electrolyte disturbances, and delayed growth and development. They are often associated with extremely increased numbers of circulating eosinophils. However, the clinical significance of eosinophil expansion has not been thoroughly investigated.
Methods : This study attempted to determine the significance of eosinophilia and eosinophil activation in infant cases of AD by comparing multiple clinical parameters, indexes of eosinophil activation, and levels of serum cytokines. CD69 expression was determined by flow cytometry. The clinical severity of AD was graded by the severity SCORing of atopic dermatitis (SCORAD) method. Patients were classified into two groups, with and without CD69 on eosinophils. Nuclear lobes were evaluated under a microscopy. Serum levels of eosinophil-derived neurotoxin (EDN), interleukin (IL)-12, IL-18, IL-4, IL-5 and interferon (IFN)-γ were determined by enzyme-linked immunosorbent assay.
Results : Patients with CD69-positive eosinophils had significantly higher numbers of eosinophils and platelets, total IgE, and eosinophil nuclear lobes. They also showed growth failure, developmental delay, low serum albumin, and electrolyte disturbances. EDN and IL-18 levels were significantly increased in this group, but the levels of IL-4, IL-5 and IL-12 were not significantly different between the two groups. IFN-γ was not detectable in all patients with AD. Surface expression of CD69 indicates intense systemic allergic inflammation induced in severe cases of AD.
Conclusions : Evaluation of eosinophil activation and early therapeutic intervention is mandatory for the treatment of severe AD during infancy.     

转录因子T-bet、GATA-3在过敏性紫癜患儿发病机制中的作用

目的 探讨转录因子T-bet和GATA-3在过敏性紫癜(HSP)患儿发病机制中的作用.方法 本院儿科2009年2月-2010年2月收治急性期HSP患儿46例(HSP组)以及健康对照儿童30例(健康对照组).采用SYBR Green I实时荧光定量PCR方法检测其外周血单个核细胞T-bet mRNA、GATA-3 mRNA的表达.应用Luminex-100液相芯片技术检测其血浆细胞因子IL-2、IL-4、IFN-γ水平.结果 HSP组患儿外周血单个核细胞T-bet mRNA相对表达水平(53.98±35.79)低于健康对照组(181.56±96.90)(P＜0.001).GATA-3 mRNA相对表达水平(964.30±655.18)高于健康对照组(78.09±57.20)(P ＜0.001).HSP组血浆细胞因子IL-2[( 16.54±7.38) ng?L-1],IFN-γ[(11.31±8.02) ng?L-1]的表达显著低于健康对照组[(35.73±22.66) ng?L-1,(30.67±21.29) ng?L-1](P＜0.001,0.05),IL-4[(74.66±26.15) ng.L-1]的表达高于健康对照组[(51.81±27.76) ng?L-1].IFN-γ水平与T-bet mRNA表达呈正相关(r=0.882,P＜0.01);IL4水平与GATA-3 mRNA的表达呈正相关(r=0.886,P＜0.01).结论 HSP患儿急性期存在Th1/Th2失衡,主要表现为Th2优势活化,该失衡与其特异性转录因子T-bet mRNA表达降低、GATA-3 mRNA 表达增高有关,本研究为阐明Th1/Th2失衡的分子机制之一提供了实验依据.     

Intracellular production of IL-2, IL-4, IFN-γ, and TNF-α by peripheral blood CD3+ and CD4+ T cells in children with atopic dermatitis

The role of the type-2 T helper (Th2) cell-mediated immune response in the immunopathogenesis of atopic dermatitis (AD) is well documented. Whether polarized immunoresponse is confined to antigen-specific T cells or is distributed among all T cell subsets is still controversial. We investigated frequencies of interleukin-2 (IL-2), IL-4, interferon-gamma (IFN-γ), and tumor necrosis factor-alpha (TNF-α) producing CD3⁺ and CD4⁺ T cells in peripheral blood from children with atopic dermatitis and healthy subjects with and without in vitro stimulation. Children with severe AD had a significantly lower percentage of CD4⁺ T cells spontaneously expressing IL-4 compared with healthy controls (p <0.01). Polyclonal stimulation significantly increased cytokine production in both AD patients and healthy individuals. Frequencies of CD3⁺ and CD4⁺ producing IL-2, IL-4, IFN-γ, and TNF-α after in vitro stimulation with phorbol-12-myristate 13-acetate (PMA) + ionomycin were comparable in the AD and control groups. In response to PMA/ionomycin, children with AD and asthma symptoms had a significantly lower percentage of CD3⁺ T cells producing TNF-α. We failed to demonstrate evidence of an imbalance with respect to type-2 cytokine productions in children with AD. Comparable induction of Th1 and Th2 cytokines in polyclonally stimulated peripheral CD3⁺ and CD4⁺T cells from AD patients and controls puts into question the polarized Th2 immune response as a general characteristic of T cells in children with atopic dermatitis.     

Evidence of Circulating Interferon-γ in Newly Diagnosed Diabetic Children

ABSTRACT. Acid-stable interferons (IFN-α or IFN-β) are produced by nucleated cells infected by virus, while acid-labile interferon (IFN-γ) is synthesized by activated T-lymphocytes. IFN-γ or an atypical form of acid-labile IFN-α have been observed in the circulation of some patients with autoimmune disease. It is believed that autoimmunity and/or viral infections are involved in the pathogenesis of insulin dependent diabetes mellitus. We therefore examined the sera of newly diagnosed diabetic children for the presence of virus-induced or acid-labile IFN. Significant IFN levels (≥8 U/ml) were observed in 11 of 29 patients when compared to 31 healthy children in the same age range. The inhibitor is characterized by species specificity, acid-lability and neutralization with anti-serum for IFN-γ.     

重症肺炎支原体肺炎患儿肺泡灌洗液中Th1/Th2细胞免疫应答状况的研究

目的：检测重症肺炎支原体肺炎（MPP）患儿肺泡灌洗液(BALF)和血清中干扰素-γ（IFN-γ)、白细胞介素-4（IL-4）,研究Th1/Th2细胞免疫应答的状况及意义,并评价BALF中细胞因子检测在MPP诊治中的临床价值。方法：采用双抗体夹心ELISA检测25例重症MPP患儿BALF和血清中IL-4及IFN-γ的浓度,并设支气管异物组（25例）和MPP轻症组（25例）作为对照。结果：重症MPP患儿BALF中IL-4和IFN-γ水平及IL-4/IFN-γ比值明显高于支气管异物对照组,差异有统计学意义(P<0.01或0.05)。重症MPP患儿血清中IL-4水平及IL-4/IFN-γ比值明显高于支气管异物组和MPP轻症组,差异有统计学意义(P<0.01或0.05)。重症MPP患儿BALF中IL-4水平及IL-4/IFN-γ比值高于血清标本,差异有统计学意义(P<0.05)。结论：重症MPP患儿存在Th1/Th2失衡, 以Th2反应占优势;BALF中细胞因子的检测较之血清更为敏感,在MPP诊治中具有较高价值。