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L W Poulter

Publications and source records attributed to L W Poulter.

At least 19 recordsLinked to original sources
PubMed1999

The reproducibility of repeat measures of airway inflammation in stable atopic asthma.

Measures of airway inflammation are increasingly being used as outcome measures in asthma intervention studies. Meaningful interpretation of observed changes in bronchial mucosal cell numbers should depend, in part, on the reproducibility of repeat measures over time. We wanted to investigate the reproducibility of immunopathologic and physiologic parameters after short and long measurement intervals. We therefore performed spirometry, bronchial provocation challenge, and fiberoptic bronchoscopy with endobronchial biopsy (always right upper lobe second-generation bronchus) at baseline, after 2 wk, and again after 8 wk on nine subjects with stable atopic asthma (receiving inhaled placebo and beta-agonist therapy only). Numbers of T cells, memory T cells (CD45Ro(+)), macrophages (CD68(+)), and eosinophils (EG1(+) and EG2(+)) on immunohistochemical stains of bronchial biopsies were quantified by computerized image analysis. Intraclass correlation coefficients (ICCs) of reproducibility were calculated for repeat measures of each parameter and a high ICC (greater than 0.6) was interpreted as "highly reproducible." Repeat measures of FEV(1), FEF(25-75%), and PC(20) were highly reproducible after short (2-wk) and long (8-wk) intervals. Only repeat measures of EG2(+) had an ICC greater than 0.6 after 8 wk. Repeat measures of CD45Ro(+), EG2(+), and T cell numbers (but not CD68(+) and EG1(+) cells) are highly reproducible and reliable parameters of asthmatic airway inflammation after a 2 wk interval.

Adolescent↗
PubMed1998

The role of apoptosis in the resolution of T cell-mediated cutaneous inflammation.

We have investigated cutaneous purified protein derivative-induced delayed-type hypersensitivity (DTH) responses in healthy volunteers to determine features associated with both the generation and resolution of the reaction. The clinical peak of the response occurred at day 3; however, T cell numbers were maximal on day 7. There was a preferential increase of CD4+ CD45RO+ T cells on day 7, which was largely due to proliferation, since a mean of 19% was in cycle. The proliferation of this subset was associated with the presence of IL-15, which was expressed as early as 12 h, and IL-2, which showed peak expression at 7 days. By day 14, there was a significant decrease in both the mean T cell number/unit area and IL-2 and IL-15 expression in perivascular infiltrates. Maximal CD95 (Fas/Apo-1) ligand and TNF-alpha expression were observed at 7 days and were associated with the presence of 1.83% (range 0.81-2.48%) apoptotic T cells. At 14 days, CD95 ligand and TNF-alpha expression were reduced significantly, and the presence of 2.5% (range 1.5-3.75%) of apoptotic T cells at this time was probably due to cytokine deprivation, associated with decreased Bcl-2 relative to Bax expression. The induction and resolution of the Mantoux reaction may depend on the expression of cytokines, such as IL-2 and IL-15, which regulate both proliferation and apoptosis in T cells. Failure to control either of these phases of the Mantoux reaction may contribute to the chronicity of inflammatory responses in certain cutaneous diseases.

Adult↗
PubMed1998

Changes in CD23 expression of blood and skin in atopic eczema after Chinese herbal therapy.

BACKGROUND: Aberrant expression of CD23 (low affinity IgE receptor) on cells of the monocyte/macrophage series in peripheral blood and lesional skin of patients with atopic eczema has been demonstrated. It is not known whether this abnormality results from a fundamental systemic problem of the monocytes of these patients or reflects local changes to cell populations within the skin tissues. OBJECTIVES: This study was designed to determine whether this aberrant expression was caused by local cutaneous influences on mature cells or fundamental changes in monocyte differentiation. The possible relationship between these aberrations and clinical severity was also investigated by repeating these immunopathological studies after a course of efficacious treatment with Chinese herbal therapy (CHT). METHODS: Peripheral blood mononuclear cells were obtained from patients with atopic eczema before, and after 8 weeks of treatment. Efficacy of CHT was quantified on clinical grounds. Monocytes were isolated by adherence to plastic and cultured for up to 7 days. Samples were harvested at 2, 5 and 7 days of culture and cytospins prepared. Immunocytochemical staining to identify phenotypic subsets was performed on the monocytes at time 0 and on maturing cells from culture. This immunocytology was quantified using computerized image analysis equipment to determine the emergence of macrophage subsets and their level of CD23 expression. Biopsies were taken from lesional skin before and after treatment and immunohistology was performed on cryostat sections to determine the number of antigen presenting cells expressing CD23 as well as the level of expression of these molecules. RESULTS: The results showed that increased numbers of monocytes from patients with atopic eczema express CD23 at day 0 and that cultured monocytes from these patients differentiate faster during the 7 day culture period as compared to normal controls. Efficacious treatment did not affect the number of peripheral blood monocytes expressing CD23. However, treatment did lead to a significant decrease in the number of CD23+ mature macrophages in the skin as well as a reduction in the level of expression of this moiety. These results demonstrate that changes in clinical severity are more closely related to the expression of CD23 on mature antigen presenting cells in lesional skin rather than to differentiating peripheral blood monocyte CD23 expression. CONCLUSIONS: These results suggests that local factors within lesional skin govern the accumulation and the expression of CD23 on mature macrophages and that these factors may be more relevant to the pathogenesis of the disease than aberrations in CD23 expression that may occur systemically.

Adolescent↗
PubMed1998

Dysregulation of monocyte differentiation in asthmatic subjects is reversed by IL-10.

BACKGROUND: IL-10 can modulate the differentiation of normal monocytes to macrophages, increasing the proportion of maturing cells with a phenotype consistent with T cell suppressive activity. Analysis of the immunopathology in endobronchial biopsies from asthmatic subjects has revealed significantly reduced proportions of suppressive macrophage populations associated with chronic T-cell mediated inflammation. OBJECTIVE: This study investigates whether the altered homeostasis within the lung macrophage populations in asthma is reflected in aberrant differentiation of peripheral blood monocytes and whether this differentiation may be influenced by IL-10. METHODS: Monocytes from 14 normal individuals and 14 atopic asthmatics were grown in culture for 7 days in the presence or absence of IL-10, added on day 5. Double immunofluoresence studies were performed on cytospins of the differentiated macrophages using the monoclonal antibodies RFD1 and RFD7 to distinguish inductive and suppressive macrophages by their respective phenotypes. HLADR expression was quantified using the monoclonal antibody RFDR1. Macrophage function was determined by quantifying allostimulation in a mixed leucocyte reaction and by measuring TNFalpha and TGFbeta production. RESULTS: With no cytokine addition the proportion of maturing macrophages with a suppressive phenotype (D1+D7+) at day 7 was lower in the asthmatic samples (18%) compared with normals (25%). IL-10 increased the proportion of suppressive cells in cultures of both asthmatic and normal monocytes with the increase in the asthmatic subjects (94% increase) being significantly greater than that in normal subjects (32% increase) (P<0.01). Asthmatic monocytes had a greater effect in stimulating MLR than normals (P < 0.05) but the addition of IL-10 reduced T cell proliferation in an MLR to a equivalent level in both groups. CONCLUSIONS: These results suggest that a fundamental problem may exist in the differentiation of monocytes in asthma which may be reversed by IL-10.

Adolescent↗
PubMed1998

Changes to the cytokine microenvironment in the genital tract mucosa of HIV+ women.

As previous studies have indicated that genital tract mucosal T cell function may be impaired in HIV infection, we investigated the T cell cytokine mRNA in the genital tract mucosa of HIV-infected women to determine if there are alterations in the cytokine profile which may explain the T cell impairment. The in situ hybridization technique was used to investigate the T helper-1 (Th1: IL-2, interferon-gamma (IFN-gamma)) and Th2 cytokine (IL-4, IL-5, IL-10) mRNA profile in cervical biopsies from 10 HIV+ and 10 HIV- subjects. Cervical intraepithelial neoplasia (CIN) and genital infection had previously been excluded and the distribution of immunocompetent cells within the cervical mucosa was known for each subject. Non-parametric tests were used to compare the optical density (OD) of cytokine mRNA in the HIV+ and HIV- groups. Comparisons were also made between peripheral CD4 lymphocyte counts, cervical CD4/CD8 T lymphocyte ratios and cytokine mRNA OD in HIV+ subjects. The HIV+ women had significantly higher mRNA OD for the Th2 cytokines IL-4, IL-5 and IL-10 than HIV women. There was also significantly lower IL-2 mRNA OD in the former group. HIV+ women had lower IFN-gamma mRNA than HIV- women, but the difference was not statistically significant. There was no correlation between cytokine mRNA OD and peripheral CD4 count or cervical CD4/CD8 ratio. The predominance of Th2 cytokines, which are immuno-inhibitory, in the cervical mucosa of HIV+ women may underlie the impaired cytotoxic potential observed in the CD8+ T lymphocytes and may contribute to the susceptibility of HIV-infected women to recurrent genital tract infections and cervical neoplasia.

Adult↗
PubMed1998

Fluticasone propionate induced alterations to lung function and the immunopathology of asthma over time.

BACKGROUND: Inhaled corticosteroids are the most widely used treatment for asthma, a disease characterised by both functional and immunopathological abnormalities. This study investigated the relative effects of inhaled corticosteroids on these two features of asthma over time. METHODS: A randomised, double blind, placebo controlled, parallel group study with inhaled fluticasone propionate, (FP 2 mg daily) was conducted in 27 patients with asthma. Following baseline analysis, the study tested the effects of short term (two weeks) and longer term (eight weeks) treatment. At each time point (0, 2, and 8 weeks) lung function tests were performed and endobronchial biopsy specimens obtained to determine the distribution and number of lymphocyte, macrophage and eosinophil subsets using immunohistological analysis. Twenty three patients completed the study, 11 on FP and 12 placebo. RESULTS: FEV1, delta FEV1, FEF25-75, and FEV1/FVC all improved after two weeks of FP treatment. This improvement was maintained but not increased after eight weeks. PC20FEV1 showed a trend to increase but was not significantly improved at eight weeks. No significant changes were seen in the placebo group. The numbers of T cells, macrophages, and eosinophils in the bronchial wall were reduced by two weeks of treatment with FP but were unaltered by placebo. The improvement offered by FP continued over the eight week period. Reductions in CD4:CD8 ratio and numbers of activated (EG2+) eosinophils were only significant after eight weeks of treatment. CONCLUSIONS: These results reveal that FP influences both functional and immunopathological parameters of asthma. Temporal relationships suggest that these are parallel but not necessarily interrelated effects. While short term treatment is effective in "normalising" the functional abnormalities in asthma, the impact of FP on bronchial inflammation appears to be progressive, taking up to eight weeks and more.

Administration, Topical↗
PubMed1998

Drug trials.

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Administration, Inhalation↗
PubMed1998

Changes in lung lymphocyte populations reflect those seen in peripheral blood in HIV-1 positive individuals.

We have investigated the level of lymphocytosis present in the lung of human immunodeficiency virus (HIV)-1+ infected patients with and without pulmonary disease and how changes in natural killer (NK), B and T-cells seen in peripheral blood (PB) compare with those seen in bronchoalveolar lavage fluid (BALF). Lymphocyte subpopulations and their expression of activation, cytotoxic markers and memory status were characterized by triple immunofluorescence. Macrophages accounted for over 80% of the BAL cells. Only three out of 72 patients had a lymphocyte percentage >30%. No statistically significant differences in the relative proportions of NK, CD4 and CD8 populations were seen in BALF when compared to PB, except for a twofold increase in the percentage of activated CD8 cells in BALF. The only differences in BALF populations between the HIV-1+ groups were a lower percentage of CD4+ cells, and a higher percentage of activated CD8+ cells in the patients with pneumonitis. In the present cohort of patients there was little evidence for an overall lymphocytosis in bronchoalveolar lavage fluid of HIV-1+ subjects. Changes observed in lymphocyte subsets of bronchoalveolar lavage fluid populations reflected those in peripheral blood, and were similar for patients with and without pneumonitis. Evidence of increased CD8 subset activity in bronchoalveolar lavage fluid did, however, emerge.

AIDS-Related Opportunistic Infections↗
PubMed1997

Allergen-induced CD30 expression on T cells of atopic asthmatics.

BACKGROUND: The importance of TH2-type T cell cytokines in atopic disease is widely accepted. CD30, a member of the TNF/NGF receptor superfamily, is expressed on a proportion of activated CD45RO+ T cells and has been proposed as a marker for TH2 phenotype. CD30 ligand-CD30 interaction has been shown to positively influence development of the TH2 phenotype, and serum levels of soluble CD30 (sCD30) have been used as prognostic markers in HIV, SLE, Epstein-Barr Virus infection and Hodgkin's Lymphoma but not as yet in allergic disease. OBJECTIVES: To establish if serum levels of sCD30 are elevated in atopic asthma and determine whether allergen-induced proliferation/activation of PBMCs from atopic asthmatics promotes CD30 expression on CD4+ T lymphocytes. Further, to determine if expression of CD30 and sCD30 correlate with disease severity. METHODS: Eighteen atopic asthmatics were each assigned a symptomatic disease score based on symptoms and bronchodilator rescue usage. Serum sCD30 was measured in peripheral blood by ELISA. PBMCs from atopic asthmatics were analysed with flow cytometry to obtain the proportions of CD4+ T cells expressing CD45RO and CD30. The cells were then cultured for 10 days with IL-2 with or without house dust mite antigen. A proliferation index was recorded and expression of CD30 and CD45RO retested. As a control, stimulation with PHA was used. Results with patients' PBMCs were compared with results of a parallel analysis of PBMCs from non-atopic healthy controls. RESULTS: Serum sCD30 was elevated in the 18 atopic asthmatics compared with a group of normal subjects but levels did not correlate with symptomatic disease activity. CD4CD45RO expression was low (14%) in atopic asthmatic peripheral blood but increased to 41% after 10 days culture with allergen. The CD4:CD8 ratio increased after Der p stimulation. A significant rise in the percentage of CD4+ T cells expressing surface CD30 (29%) was seen along with increased mean fluorescence intensity. Both these results correlated with symptomatic disease severity score. Non-specific PHA stimulation failed to significantly affect CD30 expression. CONCLUSIONS: There is a specific response to allergen in atopic asthma which causes significant increases in CD30 expression. This may correlate with disease severity.

Adolescent↗
PubMed1997

Progression of HIV disease is associated with increased expression of Fc gammaRI and CR1 on alveolar macrophages.

The expression of receptors for complement and the Fc region of immunoglobulin by alveolar macrophages (AM) constitutes a valuable aid to effector function of these cells. However, during HIV infection such expression may also act to increase binding of immune complexes, thus facilitating viral infection of these cells. This study was designed to determine whether changes in the expression of these receptors occurs in situ during HIV infection. Lung macrophages were isolated by bronchoalveolar lavage in groups of HIV+ subjects segregated on the basis of peripheral CD4 count. A group of normal subjects was also investigated. Expression of CR1 and Fc gammaRI was quantified by measuring the optical density of reaction product following controlled immunoperoxidase staining with MoAbs CD35 and CD64. Both CR1 and Fc gammaRI were increased over normal in all HIV+ subjects. This increase was progressive with advancing disease as determined by correlation with declining peripheral CD4 count. Comparison of asymptomatic and symptomatic subjects with HIV infection showed no difference in CR1 expression but a rise in Fc gammaRI expression in the latter group. An overall inverse correlation was also found between peripheral CD4 count and Fc gammaRI expression, but not CR1 expression. These data demonstrate a significant increase in the expression of these receptors on AM from HIV+ subjects, and show that this increase may occur before any symptoms in these patients.

Adult↗
PubMed1997

Corticosteroids restore the balance between locally produced Th1 and Th2 cytokines and immunoglobulin isotypes to normal in sarcoid lung.

In this study, we have investigated the balance between Th1- and Th2-like activity in the lungs in sarcoidosis and have determined the effect of corticosteroid treatment on this. Twenty-one patients with acute untreated sarcoidosis were investigated by bronchoalveolar lavage (BAL) and compared with 11 normal volunteers. Sixteen of the sarcoid patients required corticosteroid therapy and seven of these were reinvestigated after 2-3 months' treatment. In order to assess Th1- and Th2-like activity in the lungs, IgG subclasses and IgE were measured in BAL fluid and serum, and IL-2, IL-4 and interferon-gamma (IFN-gamma) in BAL. In patients with untreated sarcoidosis, albumin-corrected BAL/serum ratios for IgG4 and IgE were significantly reduced (IgG4, 1.04 +/- 0.18 (mean +/- s.e.m.); IgE 9.58 +/- 3.11) compared with those in normal controls (IgG4 5.3 +/- 0.72, P < 0.001; IgE 67.7 +/- 28.9, P < 0.01). Estimates of actual levels of immunoglobulins produced in the lungs were also made and showed extremely high levels of total IgG in sarcoid patients (39.56 +/- 8.2 mg/l) compared with controls (1.17 +/- 0.5 mg/l, P < 0.001). Although there was no difference between the groups in amount of IgG4 locally produced, the proportion of total IgG which was IgG4 was greatly reduced in those with sarcoidosis (1.6 +/- 0.4% compared with 38.5 +/- 3.2%; P < 0.001). Lavage levels of IL-4 were also reduced in sarcoid patients (IL-4 2.103 +/- 0.21 pg/ml) compared with those in normals (IL-4 6.8 +/- 1.05; P < 0.001). Levels of IL-2 were lower (7.63 +/- 0.51 pg/ml compared with 9.4 +/- 0.95 pg/ml), but this difference was not significant. IFN-gamma, however, could not be detected above 0.4 pg/ml in any of the normal lavage fluid, but was detectable in 12/21 patients with sarcoidosis (chi2 = 7.74; P < 0.001). These changes reverted towards normal on treatment with oral corticosteroids. The mean albumin-corrected BAL/serum ratio for IgG4 before treatment was 0.88 +/- 0.33 compared with 5.5 +/- 2.1 (P < 0.05) on treatment, and for IgE before treatment 9.52 +/- 2.15 compared with 50.8 +/- 17.9 (P < 0.05) on treatment. Total IgG produced in the lung fell from 26.16 +/- 7.9 to 6.12 +/- 2.4 mg/l (P < 0.001) on treatment, and the proportion of IgG4 locally produced rose from 2.3 + 0.8% to 23.9 +/- 6.1% (P < 0.01). The mean level of IL-4 in lavage before treatment was 2.53 +/- 0.34 pg/ml compared with 4.7 +/- 0.34 (P < 0.001) on treatment. Levels of IL-2 also rose significantly on treatment from 8.74 +/- 0.95 pg/ml before to 14.44 +/- 1.38 pg/ml (P < 0.001) on treatment. Levels of IFN-gamma fell from 1.65 +/- 0.43 pg/ml before treatment to undetectable levels in all patients (P < 0.001) on treatment. These results demonstrate an imbalance between Th1- and Th2-like activity in the lungs in sarcoidosis, with suppression of Th2 and increase in Th1. Corticosteroid therapy restores the normal balance between Th1 and Th2 cytokines and immunoglobulins in the lungs, suggesting an effect on local immune regulation.

Adolescent↗
PubMed1997

T-cell cytokines may control the balance of functionally distinct macrophage populations.

As monocytes differentiate into mature macrophages, subsets emerge that exhibit stimulatory, suppressive or phagocytic potential. These functionally distinct subsets can be discriminated using monoclonal antibodies RFD1 and RFD7. As examples of all these subsets have been repeatedly identified within the macrophage pool in a variety of organs the overall functional capacity of this pool will depend on the relative balance of these subpopulations. This study investigates whether this balance present in mature macrophage populations can be regulated by the local influence of T-cell-derived cytokines. The dose-dependent effect of cytokines interferon-gamma (IFN-gamma), interleukins (IL) IL-2, IL-4 and IL-10 on the phenotype and function of monocyte-derived macrophages was determined. Subsets of mature cells were quantified by identifying RFD1- RFD7- stimulatory cells (D1+); RFD1- RFD7+ phagocytes (D7+) and RFD1+ RFD7+ suppressive cells (D1 D7+). IFN-gamma and IL-4 increased the relative proportions of D1+ stimulatory cells and upregulated HLA-DR expression. IFN-gamma also increased the capacity of the mature macrophage pool to stimulate T-cell proliferation. IL-10 reduced the proportions of D1+ stimulatory cells while promoting the differentiation of D7+ phagocytes and D1/D7+ suppressive cells. IL-10 induced changes also reduced the functional capacity of the mature populations to stimulate T cells in auto and allogenic mixed lymphocyte reactions (MLR). IL-2 had no effect on differentiation of monocytes. Thus IL-4 and IFN-gamma are seen to induce the development of stimulatory macrophages while IL-10 promotes differentiation of monocytes to mature phagocytes and suppressive macrophages. It is concluded that mature macrophage phenotype is 'plastic' and under the control of T-cell-derived mediators. Furthermore, within the differentiating monocytes, phenotypic change appears to carry with it functional change, thus retaining the relationship between antigen expression and activity in the mature macrophage populations.

Adult↗
PubMed1997

Functionally relevant changes occur in HIV-infected individuals' alveolar macrophages prior to the onset of respiratory disease.

OBJECTIVE: We have compared the phenotypic and functional changes found in alveolar macrophages recovered from the lungs of 39 HIV-positive individuals with no respiratory disease with those from 33 HIV-positive individuals with pneumonitis and 31 healthy controls. METHODS: Bronchoalveolar lavage (BAL) cell cytospin preparations were stained using monoclonal antibody immunoperoxidase and double immunofluorescence techniques. Cytokine levels within supernatant BAL were determined using enzyme immunoassay. RESULTS: There were marked differences in alveolar macrophage phenotype between the three groups. In particular, the relative proportion of cells staining RFD1+RFD7- (inducer cells) was reduced in the HIV-positive individuals without respiratory disease. This was correlated with measures of declining systemic immunity. Patients with pneumonitis had the highest levels of measured cytokines [interleukin-1 beta, tumour necrosis factor-alpha and transforming growth factor (TGF)-beta 2], followed by the HIV-positive individuals without respiratory disease. In this latter population a negative correlation was found between active (non acid dissociated) TGF-beta 2 and blood CD4 cell count. CONCLUSIONS: The differences between the three groups suggest that alterations of potential relevance to the pulmonary immune response are occurring in alveolar macrophages prior to the onset of respiratory disease. This study confirms the importance of investigating asymptomatic HIV-positive individuals.

AIDS-Related Opportunistic Infections↗
PubMed1997

Role of bronchoalveolar lavage in predicting survival of patients with human immunodeficiency virus infection.

In this multicenter study, we investigated the prognostic factors that influence the risk of death in patients with human immunodeficiency virus (HIV) infection. Clinical and laboratory indices obtained from 161 HIV-seropositive patients who underwent a detailed morphologic and immunophenotypic evaluation of bronchoalveolar lavage (BAL) and peripheral blood cell populations were retrospectively analyzed. In 155 patients, death occurred within the 48-mo follow-up (mean follow-up: 14.8 mo; range: 1 to 48 mo). In the univariate analysis, the patient's age (> 30 yr), HIV disease status, HIV transmission category, number of opportunistic pathogens isolated from the BAL, percentage of BAL neutrophils, and low number of BAL CD4 T cells were predictive of increased mortality. In contrast, the presence of an alveolitis or an increase in the numbers of alveolar macrophages and CD3 T cells was associated with a decreased mortality. In the multivariate analysis, significant independent predictors were age, risk factor for HIV, and presence of an alveolitis. Furthermore, patients with a low number of BAL CD4 T cells had a particularly poor prognosis while the CD4 T-cell count in the peripheral blood (< 50 cells/mm3 in the majority of our patients) had a negligible effect on predicting survival. Our findings suggest the clinical utility of BAL analysis in patients infected with HIV.

AIDS-Related Opportunistic Infections↗
PubMed1997

Allergen-induced cytokine production in atopic disease and its relationship to disease severity.

The Th2 cytokines, interleukin (IL)-4 and IL-5, have an important role in atopic disease. CD30 is a transmembrane molecule that may be expressed on a proportion of activated T-lymphocytes and has been reported to be a marker for Th2 phenotype. Our objective was to compare the in vitro cytokine responses and CD30 expression of peripheral blood mononuclear cells (PBMCs) to stimulation with house dust mite antigen (Dermatophagoides pteronyssinus) in atopic asthmatics, atopic nonasthmatics, and normal subjects, and to see if atopic asthmatic cytokine production correlated with symptomatic disease activity and whether cytokine production was allergen-specific. Eighteen atopic asthmatics (all were allocated a symptomatic disease score), 6 atopic nonasthmatics, and 7 healthy nonatopic individuals were studied. Resting serum IL-4 levels were measured, then PBMCs were separated using Lymphoprep density centrifugation and cultured in modified RPMI 1640 medium. PBMCs were stimulated with IL-2 alone or with D. pteronyssinus (1,000 subcutaneous units/ml) with IL-2 and harvested after 5 and 10 d. Using monoclonal antibodies and flow cytometry we obtained the percentage of CD4+ T cells expressing CD30 and the intensity of CD30 staining. Culture supernatants were analyzed for IL-4 and interferon gamma (IFN-gamma) using an enzyme-linked immunosorbent assay. In 9 atopic asthmatics PBMCs were also stimulated nonspecifically using phytohemagglutinin (PHA). IL-4 was detectable in the serum of atopic subjects but not in normal subjects. Stimulation of PBMCs with D. pteronyssinus produced significant amounts of IL-4 in atopic asthmatics and atopic nonasthmatics, but minimal quantities in normal subjects. Much lower levels of IFN-gamma were produced by atopic asthmatics in response to D. pteronyssinus compared to atopic nonasthmatics. IFN-gamma levels had an inverse correlation with asthmatic symptom score. CD4+ T-cell expression of CD30 also correlated inversely with IFN-gamma production and IFN-gamma:IL-4 ratio. PHA produced minimal levels of IL-4 compared to specific allergen stimulation. It is concluded that different groups of atopic patients exhibit different patterns of allergen-induced cytokine production. In vitro allergen-induced cytokine production in atopic asthmatics correlated with symptomatic disease activity, and is allergen-specific.

Adolescent↗
PubMed1997

Lung immunopathology in cases of sudden asthma death.

The histopathology of airway inflammation in rare cases of sudden asphyxic asthma death (SAAD) is unclear. This study examines, for the first time, the relative disposition of lymphocyte and macrophage subsets and eosinophils in proximal and distal tissues of such cases. Multiple resection specimens from five cases of SAAD were studied. Tissue blocks were obtained at necroscopy and immediately frozen in liquid nitrogen within 18 hours of death (death occurring within 1 h of the onset of an unprovoked asphyxic asthma attack). After immunohistological staining, frozen sections underwent semi-quantitative analysis (cell counts per unit area) for T-cells, macrophages and eosinophils using computerized imaging systems. Subsets of T-cells and macrophages were estimated using double immunofluorescence techniques. Variability within samples, between samples and between cases was compared. These cases of fatal asthma showed infiltrates of T-cells, macrophages and eosinophils within peribronchial tissues. Distinct from stable asthma, a CD8+ T-cell dominance was found. A high proportion of eosinophils were activated (EG2+), whereas the relative proportion of antigen-presenting cells (RFD1+) did not seem to be abnormal, although numbers of these cells were high. These features were seen both in proximal and distal tissues. The variability of these parameters within an individual was 9.4-15.2%, however, the variability between individual cases was greater. Sudden asphyxic asthma is associated with inflammatory infiltrates both of proximal and distal lung tissues. In contrast to stable asthma, this infiltrate contains large numbers of CD8+ T-cells, suggesting distinct qualitative as well as quantitative characteristics in the immunopathology of sudden asthma death.

Acute Disease↗
PubMed1997

Modulation by Chinese herbal therapy of immune mechanisms in the skin of patients with atopic eczema.

Ten patients with atopic eczema (AE) received treatment with Chinese herbal therapy (CHT; Zemaphyte) for 2 months. The severity of the eczema was recorded and skin biopsies were taken from lesional (L) and non-lesional (NL) skin before and after treatment. The skin biopsies were stained to detect T-cell subsets (CD4, CD8, CD45Ro and CD25), macrophage subsets (RFD7), dendritic cells (RFD1). Langerhans cells (CD1), HLA-DR, low-affinity IgE receptors (CD23) and high-affinity IgE receptors (15A5, 22H7). A quantitative assessment of the numbers of positively stained cells was made. Monoclonal antibody binding specifically to CD23(Fc epsilon RII) was used, in combination with cell subset monoclonal antibodies to quantify the cellular distribution of CD23 antigen in the skin. Following 2 months of treatment with CHT, erythema was reduced by 53%. There was also a significant reduction in HLA-DR expression. The numbers of RFD1 + CD23 +, RFD7 + CD23 +, CD1 + CD23+ and CD25 + cells in lesional skin decreased significantly after treatment (RFD1 + CD23 + from 0.39 to 0.21, RFD7 + CD23 + from 0.29 to 0.16. CD1 + CD23 + from 0.24 to 0.09, CD25 + from 0.84 to 0.31 in epidermis and from 1.62 to 0.94 in dermis (mean cells numbers per unit area). No significant change in cell numbers in NL skin or expression of Fc epsilon RI in either L or NL samples was observed after treatment. This study confirms that CHT is clinically efficacious and that clinical improvement is associated with a significant reduction in antigen-presenting cells expressing CD23.

Adult↗