Bronchoalveolar Lavage Fluid CD4 Research Articles

Low BALF CD4 T cells count is associated with extubation failure and mortality in critically ill covid-19 pneumonia

Background Critically ill COVID-19 pneumonia is one of the main causes of extubation failure and mortality. Understanding clinical characteristics, laboratory profiles and bronchoalveolar lavage fluid (BALF) immunopathology may help improve outcomes in critically ill COVID-19 pneumonia. We aimed to describe clinical characteristics, laboratory profiles and BALF immunopathology based on lung severity in critically ill COVID-19 pneumonia patients. Materials and methods Forty critically ill severe pneumonia patients requiring invasive mechanical ventilation in Cipto Mangunkusumo General (National Tertiary Referral Hospital), Indonesia within November 2020–January 2021 were enrolled in this study. Early BALF collection was performed after patients’ intubation. Clinical characteristics, laboratory profiles and BALF biomarkers (sTREM-1, alveolar macrophage amount and function, IL-6, IL-17, CD4 T-cells, Tregs, SP-A and Caspase-3) were observed and analysed. Outcomes were measured based on extubation failure (within 19 days) and 28-days mortality. Univariate and bivariate analyses were performed. Results Early bronchoscopy was performed in an average of 4 h (SD = 0.82) after patients’ intubation. Twenty-three and twenty-two patients had extubation failure (within 19 days) and 28-days mortality, respectively. In the baseline clinical characteristics of critically ill COVID-19 patients, we found no significant differences in the extubation and mortality status groups. In the laboratory profiles of critically ill COVID-19 patients, we found no significant differences in the extubation status groups. In critically ill COVID-19 pneumonia patients, there was a significant high D-dimer levels in survived group (p = .027), a significant low BALF CD4 T-cells count in the right lung (p = .001) and a significant low BALF CD4 T-cells count (p = .010 and p = .018) in severely affected lung with extubation failure and mortality. Conclusions BALF CD4 T-cells count evaluation of severely affected lung is associated with early extubation failure and mortality in critically ill COVID-19 pneumonia patients. KEY MESSAGE Few studies have been conducted during the peak COVID-19 period analysing combined bronchoalveolar lavage fluid (BALF) immunopathology biomarkers within four hours of intubation to assess extubation failure and mortality. In this study, we reported eight BALF immunopathology biomarkers (sTREM-1, alveolar macrophage, IL-6, IL-17, CD4 T-cells, Tregs, SP-A and Caspase-3). We found significantly low BALF CD4 T-cells count in the right lung, and low BALF CD4 T-cells count in severely affected lung of critically ill COVID-19 pneumonia patients in extubation failure and mortality.

Autocrine vitamin D signaling switches off pro-inflammatory programs of TH1 cells.

The molecular mechanisms governing orderly shutdown and retraction of CD4+ T helper (Th)1 responses remain poorly understood. Here, we show that complement triggers contraction of Th1 responses by inducing intrinsic expression of the vitamin D (VitD) receptor (VDR) and the VitD-activating enzyme CYP27B1, permitting T cells to both activate and respond to VitD. VitD then initiated transition from pro-inflammatory IFN-γ + Th1 cells to suppressive IL-10+ cells. This process was primed by dynamic changes in the epigenetic landscape of CD4+ T cells, generating super-enhancers and recruiting several transcription factors, notably c-JUN, STAT3 and BACH2, which together with VDR shaped the transcriptional response to VitD. Accordingly, VitD did not induce IL-10 in cells with dysfunctional BACH2 or STAT3. Bronchoalveolar lavage fluid CD4+ T cells of COVID-19 patients were Th1-skewed and showed de-repression of genes down-regulated by VitD, either from lack of substrate (VitD deficiency) and/or abnormal regulation of this system.

Chemotherapy-induced changes in bronchoalveolar lavage fluid CD4\u2009+\u2009and CD8\u2009+\u2009cells of the opposite lung to the cancer

Published articles support the effect of chemotherapy in the immune environment of tumors, including lung carcinomas. The role of CD4 + T-cells is crucial for expansion and accumulation of other antigen-specific immune cells, and the participation of CD8 + cells in tumor killing activity has been confirmed by many studies. However, little is known about the effect of chemotherapy on the healthy lung parenchyma from lung cancer patients, and whether there are differences between the different chemotherapy compounds used to treat this patient population. The aim of our study was to explore the effect of chemotherapy on CD4 + and CD8 + cells in the bronchoalveolar lavage fluid (BALF) of the healthy lung in patients treated with standard chemotherapy regimens. Fifteen patients underwent BAL, in the healthy lung before and after six chemotherapy courses. Platinum-based regimens included vinolerbine (VN) in 6 patients, gemcitabine (GEM) in 4 patients and etoposide (EP) in 5 patients. All patients but one were males and smokers (93%). The median age of patients was 56 years (42–75). No significant difference was noted in the patients’ age between the three treated groups. Furthermore, between the three groups, no significant changes in the means of CD4 + and CD8 + cells were noted. However, when we compared the mean CD4 + cells before and after chemotherapy within each group, changes were noted when comparing VN before versus after (p = 0.05), GEM before versus after (p = 0.03), and EP before versus after (p = 0.036). In our pilot study, changes were noted in BALF CD4 + cells for the three most applied regimens at the normal lung parenchyma.

T-cell receptor-HLA-DRB1 associations suggest specific antigens in pulmonary sarcoidosis.

In pulmonary sarcoidosis, CD4(+) T-cells expressing T-cell receptor Vα2.3 accumulate in the lungs of HLA-DRB1*03(+) patients. To investigate T-cell receptor-HLA-DRB1*03 interactions underlying recognition of hitherto unknown antigens, we performed detailed analyses of T-cell receptor expression on bronchoalveolar lavage fluid CD4(+) T-cells from sarcoidosis patients.Pulmonary sarcoidosis patients (n=43) underwent bronchoscopy with bronchoalveolar lavage. T-cell receptor α and β chains of CD4(+) T-cells were analysed by flow cytometry, DNA-sequenced, and three-dimensional molecular models of T-cell receptor-HLA-DRB1*03 complexes generated.Simultaneous expression of Vα2.3 with the Vβ22 chain was identified in the lungs of all HLA-DRB1*03(+) patients. Accumulated Vα2.3/Vβ22-expressing T-cells were highly clonal, with identical or near-identical Vα2.3 chain sequences and inter-patient similarities in Vβ22 chain amino acid distribution. Molecular modelling revealed specific T-cell receptor-HLA-DRB1*03-peptide interactions, with a previously identified, sarcoidosis-associated vimentin peptide, (Vim)429-443 DSLPLVDTHSKRTLL, matching both the HLA peptide-binding cleft and distinct T-cell receptor features perfectly.We demonstrate, for the first time, the accumulation of large clonal populations of specific Vα2.3/Vβ22 T-cell receptor-expressing CD4(+) T-cells in the lungs of HLA-DRB1*03(+) sarcoidosis patients. Several distinct contact points between Vα2.3/Vβ22 receptors and HLA-DRB1*03 molecules suggest presentation of prototypic vimentin-derived peptides.

Therapeutic granulocyte and monocyte apheresis (GMA) for treatment refractory sarcoidosis: a pilot study of clinical effects and possible mechanisms of action.

Sarcoidosis is a systemic, inflammatory disorder, which in a proportion of patients runs a chronic progressive course despite immunosuppressive treatment. Therapeutic granulocyte and monocyte apheresis (GMA) has been shown to be an effective treatment option for other systemic inflammatory disorders, but has not yet been investigated in sarcoidosis. The aim of this study was to evaluate the response to GMA in sarcoidosis. Seven patients with sarcoidosis refractory to standard immunosuppressive therapy received 10 GMA sessions. All patients underwent chest X-ray, spirometry, a Chronic Respiratory Disease Questionnaire (CRQ-SAS), blood tests and bronchoscopy with bronchoalveolar lavage (BAL) before treatment and at 2-4 weeks and 3 months (except bronchoscopy) after the last treatment session. Bronchoalveolar lavage fluid (BALF) cell differential counts were recorded and T cells from blood and BALF were analysed for markers of activity, differentiation and T regulatory function. Compared to baseline, five of seven patients reported an improvement in dyspnoea score. In BALF there was an increase in the percentage of macrophages and a decrease in the percentage of lymphocytes and CD4(+) /FoxP3(+) T cells. Furthermore, the decrease in BALF CD4(+) /FoxP3(+) T cells correlated significantly with an improvement in dyspnoea score. In peripheral blood there was a statistically significant increase in the percentage of CD4(+) /CD27(-) T cells and a trend towards an initial increase in the percentage of CD4(+) /FoxP3(+) T cells, followed by a statistically significant decrease. The effects of GMA on regulatory T cells are consistent with those observed in other inflammatory disorders and could potentially translate into a clinical benefit.

Potential Prognostic Value of Intracellular Cytokine Detection by Flow Cytometry in Pulmonary Sarcoidosis

In pulmonary sarcoidosis, differential cytokine production in the lungs could be related to variable prognosis of patients at different stages of disease. Twenty patients with pulmonary sarcoidosis (10 at radiographic stage I and 10 at stages II-IV), as well as 10 age-matched healthy volunteers participated in the study. A 4-colour flow cytometric technique was used to measure interferon-γ (IFN-γ), interleukin (IL)-2, tumour necrosis factor-α (TNF-α), IL-4, and IL-13 production in phorbol myristate acetate (PMA)/ionomycin-stimulated CD4+ and CD8+ T cells from bronchoalveolar lavage fluid (BALF) and peripheral blood (PB) of patients, and PB of control subjects. CD4+ T cells from patients showed higher expression of IFN-γ in BALF than in PB. Significant correlations were observed between the percentages of BALF CD4+ and CD8+ T cells expressing intracellular IFN-γ, IL-2, and TNF-α. Stage I patients had lower percentages of IFN-γ-producing CD4+ and CD8+ T cells, as well as TNF-α-producing CD8+ T cells, in BALF (but not in PB) than stage II-IV patients. A decreased TH1 and TC1 response was demonstrated in BALF of patients at stage I of disease, which could explain their anticipated better prognosis.

Diagnostic value of CD103 expression in bronchoalveolar lymphocytes in sarcoidosis

Pulmonary sarcoidosis is frequently characterized by a CD4(+)/CD8(+) ratio ≥3.5 in bronchoalveolar lavage fluid (BALF), although up to 40% of the cases present a normal or even decreased ratio, pointing out its variability and limitation as a diagnostic marker for sarcoidosis. Lung lymphocytes within the bronchial epithelium, the alveolar walls, and BALF express the integrin CD103. Our aim was to compare the expression of CD103 in BALF T-lymphocytes between sarcoidosis and other interstitial lung diseases (ILD) and to evaluate its relevance as a BALF diagnostic marker for sarcoidosis. A total of 86 patients with ILD (mean age±standard deviation, 42.6±16.6 years; 60.5% female), who underwent BALF as part of their initial diagnostic work-up, were enrolled into 2 groups: sarcoidosis (n=41) and other ILD (n=45). Area under the receiver operating characteristic (ROC) curve (AUC) was used to describe the performance of CD103 for sarcoidosis diagnosis. Sarcoidosis patients presented a significantly reduced CD103 expression in BALF T-lymphocytes, more pronounced in the CD4(+) subset. The BALF CD103(+)CD4(+)/CD4(+) ratio for a cutoff point of 0.45 was associated with a better diagnostic performance for sarcoidosis (AUC: 0.86 [95% confidence interval (95% CI): 0.78-0.94]; sensitivity: 81%; specificity: 78%), even for those with a CD4(+)/CD8(+) ratio <3.5 (AUC: 0.79 [95% CI: 0.64-0.93]; sensitivity: 75%; specificity: 78%). Assessment of CD103 expression in BALF CD4(+) T-lymphocytes may be a reliable tool for sarcoidosis diagnosis, independently of CD4(+)/CD8(+) ratio, pointing out the relevance of evaluating the CD103(+)CD4(+)/CD4(+) ratio in the ILD diagnostic work-up.

Deficiency of pulmonary Vα24 Vβ11 natural killer T cells in corticosteroid-naïve sarcoidosis patients

Invariant natural killer T (NKT) cells might contribute to the amplified and prolonged T-cell immune response that characterizes sarcoidosis. Therefore, we want to investigate the frequency and distribution of pulmonary invariant NKT cells in corticosteroid-naïve patients with sarcoidosis. We used multi-parameter flow cytometry with antibodies against CD3, CD4, CD8, CD14, CD19, CD45, CD16/56, TCR Valpha24, and TCR Vbeta11, on bronchoalveolar lavage fluid (BALF), to examine the frequency and distribution of pulmonary invariant NKT cells in 47 newly diagnosed sarcoidosis patients and in 8 control subjects. The frequencies of BALF Valpha24 Vbeta11 invariant NKT cells were significantly lower in patients with sarcoidosis in comparison to control subjects. Moreover, lower invariant NKT cell frequencies in patients with sarcoidosis significantly correlated with exaggerated BALF lymphocytosis and CD4 T cell responses. This study demonstrated a pulmonary deficiency in the frequency of a subset of T cells with immunoregulatory function in patients with sarcoidosis.

Altered expression of T cell Immunoglobulin-Mucin (TIM) molecules in bronchoalveolar lavage CD4+ T cells in sarcoidosis

BackgroundActivated T helper (Th)-1 pulmonary CD4+ cells and their mediators are essential for the inflammation and granulomatous process in sarcoidosis. Recently, T-cell immunoglobulin and mucin domain (TIM) molecules were suggested to be important regulators of immune function. In this study, we wanted to investigate whether TIM molecules could play a role in sarcoidosis.MethodsWe used real-time polymerase chain reaction to investigate the differential gene expression of TIM-1 and TIM-3 as well as a few Th1 and Th2 cytokines (IL-2, IFN-γ, IL-4, IL-5 and IL-13) in CD4+ T cells isolated from bronchoalveolar lavage fluid (BALF) of patients (n = 28) and healthy controls (n = 8). Using flow cytometry, we were also able to analyse TIM-3 protein expression in 10 patients and 6 healthy controls.ResultsA decreased TIM-3 mRNA (p < 0.05) and protein (p < 0.05) expression was observed in patients, and the level of TIM-3 mRNA correlated negatively with the CD4/CD8 T cell ratio in BALF cells of patients. Compared to a distinct subgroup of patients i.e. those with Löfgren's syndrome, BALF CD4+ T cells from non- Löfgren's patients expressed decreased mRNA levels of TIM-1 (p < 0.05). mRNA expression of IL-2 was increased in patients (p < 0.01) and non-Löfgren's patients expressed significantly higher levels of IFN-γ mRNA (p < 0.05) versus patients with Löfgren's syndrome.ConclusionThese findings are the first data on the expression of TIM-1 and TIM-3 molecules in sarcoidosis. The reduced TIM-3 expression in the lungs of patients may result in a defective T cell ability to control the Th1 immune response and could thus contribute to the pathogenesis of sarcoidosis. The down-regulated TIM-1 expression in non-Löfgren'spatients is in agreement with an exaggerated Th1 response in these patients.

CHEMOKINE RECEPTORS IN A REGULATION OF INTERSTITIAL LUNG FIBROSIS AND INFLAMMATION

Sarcoidosis and extrinsic allergic alveolitis (EAA) are granulomatous lung diseases with predominantly Th1 immune response. In this prospective study, the authors analyzed the expression of chemokine receptors CXCR2, CXCR3, and CCR3 on bronchoalveolar lavage fluid (BALF) CD4 T cells of patients either with EAA or sarcoidosis. The authors investigated the correlation of chemokine receptors expression, lymphocyte and neutrophil counts in BALF, and high-resolution tomography (HRCT) pattern. Thirteen sarcoidosis and 6 EAA patients were enrolled in the study. The expression of chemokine receptors on BALF CD4 T cells were analyzed by flow cytometry. HRCT scoring system according to Kazerooni was used for evaluation of the disease extent. The authors have found positive correlation between BALF CD4 T-cell CXCR3 expression and HRCT alveolar score in EAA patients (P <. 01). CXCR2 expression on BALF CD4 T cells and interstitial HRCT score did not show a correlation either in the EAA or the sarcoidosis group. Positive correlation between CCR3 expression on CD4+ T cells and HRCT interstitial score was proven in the EAA group (P <. 05). The authors conclude that Th2 predominant immune response may play an important role in chronic EAA pathogenesis. The role of chemokine receptors in the pathogenesis of EAA and sarcoidosis should be presumed and investigated.

Analysis of regulatory T cell associated forkhead box P3 expression in the lungs of patients with sarcoidosis

In pulmonary sarcoidosis, the typical T helper 1-mediated immune response in the lungs has been proposed to be co-ordinated by regulatory T cells; however, their exact role needs to be clarified. We used real-time polymerase chain reaction to study genes involved in regulatory T cell functions in CD4+ T cells isolated from bronchoalveolar lavage fluid (BALF) of patients (n = 24) and healthy subjects (n = 7). The genes included the transcription factor forkhead box P3 (FoxP3), interleukin (IL)-10, transforming growth factor-beta1 and chemokine receptor 2 (CCR2). The same genes were also studied in isolated BALF CD4+ T cell receptor AV2S3+ and AV2S3(-) T cells of patients with lung-restricted AV2S3 T cell expansions (n = 12). Intracellular staining of the FoxP3 protein was performed additionally in 14 patients and nine healthy subjects. mRNA expression of FoxP3, CCR2 and IL-10 was decreased significantly in BALF CD4+ T cells of patients. Flow cytometric analysis of CD4+ T cells also demonstrated a decreased frequency of FoxP3+ cells in the BALF and blood of sarcoidosis patients as well as a reduced intensity (mean fluorescence intensity) of FoxP3 expression in BALF FoxP3+ cells of patients. BALF CD4+AV2S3+ T cells expressed significantly lower levels of FoxP3 and CCR2 mRNA versus BALF CD4+AV2S3- T cells. The main conclusion of our study is that there is a reduced expression of regulatory T cell associated genes in BALF CD4+ T cells in sarcoidosis. In addition, our data suggest an effector function of AV2S3+ lung-accumulated T cells in sarcoidosis.

Induced Sputum versus Bronchoalveolar Lavage Fluid in the Evaluation of Patients with Idiopathic Pulmonary Fibrosis

Background: Induced sputum (IS) has been proposed as a useful noninvasive method for the assessment of airway diseases. Bronchoalveolar lavage fluid (BALF), an important tool for evaluating interstitial lung diseases, has limited utility due to its invasiveness and the difficulties of performing it in severely ill patients, while it is impractical for follow-up evaluation. Objectives: The aim of this study was to investigate the differences and the possible correlation of cell differential and lymphocyte subpopulations between BALF and IS samples in patients with idiopathic pulmonary fibrosis (IPF). Methods: We studied prospectively 20 patients (18 male, 2 female) of median age 67 years (range 40–75) with IPF and 10 normal subjects (5 female, 5 male) of median age 59 years (range 36–70). IS was performed with hypertonic saline solution using an ultrasonic nebulizer (Ultraneb 2000). BALF was performed by a conventional procedure using fiberoptic bronchoscopy within 3 days from IS. May-Grünewald-Giemsa-stained preps were differentially counted and T-lymphocyte subsets were analyzed by a flow-activated cell sorter. Results: The percentage of macrophages was significantly lower in IS than in BALF (p < 0.0001), while the neutrophils were lower in BALF (p < 0.0001). A significant correlation was found between BALF and IS eosinophil counts (r = 0.54, p = 0.01) and CD4+/CD8+ ratio (r = 0.74, p < 0.0001). Conclusion: Our data suggest that different information is obtained by IS and BALF and thus, the two methods are complementary in IPF.

Expression of Th1 markers by lung accumulated T cells in pulmonary sarcoidosis.

The balance between Th1 and Th2 T cells, classified by virtue of their cytokine production can in an immune response influence the phenotype and progression of several clinical diseases. In this study, we examined the expression of Th1 associated chemokine and cytokine receptors CXCR3, CCR5, and interleukin (IL)-12R, IL-18R, respectively, as well as of the Th2 associated chemokine receptors CCR4 and CXCR4 on CD4+ and CD8+ T cells. Eighteen patients with untreated pulmonary sarcoidosis. We used monoclonal antibodies and flow cytometry to analyse the expression of chemokine receptors CXCR3, CXCR4, CCR4 CCR5 and cytokine receptors IL-12R, IL-18R in combination with anti-CD4 and anti-CD8 mAbs in bronchoalveolar lavage fluid (BAL) and peripheral blood lymphocytes (PBL) from sarcoidosis patients. There were significantly more BAL CD4+ T cells expressing CXCR3, CCR5, IL-12R and IL-18R compared with paired PBL CD4+ T cells. In contrast, the Th2 associated chemokine receptors CXCR4 and CCR4 were expressed by a fewer percentage of BAL CD4+ compared with PBL CD4+ T cells. There was a positive correlation between the percentage of BAL lymphocytes and the number of CXCR3 and CCR5 expressing CD4+ BAL T cells. Also, the number of CD4+ IL-18R+ BAL fluid cells correlated negatively with disease duration. The lung accumulation of CXCR3, CCR5, IL-12R and IL-18R expressing T cells is in line with previous reports showing elevated levels in the lung of the corresponding ligands in sarcodosis. Blocking such ligands and/or receptors may develop into a future immunomodulatory therapy.

Rhinitis/Bronchopneumonia syndrome in Irish Wolfhounds.

This study describes the clinical, immunologic, genetic, and pathologic features of Irish Wolfhounds with rhinitis/bronchopneumonia syndrome. The dogs examined were from Belgium, The Netherlands, UK, Canada, Germany, and Switzerland. Signs included transient to persistent mucoid or mucopurulent rhinorrhea, cough, and respiratory dyspnea. Radiographic, rhinoscopic, and bronchoscopic findings were variable. Analysis of ciliary ultrastructure was performed in 5 affected dogs, but no characteristic primary ciliary defects (primary ciliary dyskinesia) were detected. Serum and bronchoalveolar lavage fluid (BALF) concentrations of IgA, IgG, and IgM were determined in some affected dogs and clinically normal Irish Wolfhounds. Serum IgA concentration was below the reference range in 5 of 8 affected dogs tested, whereas BALF IgA concentration was above the normal range in 2 affected adult dogs. The CD4 to CD8 lymphocyte subset ratio (CD4:CD8) in peripheral blood was tested in 3 affected dogs and was within the normal range. BALF CD4:CD8 was tested in 1 affected dog and was higher than the normal range. Decreased neutrophil phagocytosis was observed in 1 of the 4 dogs tested. Analysis of pedigrees of the Belgian, Canadian, German, and Swiss dogs revealed common ancestry, suggesting a heritable syndrome.

In vitro response of lymphocytes from bronchoalveolar lavage fluid and peripheral blood to mitogen stimulation during natural maedi-visna virus infection

To investigate the effects of maedi-visna virus (MVV) infection on cell-mediated immunity, the in vitro response of bronchoalveolar lavage fluid (BALF) and peripheral blood (PB) lymphocytes (PBL) to exogenous mitogen was analysed. BALF and PBL from control ( n = 9) and MVV-infected ( n = 7) animals were cultured for 3 days in the presence and absence of concanavalin A (Con A). Lymphocyte expression of the interleukin-2 receptor (IL-2R) antigen, a parameter of lymphocyte activation, was quantified by dual-colour flow cytometry using the bovine anti-IL-2R monoclonal antibody IL-A111. IL-2R expression by lymphocytes in BALF and PB from control and MVV-infected animals, with and without Con A stimulation, were compared. In the absence of Con A stimulation, the proportion of cultured BALF CD8 + and γδ T cells expressing IL-2R was significantly ( P < 0.05) lower for MVV-infected animals than for controls. After Con A stimulation the proportion of BALF CD4 + lymphocytes from MVV-infected animals that expressed IL-2R remained significantly ( P < 0.05) lower than for controls. Comparisons within group showed that, after Con A stimulation, the proportion of all the T cell subsets in the control group expressing IL-2R, namely CD4 + ( P < 0.001), CD8 + ( P < 0.001) and γδ T cells ( P < 0.05), was significantly increased. In the MVV-infected group, this increase was significant ( P < 0.05) for CD4 + and CD8 + T cells, but not for γδ T cells. In vitro mitogen stimulation of PB T lymphocytes from both control and MVV-infected animals induced a significant elevation in the proportion of all T cell subsets expressing IL-2R when compared to cultured unstimulated control cells. However, there was considerable heterogeneity in the response to Con A of PB T cells from both groups of animals. The expression of IL-2R followed a different pattern to that of BALF lymphocytes, the proportion of unstimulated γδ/IL-2R + T cells from MVV-infected animals being significantly ( P < 0.05) higher than that of controls, and the proportion of cultured unstimulated CD8 +/IL-2R + T cells from MVV-infected animals being significantly ( P < 0.05) lower than that from controls. From these studies it can be concluded that the BALF T lymphocyte immune dysfunction observed during natural MVV infection, characterized by impaired IL-2R expression, is maintained under in vitro conditions.

Increase of Activated T-cells in BAL Fluid of Japanese Patients With Bronchiolitis Obliterans Organizing Pneumonia and Chronic Eosinophilic Pneumonia

To study the role of T cells in bronchiolitis obliterans organizing pneumonia (BOOP) and chronic eosinophilic pneumonia (CEP) and to examine the influence of differing racial background, T-cell subsets in bronchoalveolar lavage (BAL) fluid (BALF) and in peripheral blood of 8 Japanese patients with idiopathic BOOP and 5 with CEP were compared with those of 15 normal subjects. The BALF pattern in BOOP was characterized by a significantly high number and percentage of lymphocyte and by a low CD4 to CD8 ratio compared with patients with CEP and healthy volunteers. Patients with CEP showed a significantly higher percentage of BALF eosinophils compared with other groups. There was no significant difference in BALF CD4 to CD8 ratio between patients with CEP and volunteers. Two-color analysis of T-cell subsets revealed that CD3+HLA-DR+ cells (activated T cell) in BALF of patients with BOOP and CEP increased significantly compared with volunteers, while BALF CD3+CD25+ cells (interleukin 2 receptor+ T-cell) did not. In addition, BALF CD8+HLA-DR+ cells (activated suppressor/cytotoxic T cell) in patients with BOOP and CD4+HLA-DR+ cells (activated helper T cell) in patients with CEP were significantly higher than levels detected in healthy subjects. The percentage of CD8+CD57+ cells and the number of CD8+CD11b- cells (cytotoxic T cell) in BALF were significantly higher in patients with BOOP compared with patients with CEP and healthy volunteers. There were no significant differences in the expression of peripheral blood T-lymphocyte surface antigens among the groups. These findings indicate that cytotoxic T cells in Japanese patients with idiopathic BOOP and helper T cells in CEP appear in the lungs is consistent with a previous report in Caucasians, supporting the hypothesis that T cells may play an important role in the pathogenesis of these diseases.

Activated memory T helper cells in bronchoalveolar lavage fluid from patients with atopic asthma: relation to asthma symptoms, lung function, and bronchial responsiveness.

Bronchial mucosal inflammation and epithelial damage are characteristic features of asthma. Activation of T helper lymphocytes may contribute to this process by mechanisms including the release of cytokines promoting eosinophil infiltration and activation. Bronchial washings and bronchoalveolar lavage fluid were obtained from 29 atopic asthmatic patients (19 with current symptoms and 10 symptom free) and 13 normal volunteers. Flow cytometry was used to assess T cell phenotype and activation status in bronchoalveolar lavage fluid and peripheral blood, and differential cell counts were made on bronchial washings and bronchoalveolar lavage fluid. Findings were related to severity of disease as reflected by symptom scores, baseline lung function, and airway responsiveness. CD4 T lymphocytes in bronchoalveolar lavage fluid and blood from asthmatic patients were activated by comparison with controls (CD4 CD25, median 16.8% v 8.7% for bronchoalveolar lavage fluid, and 15.3% v 8.7% in blood). Bronchoalveolar lavage fluid CD4 T cells from both asthmatic patients and controls were of memory phenotype (95.8% and 96.8% CD45RO and 1.7% and 0.4% CD45RA respectively), whereas both CD45RO and CD45RA T cells were present in blood. Patients with asthma and current symptoms showed increased bronchoalveolar T cell activation compared with patients without symptoms (CD4 CD25 18.7% v 12.3%). Within the asthmatic group there was a significant association between CD4 CD25 lymphocytes and asthma symptom scores (rs = 0.75), airway methacholine responsiveness (log PC20, rs = -0.43) and baseline FEV1 (rs = -0.39). A correlation was also found between CD4 CD25 lymphocytes and eosinophils in bronchoalveolar lavage fluid (rs = 0.48). Eosinophils in bronchoalveolar lavage fluid were increased in asthmatic patients compared with controls and the percentage of eosinophils in bronchoalveolar lavage fluid correlated with asthma symptom score. A relation was found between percentage of epithelial cells in bronchoalveolar lavage fluid and FEV1 and methacholine PC20. These results support the hypothesis that selective activation of memory CD4 T cells contributes to eosinophil accumulation, bronchial hyperresponsiveness, and symptoms in asthma.