Morphometric markers for the evaluation of preneoplastic lesions in the lung. Diagnostic evaluation by high-resolution image analysis of atypical cells in sputum specimens

A review is presented of the Baylor College of Medicine/NASA/Lyndon Johnson Space Center high-resolution image analysis system for the detection of preneoplastic lesions of the lung in sputum specimens. For each specimen, 200 cells are graded as to their Atypia Status Index (ASI), a numerical classification based on a weighted composite of morphometric markers identified in the digitized images. The ASI values, which place individual cells within categories ranging from squamous metaplastic to carcinomatous, form the basis of the Cell Atypia Profile (CAP), which reflects the overall status of the patient's bronchial epithelium and can be used to diagnose and monitor epithelial atypias. Initial studies have shown the ASI and CAP to be accurate indices, whose application in the studies of sputum of individuals at high risk for the development of lung cancer (cigarette smokers over 45 years of age and industrially exposed workers) could lead to the early detection of preneoplastic lung lesions and to effective early clinical intervention, including the cessation of smoking or the application of beta-carotone or retinoids, which reportedly arrest the progression of bronchial epithelial atypias. Computer-assisted cell image analysis of morphometric markers in cells in sputum specimens appears to be uniquely applicable for surveillance of individuals at risk for carcinoma of the lung.     

Nuclear segmentation of bronchial epithelial cells by minimax and thresholding techniques. A comparison

Two nuclear segmentation methods, Baky's minimax algorithm and thresholding, were compared on a sample of 879 atypical bronchial epithelial cells in sputum. Nuclear-cytoplasmic (N/C) ratios for all cells were determined by each segmentation method and compared to a visually determined value. Cells were categorized by atypia class (from metaplastic through malignant), by staining characteristics (orangeophilic and nonorangeophilic) and by method of digitization (either scanning microphotometry or video system). The method of digitization was confounded by subject differences. The results indicated that with most classes of atypia, N/C ratios determined by minimax were closer to the visually derived values than were those of thresholding, particularly with orangeophilic cells. Both methods become progressively less accurate, as compared to the visual procedure, as the degree of atypia increases.     

Fine needle aspiration cytologic features of mammary phyllodes tumors

OBJECTIVE: To evaluate specific diagnostic fine needle aspiration cytologic (FNAC) features of phyllodes tumor (PT), particularly in the differentiation from fibroadenoma (FA). STUDY DESIGN: Twenty-eight FNAC of PT were reviewed for smear cellularity, epithelial and stromal fragments, their size and atypia, epithelial/stromal area ratio, background single stromal cells (oval or columnar), multinucleated giant cells, and squamous and apocrine cells. Twenty-one FNAC of fibroadenoma were also assessed for comparison. RESULTS: PT was significantly larger than FA. Epithelial fragments were found in all cases, with atypia present in PT. Stromal fragments were present in half the cases; there was no difference in stromal size, but the epithelial/stromal area ratio was significantly lower in PT than FA. Single columnar stromal cells with recognizable cytoplasm and multinucleated stromal giant cells were seen in some PT but not in FA. CONCLUSION: Cytologic diagnosis of PT remains difficult, with significant overlap with FA. The presence of large size, low epithelial/stromal ratio, epithelial atypia, columnar stromal cells with visible cytoplasm and stromal giant cells favors a diagnosis of PT over FA.     

Diagnosis of bronchial carcinoma on sections of paraffin-embedded sputum. Sensitivity and specificity of an alternative to routine cytology.

The diagnostic accuracy of sputum cytology for the diagnosis of bronchial carcinoma using paraffin-embedded, serially sectioned and hematoxylin and eosin-stained specimens was tested in 4,297 sputum samples from 1,889 patients, 219 of whom had bronchial carcinoma. The diagnostic sensitivity depended mainly on the number of investigated samples and was 85.4% with three sufficient sputa. The sensitivity was not influenced by the histologic types, location or TNM stage of the tumor. The specificity of the method was 99.5%. In three cases localization of sputum cytologically diagnosed bronchial carcinomas was not possible immediately (occult carcinomas, pTx); in two of these cases the bronchial carcinomas were located during follow-up. The third patient died without verification of the cytologic diagnosis. According to our results, sputum cytology on serial sections is a valuable instrument for mass screening of high-risk groups for the early detection of bronchial carcinoma. Lower sensitivities of sputum cytology in mass screening programs for the early diagnosis of lung cancer are discussed critically.     

Abrasive bronchial brushing cytology. A preliminary study of 200 specimens for the diagnosis of neoplastic and nonneoplastic bronchopulmonary lesions

Two hundred subjects with chronic respiratory symptoms with a suspicion of malignancy were selected for bronchial brushing cytology. Prior sputum examination had shown malignant squamous cells in two cases only. The cytologic appearances of the brushing smears were divided into five categories: 41 (20.5%) smears with positively malignant cells; 20 (10%) smears predominantly showing chronic inflammatory features; 31 (15.5%) smears with mainly acute inflammatory changes; 60 (30%) smears with normal cytologic features; and 48 (24%) smears unsatisfactory for cytologic interpretation. Thirteen patients with a positive cytology had a positive tissue biopsy for malignancy. Among the group with chronic inflammatory changes, acid-fast bacilli were identified in nine cases, and one smear showed frank tuberculous granuloma. In the unsatisfactory group, two cases showed malignant cells in the postbrushing sputum. There was one false-negative report for malignancy in the entire study. This study confirms the sensitivity and accuracy of bronchial brushing cytology in the diagnosis of various bronchopulmonary lesions, especially malignancy and pulmonary tuberculosis, in India.     

Gynecomastia: cytologic features and diagnostic pitfalls in fine needle aspirates.

OBJECTIVE: To illustrate some of the uncommon cytologic findings of gynecomastia, such as apocrine metaplasia, cellular atypia and foamy macrophages, that can be misinterpreted as evidence of malignancy. STUDY DESIGN: The clinical data and fine needle aspiration (FNA) cytologic material from 100 men with the diagnosis of gynecomastia were retrospectively reviewed. The excisional biopsy slides were available for 16 cases. For comparison, FNA smears from five men with breast lesions other than gynecomastia were studied. RESULTS: The patients ranged in age from 23 to 91 years. Cytologic findings were as follows: cohesive sheets of cells containing 20-1,000 cells (98%); scattered, single, bipolar cells (78%); spindle cells (68%); ductal epithelial atypia (26%); apocrine metaplasia (8%); and foamy histiocytes (12%). In nine cases the atypia was marked, and in two of them the possibility of malignancy could not be ruled out. Surgical follow-up on 16 patients, including the cases with marked atypia, showed gynecomastia. In one case, gynecomastia was associated with intraductal papilloma. No correlation between the underlying etiology and atypical cytologic features of gynecomastia was identified. CONCLUSION: Apocrine metaplasia and epithelial atypia are common findings in gynecomastia. Attention to the cell patterns, the presence of sheets of ductal cells and absence of atypical single cells will point to the correct diagnosis.     

Diagnostic significance of "severe dysplasia" in sputum cytology

The diagnostic significance of a cytologic diagnosis of "severe dysplasia" on sputum samples was assessed. In a group of 46 patients with diagnoses of severe dysplasia, follow-up showed no malignancy of the lung in 25 patients (54%) and a malignant process in 21 patients (46%). These groups were compared to 52 patients with correct negative and 202 patients with correct positive sputum diagnoses. Of the patient characteristics investigated, age, previous sputum production, vital capacity and low forced expiratory volume were not significantly related to a sputum cytodiagnosis of severe dysplasia. In contrast, severe dyspnea showed a significantly higher frequency in patients with a sputum cytodiagnosis of severe dysplasia, but without an underlying malignant lung process. Follow-up disclosed a malignant tumor in 10 of 13 patients with disease; the presence of severely dysplastic cells in sputum specimens from such patients should be considered a warning signal for an underlying malignant lung process. Since severe dysplasia should be considered a premalignant epithelial lesion, patients with sputum cytodiagnoses of severe dysplasia should undergo bronchoscopy, with multiple bronchial brushings of all areas showing suspicious mucosal changes, together with segmental bronchial washings. In case a malignant process cannot be located, sputum examinations should be repeated at three-month intervals.     

Flow cytometric enrichment for respiratory epithelial cells in sputum.

BACKGROUND: Induced sputum, in contrast to bronchoscopic biopsies and lavages, is an easily obtained source of biological specimens. However, obtaining abnormal exfoliated cells for detailed molecular studies is limited because respiratory epithelial cells comprise only about 1% of sputum cell populations. METHODS: We developed a multiparameter flow sorting strategy to purify epithelial cells from nonepithelial sputum cells, using anti-cytokeratin antibody AE1/AE3 to recognize human epithelial cells and DAPI to stain DNA. We excluded cells with a high degree of side-scatter, which were composed predominantly of squamous cells and contaminating macrophages. The remaining cytokeratin-positive respiratory epithelial cells were then sorted based on anti-cytokeratin (PE) vs DNA (DAPI) parameters. RESULTS: In this proof of principle study, the AE1AE3 cytokeratin/DNA flow sorting strategy enriched rare diploid respiratory epithelial cells from an average of 1.1% of cells in unsorted induced sputum samples to average purities of 42%. Thus, AE1AE3 flow-sorting results in a 38-fold enrichment of these cells. CONCLUSIONS: We report a multiparameter flow cytometric assay to detect and enrich rare respiratory epithelial cells from induced sputum samples to average purities of 42%. With further development, this methodology may be useful as part of a molecular screening approach of populations at high risk for lung cancer.     

Identification of candidate biomarkers for early detection of human lung squamous cell cancer by quantitative proteomics

To discover novel biomarkers for early detection of human lung squamous cell cancer (LSCC) and explore possible mechanisms of LSCC carcinogenesis, iTRAQ-tagging combined with two dimensional liquid chromatography tandem MS analysis was used to identify differentially expressed proteins in human bronchial epithelial carcinogenic process using laser capture microdissection-purified normal bronchial epithelium (NBE), squamous metaplasia (SM), atypical hyperplasia (AH), carcinoma in situ (CIS) and invasive LSCC. As a result, 102 differentially expressed proteins were identified, and three differential proteins (GSTP1, HSPB1 and CKB) showing progressively expressional changes in the carcinogenic process were selectively validated by Western blotting. Immunohistochemistry was performed to detect the expression of the three proteins in an independent set of paraffin-embedded archival specimens including various stage tissues of bronchial epithelial carcinogenesis, and their ability for early detection of LSCC was evaluated by receiver operating characteristic analysis. The results showed that the combination of the three proteins could perfectly discriminate NBE from preneoplastic lesions (SM, AH and CIS) from invasive LSCC, achieving a sensitivity of 96% and a specificity of 92% in discriminating NBE from preneoplatic lesions, a sensitivity of 100% and a specificity of 98% in discriminating NBE from invasive LSCC, and a sensitivity of 92% and a specificity of 91% in discriminating preneoplastic lesions from invasive LSCC, respectively. Furthermore, we knocked down GSTP1 in immortalized human bronchial epithelial cell line 16HBE cells, and then measured their susceptibility to carcinogen benzo(a)pyrene-induced cell transformation. The results showed that GSTP1 knockdown significantly increased the efficiency of benzo(a)pyrene-induced 16HBE cell transformation. The present data first time show that GSTP1, HSPB1 and CKB are novel potential biomarkers for early detection of LSCC, and GSTP1 down-regulation is involved in human bronchial epithelial carcinogenesis.     

Cytologic findings of breast ductal lavage and concurrent fine needle aspiration in pleomorphic lobular carcinoma in situ: a case report

BACKGROUND: Breast ductal lavage (DL) is a noninvasive procedure for sampling ductal epithelial cells. Patients at risk for breast cancer or with prior history can be monitored by DL. This report compares cytomorphology in concurrent DL, fine needle aspiration (FNA) and histology in a case of pleomorphic lobular carcinoma in situ (PLCIS) with signet ring features. CASE: A 57-year-old woman had DL and FNA performed after quadrantectomy for lobular carcinoma in situ with signet ring cell features. DL and FNA were diagnosed as suspicious and positive for malignancy, respectively. Subsequent biopsy showed PLCIS. Cytomorphologic features of DL, FNA and histology were compared. DL showed epithelial cells in small clusters or single-file arrangement and single-lying; in FNA, single cells predominated. DL and FNA showed nuclear atypia and cytoplasmic vacuoles, the latter more prevalent in FNA. Both samples showed cells with signet ring features. The atypical epithelial cells present in DL and FNA were identical to those seen in the histologic material. CONCLUSION: Cytomorphologic findings in DL, although less striking, are comparable to those seen in FNA. Architecture, nuclear atypia and intracytoplasmic vacuoles are helpful features in DL for establishing a diagnosis of suspicious if not positive for malignancy in LCIS.     

Production of tissue-engineered three-dimensional human bronchial models

We have reported morphological and functional features of cells isolated from human bronchial biopsies. Both epithelial and fibroblastic cells were isolated from the same biopsies using collagenase. A few models have been established to study normal bronchial response to various agents and to understand the mechanisms responsible for some disorders, such as asthma. We produced three-dimensional bronchial equivalents in culture, using human epithelial and fibroblastic cells. We previously showed that peripheral anchorage can prevent the dramatic collagen contraction in gels seeded with fibroblasts when properly adapted to the size and type of cultured tissues. Our bilayered bronchial constructs were anchored and cultured under submerged conditions and at the air-liquid interface. Three culture media were compared. Serum-free medium supplemented with retinoic acid (5 x 10(-8) M) was found to be the best for maintenance of bronchial cell properties in the reconstructed bronchial tissue. Immunohistological and ultrastructural analyses showed that these equivalents present good structural organization, allowing ciliogenesis to occur in culture. Moreover, human bronchial goblet cells could differentiate and secrete mucus with culture time. Laminin, a major constituent of the basement membrane and basal cells, was also detected at the mesenchymoepithelial interface. Such models will be useful for studying human bronchial properties in vitro.     

Comparison of nasal and bronchial epithelial cells obtained from patients with COPD

For in vitro studies of airway pathophysiology, primary epithelial cells have many advantages over immortalised cell lines. Nasal epithelial cells are easier to obtain than bronchial epithelial cells and can be used as an alternative for in vitro studies. Our objective was to compare nasal and bronchial epithelial cells from subjects with COPD to establish if these cells respond similarly to pro-inflammatory stimuli. Cell cultures from paired nasal and bronchial brushings (21 subjects) were incubated with cigarette smoke extract (CSE) prior to stimulation with Pseudomonas aeruginosa lipopolysaccharide. IL-6 and IL-8 were measured by ELISA and Toll-like receptor 4 (TLR-4) message and expression by RT-PCR and FACS respectively. IL-8 release correlated significantly between the two cell types. IL-6 secretion was significantly less from bronchial compared to nasal epithelial cells and secreted concentrations did not correlate. A 4 h CSE incubation was immunosuppressive for both nasal and bronchial cells, however prolonged incubation for 24 h was pro-inflammatory solely for the nasal cells. CSE reduced TLR-4 expression in bronchial cells only after 24 h, and was without effect on mRNA expression. In subjects with COPD, nasal epithelial cells cannot substitute for in vitro bronchial epithelial cells in airway inflammation studies.     

Localization of human airway trypsin-like protease in the airway: an immunohistochemical study

Human airway trypsin-like protease (HAT) has been isolated from mucoid sputum of patients with chronic airway diseases. In order to clarify the cellular source of this novel protease in the human airway, we examined the localization of immunoreactive HAT in bronchial tissues obtained at surgery and fixed in 4% paraformaldehyde using an extremely sensitive immunohistochemical technique called a catalyzed signal amplification method and a monoclonal antibody against recombinant HAT. HAT immunoreactivity was demonstrated in cytoplasm of ciliated cells of bronchial epithelium and/or at the basal part of cilia. No positive reaction was found in submucosal glands or mast cells. The heterogeneous distribution of HAT immunoreactivity within the bronchial epithelium indicates that its expression might be changeable and that it might be closely related to the physiological status of the airway epithelium. Non-specific but intense reaction caused by endogenous avidin-binding activity (EABA) was selectively detected in submucosal glands, but was effectively blocked by successive treatments with avidin and biotin. These results indicate that HAT may be synthesized in the ciliated cells and that it may play some physiological roles within the epithelial layer and on the airway surface. It is necessary to keep in mind that some cells show strong EABA, especially when a highly sensitive immunohistochemical technique is applied.     

Membrane antigens of human bronchial epithelial cells identified by monoclonal antibodies

Summary Subpopulations of normal bronchial epithelial cells were identified using a series of murine monoclonal antibodies. These antibodies were used to stain intact bronchial epithelial cells in culture by indirect immunofluorescence. LAM 2 reacted with 80%, LAM 6 with 75%, LAM 7 with 60%, and LAM 8 with 5% of these cells. Sections of human bronchial epithelium were also stained with these antibodies by immunoperoxidase methods. LAM 2 was found to bind with 80%, LAM 6 with 65%, LAM 7 with 50%, and LAM 8 with less than 1% of bronchial epithelial cells. LAM 2 stained both columnar epithelial cells and basal cells; LAM 6 stained mainly basal cells and only a small proportion of columnar cells; LAM 7 showed specificity for basal cells; LAM 8 distinctly stained single cells in the basal cell layer. These antibodies were previously shown to react with the surface membrane of human lung carcinomas, ranging from the broad reactivity of LAM 2 with small cell and non-small cell lung cancers to the highly restricted reactivity of LAM 8 with small cell carcinomas of the lung. Thus, membrane antigens have been identified in bronchial epithelial cells by monoclonal antibodies which exhibit a similar range of cellular reactivity in vitro as in vivo. Inasmuch as these antibodies recognize subsets of cells which could not be easily distinguished by morphologic characteristics, these reagents may be useful in classifying bronchial epithelial cells.     

Infection of cultured human airway epithelial cells by influenza A virus

The lack of an adequate in vitro model has hampered study of the cellular basis by which influenza A virus causes disease in the human airway. We report in vitro infection of human airway epithelial cells by influenza A virus. Fetal and adult human tracheal and bronchial epithelial cells cultured from explants and SV40 transformed adult human tracheal epithelial cells were exposed to a recently isolated strain of influenza A virus (H1N1) and a laboratory passaged strain (WSN) of influenza A virus at similar multiplicity of infection. All cultures derived from explants showed hemadsorption (approximately 30% of the cells) with the H1N1 virus. No hemadsorption was detected with the WSN virus. One of two transformed cell lines showed a 5-10% hemadsorption to cells after H1N1 exposure and none following exposure to WSN. Immunofluorescent staining for influenza A-specific antigens in virus-exposed, explant-derived cells indicated viral infection and replication in these cells. Hemagglutinating material in the growth medium of infected, explant-derived cell lines, increased as a function of time, indicating the production of virus proteins. Exposure of rhesus monkey kidney cells and new human tracheal epithelial cultures to supernatant from these cells resulted in hemadsorption, indicating the presence of infectious virus in the supernatant. Light microscopic examination of virally infected bronchial epithelial cells demonstrated that the common types of cytopathic changes were rarely seen while cell proliferation continued over time. The data indicate that influenza A virus can infect, replicate, and produce infectious virus in cultured human tracheal and bronchial epithelial cells.     

Diagnosis and typing of lung carcinomas by cytopathologic methods. A review of 108 cases

A correlative review was made of the type of cytology specimens (sputum, bronchial washing and bronchial brushing) together with the corresponding histopathologic specimens of 108 patients. One hundred patients had primary pulmonary carcinomas diagnosed histopathologically (84) or clinically (16); 5 had carcinomas metastatic to the lungs and 3 had apparently false-positive cytologic results for lung cancer. The correlative review was used to determine the diagnostic reliability of pulmonary cytopathologic techniques in the detection and classification of lung carcinomas (i.e., the sensitivity and accuracy). The overall sensitivities of sputum, bronchial washing and bronchial brushing cytology were 60%, 66% and 77%, respectively (p less than 0.05). Bronchial brushing had a higher sensitivity (80%) for peripheral and metastatic lesions than did sputum (37%) or bronchial washing (60%). The overall accuracies of sputum, bronchial washing and bronchial brushing cytology were 79%, 75% and 76%, respectively, which is not statistically different. Regardless of the sampling methods, cytologic typing of squamous-cell and small-cell carcinomas was highly accurate but was less satisfactory for the other types of lung carcinomas. In the 16 cases in which endoscopic biopsies were either not attempted or gave negative results, one or more pulmonary cytologic specimens showed malignant cells. It is concluded that: (1) pulmonary cytopathologic techniques have excellent sensitivity and accuracy in the diagnosis of lung carcinomas; (2) they may establish the diagnosis of pulmonary carcinomas when endoscopic biopsies give negative results; and (3) they are particularly helpful in cases in which endoscopic biopsies suffer from a low yield (peripheral lesions) or create a considerable danger to the patients (iatrogenic hemorrhage).     

Diagnosis of pulmonary hamartoma by fine needle biopsy

OBJECTIVE: To review the features of pulmonary hamartoma (PH) on fine needle biopsy (FNB), with emphasis on features that allow specific diagnosis. STUDY DESIGN: Fourteen cases of PH diagnosed on FNB were reviewed. The presence and volume of aspirate components were recorded. Attention was paid to features that might lead to false positive diagnosis of malignancy. Immunohistochemical staining for S100 was performed on cell block material. RESULTS: Fibromyxoid stroma and chondroid material were seen in 93% and 79% of cases, respectively; 71% demonstrated both components. Fibromyxoid stroma was prominent in the majority of cases; chondroid material was less abundant, being scanty in over half of cases. There were no cases in which epithelial cells represented the sole prominent component, and significant epithelial atypia was not identified. S100 staining was demonstrable in all cases in which stromal material was present in the cell block. CONCLUSION: A correct specific diagnosis of pH requires identification and correct interpretation of either fibromyxoid stroma or cartilaginous material. These components may show variable appearance on smears, with a range of potential mimics and pitfalls, but specific features are recognizable. Immunohistochemical staining of stromal material with S100 may lend support to the diagnosis.     

Detection of K-ras and p53 mutations in sputum samples of lung cancer patients using laser capture microdissection microscope and mutation analysis

Mutations in the p53 tumor suppressor gene and the K-ras oncogene have been frequently found in sputum and bronchoalveolar lavage (BAL) samples of lung cancer patients and other patients prior to presenting clinical symptoms of lung cancer, suggesting that they may provide useful biomarkers for early lung cancer diagnosis. However, the detection of these gene mutations in sputum and BAL samples has been complicated by the fact that they often occur in only a small fraction of epithelial cells among sputum cells and, in the case of p53 gene, at many codons. In this study, sputum cells were collected on a filter membrane by sputum cytocentrifugation and morphologically analyzed. Epithelial cells were selectively taken by using a laser capture microdissection microscope and analyzed by polymerase chain reaction (PCR) and single-stranded conformational polymorphism (SSCP) for p53 mutations and by PCR and denaturing gradient gel electrophoresis (DGGE) for K-ras mutations. This method was used to analyze sputum of 15 Chinese women with lung cancer from Xuan Wei County, China and detected mutations in sputum of 7 (46.7%) patients, including 5 patients with p53 mutations, 1 patient with a K-ras mutation, and 1 patient with K-ras and p53 mutations. For comparison, only two of the mutations were detected by conventional methods. Therefore, the laser capture/mutation analysis method is sensitive and facilitates the detection of low-fraction mutations occurring throughout the p53 and K-ras genes in sputum of lung cancer patients. This method may be applicable to the analysis of epithelial cells from clinically normal sputum or BAL samples from individuals with a high risk for developing lung cancer.     

Biliary tract brush cytology

OBJECTIVE: To prospectively review brush smears obtained during endoscopic retrograde cholangiopancreatography (ERCP) primarily from the biliary tree. STUDY DESIGN: A total of 175 specimens from 147 patients were included in the study. The smears, prepared directly from the endoscopic brush, were stained by the Papanicolaou technique and analyzed for standard cytologic features. RESULTS: The smears were categorized into benign/reactive, significant atypia and suspicious/positive. The consistent features seen in suspicious or positive smears were tightly cohesive, small, three-dimensional cell clusters that formed cell balls. The cells in the clusters displayed features of malignant cells. CONCLUSION: ERCP-guided brushing is a safe diagnostic procedure for the evaluation of biliary tree lesions. Small, three-dimensional epithelial clusters with marked atypia signify malignancy and warrant the diagnosis of a malignant neoplasm even when only one or two such clusters are seen in the smears. Single cells, cytoplasmic vacuoles and prominent nucleoli are not essential for a diagnosis of malignancy.     

Adherence of airway neutrophils and inflammatory response are increased in CF airway epithelial cell-neutrophil interactions

Persistent presence of PMN in airways is the hallmark of CF. Our aim was to assess PMN adherence, percentage of apoptotic airway PMN (aPMN), and IL-6 and IL-8 production when aPMN are in contact with airway epithelial cells. Before coculture, freshly isolated CF aPMN have greater spontaneous and TNF-alpha-induced apoptosis compared with blood PMN from the same CF patients and from aPMN of non-CF patients. We then examined cocultures of PMN isolated from CF and non-CF airways with bronchial epithelial cells bearing mutated cftr compared with cftr-corrected bronchial epithelial cells. After 18-h coculture, the number of CF aPMN adhered on cftr-deficient bronchial epithelial cells was 2.3-fold higher compared with the coculture of non-CF aPMN adhered on cftr-corrected bronchial epithelial cells. The percentage of CF apoptotic aPMN (9.5 +/- 0.2%) adhered on cftr-deficient bronchial epithelial cells was similar to the percentage of non-CF apoptotic aPMN adhered on cftr-corrected bronchial epithelial cells (10.3 +/- 0.7%). IL-6 and IL-8 levels were enhanced 6.5- and 2.9-fold, respectively, in coculture of CF aPMN adhered on cftr-deficient bronchial epithelial cells compared with coculture of non-CF aPMN adhered on cftr-corrected bronchial epithelial cells. Moreover, blocking surface adhesion molecules ICAM-1, VCAM-1, and E-selectin on cftr-deficient bronchial epithelial cells with specific MAbs inhibited the adherence of CF aPMN by 64, 51, and 50%, respectively. Our data suggest that in CF patients a high number of nonapoptotic PMN adhered on airway epithelium associated with elevated IL-6 and IL-8 levels may contribute to sustained and exaggerated inflammatory response in CF airways.