Quantification of cell loss during bronchoalveolar lavage fluid processing. Effects of fixation and staining methods

Role of Immunocytochemistry in the Cytological Diagnosis of Pulmonary Tumors

Pulmonary cytology is a challenging diagnostic tool, and it is usually evaluated considering medical history and radiological findings in order to reach an accurate diagnosis. Since the majority of lung cancer patients have an advanced stage at diagnosis, a cytological specimen is frequently the only material available for diagnosis and further prognostic/predictive marker determination. Several types of specimens can be obtained from the respiratory system (including sputum, bronchoalveolar lavage, bronchial brushing, fine needle aspiration, and pleural fluid) with different technical preclinical management protocols and different diagnostic yields. Immunocytochemistry (ICC) has a pivotal role in the determination of diagnostic, prognostic, and predictive markers. Therefore, limited cytology samples are to be used with a cell-sparing approach, to allow both diagnostic ICC evaluation as well as predictive marker assessment by ICC or specific molecular assays. In this review, we describe the most common ICC markers used for the diagnosis and prognostic/predictive characterization of thoracic tumors in different cytological specimens.

Effects of on-slide fixation on the cell quality of cytocentrifuged equine bronchioalveolar lavage fluid

BACKGROUND

During bronchoalveolar lavage fluid (BALF) sample preparation in horses, several technical aspects can affect sample variability. To date, the effects of different fixatives on prepared equine BALF films have been insufficiently investigated.

OBJECTIVES

This study aimed to determine the effect of various on-slide fixation methods on cell quality, including spray fixation of wet films, and acetone and methanol fixation of air-dried samples in comparison with unfixed, air-dried films.

METHODS

Cytocentrifuged BALF samples from 5 horses were fixed in a wet state using a commercially available fixation spray. They were also fixed with acetone or methanol after air-drying using standard protocols or were air-dried with no fixation. After different postfixation storage durations and temperatures, the samples were stained with May-Grünwald Giemsa or immunocytochemistry stains. Subsequently, differential cell counts (DCCs) were performed, cell areas were measured, and cell morphologies and immunocytochemical staining intensities were assessed semiquantitatively.

RESULTS

Optimal cell morphology results were achieved with the wet-spray fixation method. Acetone and methanol fixation, especially when performed at -20°C, caused reduced cell morphology quality, thereby significantly altering DCCs. For storage of unstained samples for 1 week at room temperature, no significant changes in cell morphology were observed for either fixation method. Wet-spray fixation resulted in enhanced preservation of macrophage, granulocyte, and mast cell sizes compared with air-drying techniques. Immunocytochemical staining of unfixed and acetone-fixed samples was the most intense.

CONCLUSIONS

Wet-spray fixation resulted in the best preservation of cellular morphology and less cell shrinkage compared with unfixed specimens and is, therefore, recommended for BALF cytology.

HOPE-BAL: improved molecular diagnostics by application of a novel technique for fixation and paraffin embedding

The bronchoalveolar lavage (BAL) and its cells have been widely used as a support for clinical diagnosis and as a versatile tool for research questions since many years. Because there are no sufficient possibilities of long-term storage, the authors explore in this study the utility of a new fixative for fixation and paraffin embedding of human lavage cells with the possibility of implementing standard molecular biology techniques. HOPE-fixed, paraffin-embedded BAL cells of patients with different lung diseases (asthma, chronic obstructive pulmonary diseases, tuberculosis, sarcoidosis, emphysema, and fibrosis) were subjected to immunohistochemistry, in situ hybridization, quantitative polymerase chain reaction, and transcription microarray analysis. Furthermore, two-dimensional gel electrophoresis was conducted to evaluate the range of possible applications for research, diagnostics, and further implementing in biobanks. The authors show, by targeting some exemplary molecules, the power of screening and validating HOPE-BAL for new biomarkers. The transforming growth factor β signaling pathway may play a central role in immunomodulation upon infection as well as asthma. Furthermore, haptoglobin was overexpressed in asthma and sarcoidosis. Because of the excellent preservation of nucleic acids, protein, and morphologic structures, HOPE-BAL is a step forward into enhanced molecular diagnostics and biobanking in pulmonary medicine.

Pediatric bronchoalveolar lavage: practical considerations and future prospects

Despite the utilization of bronchoalveolar lavage (BAL) in children since the early 1970s, several challenges remain once the procedure is complete. These include little documentation on normal controls, the limitations due to the size of the patient, and uniform processes for assessment. It was not until 1995 that a taskforce on pediatric BAL was formed by the European Respiratory Society, and to our knowledge, they remain the only committee evaluating the process [1]. We examined our procedures and reviewed the literature in an attempt to document the most fruitful practices that would allow improved data comparison and introduce possible investigations.

Comparison of bronchoalveolar lavage cytospins and smears in dogs and cats

Differences in the cytological interpretation of bronchoalveolar lavage fluid (BALF) after cytospin preparation (CP) or manual smearing of pelleted cells preparation (MSP) were investigated in client-owned dogs and cats with inflammatory or infectious lower respiratory disease. Bronchoalveolar lavage fluid from healthy cats was also examined. With MSP, cell lysis was more frequently observed, and cellular distribution was more heterogeneous throughout the slide. When samples from healthy and diseased animals were considered together, a significantly greater percentage of neutrophils was seen on CP than on MSP slides (P<0.002). Cytospin preparations were considered of better quality in all individual comparisons. Cytospin preparation is advised in the evaluation of BALF with low total cell count. When only MSPs are evaluated, clinicians should be aware that differential neutrophil counts may underestimate the counts found on CP slides.

Competition between elastase and related proteases from human neutrophil for binding to alpha1-protease inhibitor

The protease-antiprotease imbalance that is characteristic of most inflammatory lung disorders depends on the spatial-temporal regulation of active inhibitor and protease concentrations in lung secretions. We have studied the competition between the three main serine proteases from human neutrophil primary granules in their binding to alpha1-Pi, the main serine proteases inhibitor in lung secretions. Elastase was the only target of alpha1-Pi when identical molar amounts of purified inhibitor and the three proteases were tested together. The other two proteases were only inhibited once elastase was saturated. Elastase remained the preferred target of inhibitors when bronchoalveolar lavage fluids from patients with lung pneumonia and acute respiratory distress syndrome were used as the source of inhibitors, in spite of the presence of additional inhibitors in lung secretions. Since neutrophil proteases are expressed at the neutrophil surface, we also measured residual activities of membrane-bound proteases after purified neutrophils were incubated with bronchoalveolar fluids. Again, elastase was the preferred target of the inhibitors. We conclude that protease 3 and cathepsin G are not controlled as efficiently as elastase in lung secretions, a feature that must be taken into account when developing inhibitor-based anti-inflammatory therapies.

Cytological analysis of equine bronchoalveolar lavage fluid. Part 2: Comparison of smear and cytocentrifuged preparations

The aim of this study was to develop a diagnostically useful smear method for preparation of equine bronchoalveolar lavage fluid (BALF) for use by practitioners. A smear method for equine BALF preparation which included the addition of serum was developed, and cell morphology, differential cell counts (DCC) and repeatability of counting DCC compared with those of cytocentrifuged BALF preparations. BALF samples (n = 21) were collected from 5 control horses and 5 heaves-susceptible horses. Smear preparations of BALF produced smaller, darker, staining cells, making cytological identification more difficult than on cytocentrifuged preparations. There was a significantly higher (P<0.01) macrophage DCC and lower lymphocyte DCC on cytocentrifuged compared to smear preparations. Mast cell and eosinophil DCC were significantly higher (P<0.05) on cytocentrifuged compared to smear preparations of BALF. Smear preparations were shown to be reliable for the cytological diagnosis of equine neutrophilic pulmonary disease and offer practitioners an alternative to sending equine BALF to a laboratory for processing and cytological analysis.

Bronchoalveolar lavage in asthma research

A great deal of information about the pathophysiology of asthma and its treatment have been obtained through the use of bronchoalveolar lavage (BAL), especially in combination with airway biopsies. The introduction of highly sophisticated methods for examining BAL aspirate, including fluorocein activated cell scanning (FACS) analysis and molecular biology techniques has emphasized the potential power of this method of airway investigation. For those contemplating the use of BAL in asthma research programmes, we hope that this review will provide a useful insight into the current state of knowledge about the technique and its application, and that it will provide a solid platform for study design.

[Quality and selection of samples of bronchoalveolar lavage (BAL) in diffuse pneumopathies]

Bronchoalveolar lavage (BAL) samples used to study immune or inflammatory response in interstitial lung disease must be representative of the lower respiratory tract. Thus, the selection of suitable samples must be part of routine practice. To assess the incidence of unsuitable BAL samples used for cytology and to determine the relation between parameters related to underlying disease and the quality of samples. One hundred sixty-one patients were enrolled. Seventy-two were HIV positive and had diffuse pulmonary infiltrates, 34 had idiopathic pulmonary fibrosis (IPF), 10 had sarcoidosis, 10 had hypersensitivity pneumonitis, 19 had interstitial lung disease and collagen diseases and 2 had pulmonary eosinophilia. Fourteen individuals formed the control group. The quality study was carried out by staining the BAL samples following a modified Wright-Giemsa technique and evaluating the samples by the selection criteria described by Chamberlain and colleagues (1987). We identified unsuitable samples from 53% of the HIV positive patients, from 35% of the IPF patients and from 21% of the interstitial lung disease patients with associated connective tissue disease. In the other groups, all samples were suitable for analysis. Intolerance of BAL with decreasing percentage of fluid recovered was significantly associated with sample quality, particularly in the IPF group. The cytology results that invalidated the samples differed by group. In all groups, unsuitable specimens had low cell counts. The finding or not of evidence of associated infection in HIV-infected patients, on the other hand, did not appear to determine sample quality in and of itself, although it did in samples related to other entities. We can predict that a high rate of unsuitable BAL samples will come mainly from patients with diffuse lung disease associated to HIV infection, IPF and interstitial lung disease with associated connective tissue disease. Tolerance to the technique influences quality of the specimen obtained and, therefore, should be taken into account in interpreting the findings of cytology. The criteria applied by the various teams using BAL should be unified, and it should be determined whether the exclusion of inappropriate samples affects the final composition of study groups.

Imaging of pulmonary disease in rheumatoid arthritis using J001X scintigraphy: preliminary results

The purpose of this study was to determine the ability of technetium-99m J001X scintigraphy to image active pulmonary involvement in patients suffering from rheumatoid arthritis (RA). J001X is a fully characterized acylated poly(1,3)galactoside, isolated from Klebsiella membranes, which is able to bind recruited macrophages after aerosol administration. J001X scintigraphy was compared with high-resolution computed tomography (HRCT), pulmonary function tests (PFTs) and bronchoalveolar lavage (BAL) in 15 patients suffering from RA. Patients were considered to have pulmonary involvement when they had an interstitial syndrome on HRCT and a decrease of 20% in TCO/VE (transfer coefficient) on PFTs and/or an abnormal BAL (lymphocytosis higher than 20% and/or percentage of neutrophils higher than 10%). Pulmonary involvement was present in eight patients, and absent in seven. Of the eight patients with pulmonary involvement, all had abnormal BAL, two had an interstitial syndrome on HRCT, two had decreased TCO/VE and three had positive J001X scintigraphy. Of the seven patients without pulmonary involvement, six had normal BAL (not available in one), two had an interstitial syndrome on HRCT, one had decreased TCO/VE and two had positive J001X scintigraphy. According to our gold standard of pulmonary involvement, the sensitivity of J001X scintigraphy for the detection of pulmonary involvement in RA was 37.5%, the specificity was 71.4% and the positive predictive value was 60%. The ability of J001X scintigraphy to detect active pulmonary involvement during RA appears unclear in this study but it may detect processes unnoticed by the other modalities. These patients will be followed 12 and 24 months later and the changes in J001X scintigraphy, HRCT and PFTs will be compared to demonstrate whether J001X scintigraphy is able to assess an active process in the pulmonary involvement during RA and to specify its predictive value.

Alveolar lavage fluid (ALF) of normal volunteer subjects: cytologic, immunocytochemical, and biochemical reference values

OBJECTIVE

Pooled bronchoalveolar lavage fluid (BALF), the return of lavage, contains both bronchial and alveolar material which differ from each other. Artifacts may be created by filtering, centrifuging and washing cells before cytopreparation. This study presents reference values of healthy volunteers for the alveolar sample, ALF, cytopreparation being performed without filtration or centrifugation.

METHODS

Eighteen healthy, non-smoking volunteers underwent a standard bronchoalveolar lavage using 10 aliquots of 20 ml of saline. Excluding the return of the first and second aliquots, the rest were pooled and examined cytologically, immunocytochemically and biochemically. The mean, standard deviation, and 95% confidence limits were calculated for the following variables: amount of return, estimated content of epithelial lining fluid (ELF), total and differential cell counts on filter and cytocentrifuge (CCF) preparations, computed cell counts per unit volume of ALF, distribution of lymphocyte subgroups CD3+CD2, CD4, CD8, CD19, CD25 and CD57, and the ratio of CD4 to CD8, the amounts of lymphocytes in the same subgroups per volume of ALF, and the concentrations of total protein, albumin, immunoglobulins A, G and M, hyaluronic acid, eosinophilic cationic protein (ECP), procollagen III aminoterminal propeptide (PCP) and beta 2-microglobulin in ALF and in ELF, as well as the ratios of the concentrations of the solutes in ALF to the same in serum.

RESULTS

The 95% confidence limits of means for the most important variables were as follows: estimated ELF content 0.42-0.74%; total cells in ALF 76.6-143.0 x 10(6) l-1; distribution of inflammatory cells on filter and CCF slides: macrophages 74.9-83.6 and 81.4-90.1%, lymphocytes 13.1-22.5 and 8.1-16.4%, and neutrophils 1.0-4.1 and 0.7-2.7%, respectively; distribution of lymphocyte subsets: CD3+CD2 85.6-90.6%, CD4 44.3-53.1%, CD8 26.9-35.8%; concentration of solutes in ALF: total protein 44.8-61.3 mg l-1, albumin 15.4-22.2 mg l-1, IgA 1.8-3.4 mg l-1, IgG 3.1-6.1 mg l-1, IgM 0.05-0.26 mg l-1, hyaluronic acid 8.8-11.1 micrograms l-1, ECP 0.19-0.77 micrograms l-1, PCP 0.005-0.58 micrograms l-1, beta 2-microglobulin 62.2-81.5 micrograms l-1.

CONCLUSIONS

Our results show that excluding the bronchial sample from ALF of volunteer subjects and omitting filtering and washing before cytopreparation produces cytologic, immunocytochemical and biochemical reference values with reasonable 95% confidence limits to be used in clinical settings.