Bronchoalveolar lavage in lung transplantation

Hypermethylation of MDFI promoter with NSCLC is specific for females, non-smokers and people younger than 65

Non-small cell lung carcinoma (NSCLC) is a major subtype of lung cancer. Aberrant DNA methylation has been frequently observed in NSCLC. The aim of the present study was to investigate the role of MyoD family inhibitor (MDFI) methylation in NSCLC. Formalin-fixed paraffin-embedded tumor tissues and adjacent non-cancerous tissues were collected from a total of 111 patients with NSCLC. A methylation assay was performed using the quantitative methylation-specific polymerase chain reaction method. The percentage of methylated reference was used to represent the methylation level of the MDFI promoter. Data mining of a dataset from The Cancer Genome Atlas (TCGA) demonstrated that MDFI promoter methylation levels were significantly increased in 830 tumor tissues compared with 75 non-tumor tissues (P=0.012). However, the results on tissues obtained in the present study indicated that the MDFI promoter methylation levels in tumor tissues were not significantly different compared with those in the adjacent non-tumor tissues (P=0.159). Subsequent breakdown analysis identified that higher MDFI promoter methylation levels were significantly associated with NSCLC in females (P=0.031), but not in males (P=0.832). Age-based subgroup analysis demonstrated that higher MDFI promoter methylation levels were significantly associated with NSCLC in younger patients (≤65 years; P=0.003), but not in older patients (P=0.327). In addition, the association of MDFI methylation with NSCLC was significant in non-smokers (P=0.014), but not in smokers (P=0.832). Similar results also have been determined from subgroup analysis of the TCGA datasets. The Gene Expression Omnibus database indicated MDFI expression restoration in partial lung cancer cell lines (H1299 and Hotz) following demethylation treatment. However, it was identified that MDFI promoter hypermethylation was not significantly associated with prognosis of NSCLC (P>0.05). In conclusion, the present study indicated that the association of higher methylation of the MDFI promoter with NSCLC may be specific to females, non-smokers and people aged ≤65.

Cytological monitoring of peripheral blood, bronchoalveolar lavage fluid, and transbronchial biopsy specimens during acute rejection and cytomegalovirus infection in lung and heart--lung allograft recipients

STUDY OBJECTIVES

Acute rejection and cytomegalovirus (CMV) infection are important complications after lung and heart--lung transplantation. We sought to investigate whether acute rejection and CMV infection demonstrated as CMV antigenemia had an effect on the cell profiles of peripheral blood (PB), bronchoalveolar lavage fluid (BAL-F), or TBB histology.

PATIENTS AND DESIGN

In this prospective study, composition of cells in PB, BAL-F, and TBB samples from 20 lung or heart-lung transplantation patients were analyzed during episodes of acute rejection or CMV antigenemia. Rejection was graded according to the International Society for Heart and Lung Transplantation criteria. As controls, samples with no evidence of rejection or infection were used. To evaluate the effect of time on cellular findings, samples were divided into three groups according to time after transplantation: 1--30, 31--180, and more than 180 d after transplantation.

RESULTS

Acute rejection was associated with mild blood basophilia (p<0.05; specificity 94%, sensitivity 42%). In BAL-F during rejection, the number of basophils (p<0.05), eosinophils (p<0.05), and lymphocytes (p<0.05; specificity 77%, sensitivity 64%) was increased compared to controls during the post-operative month 1. Later-occurring rejections were associated with increased amounts of neutrophils in BAL-F (p<0.05; specificity 82%, sensitivity 74%). In TBB histology, acute rejections were associated with perivascular and/or peribronchial infiltration of lymphocytes (p<0.001) and plasma cells (p<0.05) compared to controls. In our patients receiving gancyclovir prophylaxis, CMV antigenemia did not significantly alter the cell profiles in PB and BAL-F nor the inflammatory cell picture in TBB histology.

CONCLUSION

TBB histology remains the 'gold standard' for diagnosing rejection in lung and heart-lung transplantation patients, as the inflammatory cell findings in TBB specimens are highly specific for rejection. The cellular changes associated with rejection, mild PB basophilia and increased proportions of lymphocytes in early- and neutrophils in later-occurring rejection, observed in BAL-F cannot be considered specific for rejection, but may warrant clinical suspicion of rejection.

Bronchoalveolar lavage in lung transplantation. State of the art

Fiberoptic bronchoscopy with bronchoalveolar lavage (BAL) has become a crucial tool in the management of lung transplant recipients. Detection of pulmonary infectious pathogens by culture, cytology, and histology of BAL, protected brush specimens, and transbronchial biopsies (TBB) is highly effective. Morphologic and phenotypological analyses of BAL cells may be suggestive for certain complications after lung transplantation. For interpretation of BAL findings, the natural course of BAL cell morphology and phenotypology after lung transplantation must be considered. During the first 3 months after pulmonary transplantation, elevated total cell count in BAL and neutrophilic alveolitis are common, representing the cellular response to graft injury and interaction of immunocompetent cells of donor and recipient origin. With increasing time after transplantation the CD4/CD8 ratio decreases due to lowered percentages of CD4 cells in BAL. During bacterial pneumonias, the cellular profile of BAL is characterized by a marked granulocytic alveolitis. Lymphocytic alveolitis with a decreased CD4/CD8 ratio is suggestive of acute rejection, but is also found in viral pneumonias and obliterative bronchiolitis. In the case of a combined lymphocytosis and neutrophilia without any evidence of infection, obliterative bronchiolitis should be considered. Functional analyses of BAL cells can give additional information about the immunologic status of the graft, even before histologic changes become evident but have not been established in routine transplant monitoring. However, functional studies suggest an important role of activated, alloreactive and donor-specific T lymphocytes in the pathogenesis of acute and chronic lung rejection. Investigations of soluble components in BAL have given further insight into the immunologic processes after lung transplantation. In this overview, the characteristics of BAL after lung transplantation will be summarized, and its relevance for the detection of pulmonary complications will be discussed.

Endoscopic monitoring of lung transplantation

Endoscopic monitoring of the pediatric lung allograft is an important adjunct in the management of the younger transplant recipient. Currently, this invasive monitoring is undertaken when clinically indicated, therefore highlighting the importance of non-invasive monitoring. Although transbronchial biopsy is a useful tool to diagnose acute rejection, it is of less utility for diagnosing obliterative bronchiolitis and other methods of assessing this disease should be undertaken.

Anaesthesia for patients after lung transplantation

PURPOSE

The purpose of this article is to review the literature on post lung transplant patients presenting for surgery and anaesthesia and to provide insight into their perioperative management.

SOURCE

Articles and books were identified via a Medline search and through a review of the bibliographies of these sources.

PRINCIPLE FINDINGS

Single and double lung transplantation is becoming more common and the period of survival is increasing. As a result, more of these patients are presenting for surgery and anaesthesia. Also, it is increasingly likely that these patients may present, either for emergency or elective surgery, to anaesthetists with limited experience in this field. These patients have considerable medical, physiological and pharmacological problems which need to be understood.

CONCLUSION

Anaesthesia, local, regional, or general, can be safely delivered to these patients provided that the physiology and pathophysiology of the transplanted lung, the pharmacology of the immunosuppressive agents, and the underlying surgical condition are understood.

T cell receptor (TCR) repertoire in alloimmune responses

A large number of alloantigenic determinants could be generated by both the direct and indirect alloantigen presentation pathways. Hence, a heterogeneous population of T cells expressing a wide variety of receptors would be expected to respond to this diverse array of alloantigenic determinants. However, T cells expressing highly restricted T cell receptor (TCR) variable genes have been reported in a variety of alloimmune responses. A similar phenomenon has been observed in a wide variety of other immune responses, from those induced by superantigens, to very specific responses induced by a single peptide presented by a single MHC molecule. Given this scenario, the limited number of T cell clones which dominate an allograft rejection response, or for that matter an autoimmune response or a tumor specific response, could be therapeutically targeted by virtue of the selected TCR expression.

Analysis of bronchoalveolar lavage from human lung transplant recipients by flow cytometry

Bronchoalveolar lavage (BAL) cells and peripheral blood leucocytes (PBL) from 24 lung transplant recipients were analysed for leucocyte subsets and expression of cell surface antigens. Total and differential white cell counts were performed on BAL, and lymphocyte subsets were evaluated in both BAL and peripheral blood. Measurement of immunofluorescence by flow cytometry was used to assess the percentage of: T cells (CD3+); T-helper cells (CD4+); T-cytotoxic/suppressor cells (CD8+); and activated lymphocytes (HLA-DR+). Lymphocyte subsets in BAL demonstrated marked differences to those in blood. A lower percentage of CD3+ and CD4+ lymphocytes were found in BAL, whereas CD8+ cells were more prevalent in BAL than in PBL. The mean CD4:CD8 ratio was significantly lower in BAL (1:1) than in blood (2.1:1). In the absence of pulmonary infection, there was a trend for a lower CD4:CD8 ratio in BAL associated with acute rejection (1.1:1) and obliterative bronchiolitis (1:1), when compared to the group with no evidence of rejection (1.4:1). In the absence of pulmonary rejection, pulmonary infection was associated with a marginally lower CD4:CD8 ratio in BAL (0.7:1), than when infection was absent (1.4:1). This difference was more evident in cases of cytomegalovirus (CMV) infection with a mean CD4:CD8 ratio of 0.3:1, compared to 1.5:1 in the absence of CMV disease (P < 0.05).

Development of immunological assays to monitor pulmonary allograft rejection

BACKGROUND

At present the diagnosis of pulmonary allograft rejection is made after examination of transbronchial biopsy specimens; this method is highly invasive. A study was performed to determine whether immunological parameters measured in peripheral blood or bronchoalveolar lavage samples correlate with the histological diagnosis of rejection.

METHODS

Left unilateral pulmonary allotransplantation was performed between dogs. The animals were immunosuppressed with cyclosporin A after transplantation but the dose of this drug was gradually reduced to allow controlled rejection to take place. Rejection was diagnosed histologically. Four immunological parameters were investigated: measurement of lavage derived T cell proliferation in response to limited culture with interleukin 2; measurement of changes in the frequency of donor reactive cytotoxic T lymphocytes; assay of the level of donor cell binding IgG antibody in recipient plasma; and measurement of the antibody dependent cell mediated cytotoxic response to donor cells after labelling with recipient plasma.

RESULTS

Assays based on measurement of the function of T cells produced significant results at a time later than the histological diagnosis of severe rejection. The level of donor reactive IgG antibody increased at a time that corresponded closely with the diagnosis of severe rejection. This IgG did not activate the antibody dependent cell mediated cytotoxic effector mechanism to a significant extent.

CONCLUSIONS

Measurement of parameters of donor specific immunoreactivity can yield data which are indicative of severe pulmonary allograft rejection. These methods make use of samples which can be obtained by minimally invasive methods. Measurement of the plasma level of donor reactive IgG antibody appears to be the most useful assay. However, each of the in vitro assays used during this series of experiments was less sensitive to the onset of rejection than was routine histological examination.

Lung transplantation

Solid-organ transplantation has flourished during the last decade, with transplantation of heart and lungs becoming available to patients with end-stage cardiac or pulmonary diseases. The first lung transplant was performed in 1963 on a 58-year-old man with bronchogenic carcinoma. He survived for 18 days. During the next two decades, approximately 40 lung transplant procedures were attempted without success. These early attempts at lung transplantation were unsuccessful because of the development of lung rejection, anastomotic complications, or infection in the transplant recipients. In the early 1980s, human heart-lung transplantation was successfully performed for the treatment of pulmonary vascular disease. After this procedure, single-lung transplantation for the treatment of end-stage interstitial lung disease and obstructive lung disease was developed. More recently, the technique of double-lung transplantation has come into existence. This article reviews various aspects of lung transplantation, including immunosuppression, lung graft preservation, the various surgical techniques and types of lung transplant procedures available, recipient and donor selection criteria, and postoperative care of the transplant recipient. In addition, infectious and noninfectious complications seen in this particular patient population, including acute and chronic rejection, will be discussed.

Bronchoalveolar lavage and transbronchial biopsy in children following heart-lung and lung transplantation

Between July 1985 and March 1992, 20 children received either heart-lung (11), double lung (8), or single lung (1) transplants at our center. Since 1988, flexible fiberoptic bronchoscopy with bronchoalveolar lavage and transbronchial biopsy have been carried out to monitor for rejection or infection in these patients. As of March 31, 1992, we have performed a total of 112 transbronchial biopsies in our patients, who ranged from 6.8 to 18 years of age and 19.3 to 67.3 kg in weight. All but two of these procedures were carried out using conscious sedation and a transnasal approach. Four to seven biopsy samples were obtained at each procedure. One patient had hemorrhage (< 100 ml) and no patient had pneumothorax as a complication. Of the biopsy samples, 72.4 percent had a surface area of greater than 2 mm2, and 89.5 percent of the biopsy samples were deemed adequate for pathologic interpretation. We believe that for the majority of pediatric lung or heart-lung recipients, flexible bronchoscopy and transbronchial biopsy using conscious sedation and a transnasal approach is safe and permits the recovery of adequate tissue for pathologic evaluation. The avoidance of general anesthesia, endotracheal intubation, and mechanical ventilation at the time of bronchoscopy and transbronchial biopsy probably decreases the likelihood of pneumothorax as a complication of the procedure.

Early cellular events in the lung allograft

We hypothesized that ischemic insult to the lung allograft may render it more susceptible to rejection. Left canine single-lung allografts were subjected to usual periods of cold and warm ischemia (4 hours and 1 hour, respectively). Bronchoalveolar lavage and open lung biopsies were performed at 0, 1, 4, and 24 hours and 1 week after transplantation. Bronchoalveolar lavage fluid was examined for cellular phenotypes, lymphocyte lectin-mediated cytotoxicity, and natural killer cell cytotoxicity. Open lung biopsy specimens were examined for severity of injury/rejection and MHC class II expression. Within 1 to 4 hours of reimplantation, we observed marked influx of polymorphonuclear leukocytes and lymphocytes and an increase in lectin-mediated cytotoxicity (25.6% +/- 14.8% and 50.6% +/- 20.1% versus 5.4% +/- 7.5% preoperatively; p < 0.05). In addition, natural killer cell cytotoxicity increased from 10.2% +/- 13.5% before transplantation to 20.5% +/- 8.6% 4 hours after transplantation (p < 0.03). By 24 hours MHC class II expression became evident and continued to increase while subtle histologic evidence of rejection appeared by 1 week. We conclude that ischemia-reperfusion injury can alter the local bronchopulmonary milieu, thus rendering it more susceptible to the development of rejection.

[Lung transplantation]

Lung transplantation began to expand in 1983, after the advent of cyclosporin and the publication of the Toronto lung transplant group study. Single lung transplantation was first performed in patients with interstitial pneumopathy to be extended later to pulmonary emphysema, then to primary or secondary pulmonary arterial hypertension. Double lung transplantation provides patients suffering from chronic lung infection (e.g. cystic fibrosis) with a useful alternative to their ordinary treatment. The experience acquired throughout these years has resulted in wider criteria for patients' inclusion. More than acute rejection, bacterial infections directly condition the immediate prognosis. The frequency and severity of cytomegalovirus lung diseases lead to a discussion on the possibility of prophylactic and curative antiviral therapy. The occurrence of obliterative broncholitis, which reflects chronic lung rejection, jeopardizes the long-term results of transplantation. The functional results of the various types of lung grafting are analysed, and the position of lung transplantation in thoracic surgery is reassessed.