Alveolar lavage cytology in transplanted lungs I. Staining methods and findings in dogs with autografts and allografts without immunosuppression

Diagnostic value of plasma and bronchoalveolar lavage samples in acute lung allograft rejection: differential cytology

Diagnosis of acute lung allograft rejection is currently based on transbronchial lung biopsies. Additional methods to detect acute allograft dysfunction derived from plasma and bronchoalveolar lavage samples might facilitate diagnosis and ultimately improve allograft survival. This review article gives an overview of the cell profiles of bronchoalveolar lavage and plasma samples during acute lung allograft rejection. The value of these cells and changes within the pattern of differential cytology to support the diagnosis of acute lung allograft rejection is discussed. Current findings on the topic are highlighted and trends for future research are identified.

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.

Expression of adult T-cell leukemia-derived factor in bronchoalveolar lavage cells after canine lung transplantation

Lung transplantation is now an accepted therapeutic option for patients with end-stage lung disease, and an early diagnosis of rejection is essential in the management of these patients. Adult T-cell leukemia-derived factor (ADF), known as a human homolog of thioredoxin, has been shown to be induced by a variety of stresses. In this study we examined ADF expression in lung tissues and bronchoalveolar lavage cells after canine lung transplantation to determine whether it could be induced by allogenic stimulations and could be used to diagnose early rejection. Allotransplantations were performed in adult mongrel dogs, and immunosuppression was performed from the day of operation to the fifth postoperative day. No immunosuppressant was given from the sixth to the tenth postoperative days. Animals were put to death on the tenth postoperative day. Bronchoalveolar lavage was performed on the fifth and tenth postoperative days, and the lavage cells and lung tissues were examined immunohistochemically with anti-ADF antibody. The grades of rejection were as follows: grade 1 in two animals, grade 2 in three animals, and grade 3 in two animals. The percentages of ADF high-producer cells in bronchoalveolar lavage cells on the fifth and tenth postoperative days were 4.29% +/- 2.65% and 26.6% +/- 3.99%, respectively (p < 0.01). The percentages of ADF high-producer cells in normal healthy dogs and in those with grade 1, grade 2, and grade 3 rejection were 3.00% +/- 1.64%, 20.5% +/- 9.00%, 25.5% +/- 6.06%, and 34.5% +/- 6.50%, respectively. The percentage in each rejection group was significantly higher than that in normal healthy dogs (p < 0.05). These results suggest that examination of bronchoalveolar lavage cells with ADF staining may be useful in the early diagnosis of rejection.

Monitoring canine lung allograft rejection using Ia antigen expression by bronchoalveolar lymphocytes

The expression of Ia antigens by lymphocytes in bronchoalveolar lavage (BAL) was evaluated after canine lung allotransplantation with immunosuppression using FK-506. The expression of Ia antigens labeled using an OKIa-1 monoclonal antibody from Ortho Diagnostic Systems was measured by flow cytometry. Twenty-three adult mongrel dogs underwent left lung allotransplantation and were treated with FK-506 at a dose of 0.1 mg/kg/day intramuscularly until death. Allograft rejection was evaluated microscopically. The percentage of OKIa-1-positive cells among the BAL lymphocytes was 34.8% +/- 8.9% (mean +/- SD) from the allografted lungs showing no rejection, whereas it was 68.8% +/- 16.2% from the allografted lungs which showed rejection (P < 0.01). When a diagnosis of rejection was made prior to pathologic examination by an OKIa-1-positive lymphocyte percentage of 42% or more, the sensitivity, specificity, and accuracy of diagnosis were 100%, 87.5%, and 94.1%, respectively. Subsequently, pulse steroid therapy was attempted in those dogs with a high rate of OKIa-1-positive lymphocytes in the BAL. In 3 of 4 dogs showing histological signs of rejection, a decrease in the rate of OKIa-1-positive cells among the BAL lymphocytes corresponded to an improvement in pathologic diagnosis. In two dogs with bacterial pneumonia and pulmonary vein thrombosis, densities indistinguishable from those of rejection were seen on chest roentgenograms, but in these dogs the rate of OKIa-1-positive BAL lymphocytes was 42% or less. In conclusion, Ia antigen expression by BAL lymphocytes could be useful for monitoring rejection in lung allotransplantation.

Bronchoalveolar lavage and transbronchial lung biopsy during acute rejection and infection in heart-lung transplant patients. Studies of cell counts, lymphocyte phenotypes, and expression of HLA-DR and interleukin-2 receptor

The total and differential cell counts of 135 bronchoalveolar lavages (BAL) in 48 heart-lung transplant (HLT) patients were compared with the histologic findings in concurrent transbronchial lung biopsies (TBBs). Counts of CD3+, CD4+, and CD8+ lymphocytes were recorded, and a semiquantitative assessment of HLA-DR and interleukin-2 receptor (IL-2R) expression was made on 29 occasions. There were five diagnostic categories: normal (n = 8), acute rejection (ALR) (n = 57), treated rejection (TR) (n = 19), infection (INF) (n = 24), and chronic rejection (CR) (n = 24). Total cell counts in INF were significantly higher than counts in all the other diagnostic groups. The highest BAL lymphocyte counts, significantly higher than in INF, were found in ALR because of increased CD8+ cells, exceeding 15% in 13 of 57 BALs. TBBs in ALR by contrast showed significantly increased numbers of both CD8+ and CD4+ cells. High dose corticosteroid treatment of ALR caused a fall in cellularity of BAL and TBB specimens but not always to values seen when patients were well. During INF and CR, significantly increased numbers of PMNs were seen in the BAL. HLA-DR and IL-2R expression was enhanced in cells of BAL and TBB in all complications. BAL can only supplement at present histologic examination of TBB in the diagnosis of complications after HLT.

[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.

Bronchoalveolar lavage in lung transplantation

One of the dilemmas in the management of lung allotransplant recipients is our inability to precisely determine the cause of graft dysfunction. Differentiating between lung allograft infection, rejection, atelectasis, or ischemic injury remains a difficult task. Tests directed at identifying systemic abnormalities such as peripheral blood analysis so far have been nonspecific and unlikely to accurately and promptly represent changes occurring within the lungs. Transbronchial biopsy and bronchoalveolar lavage have emerged as two methods with the most potential for aiding in the establishment of diagnosis. This review attempts to provide the readers with a current knowledge of the cellular events in lung allograft and the status of bronchoalveolar lavage in experimental and clinical lung transplantation.