Canadian Health and Care Mall: Pulmonary Cell Populations
Pulmonary involvement by both infectious and non-infectious disorders occurs frequently in the immunosuppressed patient and is a major cause of morbidity and mortality. The alterations of systemic immune function in these patients may contribute to the high incidence of respiratory infection. It is known, however, that reactions occurring in the lung may function independently from those in the blood in both healthy and diseased states. In addition, specific defects in local pulmonary defense mechanisms have been demonstrated in at least some animal models of immunosuppression. Therefore, study of the inflammatory response in the lower respiratory tract of immunosuppressed patients would increase our understanding of the susceptibility of the lung in this setting.
Bronchoalveolar lavage (BAL) has been found to be a useful technique to sample lower respiratory tract cells and secretions in interstitial lung disease.’ In addition to its role in elucidating pathogenetic mechanisms of disease, lavage cellular profiles have been useful in characterizing several types of interstitial pneumonitis. Lavage studies have been performed in the immunosuppressed patient for the diagnosis of opportunistic infection, but there have been only a few reports on the cellular inflammatory response of the immunosuppressed patient during episodes of pneumonitis.
In the acquired immune deficiency syndrome (AIDS), Rankin et al found a marked increase in BAL neutrophils in two cases of pneumonia due to Pneumocystis carinii and cytomegalovirus. Venet et al, however, noted a BAL lymphocytosis in eight patients with pneumonitis although those with P carinii also had increased BAL neutrophils. Wallace et al, in a study of 12 AIDS patients with active pneumonitis, confirmed the presence of increased proportions of lavage lymphocytes which were found to be predominantly T cells of the suppressorсу toxic phenotype. In nonAIDS patients the only report is that of bone marrow transplant patients with CMV-associated pneumonia, where Springmeyer et al found both BAL neutrophils and lymphocytes to be increased.
We undertook this investigation to characterize the type of pulmonary cellular inflammatory response seen in immunosuppressed patients with various causes of pneumonia and to see if specific cellular differential patterns would be useful in diagnosis or as a determinant of clinical presentation or prognosis. The study reports on the results during 49 episodes of lung disease in 47 patients. Thirty-six had AIDS and 11 had conventional causes of immunosuppression. The lung disease included infectious and non-infectious causes of pulmonary infiltrates and was similar in both groups. Acquired immune deficiency syndrome is an infectious disorder that suppresses the immune system normal function. To get aqcuinted with other diseases you may here – More info about diseases and hot news – Canadian health&care Mall – canadianhealthnetmall.com.
Materials and Methods
All immunosuppressed patients who required diagnostic fiberoptic bronchoscopy because of the presence of pneumonitis underwent bronchoalveolar lavage. If an adequate return of fluid was obtained to allow both diagnostic and research studies and lavage was not grossly bloody or did not have more than 10 red blood cells for each white blood cell, the patient was included in the study.
The results from a total of 47 patients are included in this report. Thirty-six had the diagnosis of the acquired immune deficiency syndrome according to the criteria of the Centers for Disease Control. Eleven had conventional causes of immunosuppression including bone marrow transplantation (five cases), Hodgkins disease (three cases), and one case each of chronic myelocytic leukemia, diffuse histiocytic lymphoma and glioblastoma multiforme receiving steroid therapy. Two of the AIDS patients had a second BAL during a separate episode of lung disease.
The average age ± SEM of the 36 AIDS patients was 35.2 ±1.5 years. All were male and 20 had Kaposis sarcoma. Thirteen patients were smokers, and 23 were nonsmokers. The average age of the other patients was 33.4 ±5.1 years. Eight were male and three female; three were smokers.
A control group was also studied and consisted of seven patients with underlying malignancy who underwent bronchoalveolar lavage as part of a diagnostic bronchoscopy. The lungs were either normal or local lesions were present. Lavage was limited to a lung that was uninvolved by physical examination, chest roentgenogram or bronchoscopy. The average age was 51 ±4 years. Five were male and two female; one was a smoker.
Informed consent for the lavage procedure was obtained from all patients and control subjects.
The type of pulmonary abnormality present in each patient was determined on the basis of results from fiberoptic bronchoscopy and, where available, open lung biopsy >and postmortem specimens. Clinical specimens were extensively evaluated for infection and malignancy. Details of handling of pulmonary specimens and diagnostic criteria have been previously described. Patients charts were reviewed where available to assess the presence or absence of symptoms of cough or dyspnea (43 cases), chest roentgenogram abnormalities (44 cases), total peripheral white blood count with differential cell count (35 cases), and the outcome of each episode of respiratory distress (47 cases).
Fiberoptic bronchoscopy was performed with an Olympus BF-B3 bronchoscope (Olympus Corporation of America, New Hyde Park, New York). Bronchoalveolar lavage was performed by wedging the bronchoscope in an involved subsegment of the lung (usually the middle lobe or lingula). A maximum of 300 ml of 0.9 percent saline solution was instilled in 30 ml aliquots and aspirated back by gentle manual suction. The amount of lavage fluid was altered depending on the clinical situation. Aliquots of well mixed lavage were sent for clinical diagnostic studies and an aliquot was used for this study. Cells were removed from BAL by centrifugation (400 g x 10 minutes). They were washed three times in Hanks balanced salt solution (Ca++ and Mg++ free). The total number of cells present was determined by hemocytometer and differential cell counts were performed on Wrights stained cytocentrifuge preparations.
Statistical analyses were performed using the Wilcoxon signed rank test, the Students f-test, and linear regression analysis. Data are expressed as mean ± SEM. Computational assistance was provided by the NIH sponsored CLINFO project.