The motility of lung lymphocytes in hypersensitivity pneumonitis and sarcoidosis

Bronchoalveolar Lavage Lymphocytes in the Diagnosis of Hypersensitivity Pneumonitis among Patients with Interstitial Lung Disease

Rationale: Hypersensitivity pneumonitis (HP) is an interstitial lung disease (ILD) characterized by inflammation and/or fibrosis in response to an inhalational exposure.Objectives: To determine the value of bronchoalveolar lavage (BAL) fluid lymphocyte cellular analysis in the detection of HP among patients with newly detected ILD.Methods: This systematic review was undertaken in the context of development of an American Thoracic Society, Japanese Respiratory Society, and Asociación Latinoamericana del Tórax clinical practice guideline. The clinical question was, "should patients with newly detected ILD undergo BAL fluid lymphocyte analysis to diagnose HP?" MEDLINE, EMBASE, and the gray literature were searched through October 2019. Studies that reported the percentage of BAL fluid lymphocytes for various ILDs were selected for inclusion. Meta-analyses compared the mean percentage of BAL fluid lymphocytes among patients with HP with that among patients with idiopathic pulmonary fibrosis (IPF) or sarcoidosis. The sensitivity and specificity by which various percentages of BAL fluid lymphocytes distinguish HP from IPF and sarcoidosis were also evaluated.Results: Eighty-four articles were selected. No randomized trials or observational studies were identified that compared BAL fluid lymphocyte analysis with no BAL fluid lymphocyte analysis in patients with ILD. Included studies were case series describing BAL fluid cell differentials in patients with various ILDs. The percentage of BAL fluid lymphocytes was significantly higher in both fibrotic and nonfibrotic HP compared with IPF. Similarly, the percentage of BAL fluid lymphocytes was significantly higher in both fibrotic and nonfibrotic HP compared with sarcoidosis. A threshold of 20% BAL fluid lymphocytes distinguished fibrotic HP from IPF with a sensitivity and specificity of 69% and 61%, respectively, and nonfibrotic HP from IPF with a sensitivity and specificity of 95% and 61%, respectively. It distinguished fibrotic HP from sarcoidosis with a sensitivity and specificity of 69% and 26%, respectively, and nonfibrotic HP from sarcoidosis with a sensitivity and specificity of 95% and 26%, respectively.Conclusions: The percentage of BAL fluid lymphocytes is higher in HP than IPF or sarcoidosis. However, a threshold that distinguishes HP from IPF or sarcoidosis with both high sensitivity and high specificity was not identified.

Diagnosis of Hypersensitivity Pneumonitis in Adults. An Official ATS/JRS/ALAT Clinical Practice Guideline

Background: This guideline addresses the diagnosis of hypersensitivity pneumonitis (HP). It represents a collaborative effort among the American Thoracic Society, Japanese Respiratory Society, and Asociación Latinoamericana del Tórax.Methods: Systematic reviews were performed for six questions. The evidence was discussed, and then recommendations were formulated by a multidisciplinary committee of experts in the field of interstitial lung disease and HP using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach.Results: The guideline committee defined HP, and clinical, radiographic, and pathological features were described. HP was classified into nonfibrotic and fibrotic phenotypes. There was limited evidence that was directly applicable to all questions. The need for a thorough history and a validated questionnaire to identify potential exposures was agreed on. Serum IgG testing against potential antigens associated with HP was suggested to identify potential exposures. For patients with nonfibrotic HP, a recommendation was made in favor of obtaining bronchoalveolar lavage (BAL) fluid for lymphocyte cellular analysis, and suggestions for transbronchial lung biopsy and surgical lung biopsy were also made. For patients with fibrotic HP, suggestions were made in favor of obtaining BAL for lymphocyte cellular analysis, transbronchial lung cryobiopsy, and surgical lung biopsy. Diagnostic criteria were established, and a diagnostic algorithm was created by expert consensus. Knowledge gaps were identified as future research directions.Conclusions: The guideline committee developed a systematic approach to the diagnosis of HP. The approach should be reevaluated as new evidence accumulates.

Is Induced Sputum A Useful Noninvasive Tool in the Diagnosis of Pulmonary Sarcoidosis?

OBJECTIVES

In patients with pulmonary sarcoidosis, the provocation of sputum expectoration through the inhalation of hypertonic saline has been investigated as an alternative diagnostic tool for invasive procedures. We aimed to assess the diagnostic value of induced sputum (IS) by observing its cell distribution in patients with a confirmed histopathological diagnosis of sarcoidosis.

MATERIALS AND METHODS

In this prospective, cross-sectional study, we compared the IS results of 20 patients with a histopathologically confirmed pulmonary sarcoidosis diagnosis and 24 healthy volunteers. The percentages of macrophages, lymphocytes, neutrophils, and eosinophils in IS and the CD4/CD8 ratio were compared.

RESULTS

The percentage of lymphocytes in IS was significantly higher in the pulmonary sarcoidosis patients compared to the control group (41.6% vs 8.9%, p<0.001). There were no significant differences in the other IS cell percentages and CD4+/CD8+ ratio between the groups. Sputum induction was well tolerated.

CONCLUSION

Sputum induced by the inhalation of hypertonic saline is a safe, inexpensive, less invasive, and easily repeated method and can be a valuable alternative to other invasive methods in the diagnosis of pulmonary sarcoidosis.

Bronchoalveolar lavage quality influences the T4/T8 ratio in sarcoidosis

BACKGROUND

Sarcoidosis is characterised by a T-lymphocytic alveolitis with a typically increased T4/T8 ratio. The diagnostic value of this ratio is under debate.

AIM OF THE WORK

We prospectively evaluated the influence of BAL pre-lavage and the impact of bronchial contamination on BAL differential cell count in 108 BAL specimens obtained from patients with histologically confirmed sarcoidosis.

METHODS

BAL was performed by instilling 150-300 ml normal saline either in the middle lobe or the lingula. Fifty-one patients (47%) underwent additional pre-lavage with 50 ml normal saline. Bronchial contamination was assessed by semi-quantitative analysis of mucus, ciliated and squamous cells in the untreated BAL recovery.

RESULTS

Pre-lavage did neither influence the lavage cellularity nor extend of contamination of the BAL. Content of mucus and ciliated cells, indicating bronchial contamination, showed a high correlation (Kendal's tau=0.61). Presence of either mucus or ciliated cells in the BAL recovery was associated with a significant lower T4/T8 ratio (mucus: 4.9 vs. 8.0, p=0.009; ciliated cells: 4.1 vs. 7.4, p=0.001). Squamous cells in the BAL recovery representing oropharyngeal contamination did not significantly influence the T4/T8 ratio (7.7 vs. 5.6, p=0.10).

CONCLUSION

Bronchial contamination of BAL as determined by the presence of mucus and ciliated cells in the recovery decreases the T4/T8 ratio of BAL in sarcoidosis.

Induced sputum in interstitial lung diseases

PURPOSE OF REVIEW

Induced sputum is a particularly useful procedure since it provides information on the cellular and molecular constituents in inflammation. Extensive work has demonstrated the application of induced sputum in the management of asthma, chronic obstructive pulmonary disease and chronic bronchitis, but less attention has been paid to its efficacy in diagnosing interstitial lung diseases. This review analyzes the applications of induced sputum in the assessment of sarcoidosis, nongranulomatous interstitial lung diseases, occupational lung diseases and other systemic diseases with or without lung involvement.

RECENT FINDINGS

T cell subsets in induced sputum in combination with pulmonary function testing can serve as predictors with high specificity and sensitivity in diagnosing sarcoidosis, using multivariate logistic regression models which can be easily implemented in clinical practice. Differential cell counts in induced sputum are as useful as bronchoalveolar lavage for identifying neutrophilic inflammation in patients with nongranulomatous interstitial lung diseases (e.g. idiopathic pulmonary fibrosis) and detecting chronic rejection in bronchiolitis obliterans syndrome. Sputum analysis has also been shown to be a useful tool for diagnosing, assessing and monitoring occupational lung disorders.

SUMMARY

We suggest integrating induced sputum technology to the well-established criteria for the diagnosis of interstitial lung diseases, especially when there are clinical contraindications for performing bronchoscopy or when tissue confirmation is absent for any reason.

Induced sputum and bronchoalveolar lavage from patients with hypersensitivity pneumonitis

BACKGROUND AND AIM

Hypersensitivity pneumonitis (HP) is an immunologically induced inflammation of the lung parenchyma, though bronchial airways may be also involved. The aim of this study was to compare the cellular profiles of induced sputum (IS) in patients with newly diagnosed HP to that of healthy subjects, and to examine the relationship between inflammatory cells from IS and BAL.

METHODS

Nine HP patients and 9 healthy volunteers were studied. IS was obtained by inhalation of hypertonic saline solution in all subjects. Bronchoscopy was performed on a different occasion in all patients and in five controls.

RESULTS

IS was well tolerated and preferred to BAL by all subjects. Both IS and BAL from HP patients showed a significant increase in total cells (P < 0.02 and P < 0.001) and in lymphocytes (P < 0.02 and P < 0.001) and a significant decrease in macrophages (P < 0.05 and P < 0.001), when compared with normal subjects. In HP patients, total cells number in IS was higher than that in BAL (P < 0.02). Moreover, the percentage of lymphocytes was significantly lower in IS than in BAL (P < 0.001). No significant relationship was found between total cells or inflammatory cells from IS and the corresponding ones from BAL and wide limits of agreement were found between lymphocytes from IS and BAL.

CONCLUSIONS

This study demonstrated that both BAL and IS from newly diagnosed HP patients contained significantly more total cells and lymphocytes, when compared to healthy subjects. Moreover, differential cell counts in HP patients showed that IS and BAL reflected different compartments of inflammation. Thus, IS could represent a complementary, but not alternative tool to bronchoscopy both in research and in the clinical monitoring of HP patients.

Hypersensitivity pneumonitis: a multifaceted deceiving disorder

Hypersensitivity pneumonitis (HP) represents a group of immunologically mediated lung disorders provoked by recurrent exposure to various environmental agents. HP is multifaceted and may mimic almost any interstitial lung disease, some infectious diseases,and even bronchiolar disorders. In the absence of a diagnostic gold standard,diagnosis of HP requires a combination of clinical, environmental, radiologic, physiologic,and pathologic findings that represent a diagnostic challenge for clinicians and-in the chronic form-even for experienced pathologists. Therapeutic approach includes avoiding further exposure and, depending on the clinical form, the administration of a course of prednisone. New anti-inflammatory, immunoregulatory, and antifibrotic drugs are urgently needed for this and other interstitial lung diseases.

Lymphocytes in the bronchoalveolar space reenter the lung tissue by means of the alveolar epithelium, migrate to regional lymph nodes, and subsequently rejoin the systemic immune system

Lymphocytes in the bronchoalveolar space are routinely obtained and examined in lung diseases such as asthma or sarcoidosis. In a pig model, labeled lymphocytes were found in regional lymph nodes after intrabronchial instillation, indicating that reentry of lymphocytes from the bronchoalveolar space into the body is possible. In the present study, the route and kinetics of the reentry of bronchoalveolar lymphocytes were investigated in a congenic rat model using immunohistochemistry on cryostat and semithin sections and confocal laser scanning microscopy. As early as 15 min after intratracheal instillation lymphocytes were found to leave the bronchoalveolar space by transmigration through alveolar but not bronchial epithelium and were observed in interstitial alveolar tissue. At 6 hr after intratracheal instillation, T and B lymphocytes appeared in the draining lymph nodes of the lung with an increase after 24 and 48 hr. The kinetic pattern clearly differed in nondraining lymph nodes and other organs. After 6 hr, only single cells were found in nondraining lymph nodes, spleen, and blood with a slight increase after 24 hr, and only occasionally were single cells seen in the liver, thymus, or Peyer's patches 24 and 48 hr after instillation. In conclusion, T and B lymphocytes can leave the alveolar space by reentry into the lung tissue through alveolar epithelium. They reach regional lymph nodes by means of lymphatic vessels and are then distributed all over the body to rejoin the systemic immune system. Coming into contact with environmental antigens, these lymphocytes could perform an important function in the lung immune system and might be a target for inhalative therapy.

Induced sputum in patients with newly diagnosed sarcoidosis: comparison with bronchial wash and BAL

OBJECTIVES

Sarcoidosis is characterized by a diffuse alveolar inflammatory process, although bronchial airways are often involved. This study compares the cellular profiles of induced sputum (IS), bronchial washing (BW), and BAL in newly diagnosed sarcoidosis patients to those in control subjects, and examines whether inflammatory cell counts from IS are correlated with inflammatory cell counts from BW and BAL in sarcoidosis patients.

PATIENTS AND MEASUREMENTS

We recruited 15 untreated patients with stage I and II pulmonary sarcoidosis and 12 healthy volunteers. Sputum was induced with hypertonic saline solution in all individuals. Bronchoscopy was performed on a different occasion in all patients and in five control subjects.

RESULTS

Mean lymphocyte counts in IS, BW, and BAL fluid from sarcoidosis patients were significantly higher than in control subjects (9.4% vs 3.8%, p < 0.05; 12.6% vs 3.9%, p < 0.05; 24.1% vs 2.6%, p < 0.05, respectively). Moreover, total cell count and percentage of epithelial cells in IS were significantly higher in sarcoidosis patients than in control subjects (p < 0.01 and p < 0.05, respectively). In sarcoidosis patients, comparison between different samples showed significantly higher percentages of macrophages in BW and BAL than in IS (p < 0.05 and p < 0.01, respectively), whereas the percentage of neutrophils was higher in IS compared with BW and BAL (p < 0.01 and p < 0.001, respectively). Finally, the percentage of lymphocytes in IS was significantly lower than that in BAL (p < 0.05) but not that in BW.

CONCLUSIONS

We demonstrated that, compared with IS in healthy control subjects, IS in untreated pulmonary sarcoidosis patients contains more total cells, lymphocytes, and epithelial cells. Although the relative proportion of inflammatory cells in the three samples differed, lymphocyte counts in IS were high. This finding suggests that IS could be used as a valuable alternative to more conventional invasive techniques in clinical assessment of pulmonary sarcoidosis patients.

Purification of the antigenic components of pigeon dropping extract, the responsible agent for cellular immunity in pigeon breeder's disease

BACKGROUND

Pigeon breeder's disease (PBD) is a lung disease caused by inhalation of antigens derived from pigeons.

OBJECTIVE

This study was undertaken to characterize the responsible component of pigeon dropping extract (PDE) for PBD.

METHODS

First, crude PDE was applied to SDS-PAGE followed by immunoblotting by using antibodies in bronchoalveolar lavage (BAL) fluid. Second, 9 bands of PDE were separated by SDS-PAGE and used for antigen-induced PBMCs. Finally, amino-terminal sequencing was conducted on an isolated 21-kd protein by 2-dimensional electrophoresis.

RESULTS

Immunoblots with BAL fluid from patients with PBD identified 9 bands. Similar patterns were observed by using BAL fluid from 10 control patients (9 with summer-type hypersensitivity pneumonitis or idiopathic pulmonary fibrosis and 1 asymptomatic breeder), except for the 21-kd protein, which was detected in 10 patients with PBD and 1 asymptomatic breeder. The stimulation indices of PBMCs determined by using proteins electroeluted from the 9 bands were higher in patients with PBD than in the 10 control patients. The 21-kd protein was separated into 5 spots by 2-dimensional electrophoresis; these spots were all reactive with BAL fluid from patients with PBD as determined by immunoblotting. The sequence of the 21-kd protein had 57% identity to a Saccharomyces cerevisiae chromosome X reading frame. A synthetic peptide, derived from the amino acid sequence of the N-terminal of the native protein, induced significant proliferation of PBMCs obtained from 5 patients with PBD, but not with PBMCs obtained from control patients.

CONCLUSION

The 21-kd protein is the only protein that identified individuals exposed to pigeons by immunoblotting. Only PBMCs from patients with PBD showed significant proliferation to the 21-kd protein and to the synthetic peptide on the basis of the N-terminal sequence of the native peptide. The 21-kd protein will be an important antigen for studies on the epidemiology, diagnosis, and pathogenesis of PBD.