The value of bronchoalveolar lavage for discrimination between healthy and diseased individuals

Abstract

BackgroundBronchoalveolar lavage (BAL) is standard diagnostic procedure. Procedural recommendations have been made by pneumological societies including normal values for interpretation of BAL cytology. These normal values derive from small studies in healthy volunteers and have never been analysed for their sensitivity and specificity.ObjectivesThis study aims to analyse sensitivity and specificity of these normal values by assessing lavage cell composition in healthy and diseased individuals.MethodsMore than 6000 BAL were retrospectively analysed for their cellular distribution including BALs of 250 healthy individuals. All BALs were obtained under similar conditions.ResultsBronchoalveolar lavage cytology of healthy individuals mirrors data from previous studies with smoking being the most important manipulator of BAL cytology. Analyses of proposed normal values demonstrate specificity between 80% and 95%, whereas sensitivity ranges between 35% and 65%. Using different mathematical models, a value summing up the differences to ATS‐proposed normal values of the cytological pattern was found to best discriminate between healthy and diseased individuals with a sensitivity of nearly 60% with a predefined specificity of 95%.ConclusionIn summary, our analysis confirmed prior results for healthy volunteers and enlarged these findings by analysing sensitivity and specificity of lavage results in an independent validation cohort of diseased individuals. Thereby, the study may influence the acceptance of BAL in the diagnostic workup of individuals with pulmonary diseases. Additionally, the study proposes a novel value that facilitates lavage interpretation and may therefore be useful in further studies.

Isolation of bacteria from artificial bronchoalveolar lavage fluid using density gradient centrifugation and their accessibility by Raman spectroscopy

“…Therefore, we used the same bacterial solution in three independent gradient centrifugation runs and plated 5 μl of each centrifugation sample on each three independent plates before and after isolation and calculated the yield (see Table 1). The number of bacteria in this test run was 5.7 × 10 3 CFU/ml, below the average bacterial load of a BAL sample of 7 × 10 4 CFU/ml [26,27]. Therefore, if an acceptable yield is possible with such a low bacterial load, this method can also be used for samples with higher concentrations.…”

“…Moreover, there are also very few bacteria in a BAL sample, and this amount also varies between individual patients. On average, BAL fluid contains 7 × 10 4 cells/ml [26,27], but samples with as few as 1000 cells/ml have been reported [28].…”

Pleural CD14+ monocytes/macrophages of healthy adolescents show a high expression of metallothionein family genes

“…However, the question remains unanswered as to what extent patient macrophages elicit properties and functionality of those found in health. For example, it is reported that bronchial lavage (BAL) macrophages from healthy individuals or patients with sarcoidosis, alveolar proteinosis, or malignancies differ significantly in their morphological and functional properties [4].…”

Fractional analysis of bronchoalveolar lavage in systemic sclerosis-associated interstitial lung disease

“…For example, although the cellular analysis of BAL fluid was not recommended for patients clinically suspected of having idiopathic pulmonary fibrosis (IPF) (14), a recent guideline suggested that a BAL fluid cellular lymphocyte analysis might play a key role in distinguishing fibrotic HP from IPF (15). Recent studies have shown new scores for discriminating between healthy and diseased individuals (16) and differentiating common variable immunodeficiencyassociated ILD from sarcoidosis (17).…”