ABSTRACT
BACKGROUND: Bronchoalveolar 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. OBJECTIVES: This study aims to analyse sensitivity and specificity of these normal values by assessing lavage cell composition in healthy and diseased individuals. METHODS: More than 6000 BAL were retrospectively analysed for their cellular distribution including BALs of 250 healthy individuals. All BALs were obtained under similar conditions. RESULTS: Bronchoalveolar 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%. CONCLUSION: In 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.
Subject(s)
Bronchoalveolar Lavage Fluid/cytology , Lung Diseases/diagnosis , Bronchoalveolar Lavage , Cell Count , Eosinophils/metabolism , Female , Humans , Lymphocytes/metabolism , Macrophages/metabolism , Male , Middle Aged , Neutrophils/metabolism , Reference Values , Retrospective Studies , Sensitivity and Specificity , Smoking/adverse effectsABSTRACT
The aim of the present study was to determine which bronchoalveolar lavage fluid (BALF) and serological parameters reflect the severity of newly diagnosed pulmonary sarcoidosis. Seventy-four previously untreated sarcoid patients were categorised into three groups: 10 patients with Löfgren's syndrome, 51 patients with stable disease and 13 patients with progressing disease requiring systemic steroid treatment. Total BALF cell count, percentage of alveolar lymphocytes and lymphocyte CD4/ CD8 ratio were not associated with severity of disease. Interestingly, a significant increase in percentages of BALF neutrophils (5.2 +/- 1.1%) and eosinophils (1.7 +/- 0.6%) was observed in sarcoid patients with progressing disease. Elevated percentages of these two cell types were the only BALF parameters associated with a more frequent necessity for systemic steroid therapy. This association between an elevated percentage of BALF neutrophils and the necessity for steroid treatment was observed in advanced as well as early sarcoidosis (radiological types I and II). Serum levels of soluble interleukin-2 receptor and neopterin were significantly elevated in progressing disease compared to stable disease or Löfgren's syndrome. The present results demonstrate that increased percentages of neutrophils (>3.0%) and eosinophils (>1%) in bronchoalveolar lavage fluid from newly diagnosed pulmonary sarcoidosis is associated with a significantly higher risk of necessity for steroid therapy and may be helpful markers of progressive disease. Furthermore, of the serological parameters investigated, only serum levels of soluble interleukin-2 receptor and neopterin were associated with disease severity.
