Predictive value of BAL cell differentials in the diagnosis of interstitial lung diseases

Abstract

The current authors aimed to quantify how the likelihood for a given diagnosis changes with the knowledge of bronchoalveolar lavage (BAL) cell differentials.As an initial estimate (a priori probability), frequencies of final diagnoses were taken. Using categorisations for cell differentials, a posteriori probabilities were then derived for each disease, according to Bayes. The analysis was performed in three of five groups of diagnoses suspected prior to BAL: interstitial lung disease (ILD; n=710), inflammatory disease (n=583), or lung tumour mimicking ILD (n=455).Overall, out of 1,971 patients, 18.3% had sarcoidosis, 7.7% usual interstitial pneumonia (UIP), 4.4% extrinsic allergic alveolitis (EAA), and 19.0% tumours. In the group with suspected ILD, the likelihood for sarcoidosis increased from 33.7 to 68.1% when lymphocyte numbers were 30-50% and granulocyte numbers were low; the likelihood for UIP increased from 15.8 to 33.3% when lymphocyte numbers werev30% with granulocytes elevated. CD4/CD8 was informative, especially in sarcoidosis and EAA. Despite considerable increases, the likelihood of rare diseases rarely reached appreciable values. Similar results were obtained in the other two groups of suspected diagnoses.In conclusion, these data suggest that bronchoalveolar lavage cell counts per se provide substantial diagnostic information only in relatively frequent diseases, such as sarcoidosis and usual interstitial pneumonia, and are less helpful in infrequent diseases.

Flow cytometry counting of bronchoalveolar lavage leukocytes with a new profile of monoclonal antibodies combination

“…The results of BAL differentials with a lymphocytic, a neutrophilic, an eosinophilic, or a mixed cellular pattern can be used as an adjunct to diagnosis in many interstitial lung diseases. If a BAL finding is compatible with the suspected diagnosis in the context of an appropriate disease history and clinical and radiological data, this can be sufficient for disease confirmation (2). Additionally, recent research have focused on the pathogenesis of various types of interstitial lung disorders where BAL cell counts may further contribute better to define these conditions or to be of some clinical value to assess the activity of disease and to provide prognostic information.…”

Value of s-ACE, BAL lymphocytosis, and CD4+/CD8+ and CD103+CD4+/CD4+ T-cell ratios in diagnosis of sarcoidosis

“…The diagnosis of sarcoidosis is supported by an elevated CD4+/CD8+ T-cell ratio, bronchoalveolar lavage (BAL) lymphocytosis and elevated serum angiotensin-converting enzyme (s-ACE). However, these parameters are variable in sarcoidosis [2][3][4].…”

Bronchoalveolar Lavage and Sampling in Pulmonary Sarcoidosis

“…Thomeer & Demedts found that a CD4/CD8 ratio of greater than 4.0 had a sensitivity of 55 % and a specificity of 94 % (Thomeer & Demedts, 1997). Welker et al found that when the CD4/CD8 ratio is combined with lymphocyte and granulocyte numbers, the probability of sarcoidosis could exceed 85 % (Welker et al, 2004). Table 1.…”

“…Bronchoalveolar lavage (BAL) is a method of sampling fluid and cells from a large area of the lung tissue by instilling and aspirating saline via a bronchoscope wedged in bronchi. BAL as a method of sampling cells is very useful in the diagnosis and differential diagnosis of sarcoidosis Welker, 2004). High lymphocytosis and CD4/CD8 ratio in bronchoalveolar lavage fluid (BALF) are the main features of sarcoidosis (Poulter, 1992).…”