A quantitative proteomic analysis of soluble bronchoalveolar fluid proteins from patients with sarcoidosis and chronic beryllium disease.

BACKGROUND

Sarcoidosis and chronic beryllium disease (CBD) are granulomatous disorders which can lead to development of chronic inflammation and fibrosis. These diseases have several similarities from their clinical aspects. The aim of this study was to compare the protein profile at the site of active inflammation i.e. the lungs of patients with sarcoidosis and CBD.

METHODS

Bronchoalveolar lavage (BAL) proteins from patients having sarcoidosis or CBD were studied using two dimensional gel based proteomics. In this study, we used Difference Gel Electrophoresis (DIGE) proteomics approach to analyse the protein expression profiles from sarcoidosis patients (n=4), CBD (n=4) and healthy controls (n = 5). Subsequently, differentially expressed proteins were identified by using mass spectrometry.

RESULTS

We found 37 protein-spots with statistically different expression levels, and identified 14 of these proteins. The protein expression levels of peroxiredoxin 5, heat shock protein 70, complement C3, annexin A2 and transthyretin were significantly different in sarcoidosis versus control group. The proteins; hemopexin, beta2-microglobulin, alpha-1 antitrypsin, cystatin B, IgG kappa chain, apolipoprotein A1, and albumin were significantly different between CBD versus control group. When comparing CBD versus sarcoidosis, we found superoxide dismutase and hemoglobin upregulated in the CBD group.

CONCLUSIONS

By using quantitative proteomics, we were able to find proteins with different expression levels in both diseases.