Comparative proteomics of respiratory exosomes in cystic fibrosis, primary ciliary dyskinesia and asthma.

Cystic fibrosis (CF) and primary ciliary dyskinesia (PCD) are pulmonary genetic disorders associated with inflammation and heterogeneous progression of the lung disease. We hypothesized that respiratory exosomes, nanovesicles circulating in the respiratory tract, may be involved in the progression of inflammation-related lung damage. We compared proteomic content of respiratory exosomes isolated from bronchoalveolar lavage fluid in CF and PCD to asthma (A), a condition also associated with inflammation but with less severe lung damage. BALF were obtained from 3 CF, 3 PCD and 6 A patients. Exosomes were isolated from BALF by ultracentrifugations and characterized using immunoelectron microscopy and western-blot. Exosomal protein analysis was performed by high-resolution mass spectrometry using label-free quantification. Exosome enrichment was validated by electron microscopy and immunodetection of CD9, CD63 and ALIX. Mass spectrometry analysis allowed the quantification of 665 proteins, of which 14 were statistically differential according to the disease. PCD and CF exosomes contained higher levels of antioxidant proteins (Superoxide-dismutase, Glutathione peroxidase-3, Peroxiredoxin-5) and proteins involved in leukocyte chemotaxis. All these proteins are known activators of the NF-KappaB pathway. Our results suggest that respiratory exosomes are involved in the pro-inflammatory propagation during the extension of CF or PCD lung diseases. SIGNIFICANCE: The mechanism of local propagation of lung disease in cystic fibrosis (CF) and primary ciliary dyskinesia (PCD) is not clearly understood. Differential Proteomic profiles of exosomes isolated from BAL from CF, PCD and asthmatic patients suggest that they carry pro-inflammatory proteins that may be involved in the progression of lung damage.

Evaluation of chronic recurrent multifocal osteitis in children by whole-body magnetic resonance imaging.

OBJECTIVES: Chronic recurrent multifocal osteomyelitis (CRMO) is a non-infectious inflammatory bone disease of unknown origin. The extension of CRMO is currently evaluated with bone scintigraphy. The objectives of our study are to describe the results of the non-invasive whole-body magnetic resonance imaging (WB MRI) procedure in children with CRMO, and to discuss the interest of WB MRI in CRMO's follow-up. METHODS: We performed a retrospective chart review of children followed for CRMO in the French center for auto-inflammatory disorders, selecting those who had a WB MRI at diagnosis and/or during follow-up. Clinical, biological, pathological and imaging findings were depicted. RESULTS: There were six girls and three boys, aged 8 to 14 years. All had multiple painful localizations with increased inflammatory markers, except one. The most frequent sites involved on WB MRI were the pelvis, the femurs and the tibias. We also described extra-osseous lesions (intra-articular effusion, myositis) and for the first time polyseritis that could not be caught by X-rays or scintigraphy. Comparison with scintigraphy in three patients showed that spinal, pelvic and femoral lesions were better seen with WB MRI. WB MRI at 12 months follow-up was available in five patients, showing a clear improvement in four of them. Surprisingly, the last patient had a clinical improvement with worsening lesions on WB MRI. CONCLUSION: The WB MRI may contribute to the diagnosis and facilitate the follow-up of children with CRMO. This non-invasive, non-irradiating procedure will also allow depicting more precisely the natural history of bone and extra-osseous lesions in CRMO.