Triggering receptor expressed on myeloid cells: role in the diagnosis of lung infections.
The triggering receptor expressed on myeloid cells (TREM)-1 is a recently described molecule, which plays an important role in myeloid cell-activated inflammatory responses. TREM-1 is expressed on blood neutrophils and monocytes, and also on alveolar macrophages, thus suggesting a potential role in lung inflammatory responses against infections. To investigate the differential expression of TREM-1 in lung infections, its levels were assessed in bronchoalveolar lavage specimens from patients with community-acquired pneumonia or tuberculosis. TREM-1 was also investigated in patients with interstitial lung diseases, as a model of noninfectious inflammatory disease of the lung. TREM-1 expression was significantly increased in lung neutrophils and in lung macrophages of patients with pneumonia (n=7; 387.9+/-61.4 and 660.5+/-18.3, respectively) compared with patients with pulmonary tuberculosis (n=7; 59.2+/-13.1 and 80.6+/-291.2) and patients with interstitial lung diseases (n=10; 91.8+/-23.3 and 123.9+/-22.8). In contrast, TREM-1 expression on peripheral blood neutrophils was no different among the three groups. In conclusion, these data suggest that triggering receptor expressed on myeloid cells-1 is selectively expressed in the lungs of patients with pneumonia caused by extracellular bacteria and not in patients with tuberculosis, providing a potential marker for differential diagnosis.
Section of Respiratory Diseases, Dept of Oncology and Haematology, University of Modena and Reggio Emilia, Modena, Italy.
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Richeldi
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Mariani
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Losi
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Maselli
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Corbetta
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Buonsanti
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Colonna
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Sinigaglia
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Panina-Bordignon
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Fabbri
D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology*; D017714:Community-Acquired Infections / Q000175:diagnosis; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000032:analysis; D017563:Lung Diseases, Interstitial / Q000175:diagnosis*; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis*; D022423:Myeloid Cells / Q000378:metabolism / Q000502:physiology; D018410:Pneumonia, Bacterial / Q000175:diagnosis*; D011336:Probability; D011446:Prospective Studies; D011971:Receptors, Immunologic / Q000032:analysis*; D012680:Sensitivity and Specificity; D000073871:Triggering Receptor Expressed on Myeloid Cells-1; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis*
D018836:Inflammation Mediators; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; C408842:TREM1 protein, human; D000073871:Triggering Receptor Expressed on Myeloid Cells-1