PT  - JOURNAL ARTICLE
AU  - Erica Bazzan
AU  - Mariaenrica Tinè
AU  - Claudia Radu
AU  - Graziella Turato
AU  - Elena Mutti
AU  - Paolo Simioni
AU  - Riccardo Cazzuffi
AU  - Simonetta Baraldo
AU  - Marina Saetta
AU  - Manuel G. Cosio
TI  - Phenotypes of alveolar macrophages in normal human lung and their polarization with disease
DP  - 2014 Sep 01
TA  - European Respiratory Journal
PG  - P1472
VI  - 44
IP  - Suppl 58
4099  - http://erj.ersjournals.com/content/44/Suppl_58/P1472.short
4100  - http://erj.ersjournals.com/content/44/Suppl_58/P1472.full
SO  - Eur Respir J2014 Sep 01; 44
AB  - BACKGROUND Macrophages are crucial components of innate immunity. During inflammatory responses monocytes are recruited into tissues, skewed first toward unpolarized macrophages (M0) and then polarized toward proinflammatory M1 or antiinflammtory M2 functional phenotype. However the different macrophages polarization (M0, M1, M2) in normal human lungs and their plasticity with the disease is not understood.AIM To investigate the phenotype of alveolar macrophages (AM) in normal human lung tissue and their change with disease.METHODS M1 (iNOS+), M2 (CD206+) and M0 (iNOS-/CD206-) AM were studied by immunohistochemical and immunofluoresence techniques in human lung sequential slides of 17 nonsmokers (11 with tumor and 6 donors without tumor) 13 smokers without COPD and 23 COPD (11 severe and 12 mild/moderate). Positive AM were counted and expressed as percentage of total AM.RESULTS Baseline AM population in normal donor lungs comprised 57%(31-68) of M0, 31%(24-60) of M1 and 7%(4-16) of M2. However, in nonsmokers with lung cancer M2 increased to 43%(2-65), but not the M1. In smokers M2 [68%(40-86)] was higher than in nonsmokers [43%(2-65)] but did not increase further with COPD severity [61%(36-94) in mild/moderate COPD and 78%(53-98) in severe COPD]. M1 is minimally present in nonsmokers [24%(3-38)] and increases gradually and significantly with worsening COPD [68%(40-93) in mild/moderate COPD and 84%(36-99) in severe COPD].CONCLUSION The baseline (normal) AM polarization is mainly M0 with a small percentage of proinflammatory M1, which increases along with worsening COPD. M2 increase is probably partially related to the presence of cancer.