TY - JOUR
T1 - Immune activation in α1-antitrypsin-deficiency emphysema
T2 - Beyond the protease-antiprotease paradigm
AU - Baraldo, Simonetta
AU - Turato, Graziella
AU - Lunardi, Francesca
AU - Bazzan, Erica
AU - Schiavon, Marco
AU - Ferrarotti, Ilaria
AU - Molena, Beatrice
AU - Cazzuffi, Riccardo
AU - Damin, Marco
AU - Balestro, Elisabetta
AU - Luisetti, Maurizio
AU - Rea, Federico
AU - Calabrese, Fiorella
AU - Cosio, Manuel G.
AU - Saetta, Marina
PY - 2015/2/15
Y1 - 2015/2/15
N2 - Rationale: α1-Antitrypsin (AAT) is a potent protease inhibitor, deficiency of which is associated with the presence of emphysema. An imbalance of elastase and antielastase, along with innate inflammation in the lung, is believed to cause lung destruction in α1-antitrypsin deficiency (AATD). It is now apparent that AAT has important immune-regulatory roles that would be lost in AATD, yet adaptive immune responses in the lung have not been investigated in patients with AATD. Objectives: To assess the adaptive immune response in severe AATD emphysema and compare it with that present in "usual" chronic obstructive pulmonary disease (COPD). Methods: The immune inflammatory response in explanted lungs from 10 subjects with AATD was characterized and quantified, and the results were compared with those of 26 subjects with usual COPD and those of 17 smoking and 11 nonsmoking control subjects with normal lung function. Measurements and Main Results: Lymphoid follicles (LFs) in AATD and usual COPD were markedly increased when compared with control groups. Molecular analysis of B lymphocytes in LFs showed predominantly mono/oligoclonality. LF number correlated negatively with FEV1/FVC. B lymphocytes and CD4+ and CD8+ T lymphocytes were significantly increased in AATD and usual COPD when compared with control groups. IL-32, an important cytokine in induction of autoimmunity, was markedly up-regulated in AATD and usual COPD. Conclusions: An important adaptive immune inflammation, comprising B, CD4+, and CD8+ lymphocytes, and LFs, is a prominent feature in AATD. These results change the paradigm of the mechanism of AATD-induced emphysema from a pure elastase-antielastase imbalance to a much more complex one involving the adaptive immune system, similarly to what occurs in usual COPD.
AB - Rationale: α1-Antitrypsin (AAT) is a potent protease inhibitor, deficiency of which is associated with the presence of emphysema. An imbalance of elastase and antielastase, along with innate inflammation in the lung, is believed to cause lung destruction in α1-antitrypsin deficiency (AATD). It is now apparent that AAT has important immune-regulatory roles that would be lost in AATD, yet adaptive immune responses in the lung have not been investigated in patients with AATD. Objectives: To assess the adaptive immune response in severe AATD emphysema and compare it with that present in "usual" chronic obstructive pulmonary disease (COPD). Methods: The immune inflammatory response in explanted lungs from 10 subjects with AATD was characterized and quantified, and the results were compared with those of 26 subjects with usual COPD and those of 17 smoking and 11 nonsmoking control subjects with normal lung function. Measurements and Main Results: Lymphoid follicles (LFs) in AATD and usual COPD were markedly increased when compared with control groups. Molecular analysis of B lymphocytes in LFs showed predominantly mono/oligoclonality. LF number correlated negatively with FEV1/FVC. B lymphocytes and CD4+ and CD8+ T lymphocytes were significantly increased in AATD and usual COPD when compared with control groups. IL-32, an important cytokine in induction of autoimmunity, was markedly up-regulated in AATD and usual COPD. Conclusions: An important adaptive immune inflammation, comprising B, CD4+, and CD8+ lymphocytes, and LFs, is a prominent feature in AATD. These results change the paradigm of the mechanism of AATD-induced emphysema from a pure elastase-antielastase imbalance to a much more complex one involving the adaptive immune system, similarly to what occurs in usual COPD.
KW - Autoimmunity
KW - Chronic obstructive pulmonary disease
KW - Lymphocytes
KW - Lymphoid follicles
KW - α-antitrypsin
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U2 - 10.1164/rccm.201403-0529OC
DO - 10.1164/rccm.201403-0529OC
M3 - Article
C2 - 25412116
AN - SCOPUS:84922895336
VL - 191
SP - 402
EP - 409
JO - American Journal of Respiratory and Critical Care Medicine
JF - American Journal of Respiratory and Critical Care Medicine
SN - 1073-449X
IS - 4
ER -