PT  - JOURNAL ARTICLE
AU  - Maha Zohra Ladjemi
AU  - Marylène Lecocq
AU  - Chantal Fregimilicka
AU  - Caroline Bouzin
AU  - Monique Delos
AU  - Bruno Detry
AU  - Charles Pilette
TI  - IgA expression in peribronchial and lung follicular B cells from COPD patients
AID  - 10.1183/13993003.congress-2016.PA3992
DP  - 2016 Sep 01
TA  - European Respiratory Journal
PG  - PA3992
VI  - 48
IP  - suppl 60
4099  - http://erj.ersjournals.com/content/48/suppl_60/PA3992.short
4100  - http://erj.ersjournals.com/content/48/suppl_60/PA3992.full
SO  - Eur Respir J2016 Sep 01; 48
AB  - Rationale: Chronic obstructive pulmonary disease (COPD) is a lung disorder associated with aberrant immune and structural responses of the airways to inhaled toxics. While accumulation of B cells and formation of lymphoid follicles (LF) have been described in COPD airways, the functional status of lung B cells remains poorly known.Objectives: The aim of this study was to further characterize LF observed in COPD airways, in terms of IgA expression.Methods: The presence of LF and CD20 and CD21 expression were determined within the lung from COPD patients (n=21) versus controls (n=18), while intra-follicular IgA expression was assessed by immunohistochemistry (quantified by TissueIA software, Leica microsystems).Results: A significant increase was observed both in the percentage of B cells among total cells as well as the number of peri-bronchial and parenchymal LF in lung tissue of severe COPD patients as compared to controls (respectively p=0.02 and p=0.03). While these LF were clearly observed in COPD, 47% of these were displaying evidence of CD21+ follicular DCs. In another hand, IgA+ B-cell numbers were up-regulated in LF from severe COPD patients compared with controls, particularly in distal airways (p=0.02).Conclusions: This study shows that IgA production occurs within LF from severe COPD, presumably representing an end-stage feature of exacerbated mucosal immune responses against cigarette smoke and/or chronic infection. In addition, these LF are observed in the absence of CD21+ follicular DCs.