To investigate the relationship between BAL cells, including macrophages, neutrophils, eosinophils, T lymphocytes (TLs) (CD3+) and their subpopulations (CD4+, CD8+, CD4+/CD8+ ratio and CD8+38+) with lung function indices and grade of dyspnoea, in IPF patients.
Twenty six patients with IPF were studied, 17 males age of 63 ± 9 years (mean ± SD). Differential BAL cell counts were evaluated on May-Gr_nwald-Giemsa stained cytospins and expressed as percentages of total cells. BAL lymphocyte subsets were evaluated by flow cytometry and expressed as percentages of lymphocytes. FEV1, FVC, TLC, DLCO, PaO2, PaCO2 and P(A-a)O2 were measured in all. The level of dyspnoea was assessed by the Medical Research Council (MRC) chronic dyspnoea scale.
CD8+ TLs showed a positive correlation with the MRC (r=0.462, p=0.023), the CD4+/CD8+ ratio an inverse (r=-0.537, p=0.006). Activated CD8+ TLs, identified by the expression of the activation marker CD38+, were inversely related to the FEV1 and FVC (r=-0.533, p=0.032 and r=-0.592, p=0.02, respectively). The neutrophils showed a significant positive correlation with the MRC (r=0.421, p=0.032), and negative correlations with the DLCO (r=-0.535, p=0.005), PaO2 (r=-0.436, p=0.033), and PaCO2 (r=-0.516, p=0.010). No other significant correlations could be identified.
In IPF BAL neutrophils and CD8+ TLs are associated with the grade of dyspnoea and functional parameters of disease severity.
Both BAL neutrophils and CD8+ TLs might play a role in IPF pathogenesis.
Effrosyni Manali, None.