Avaliação quantitativa das fibras elásticas na doença pulmonar obstrutiva crônica

Abstract

Objective: To quantify elastic fibers (EFs) and smooth muscle (SM) cells, as well as CD4 + and CD8 + T lymphocytes, in stable chronic obstructive pulmonary disease (COPD). Methods: Surgical specimens were obtained from 15 COPD patients, 18 smokers without airflow limitation, and 14 nonsmokers. Histological and immunohistochemical methods were employed in order to quantify EFs, SM cells, CD4 + T cells, and CD8 + T cells. Results: There was no significant difference in EF numbers among the three groups (p > 0.05). The number of EFs per unit area of lung tissue (mm 2 ) and the percentage of EFs in the lung tissue were similar among the three groups. The numbers of SM cells were found to be higher in the COPD patients than in the smokers (p = 0.003) or in the nonsmokers (p = 0.009). There was a tendency toward an increase in CD8 + T-cell counts in the COPD patients. In specimens collected from the COPD patients, CD4 + T-cell counts were lower than in those collected from the smokers (p = 0.015) or from the nonsmokers (p = 0.003). There was a weak correlation between CD4 + T-cell count and the ratio of forced expiratory volume in one second to forced vital capacity (r 2 = 0.003). Conclusions: The EF counts were similar among the three groups. Hypertrophy/hyperplasia of airway wall SM cells was found in the COPD patients and in the smokers, indicating that airway remodeling occurs in smokers. The CD4/CD8 ratio was lower in the COPD patients.

Inhaled Steroids Modulate Extracellular Matrix Composition in Bronchial Biopsies of COPD Patients: A Randomized, Controlled Trial

“…Our findings extend previous observations, showing no difference in the percentage elastic fibers in COPD patients and smokers without airway obstruction [11], [28]. We observed no significant difference in versican and decorin content between current and ex-smokers with COPD, which is in line with an in vitro study with cultured lung fibroblasts of moderate COPD patients and control subjects.…”

Células inflamatórias e seus mediadores na patogênese da DPOC

“…Também foi publicado recentemente que o volume de fibras elásticas nos alvéolos e pequenas vias aéreas está reduzido nos pacientes com DPOC 36 . No entanto, Rufino et al demonstraram que a quantidade de fibras elásticas não está reduzida no parênquima pulmonar de pacientes com enfisema quando comparado a controles não tabagistas e sugeriram que as fibras pudessem estar rompidas ou funcionalmente alteradas 37 . A diferença dos dados obtidos pode ser explicada pelas diferentes metodologias empregadas ou pelo perfil de pacientes estudados, mas chamam a atenção para a necessidade de mais estudos.…”