Estimation of minimal clinically important difference in EQ-5D visual analog scale score after pulmonary rehabilitation in subjects with COPD.

BACKGROUND: The effect of pulmonary rehabilitation (PR) on the EuroQol Group's 5-dimension questionnaire (EQ-5D) in COPD has been poorly investigated. In addition, conflicting results were reported about the visual analog scale component of EQ-5D (EQ-VAS). The purpose of this study was to evaluate the responsiveness of EQ-VAS to PR and its relationship with clinical and functional parameters in subjects with COPD, as well as to define the minimal clinically important difference (MCID) estimate for the EQ-VAS after PR. METHODS: A total of 468 in-patients with stable moderate-to-severe COPD, allocated to a 3-wk PR program, were retrospectively evaluated. EQ-VAS was assessed before and after PR, and its relationship with baseline pulmonary function, changes in 6-min walk test, and baseline, and transitional dyspnea index (BDI/TDI) after PR were evaluated. Using an anchor-based approach and receiver operating characteristic curves, the EQ-VAS change cutoff that identified subjects achieving the known MCID for TDI after PR was identified. RESULTS: Four hundred and thirty-nine subjects (94%, mean FEV1 55.3% predicted) completed pre- and post-PR EQ-VAS scores. After PR, EQ-VAS increased from 58 ± 17 to 72 ± 15 (ΔEQ-VAS 14 ± 12, P < .001). ΔEQ-VAS was negatively related to baseline FEV1 (r = -0.32, P < .001) and positively to TDI (r = 0.50, P < .001) and 6-min walk distance (r = 0.46, P < .001) changes. Receiver operating characteristic curves identified an EQ-VAS change cutoff of 8 as the best discriminating value to identify the MCID for TDI (0.78 sensitivity and 0.81 specificity; area under curve: 0.845, P < .001). CONCLUSIONS: Our study shows that, in in-patients with stable moderate-to-severe COPD, EQ-VAS is a valid and reliable tool to assess the responsiveness to PR, with an estimated MCID of 8 points. The EQ-VAS can be a practical alternative to more time-consuming measures of health-related quality of life.

Decreased maturation of dendritic cells in the central airways of COPD patients is associated with VEGF, TGF-ß and vascularity.

BACKGROUND: Dendritic cells (DCs) have a pivotal role in the onset and regulation of innate and adaptive immune responses. Moreover, DCs can interact with angiogenic modulators, resulting in modification of their biology and participation in angiogenesis. OBJECTIVES: This study was designed to evaluate the relationship between the density of DCs, vascularity and expression of angiogenic factors [vascular endothelial growth factor (VEGF), transforming growth factor (TGF)-ß and basic fibroblast growth factor (bFGF)] in the central airways of chronic obstructive pulmonary disease (COPD) patients. METHODS: The study included 20 patients with moderate/severe COPD and 8 healthy control subjects. Bronchial biopsies were evaluated by immunohistochemistry. Specimens were examined for CD83 and CD207 to mark mature and immature DCs, respectively, for collagen IV to evaluate vascularity, and for VEGF, TGF-ß and bFGF. RESULTS: Compared to controls, COPD patients had a significant reduction of CD83+ cells and an increased CD207/CD83 ratio (p < 0.05). Vascularity, VEGF, TGF-ß and bFGF were also significantly increased in COPD patients as compared to controls (p < 0.01). In COPD patients, CD83+ cells were inversely related to VEGF and TGF-ß expression (p < 0.05). Moreover, the CD207/CD83 ratio was positively related to VEGF, TGF-ß and vascularity (p < 0.05). Finally, CD207+ cells were inversely related to FEV1 (p < 0.05). CONCLUSION: Our results show a reduced maturation of DCs in COPD that was related to airway vascularity and angiogenic factors (VEGF and TGF-ß). Additionally, immature DCs were significantly related to disease severity. We propose that the interplay between airway vascular changes, on one hand, and DCs maturation on the other, may play a key role in the pathogenetic mechanisms of COPD.

Six-minute walking distance improvement after pulmonary rehabilitation is associated with baseline lung function in complex COPD patients: a retrospective study.

INTRODUCTION: Conflicting results have been so far reported about baseline lung function, as predicting factor of pulmonary rehabilitation (PR) efficacy. AIM: To ascertain whether or not baseline lung function could predict a benefit in terms of a significant change in 6-min walk test (6 MWT) after PR. METHODS: Seventy-five stable moderate-to-severe COPD inpatients with comorbidities (complex COPD), allocated to a three-week PR program, were retrospectively evaluated. Pulmonary function, 6 MWT, dyspnea (BDI/TDI), and quality of life (EQ-VAS) were assessed before and after PR program. The patients were divided into two groups depending on the change in 6 MWT (responders > 30 m and nonresponders ≤ 30 m). Logistic regression analysis was used. Results. After PR, 6 MWT performance all outcome measures significantly improved (P < 0.01). Compared to nonresponders (N = 38), the responders (N = 37) had lower values in baseline lung function (P < 0.01). Logistic regression analysis showed that FEV1 < 50% pred and TL, CO < 50% pred were independent predictors of PR efficacy. CONCLUSIONS: Our study shows that in stable moderate-to-severe complex COPD inpatients, baseline lung function may predict the response to PR in terms of 6 MWT. We also found that complex COPD patients with poor lung function get more benefit from PR.

Hyaluronic acid : perspectives in lung diseases.

Hyaluronic acid (HA) is a non-sulphated glycosaminoglycan. It is a natural polymer characterised by a coiled linear chain in particularly well-hydrated configuration composed of repeating disaccaride units. In mammals, its molecular weight can be extremely wide, ranging from 20 to 4,000 kDa. High molecular mass forms are provided with anti-inflammatory properties. A unique characteristic of HA is hydration (up to 6,000 molecules water/molecule of HA) with a major role in the regulation of fluid balance in the interstitium, a fundamental activity on the amorphous colloidal matrix gluing connective cell and fibers, and many other biological functions including lubrication, solute transport and microcirculatory exchange. HA has been widely used in the treatment of eye, ear, joint and skin disorders; in the last 15 years HA has been also proposed successfully in the treatment of a number of lung diseases in vitro, experimental animals and humans. In particular, inhaled HA at relatively high molecular weight has been proven to prevent bronchoconstiction induced in asthmatics by direct and indirect challenges such as inhalation of methacholine, inhalation of ultrasonically nebulised distilled water, muscular exercise. More recently, in patients affected by chronic obstructive pulmonary diseases, we have demonstrated that repeated administrations of inhaled HA (daily, for 8 weeks) induce significant increase in bronchial patency as well as progressive lung deflation with decrease of residual volume. In conclusion there are elements that can let us state that is perhaps time to change the focus to connective tissue and extracellular matrix substances such as HA, in order to prevent and treat chronic lung diseases.