Objective: The aim of this study was to examine the parenchymal and extracellular matrix remodeling process in two histologic patterns-nonspecific interstitial pneumonia (NSIP) and usual interstitial pneumonia (UIP)-in cases of idiopathic and sclerosis/systemic sclerosis (SSc)-associated interstitial pneumonia. Methods: We examined 15 cases of idiopathic NSIP, 10 cases of idiopathic UIP, 5 cases of SSc-UIP and 9 cases of SSc-NSIP. In the lung parenchyma, epithelial cells, endothelial cells and myofibroblasts were evaluated by immunohistochemical staining, whereas histochemical staining was used in order to evaluate collagen/elastic fibers in the extracellular matrix. Results: The percentage of surfactant protein A-positive epithelial cells was significantly greater in idiopathic NSIP than in SSc-NSIP, as well as being greater in idiopathic UIP than in SSc-UIP. Idiopathic NSIP and idiopathic UIP presented significantly higher immunoexpression of alpha smooth muscle actin in myofibroblasts than did SSc-NSIP and SSc-UIP. The percentage of CD34 endothelial cells in the pulmonary microvasculature was significant lower in idiopathic UIP than in SSc-UIP. The density of collagen fibers was significantly greater in idiopathic NSIP and idiopathic UIP than in SSc-NSIP and UIP. In contrast, the elastic fiber density was significantly lower in idiopathic UIP than in SSc-UIP. Conclusions: Increased collagen synthesis, destruction of elastic fibers, high myofibroblast proliferation and poor microvascularization might represent a remodeling process found in idiopathic interstitial pneumonia, whereas the reverse might represent a repair process in SSc-associated interstitial pneumonia.

Keywords: Epithelial cells; Neovascularization, pathologic; Collagen; Elastin; Idiopathic interstitial pneumonias; Scleroderma, systemic.

Objective: To determine the prevalence of gastroesophageal reflux disease (GERD) and to evaluate its clinical presentation, as well as the esophageal function profile in patients with idiopathic pulmonary fibrosis (IPF). Methods: In this prospective study, 28 consecutive patients with IPF underwent stationary esophageal manometry, 24-h esophageal pH-metry and pulmonary function tests. All patients also completed a symptom and quality of life in GERD questionnaire. Results: In the study sample, the prevalence of GERD was 35.7%. The patients were then divided into two groups: GERD+ (abnormal pH-metry; n = 10) and GERD− (normal pH-metry; n = 18). In the GERD+ group, 77.7% of the patients presented at least one typical GERD symptom. The pH-metry results showed that 8 (80%) of the GERD+ group patients had abnormal supine reflux, and that the reflux was exclusively in the supine position in 5 (50%). In the GERD+ and GERD− groups, respectively, 5 (50.0%) and 7 (38.8%) of the patients presented a hypotensive lower esophageal sphincter, 7 (70.0%) and 10 (55.5%), respectively, presenting lower esophageal dysmotility. There were no significant differences between the groups regarding demographic characteristics, pulmonary function, clinical presentation or manometric findings. Conclusions: The prevalence of GERD in the patients with IPF was high. However, the clinical and functional characteristics did not differ between the patients with GERD and those without.

Keywords: Pulmonary fibrosis; Gastroesophageal reflux; Prevalence; Manometry; Esophageal pH monitoring.