Smoking-related idiopathic interstitial pneumonia.

Cigarette smoking is a key factor in the development of numerous pulmonary diseases. An international group of clinicians, radiologists and pathologists evaluated patients with previously identified idiopathic interstitial pneumonia (IIP) to determine unique features of cigarette smoking. Phase 1 (derivation group) identified smoking-related features in patients with a history of smoking (n=41). Phase 2 (validation group) determined if these features correctly predicted the smoking status of IIP patients (n=100) to participants blinded to smoking history. Finally, the investigators sought to determine if a new smoking-related interstitial lung disease phenotype could be defined. Phase 1 suggested that preserved forced vital capacity with disproportionately reduced diffusing capacity of the lung for carbon monoxide, and various radiographic and histopathological findings were smoking-related features. In phase 2, the kappa coefficient among clinicians was 0.16 (95% CI 0.11-0.21), among the pathologists 0.36 (95% CI 0.32-0.40) and among the radiologists 0.43 (95% CI 0.35-0.52) for smoking-related features. Eight of the 100 cases were felt to represent a potential smoking-related interstitial lung disease. Smoking-related features of interstitial lung disease were identified in a minority of smokers and were not specific for smoking. This study is limited by its retrospective design, the potential for recall bias in smoking history and lack of information on second-hand smoke exposure. Further research is needed to understand the relationship between smoking and interstitial lung disease.

Gastroesophageal reflux incites interstitial lung disease in systemic sclerosis: clinical, radiologic, histopathologic, and treatment evidence.

OBJECTIVES: Interstitial lung disease (ILD) is currently the main cause of death in systemic sclerosis (SSc) and has an unknown pathogenesis. Gastroesophageal reflux (GER) has been strongly implicated as a cause of ILD in several lung diseases, including SSc-ILD. This review summarizes clinical, radiologic, histopathologic, and treatment aspects of GER in SSc-ILD. METHODS: The PubMed database was searched using the following keywords: "systemic sclerosis, scleroderma, interstitial lung disease, and gastroesophageal reflux." The research was limited to English-language studies that included SSc patients with ILD. RESULTS: Pulmonary function tests were related with the presence of GER in several esophageal functional tests (esophageal endoscopy, pH monitoring, and manometric analysis). Regarding the histopathologic data, a pattern called centrilobular fibrosis was described in 21% of 28 lung biopsies, with a bronchocentric distribution and with an intraluminal content resembling gastric fluid. Radiologic evidence of esophageal dilation is very frequent in SSc patients, and consolidation with a patchy distribution was almost exclusively found in SSc patients with centrilobular fibrosis lung pattern. Furthermore, high levels of serum KL-6, a marker of epithelial injury, are indicative of active ILD in SSc disease. CONCLUSIONS: The association of GER with SSc-ILD is strongly supported by several studies. An aggressive treatment for reflux is recommended in all SSc patients with ILD; however, future studies need to be performed to prove a long-term benefit.