Long-term outcomes in patients with COPD treated with non-invasive ventilation for acute hypercapnic respiratory failure.

PURPOSE: Chronic Obstructive Lung Disease (COPD) remains a major cause of morbidity and mortality across the world. We evaluated survival over 9 years in a cohort of patients with COPD requiring acute inpatient non-invasive ventilation (NIV). We analyzed prognostic indices to evaluate if they were associated with mortality. PATIENTS AND METHODS: We performed a retrospective chart review of all patients who were admitted to St. James's Hospital respiratory ward with COPD and acute hypercapnic respiratory failure who required NIV over a 12-month period and followed their outcomes over 9 years. We investigated the association between survival and potential prognostic variables using univariate analysis and multivariate Cox proportional hazards model. We evaluated the association between survival and the following parameters: age, gender, multiple admissions requiring NIV (> 1 admission in within 12 months of index presentation), home NIV use preadmission, initial arterial blood gas pH, days spent on NIV, serum albumin and serum albumin to serum CRP ratio at admission. RESULTS: Ninety-nine patients with COPD and acute hypercapnic respiratory failure were identified over a 12-month period from January to December 2011. Survival at 1, 2, 5 and 9 years was 65% (n = 64), 42% (n = 42), 25% (n = 25) and 21% (n = 21), respectively. Increasing age (p value < 0.001) and a lower serum albumin (p value < 0.005) were associated with a higher mortality. There was a trend towards improved survival in the group who were treated with home NIV prior to admission compared to no NIV therapy at home but this did not reach statistical significance (Fig. 3, p value = 0.088). CONCLUSION: This study highlights the long-term mortality in patients with COPD admitted with hypercapnic respiratory failure requiring NIV and correlates with prior studies. Increasing age and lower serum albumin were associated with increased mortality. Home NIV may have a protective long-term survival benefit in patients with COPD who have been admitted for acute NIV.

IL-25 and type 2 innate lymphoid cells induce pulmonary fibrosis.

Disease conditions associated with pulmonary fibrosis are progressive and have a poor long-term prognosis with irreversible changes in airway architecture leading to marked morbidity and mortalities. Using murine models we demonstrate a role for interleukin (IL)-25 in the generation of pulmonary fibrosis. Mechanistically, we identify IL-13 release from type 2 innate lymphoid cells (ILC2) as sufficient to drive collagen deposition in the lungs of challenged mice and suggest this as a potential mechanism through which IL-25 is acting. Additionally, we demonstrate that in human idiopathic pulmonary fibrosis there is increased pulmonary expression of IL-25 and also observe a population ILC2 in the lungs of idiopathic pulmonary fibrosis patients. Collectively, we present an innate mechanism for the generation of pulmonary fibrosis, via IL-25 and ILC2, that occurs independently of T-cell-mediated antigen-specific immune responses. These results suggest the potential of therapeutically targeting IL-25 and ILC2 for the treatment of human fibrotic diseases.

Intestinal epithelium is more susceptible to cytopathic injury and altered permeability than the lung epithelium in the context of acute sepsis.

Mitochondrial morphology and function are altered in intestinal epithelia during endotoxemia. However, it is unclear whether mitochondrial abnormalities occur in lung epithelial cells during acute sepsis or whether mitochondrial dysfunction corresponds with altered epithelial barrier function. Thus, we hypothesized that the intestinal epithelium is more susceptible to mitochondrial injury than the lung epithelium during acute sepsis and that mitochondrial dysfunction precedes impaired barrier function. Using a resuscitated feline model of Escherichia coli-induced sepsis, lung and ileal tissues were harvested after 6 h for histological and mitochondrial ultrastructural analyses in septic (n = 6) and time-matched controls (n = 6). Human lung epithelial cells (HLEC) and Caco-2 monolayers (n = 5) were exposed to 'cytomix' (TNFα: 40 ng/ml, IL-1ß: 20 ng/ml, IFNγ: 10 ng/ml) for 24-72 h, and measurements of transepithelial electrical resistance (TER), epithelial permeability and mitochondrial membrane potential (ΔΨ) were taken. Lung epithelial morphology, mitochondrial ultrastructure and pulmonary gas exchange were unaltered in septic animals compared to matching controls. While histologically intact, ileal epithelia demonstrated marked mitochondrial ultrastructural damage during sepsis. Caco-2 monolayers treated with cytomix showed a significant decrease in mitochondrial ΔΨ within 24 h, which was associated with a progressive reduction in TER and increased epithelial permeability over the subsequent 48 h. In contrast, mitochondrial ΔΨ and epithelial barrier functions were preserved in HLEC following cytomix. These findings indicate that intestinal epithelium is more susceptible to mitochondrial damage and dysfunction than the lung epithelium in the context of sepsis. Early alterations in mitochondrial function portend subsequent epithelial barrier dysfunction.

Inflammasome mRNA expression in human monocytes during early septic shock.

RATIONALE: Monocytes are central to the initiation of the inflammatory response in sepsis, with caspase-1 activation playing a key role. Monocyte deactivation during sepsis has been linked to poor outcomes. OBJECTIVES: Given the importance of caspase-1 in the immune response, we investigated whether monocytes from patients early in septic shock demonstrate alterations in mRNAs for caspase-1-related molecules. METHODS: Patients with septic shock (n = 26; age >18 years), critically ill intensive care unit patients (n = 20), and healthy volunteers (n = 22) were enrolled in a prospective cohort study in a university intensive care unit. Demographic, biological, physiologic, and plasma cytokine measurements were obtained. Monocytes were assayed for ex vivo tumor necrosis factor-alpha production, and fresh monocyte mRNA was analyzed by quantitative reverse-transcription polymerase chain reaction for Toll-like receptors, NOD-LRR proteins, cytokines, and nuclear factor-kappaB-related genes. MEASUREMENTS AND MAIN RESULTS: Relative copy numbers for the inflammasome mRNAs for ASC, caspase-1, NALP1, and Pypaf-7 were significantly lower in patients with septic shock compared with critically ill control subjects. NALP1 mRNA levels were linked to survival in patients with sepsis (P = 0.0068) and correlated with SAPS II scores (r = -0.63). CONCLUSIONS: These data suggest that monocyte deactivation occurs during the earliest stages of the systemic inflammatory response and that changes in inflammasome mRNA expression are part of this process.

Late reactivation of tuberculosis in an oleothorax.

The injection of oil into the pleural cavity was a widely used treatment of pulmonary tuberculosis until the advent of effective anti-tuberculous therapy. Long-term complications of oleothorax can occur when the oil is not removed. The authors present an unusual complication of oleothorax, reactivation of tuberculosis, 54 years after oil instillation.

The acute respiratory distress syndrome: a role for transforming growth factor-beta 1.

The acute respiratory distress syndrome (ARDS) remains a major cause of morbidity and mortality. Enhanced fibrosis and elevated procollagen III levels have been linked to increased mortality. We hypothesized that transforming growth factor (TGF)-beta 1 may play an important role in ARDS, given its role in stimulating fibrosis. Using reverse transcriptase in situ polymerase chain reaction (RT in situ PCR) and immunohistochemistry, we analyzed lung tissue from four fibroproliferative ARDS cases and control subjects. We also compared active TGF-beta 1 levels in the bronchoalveolar lavage (BAL) fluid of 13 de novo ARDS cases, and 7 normal control subjects. RT in situ PCR showed TGF-beta 1 mRNA expression in fibroproliferative ARDS cases. Immunohistochemistry confirmed protein expression in these samples. Controls were negative for both techniques. In the newly enrolled ARDS cases, TGF-beta 1 levels, as measured by luciferase assay, were elevated in the 11 of 13 samples, averaging 98 +/- 40 pg/mg protein. Controls had no detectable TGF-beta 1 activity. These data suggest that activation of TGF-beta 1 may be important in the early phases of acute lung injury in addition to driving fibroproliferation. These data may lead to new therapeutic approaches in ARDS through more targeted inhibition of fibrosis.