ICOS protects against mortality from acute lung injury through activation of IL-5+ ILC2s.

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease causing irreversible lung scarring and loss of pulmonary function. IPF Patients suffer from a high rate of pulmonary infections and acute exacerbations of disease that further contribute to pulmonary decline. Low expression of the inducible T-cell costimulatory molecule (ICOS) in peripheral blood mononuclear cells predicts decreased survival of IPF patients, but the mechanisms by which ICOS protects are unclear. Using a model of bleomycin-induced lung injury and fibrosis, we now demonstrate that ICOS expression enhances survival from lung injury rather than regulating fibrogenesis. Of ICOS-expressing cells, type 2 innate lymphocytes (ILC2s) are the first to respond to bleomycin-induced injury, and this expansion is ICOS dependent. Interestingly, a similar decrease in ICOS+ ILCs was found in lung tissue from IPF patients. Interleukin (IL)-5, produced primarily by ILC2s, was significantly reduced after lung injury in ICOS-/- mice, and strikingly, treatment with IL-5 protected both ICOS-/- and wild-type mice from mortality. These results imply that low ICOS expression and decreased lung ILC2s in IPF patients may contribute to poor recovery from infections and acute exacerbation and that IL-5 treatment may be a novel therapeutic strategy to overcome these defects and protect against lung injury.

Prevalence of hiatal hernia by blinded multidetector CT in patients with idiopathic pulmonary fibrosis.

Hiatal hernia (HH) is associated with gastro-oesophageal reflux (GOR) and/or GOR disease and may contribute to idiopathic pulmonary fibrosis (IPF). We hypothesised that HH evaluated by computed tomography is more common in IPF than in asthma or chronic obstructive pulmonary disease (COPD), and correlates with abnormal GOR measured by pH probe testing. Rates of HH were compared in three cohorts, IPF (n=100), COPD (n=60) and asthma (n=24), and evaluated for inter-observer agreement. In IPF, symptoms and anti-reflux medications were correlated with diffusing capacity of the lung for carbon monoxide (D(L,CO)) and composite physiologic index (CPI). HH was correlated with pH probe testing in IPF patients (n=14). HH was higher in IPF (39%) than either COPD (13.3%, p=0.00009) or asthma (16.67%, p=0.0139). The HH inter-observer κ agreement was substantial in IPF (κ=0.78) and asthma (κ=0.86), and moderate in COPD (κ=0.42). In IPF, HH did not correlate with lung function, except in those on anti-reflux therapy, who had a better D(L,CO) (p<0.03) and CPI (p<0.04). HH correlated with GOR as measured by DeMeester scores (p<0.04). HH is more common in IPF than COPD or asthma. In an IPF cohort, HH correlated with higher DeMeester scores, confirming abnormal acid GOR. Presence of HH alone was not associated with decreased lung function.

Spinal epidural hematoma in a hemophilic infant.

PURPOSE: Although intracranial hemorrhage remains a leading cause of death in hemophilia, spinal epidural hematoma is seen rarely. Decompressive laminectomy has a high associated morbidity, and recent reports have suggested that patients can be treated conservatively without surgical intervention. PATIENTS AND METHODS: We present a case of spontaneous spinal epidural hematoma diagnosed by MRI scan in a 6-month-old hemophilic infant. Immediate treatment with factor VIII replacement was instituted. RESULTS: There was rapid and complete clinical and radiographic resolution. CONCLUSION: This case shows that selected hemophilic patients with spinal epidural hematoma can be spared surgical decompression by prompt medical attention.