CRTH2 Mediates Profibrotic Macrophage Differentiation and Promotes Lung Fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a particularly deadly form of pulmonary fibrosis of unknown cause. In patients with IPF, high serum and lung concentrations of CHI3L1 (chitinase 3 like 1) can be detected and are associated with poor survival. However, the roles of CHI3L1 in these diseases have not been fully elucidated. We hypothesize that CHI3L1 interacts with CRTH2 (chemoattractant receptor-homologous molecule expressed on T-helper type 2 cells) to stimulate profibrotic macrophage differentiation and the development of pulmonary fibrosis and that circulating blood monocytes from patients with IPF are hyperresponsive to CHI3L1-CRTH2 signaling. We used murine pulmonary fibrosis models to investigate the role of CRTH2 in profibrotic macrophage differentiation and fibrosis development and primary human peripheral blood mononuclear cell culture to detect the difference of monocytes in the responses to CHI3L1 stimulation and CRTH2 inhibition between patients with IPF and normal control subjects. Our results showed that null mutation or small-molecule inhibition of CRTH2 prevents the development of pulmonary fibrosis in murine models. Furthermore, CHI3L1 stimulation induces a greater increase in CD206 expression in IPF monocytes than control monocytes. These results demonstrated that monocytes from patients with IPF appear to be hyperresponsive to CHI3L1 stimulation. These studies support targeting the CHI3L1-CRTH2 pathway as a promising therapeutic approach for IPF and that the sensitivity of blood monocytes to CHI3L1-induced profibrotic differentiation may serve as a biomarker that predicts responsiveness to CHI3L1- or CRTH2-based interventions.

Family Care Rituals in the ICU to Reduce Symptoms of Post-Traumatic Stress Disorder in Family Members-A Multicenter, Multinational, Before-and-After Intervention Trial.

OBJECTIVES: To assess the feasibility and efficacy of implementing "Family Care Rituals" as a means of engaging family members in the care of patients admitted to the ICU with a high risk of ICU mortality on outcomes including stress-related symptoms in family members. DESIGN: Prospective, before-and-after intervention evaluation. SETTING: Two U.S. academic medical ICU's, and one Italian academic medical/surgical ICU. SUBJECTS: Family members of patients who had an attending predicted ICU mortality of greater than 30% within the first 24 hours of admission. INTERVENTIONS: A novel intervention titled "Family Care Rituals" during which, following a baseline observation period, family members enrolled in the intervention phase were given an informational booklet outlining opportunities for engagement in care of the patient during their ICU stay. MEASUREMENTS AND MAIN RESULTS: Primary outcome was symptoms of post-traumatic stress disorder in family members 90 days after patient death or ICU discharge. Secondary outcomes included symptoms of depression, anxiety, and family satisfaction. At 90-day follow-up, 131 of 226 family members (58.0%) responded preintervention and 129 of 226 family members (57.1%) responded postintervention. Symptoms of post-traumatic stress disorder were significantly higher preintervention than postintervention (39.2% vs 27.1%; unadjusted odds ratio, 0.58; p = 0.046). There was no significant difference in symptoms of depression (26.5% vs 25.2%; unadjusted odds ratio, 0.93; p = 0.818), anxiety (41.0% vs 45.5%; unadjusted odds ratio, 1.20; p = 0.234), or mean satisfaction scores (85.1 vs 89.0; unadjusted odds ratio, 3.85; p = 0.052) preintervention versus postintervention 90 days after patient death or ICU discharge. CONCLUSIONS: Offering opportunities such as family care rituals for family members to be involved with providing care for family members in the ICU was associated with reduced symptoms of post-traumatic stress disorder. This intervention may lessen the burden of stress-related symptoms in family members of ICU patients.