. PPAR␥ agonists inhibit TGF-␤ induced pulmonary myofibroblast differentiation and collagen production: implications for therapy of lung fibrosis.

Objective Children undergoing cardiac surgery with cardiopulmonary bypass (CPB) are susceptible to additional inflammatory and immunogenic insults from blood transfusions. We hypothesize that washing red blood cells (RBC) and platelets transfused to these patients will reduce post-operative transfusion-related immune modulation and inflammation. Design Prospective randomized controlled clinical trial. Setting University hospital pediatric cardiac intensive care unit. Patients Children from birth to 17 years old undergoing cardiac surgery with CPB. Interventions Children were randomized to an unwashed or washed RBC and platelet transfusion protocol for their surgery and postoperative care. All blood was leukoreduced, irradiated, and ABO identical. Plasma was obtained for laboratory analysis: pre-op, immediately, six and 12 hours after CPB. Primary outcome was the 12-hour post-CPB interleukin (IL)-6: IL-10 ratio. Secondary measures were IL levels, C-reactive protein (CRP), and clinical outcomes. Measurements and main results 162 subjects were studied, 81 per group. 34 subjects (17 per group) did not receive any blood transfusions. Storage duration of blood products was similar between groups. Among transfused subjects, the 12-hour IL ratio was significantly lower in the washed group (3.8 v. 4.8; p=0.04) secondary to lower IL-6 levels (post-CPB: 65 v.100 pg/ml; p = 0.06; 6 hour: 89 v.152 pg/ml; p = 0.02; 12-hour: 84 v.122 pg/ml; p = 0.09). Post-operative CRP was lower in subjects receiving washed blood (38 v. 43 mg/L; p = 0.03). There was a numerical, but not statistically significant decrease in total blood product transfusions (203 v. 260) and mortality (2 v. 6 deaths) in the washed group compared to the unwashed group. Conclusions Washed blood transfusions in cardiac surgery reduced inflammatory biomarkers, number of transfusions, donor exposures, and were associated with a non-significant trend towards reduced mortality. A larger study powered to test for clinical outcomes is needed to determine whether these laboratory findings are clinically significant.

Infants undergoing cardiac operation can be managed with a conservative RBC transfusion strategy. Clinical indications should help guide the decision for RBC transfusion even in this uniquely vulnerable population. Larger multicenter trials are needed to confirm these results, and focus on the highest risk patients would be of great interest.

rs12252 was not associated with susceptibility to influenza-related critical illness in children or with critical illness severity. Our data also do not support it being a splice site.