Effect of hemofiltration combined with hemoperfusion on serum TNF-α in severe acute pancreatitis patients with lung injury and on RhoA serine 188 phosphorylation in endothelial cells

Abstract

Objective To study the effect of hemofiltration plus hemoperfusion(HF+HP) on removal of serum TNF-α in severe acute pancreatitis(SAP) patients with lung injury and on RhoA serine 188 phosphorylation(p-RhoA) in endothelial cells.MethodsTotally 35 SAP patients,including 28 with acute lung injury(ALI)/ acute respiratory distress syndrome(ARDS),and 20 healthy subjects were involved in this study.All the SAP patients were treated in ICU,and the 9 combined with ARDS underwent continuous veno-venous hemofiltration(CVVH) and HP therapy(HF+HP group).The serum TNF-α in SAP patients with different degrees of lung injury and the serum TNF-α in SAP patients with ARDS was determined by ELISA at different time points during HF+HP.For in vitro study the human umbilical vein endothelial cells(HUVECs) were treated with sera from SAP patients with ARDS during HF+HP,and those treated with recombinant TNF-α were taken as a positive control.The changes of p-RhoA and total RhoA were observed by Western blotting analysis.Subcellular distribution of p-RhoA protein was observed by immunofluorescence staining.ResultsWe found that,compared with SAP patients without ALI/ARDS,those with ALI/ARDS,especially those with ARDS(about 7 folds that of the normal control) had a significantly increased serum TNF-α level(P 0.05).The serum TNF-α level began to decrease in the 9 SAP patients with ARDS 6 h after HF+HP treatment,with the decrease reached maximal 20 h after treatment,closing to the level of the normal control group.Meanwhile,the arterial blood PaO2,HCO3-and PaO2/FiO2 ratio were significantly elevated after HF+HP treatment in SAP patients with ARDS(P 0.05).Western blotting analysis showed that p-RhoA level was significantly increased in HUVECs treated with the serum of HF+HP-treated SAP patients with ARDS(P 0.05),and the total RhoA protein expressions were not significantly different among different groups(P 0.05).Immunofluorescence indicated that p-RhoA was largely distributed in the cytoplasm of HUVECs,and the changes were consistent with the data from Western blotting analysis.ConclusionSAP patients with ALI/ARDS have high circulation TNF-α.Treatment with HF+HP can effectively remove the excessive TNF-α in the blood of SAP patients with ALI/ARDS and inhibit activation of RhoA,subsequently decreasing the high permeability of endothelial cells.