Abstract: Abstract］  ObjectiveTo detect the expression of Tolllike receptor 4（TLR4）, Myeloid differentiation factor 88（MyD88）and nuclear factorκB p65（NFκB p65） in cholesterol pneumonia foam cells, and to investigate their roles and relationship in the occurrence of cholesterol pneumonia and clinical significance. MethodsThe expression of TLR4, MyD88 and NFκB p65 in 45 cases of foam cells of cholesterol pneumonia and 25 cases of macrophages of usual pneumonia without the aggregation of foam cells(control groups) from surgically resecting specimens of lung that was confirmed by pathology was immunohistochemically studied. ResultsThe strong positive rate of MyD88 and NFκB p65, as well as the positive rate of TLR4, was obviously higher than that in the control(P＜005) The positive expression of TLR4,MyD88 and NFκB p65 was not related with sex(P＞005).The expression rate of TLR4,MyD88 and NFκB p65 in patience below 50 was more significant higher than the patience above 50(P＜005). Among the 45 cases of cholesterol pneumonia , there were apparently positive correlation between TLR4 and MyD88, TLR4 and NFκB, NFκB p65 and MyD88(r=0.467, 0.523,  0.491, P＜005),as well as the positive correlation. ConclusionThe expression of TLR4, MyD88 and NFκB p65 may be involved in pathogenesis of cholesterol pneumonia presenting their synergistic effect in cholesterol pneumonia, which was not related to the sex but age. With the increase in age of the cholesterol pneumonia, the positive rate of TLR4, MyD88 and NFκB p65 was decreased.

Key words: cholesterol pneumonia, Tolllike receptor 4, myeloid differentiation factor 88, NFkappa B