Study Of The Correlation Between Tumor Necrosis Factor α And Coronary Artery Lesion In Kawasaki Disease

Kawasaki disease (KD) is an acute vasculitis of childhood, manifested by fever and signs of mucocutaneous inflammation. Cardiovascular lesion, especially coronary artery lesion is main complication of KD. Coronary artery aneurysm or stenosis are the most critical complications. It's the major death cause and has a long-term impact to the children suffered from KD. Therefore, the study of developmental mechanism of coronary artery lesion in Kawasaki disease appears to be of great importance.KD involves an immune-mediated inflammatory process that leads to endothelial cell damage, and may cause potentially fatal coronary artery aneurysms. Tne immunoregulatory changes in KD are evidenced by an increase in serum levels of cytokines, such as tumor necrosis factor (TNF-α). The cytokines takes an important role in immunologic mechanism of KD, especially in those combined with coronary artery lesion.TNF-α is a proimflammatory cytokine that acts as a potent immune mediator in many infectious and autoimmune diseases. Many polymorphisms, including single nucleotide polymorphisms(SNPs), are present in the TNF gene cluster.Since TNF-α promoter polymorphisms have been associated with various autoimmune and infectious diseases, we study the possible genetic influence on the expression of TNF-α in KD patients by examining the serum levels of TNF-α, TNF-α mRNA level in PBMC and the romoter polymorphisms at positions -308 and -238. This study is aimed to investigate the genetic association of TNF-alpha romoter polymorphisms in patients with KD, and to explore possible associations with clinical manifestations of the disease, especially in those combined with coronary artery lesion.Part 1Study of expression of tumor necrosis factor a in peripheral blood and coronary artery lesion in Kawasaki diseaseObjective:To investigate the correlation among the regulation of tumor necrosis factor a at serumal and transcriptional level; the onset of KD and the complicating coronary artery lesion. Methods:1. To measure the difference of blood serum concentration of tumor necrosis factor a and soluble tumor necrosis factor receptor (STNFR) I between 40 children affected by KD and 40 normal children as control group by ELISA.2. To detect the expression of tumor necrosis factor a in peripheral blood mononuclear cell at mRNA level by comparison of 40 children affected by KD with 40 normal children as control group by real-time fluorescence quantitative polymerase chain reaction technology.Results:1. Serumal concentration of tumor necrosis factor α(TNF-α) and soluble tumor necrosis factor receptor (sTNFR) I in KD group is significantly higher than control group(P<0.01); the serumal conentration of TNF-α in CAL subgroup is higher than lesion free subgroup (P<0.05) and significantly higher than control group (P<0.01).2..Strong correlation has been shown between serumal concentration of TNF-α and STNFR I (P<0.05).3.. The mRNA expression level of TNF-α in peripheral blood mononuclear cell in KD group is higher than control group (P<0.05); expression level in CAL subgroup is higher than lesion free subgroup(P<0.05) and significantly higher than control group (P<0.01).4. The mRNA expression level of TNF-α in peripheral blood mononuclear cell has no significant correlation with peripheral blood leukocyte, volume of packed red cells, thrombocyte, C-reaction protein nor erythrocyte sedimentation rate (P>0.05). But it has significant correlation with Harada score (P<0.01).5.There exists strong correlation relationship among the mRNA expression level of tumor necrosis factor a in peripheral blood mononuclear cell, the serumal concentration of tumor necrosis factor a and concentration of soluble tumor necrosisfactor receptor (STNFR) I (P<0.05). Conclusions:1. The serumal concentration of tumor necrosis factor a and soluble tumor necrosis factor receptor (STNFR) I are There exists a linear correlation relationship between them which suggested tumor necrosis factor participate the development of coronary artery lesion in KD.3. The expression of tumor necrosis factor a in peripheral blood mononuclear cell at mRNA level is predominantly elevated in KD, especially those combined with coronary artery lesion. This elevation has a linear correlation relationship with the serumal concentration of tumor necrosis factor a and STNFR I. Those three mentioned above complement and affect each other in the developmental mechanism of coronary artery lesion in KD.Part 2 Study of the correlation between genic polymorphism of tumor necrosis factor a and coronary artery lesion in Kawasaki diseaseObjective:To investigate the correlation among G/A mononucleotide polymorphism at -308 site and -238 genic site of tumor necrosis factor a, the onset of KD and the complicating coronary artery lesion. Method:To confirm the mutational sites at -308 site and -238 genic site of tumor necrosis factor a in 100 children affected by KD and another 100 as control group, respectively. Results:1 .Allele frequency of tumor necrosis factor a at -308 site in KD group has no significant difference compared to control group(P>0.05). Allele frequency in CAL group has significant difference compared to both lesion free group and control group(P<0.05).2.The degree of thrombocyte increment and albumin decrement in children who carry tumor necrosis factor a -308 site A allele is more predominant compared tothose with G allele.3.Allele frequency of tumor necrosis factor a at -238 site in KD group has no significant difference compared to control group(P>0.05). Allele frequency in CAL group also has no significant difference compared to both lesion free group or control group(P<0.05).4.Clinical manifestation and laboratory findings in children who carry tumor necrosis factor a -238 site A allele has no significant difference compared to those with G allele (P>0.05).5. Expression level of tumor necrosis factor a in peripheral blood mononuclear cell at mRNA level in children who carry tumor necrosis factor a -308 site A allele is higher than those with G allele (P<0.05). Conclusion:1. The A allelomorphic gene at -308 genic site of tumor necrosis factor a possibly participate the coronary artery lesion in KD.2. The A allelomorphic gene at -238 genic site of tumor necrosis factor a has no significant correlation with KD or coronary artery lesion in KD.3. The G/A mutation at -308 genic site of tumor necrosis factor a take a regulate and control action to tumor necrosis factor a at transcriptional level.SummaryGenic polymorphism of tumor necrosis factor a is not only correlated with the susceptibility of KD but also the procedure of coronary artery lesion. Due to variation at transcriptional level and an influence of expression amount caused by TNF α genic polymorphism, tumor necrosis factor takes part in the patho-physiologic procedure of KD directly or indirectly. TNF genic polymorphism, especially G/A SNP at -308 site can be considered as genetic mark of KD susceptibility. With advancement in the study of TNF genic polymorphism and KD susceptibility, we are sure to make huge progress to the recognition and understanding of etiologic and pathophysiologic aspects of KD.