Cytokines as plasma markers of abdominal aortic aneurysm

The pathogenesis of abdominal aortic aneurysms (AAA) is a complex process i n which atherosclerosis and inflammation play a leading role. Cytokines are important mediators of both processes. The aim of our study was to determi ne whether plasma levels of cytokines which are most involved in AAA pathog enesis can be used as endogenous markers of AAA development, and thus to fa cilitate the decision on surgical intervention in cases when this is clinic ally unclear (e.g. small AAA). In the prospective study a total of 90 patients with AAA were examined. The se patients were divided into the following groups according to symptoms an d AAA diameter: symptomatic AAAs, including ruptures (n=16); asymptomatic A AAs (n=74); AAAs with a diameter of up to 5 cm (n=30), AAAs of 5-8 cm (n=38 ), and AAAs with a diameter over 8 cm (n=22). The average age of the patien ts was 70.7 (56-82) years. The male to female ratio was 4:1 (71:19). A cont rol group consisted of 30 healthy individuals of similar age and sex presen tation with no manifestation of atherosclerosis, Plasma levels of cytokines were assessed in venous blood by means of radio- or enzymo-immunoassay. St atistical processing of the results was conducted with ANOVA and Wilcoxon t ests with Spearman correlation, where p<0.05 was considered to be statistic ally significant. Plasma concentrations of cytokines were significantly higher in AAA patient s than in healthy individuals. In AAA patients the tumour necrosis factor-< alpha> (TNF-alpha) and interleukin (IL-8) levels were low in large and in s ymptomatic AAAs. IL-6 levels were increased with increasing AAA diameter an d symptoms. IL-8 levels (p<0.05) showed a statistically significant correla tion with the diameter, and TNF-<alpha> (p<0.05) with the symptoms of AAA. IL-1<beta>, IL-2 and IL-6 did not show any significant changes with differe nt AAA diameter or symptomatology. In Conclusion: IL-8 end TNF-alpha can be used as endogenous markers of the process of AAA development, in deciding for either surgical or endovascular treatment of patients when the clinical indication is not entirely clear.