Avaliação dos níveis de interleucina-8 e ativação do fator de transcrição nuclear NF–KB em pacientes portadores de síndromes mielodisplásicas

Abstract

The pathogenesis of myelodysplastic syndromes (MDS) is complex and multifactorial and depends on the interaction between hematopoietic cells and their microenvironment. The definite pathogenetic mechanisms are still not fully understood. Objectives: (a) To evaluate CXC chemokine ligand 8 (CXCL8 or IL-8) plasma levels and nuclear transcription factor kappa B activation (NF-kB) in patients with MDS and the possible associations with clinicopathologic variables. (b) To test possible correlation between IL-8 and NF-kB. Patients and methods: A total of 25 adults de novo MDS patients (4 RARS, 16 RCDM, 1 RAEB-I, 4 RAEB-II) were analyzed according to WHO classification and IPSS-R. Sex and age-matched healthy elderly volunteers were included as controls. IL-8 analysis was performed by Enzyme Linked ImmunoSorbent Assay kit BD OptEIA and DNA binding activity of NF-kB p65 was measured using TransAM NF-kB p65 kits®. Results: MDS patients showed higher level of IL-8 when compared to controls(p=0,0068). Patients aged 75 and above also showed significant higher levels (p=0,0357). No significant associations were found between level of IL-8 and the variables analyzed. NF-kB activity was significantly elevated in MDS patients when compared to controls (p<0,0001) and higher in patients older than 75 years(p=0,0475). NF-kB activity was significantly associated with higher serum ferritin (p=0,042) and higher percentage of blasts (p=0,0282). The study of correlation between IL8 and NF-kB showed a significant positive correlation (r=0.480; p=0.015). Discussion and conclusions: Many unraveled specific pathways involved in the complex pathophysiology of MDS have been recently described, including aberrations in cytokines and their signaling pathways. In this study elevated levels of IL-8 and NF-kB were demonstrated and an elevated NF-kB activity was significantly associated with higher serum ferritin and with blast excess, two markers of bad prognosis. A significant positive correlation between IL-8 and NF-kB was detected, corroborating the emerging concept of the important role of the niche and deregulated inflammatory signaling in MDS phenotype. The best comprehension of these mechanisms favors defining new targets for therapy.