Fatores Reguladores de Interferon (IRFs) em pacientes com Síndrome Mielodisplásica

Abstract

Myelodysplastic Syndrome (MDS) is characterized by peripheral cytopenias, defects in hematopoiesis, increased apoptosis and intramedullary risk of transformation to AML. Various advances have been made in understanding the pathogenesis of MDS and there is evidence that bone marrow failure that occurs in MDS is mediated by abnormal activation of signaling in the innate immune system. Interferon regulatory factors (IRF-Interferon Regulatory Factor) form a family of transcription factors that play a central role in regulating immune responses, differentiation and proliferation of hematopoietic cells, cell cycle regulation, apoptosis, and oncogenesis. It is believed that IRFs may have an important role in the pathogenesis of MDS. Therefore, the objective of this study was to evaluate the profile of methylation and gene expression of IRFs in bone marrow (BM) of patients with MDS. From samples of 119 patients diagnosed with MDS was conducted the study of gene expression by real-time PCR and methylation by QMSP (quantitative methilation specific PCR) of the nine family members of IRFs. The expression of genes IRF2, IRF3, and IRF7 IRF8 were different between BM cells of MDS patients and healthy individuals (P = 0.002, 0.002, 0.028 and 0.016, respectively). IRF1 a higher level of expression was associated in patients with hypocellular marrow (p = 0.018). The IRF3, and IRF7 IRF8 genes have been associated with patients in peripheral blood cytopenias (p = 0.028; 0.001; 0.008, respectively). Furthermore, methylation of IRF1, IRF2, IRF3, IRF6 and IRF8 was associated with higher risk characteristics in SMD, such as advanced forms, unfavorable karyotype, cytopenias, blast above 5% and high-risk categories established by IPSS, IPSS-R and WPSS. Multivariate analysis revealed that patients with higher expression of IRF3 had higher overall survival (p = 0.001), whereas patients with higher expression of IRF5 had 5.4 more likely to progress to AML (p <0.001 95% CI = 1098-26829 ) and 9 times more likely to come to death (p = 0.001, 95% CI 2.39 to 32.69). Ambiguously, patients with methylated IRF5 had 4 times more likely to come to death (p = 0.041, 95% CI 1.066 to 20,192). We can conclude that the expression and methylation of IRFs can have great impact prognosis in this disease. The expression of IRF3 is a favorable prognostic marker, while expression and methylation IRF5 are unfavorable prognostic markers in MDS.