IRF4 and IRF8 expression are associated with clinical phenotype and clinico-hematological response to hydroxyurea in essential thrombocythemia

Prognostic characteristics of immune subtypes associated with acute myeloid leukemia and their identification in cell subsets based on single-cell sequencing analysis

Immune genes play an important role in the development and progression of acute myeloid leukemia (AML). However, the role of immune genes in the prognosis and microenvironment of AML remains unclear. In this study, we analyzed 151 AML patients in the TCGA database for relevant immune cell infiltration. AML patients were divided into high and low immune cell infiltration clusters based on ssGSEA results. Immune-related pathways, AML pathways and glucose metabolism pathways were enriched in the high immune cell infiltration cluster. Then we screened the differential immune genes between the two immune cell infiltration clusters. Nine prognostic immune genes were finally identified in the train set by LASSO-Cox regression. We constructed a model in the train set based on the nine prognostic immune genes and validated the predictive capability in the test set. The areas under the ROC curve of the train set and the test set for ROC at 1, 3, 5 years were 0.807, 0.813, 0.815, and 0.731, 0.745, 0.830, respectively. The areas under ROC curve of external validation set in 1, 3, and 5 years were 0.564, 0.619, and 0.614, respectively. People with high risk scores accompanied by high TMB had been detected with the worst prognosis. Single-cell sequencing analysis revealed the expression of prognostic genes in AML cell subsets and pseudo-time analysis described the differentiation trajectory of cell subsets. In conclusion, our results reveal the characteristics of immune microenvironment and cell subsets of AML, while it still needs to be confirmed in larger samples studies. The prognosis model constructed with nine key immune genes can provide a new method to assess the prognosis of AML patients.

IRF4 expression is low in Philadelphia negative myeloproliferative neoplasms and is associated with a worse prognosis

Interferon regulatory factor 4 (IRF4) is involved in the pathogenesis of various hematologic malignancies. Its expression has been related to the negative regulation of myeloid-derived suppressor cells (MDSCs) and the polarization of anti-inflammatory M2 macrophages, thereby altering immunosurveillance and inflammatory mechanisms. An abnormal inflammatory status in the bone marrow microenvironment of myeloproliferative neoplasms (MPNs) has recently been demonstrated; moreover, in chronic myeloid leukemia a downregulated expression of IRF4 has been found. In this context, we evaluated the IRF4 expression in 119 newly diagnosed consecutive Philadelphia negative MPNs (Ph- MPNs), showing a low expression among the MPNs phenotypes with a more significant decrease in primary myelofibrosis patients. Lower IRF4 levels were associated with JAK2 + and triple negatives cases carrying the worst prognosis. Furthermore, the IRF4 levels were related to leukemic transformation and a shorter leukemia-free survival; moreover, the risk of myelofibrosis transformation in polycythemia vera and essential thrombocythemia patients was more frequent in cases with lower IRF4 levels. Overall, our study demonstrates an IRF4 dysregulated expression in MPNs patients and its association with a worse prognosis. Further studies could validate these data, to improve our knowledge of the MPNs pathogenesis and confirm the IRF4 role as a new prognostic factor.