MiR-181a and -b expression in acute lymphoblastic leukemia and its correlation with acute graft-versus-host disease after hematopoietic stem cell transplantation, COVID-19 and torque teno viruses

Acute lymphoblastic leukemia (ALL), a malignant transformation and proliferation of the lymphoid line of blood cells, is characterized by chromosomal abnormalities and genetic changes. The purpose of this research was the evaluation of expression level of miR-181a and -b in patients with ALL compared to the control group. Furthermore, we examined their expression level in hematopoietic stem-cell transplantation (HSCT) patients who developed acute graft-versus-host disease (aGVHD) in comparison with those without aGVHD and explore the relationship between their expression level and cytogenetic abnormalities. In this cross-sectional study, 76 newly diagnosed adult De novo ALL patients were enrolled who were admitted to our referral hospital. All patients received standard chemotherapy, consisting of daunorubicin. A total of 37 patients underwent HSCT from the related human leukocyte antigen-matched donors. ALL patients have been diagnosed with the coronavirus disease 2019 (COVID-19) and Torque teno viruses (TTVs). We assessed the expression levels of miR-181a and -b in the peripheral blood sample of ALL patients at the time of diagnosis prior to chemotherapy, and healthy matched individuals by RT–PCR. TTVs and COVID-19 load were also determined via RT–PCR. In conclusion, the expression level of miR-181a and -b were significantly higher in ALL patients than healthy controls and also increased in patients who developed aGVHD in comparison with those without aGVHD. MiR-181a and -b can be a useful biomarker in ALL and a useful indicator of aGVHD. The expression level of miR-181a in ALL patients with COVID-19 is significantly up-regulated, while it is reduced in these patients with TTV.