ABSTRACT
Background: Non-Hodgkin lymphoma (NHL) is the eleventh leading cause of cancer-related death in the world. Diffuse large B-cell lymphoma (DLBCL) is the most common type of NHL. Up to winter 2021-2022, the death toll caused by the coronavirus disease 2019 (COVID-19) has exceeded 5.6 million worldwide. Possible molecular mechanisms involved in the systemic inflammation, and cytokine storm in COVID-19 patients are still not fully understood. MicroRNA-155 (miR-155) plays a role in the post-transcriptional gene regulation of hematopoiesis, oncogenesis, and inflammation. The present study aimed to evaluate the expression of miR-155 in patients with DLBCL and/or COVID-19. Methods: A cross-sectional study was conducted from July to December 2020 in Tehran (Iran) to evaluate the expression of miR-155 in adult patients diagnosed with DLBCL and/or COVID-19. The real-time polymerase chain reaction technique was used to evaluate the expression of miR-155 in the sera of 92 adults who were either healthy or suffering from DLBCL and/or COVID-19. Relative quantification of gene expression was calculated in terms of cycle threshold (Ct) value. Data were analyzed using SPSS software, and P<0.05 was considered statistically significant. Results: The expression of miR-155 was not associated with the sex or age of the participants. In comparison with healthy individuals (-ΔCt -1.92±0.25), the expression of miR-155 increased in patients with COVID-19 (1.95±0.14), DLBCL (2.25±0.16), or both (4.33±0.65). Conclusion: The expression of miR-155 increased in patients with DLBCL and/or COVID-19.