David Langlais

What is the current knowledge on the topic? ○ Low dose-methotrexate (LD-MTX) regulates the function of key cells involved in rheumatoid arthritis (RA) pathogenesis (e.g., T cells, macrophages, neutrophils, endothelial cells and fibroblast-like synoviocytes) and, through the activation of multiple pathways, contributes to the suppression of inflammation in RA. ○ Inflammatory signaling impacts hematopoiesis by regulating hematopoietic stem and progenitor cells (i.e., HSPC, CD34+ cells).

Abstract Low dose methotrexate (LD-MTX) remains the gold standard in rheumatoid arthritis (RA) therapy. Multiple mechanisms on a variety of immune cells contribute to the anti-inflammatory effects of LD-MTX. Inflammatory signaling is deeply implicated in hematopoiesis by regulating hematopoietic stem and progenitor cell (HSPC) fate decisions; raising the question of whether HSPC are also modulated by LD-MTX. This is the first study to characterize the effects of LD-MTX on HSPC.

Conflicts of Interest The authors declare no conflicts of interest. References 1 World Malaria Report 2021. (Geneva: World Health Organization), 2021. Licence: CC BY-NC-SA 3.0 IGO. 2 WHO, “Neglected Tropical Diseases,” 2022 https://www.who.int/health-topics/neglected-tropical-diseases#tab=tab_1. 3, , and , “Plasmodium falciparum Resistance to ACTs: Emergence, Mechanisms, and Outlook,” International Journal for Parasitology: Drugs and Drug Resistance 16 (2021): 102–118.