Photo Credit: Iván Jesús Cruz Civieta
The following is a summary of “Expansion effect of romiplostim on hematopoietic stem and progenitor cells versus thrombopoietin and eltrombopag,” published in the September 2024 issue of Hematology by Tezuka et al.
Romiplostim, a thrombopoietin (TPO) receptor agonist, is approved for treating patients with refractory aplastic anemia and idiopathic thrombocytopenic purpura. Still, the mechanism of action and differences from other TPO receptor agonists remain unclear.
Researchers conducted a retrospective study comparing the expansion effect of romiplostim versus recombinant human TPO (rhTPO) and eltrombopag on human CD34+ hematopoietic stem and progenitor cells (HSPCs).
They compared the in vitro expansion effect of romiplostim on CD34+ HSPCs to rhTPO and eltrombopag, performing single-cell RNA sequencing (RNA-seq) to determine romiplostim’s molecular effects on CD34+ HSPCs at the single-cell level.
The results showed that romiplostim’s maximum expansion effect on total CD34+ cells, CD34+CD38+ progenitor cells, and CD34+CD38− immature cells was comparable to rhTPO and greater than eltrombopag, especially in CD34+CD38− immature cells. Single-cell RNA-seq analysis indicated romiplostim and eltrombopag both induced rhTPO-driven signatures. However, romiplostim induced unique molecular changes in primitive HSPC subsets related to RHOA signaling that were either partially or not caused by eltrombopag. Romiplostim did not induce TFRC expression, unlike eltrombopag.
They concluded that romiplostim expanded and affected human HSPCs similarly to rhTPO but exhibited distinct differences from eltrombopag in gene expression patterns.
Source: link.springer.com/article/10.1007/s12185-024-03853-6
