Avatrombopag for the salvage treatment of platelet transfusion refractoriness

Observation on the efficacy of TPO receptor agonists and platelet transfusion in chemotherapy-induced thrombocytopenia in malignant tumors

OBJECTIVE

To observe the clinical efficacy of TPO receptor agonists and platelet transfusion in chemotherapy-induced thrombocytopenia in malignant tumors.

METHODS

Clinical data from 120 patients with malignant tumors who developed thrombocytopenia following chemotherapy at our hospital were retrospectively collected and randomly divided into three groups: A, B, and C, with 40 patients in each group. Group A was treated with a TPO receptor agonist (avatrombopag), group B received autologous platelet transfusion, and group C received a combination of both treatments. The clinical efficacy of the three groups was compared, including platelet levels at different time points during treatment, platelet recovery time (time to reach < 50 × 109/L, ≥ 75-100 × 109/L, and ≥ 100 × 109/L), changes in serum cytokine levels (PF4, TPO, vWF) before and after treatment, and fluctuations in coagulation function indicators (APTT, PT, FIB) before and after treatment to analyze the effectiveness of each treatment regimen.

RESULTS

About clinical efficacy, the effectiveness in group A was comparable to that in group B (P > 0.05), while the effective rate in group C was significantly higher than that in groups A and B (P < 0.05). Regarding platelet counts, repeated measures analysis of variance showed significant differences in the time effect, group effect, and interaction effect for platelet counts (PLT) among the three groups (P < 0.05). Concerning platelet recovery time, the time to reach PLT < 50 × 109/L, the time to recover to 75-100 × 109/L, and the time to recover to ≥ 100 × 109/L were similar in groups A and B (P > 0.05). However, the time for these parameters in group C was significantly shorter than in groups A and B (P < 0.05). In terms of changes in platelet parameters, post-treatment levels of PF4, TPO, and vWF in all three groups were significantly higher than pre-treatment levels. The PF4, TPO, and vWF levels in groups A and B were similar (P > 0.05), whereas group C had significantly higher levels compared to groups A and B (P < 0.05). Regarding coagulation indices, post-treatment levels of APTT and PT decreased, while FIB levels increased in all three groups (P < 0.05). There were no significant differences in APTT and FIB levels between groups A and B (P > 0.05). However, group C had significantly lower APTT and higher FIB levels compared to groups A and B (P < 0.05). There were no significant differences in PT levels among the three groups post-treatment (P > 0.05).

CONCLUSION

Autologous platelet transfusion and TPO receptor agonists are effective clinical methods for treating chemotherapy-induced thrombocytopenia. The combined use of both treatments yields better therapeutic results.

Thrombopoietin improves the functions of bone marrow endothelial progenitor cells via METTL16/Akt signalling of haematological patients with chemotherapy-induced thrombocytopenia

Bone marrow endothelial progenitor cells (BM EPCs) are crucial in supporting haematopoietic regeneration, while the BM EPCs of haematological patients with chemotherapy-induced thrombocytopenia (CIT) are unavoidably damaged. Therefore, the present study aimed to examine the effect of thrombopoietin (TPO) on the recovery of BM EPCs of CIT patients and to identify the underlying mechanisms. The cell functions were determined by 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (Dil)-acetylated low-density lipoprotein (Dil-Ac-LDL) uptake and fluorescein isothiocyanate (FITC)-labeled Ulex europaeus agglutinin-I (FITC-UEA-I) binding assay, as well as proliferation, migration and tube formation experiments. Endothelial cells were transfected with METTL16 lentivirus, followed by methylated RNA immunoprecipitation sequencing. Zebrafish with vascular defect was used as the in vivo model. TPO significantly improved the quantity and functions of BM EPCs from CIT patients in vitro and restored the subintestinal vein area of zebrafish with vascular defect in vivo. Mechanically, TPO enhanced the BM EPC functions through Akt signal mediated by METTL16, which was downregulated in BM EPCs of CIT patients and involved in the regulation of endothelial functions. The present study demonstrates that TPO improves the recovery of BM EPCs from CIT patients with haematological malignancies via METTL16/Akt signalling, which provides new insights into the role of TPO in treating CIT in addition to direct megakaryopoiesis.