[A prospective study of the efficacy and safety of maintenance therapy with recombinant human thrombopoietin in patients with primary immune thrombocytopenia: a multicenter study]

Risk of thrombotic events in immune thrombocytopenia patients treated with thrombopoietic agents: a systematic review and meta-analysis

BACKGROUND

Immune thrombocytopenia (ITP), which is a well-known hemorrhagic disorder characterized by low platelet counts, has been shown to be associated with the risk of thrombosis. Thrombopoietic agents (TAs) are extensively used as second-line treatments for ITP, effectively reducing the risk of hemorrhage. However, thrombosis, a potential adverse effect of TAs, raises clinical challenges.

METHODS

The MEDLINE(PubMed), Embase, and the Cochrane Library databases were systematically searched for relevant studies, including both single-arm trials and randomized controlled trials (RCTs), without language restrictions.

RESULTS

A total of 17 RCTs comprising 2,105 patients and 29 single-arm trials comprising 3,227 patients were included. In the single-arm meta-analysis, the pooled rate of overall thrombotic events in ITP patients receiving TAs was 2.2% (95% CI 1.0% - 3.7%). In RCTs, a higher incidence of thrombosis (33/1425 vs. 4/680) and higher risk ratios (RR) of overall, arterial, and venous thrombotic events (1.73, 95% CI [0.88, 3.39], P = 0.113; RR 1.98, 95% CI [0.80, 4.92], P = 0.141; RR 1.06, 95% CI [0.46, 2.41], P = 0.895, respectively) were observed in the TAs group than in the control group, although the differences were not significant. Subgroup analysis demonstrated that hetrombopag was the only TA with no increased thrombotic risk (rate 0.3% 95% CI [0.0 - 1.5%]; RR 0.76, 95% CI [0.03, 18.41], P = 0.864) compared to eltrombopag, avatrombopag, romiplostim, and rhTPO. Subgroup analyses also revealed that ITP patients with advanced age (3.7% vs. 1.3%, P = 0.132) or with a thrombotic history (3.0% vs. 1.4%, P = 0.257), and patients who received TAs therapy for a long duration (4.7% vs. 0.1%, P < 0.001) had an increased risk of thrombosis.

CONCLUSION

Our findings suggest ITP patients treated with TAs have a nonsignificantly higher risk of overall, arterial, and venous thrombotic events. Furthermore, hetrombopag is the recommended TA to avoid thrombophilia. Patients receiving long-term TAs, as well as elderly ITP patients or those with a history of thrombosis, face an increased thrombotic risk. In general, clinicians should consider potential thrombotic risks, address underlying risk factors, and ensure ongoing monitoring and follow-up when treating ITP patients with TAs.

Combination of two target agonists of the thrombopoietin and thrombopoietin receptor in the treatment of elderly patients with refractory immune thrombocytopenia

Immune thrombocytopenia (ITP) is common in the elderly. Because of the coexistence of multiple diseases, there are many reservations regarding corticosteroid use in the elderly. Thrombopoietin (TPO) and its analogs can promote platelet production, but it is often difficult to correct TP in a short period. Recombinant human TPO (rh-TPO) acting on the cell membrane and the small-molecule TPO-receptor (MPL) agonist acting on the transmembrane receptor may have synergistic effects and accelerate platelet production because of different sites of action in the signaling pathway. In this study, two elderly patients with refractory ITP were successfully treated with two TPO-MPL signaling pathway agonists: recombinant human thrombopoietin (rh-TPO) and eltrombopag. This combination is safe with rapid and lasting effects. However, in elderly patients with refractory, recurrent, and glucocorticoid contraindications, the combination of different TPO agonists' clinical efficacy and adverse reactions needs to be further evaluated.