Thrombopoietin receptor agonist (TPO-RA) treatment raises platelet counts and reduces anti-platelet antibody levels in mice with immune thrombocytopenia (ITP)

Summary, in English

Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder in which autoantibodies and/or autoreactive T cells destroy platelets and megakaryocytes in the spleen and bone marrow, respectively. Thrombopoietin receptor agonists (TPO-RA e.g. Romiplostim and Eltrombopag) have made a substantial contribution to the treatment of patients with ITP, which are refractory to first-line treatments and approximately 30% demonstrate sustained elevated platelet counts after drug tapering. How TPO-RA induce these sustained responses is not known. We analyzed the efficacy of a murine TPO-RA in a well-established murine model of active ITP. Treatment with TPO-RA (10 ug/kg, based on pilot dose escalation experiments) significantly raised the platelet counts in ITP-mice. Immunomodulation was assessed by measuring serum IgG anti-platelet antibody levels; TPO-RA-treated mice had significantly reduced IgG anti-platelet antibodies despite the increasing platelet counts. These results suggest that TPO-RA is not only an efficacious therapy but also reduces anti-platelet humoral immunity in ITP.

• Author: Rick Kapur; Rukhsana Aslam; Edwin R. Speck; Johan M. Rebetz; John W. Semple
• Department/s: Platelet Immunology
• Publishing year: 2020
• Language: English
• Pages: 399-402
• Publication/Series: Platelets
• Volume: 31
• Issue: 3
• Links: http://dx.doi.org/10.1080/09537104.2019.1624709
• Document type: Journal article
• Publisher: Taylor & Francis
• Topic: Hematology
• Keywords: Immune thrombocytopenia (ITP); immunomodulation; platelet antibodies; platelet counts; thrombopoietin receptor agonist (TPO-RA)
• Status: Published
• Research group: Platelet Immunology
• ISBN/ISSN/Other: ISSN: 0953-7104