Thrombopoietin receptor agonists (TPO-RAs) are approved for immune thrombocytopenia (ITP), but their impact on health-related quality of life (HRQoL) remains poorly investigated in clinical practice. This observational study aimed to gain insight into real-world patient-reported experiences of the burden of ITP and TPO-RAs.
Citation: Rovó A, Cantoni N, Samii K, Rüfer A, Koenen G, Ivic S, et al. (2022) Real-world impact of primary immune thrombocytopenia and treatment with thrombopoietin receptor agonists on quality of life based on patient-reported experience: Results from a questionnaire conducted in Switzerland, Austria, and Belgium. PLoS ONE 17(4): e0267342.
primary immune thrombocytopenia pdf free
Download: https://shurll.com/2vCzVa
Patients could select a single response per statement. Data are presented as the proportion of patients per category for each statement (N = 46 for all figures). Abbreviation: ITP, immune thrombocytopenia.
Primary immune thrombocytopenia targets platelets, marks them as foreign by the immune system causing them to be eliminated in the spleen and sometimes, the liver. ITP is defined by a platelet count lower than 100,000 per microliter of blood with no other reason for low platelets.
Only a very small percent of babies born to mothers with primary ITP have low platelets at birth; there are no reports that women with gestational thrombocytopenia deliver newborns with low platelet counts. Attempting to measure the platelet count of the fetus carries significant risk, so it is not advised. However, a cord blood count can be safely completed after delivery.2
Fei Song,1,2 Hanny Al-Samkari2,3 1Department of Medicine, Massachusetts General Hospital, Boston, MA, USA; 2Harvard Medical School, Boston, MA, USA; 3Division of Hematology, Massachusetts General Hospital, Boston, MA, USACorrespondence: Hanny Al-SamkariDivision of Hematology, Massachusetts General Hospital, Suite 118, Room 112, Zero Emerson Place, Boston, MA, 02114, USATel +617-643-6214Fax +617-643-8840Email [email protected]Abstract: Immune thrombocytopenia (ITP) is an autoimmune process resulting in increased destruction and inadequate production of platelets that can result in bleeding, fatigue, and reduced health-related quality of life. While treatment is not required for many patients with ITP, the occurrence of bleeding manifestations, severe thrombocytopenia, and requirement for invasive procedures are among the reasons necessitating initiation of therapy. Corticosteroids, intravenous immunoglobulin, and anti-RhD immune globulin are typical first-line and rescue treatments, but these agents typically do not result in a durable remission in adult patients. Most patients requiring treatment therefore require subsequent line therapies, such as thrombopoietin receptor agonists (TPO-RAs), rituximab, fostamatinib, splenectomy, or a number of other immunosuppressive agents. In this focused review, we discuss management of adult ITP in the acute and chronic settings.Keywords: platelets, immune thrombocytopenia, ITP, treatment, corticosteroids, IVIG, splenectomy, thrombopoietin receptor agonist, rituximab, fostamatinib
Immune thrombocytopenia (ITP) is a complex and rare autoimmune disease characterized by reduced platelet counts (peripheral blood platelet count 12 months, more prevalent in adult patients) (2-4). This classification is important because patients with newly diagnosed and persistent ITP have significantly higher remission rates than patients with chronic ITP (2,5-8). Therefore, physicians usually recommend a more rigorous treatment plan for patients with chronic ITP, which is more predominant in adult patients (2).
Traditionally, platelet destruction in the spleen and/or liver, and less so in the periphery, is the main cause for low platelet counts in ITP. Antibody-coated platelets are destroyed by macrophages in the spleen and/or liver through interaction with Fc-gamma receptors (FcγR) (46) (Figure 1A). In the 1950s, Harrington infused blood from ITP patients to healthy volunteers, one of which was himself, and showed that most recipients demonstrated profound thrombocytopenia/low platelet counts (47). The transmissible causative factor in the blood serum was subsequently identified as an immunoglobulin, primarily immunoglobulin G (IgG), which was the first proof that a humoral factor is involved in ITP pathogenesis (48). Noteworthy, while the antiplatelet antibodies in ITP are primarily IgG, other immunoglobulin isotypes (IgA and IgM) can also be found (49). Anti-platelet antibodies are directed against platelet membrane glycoprotein (GP) or GP complexes mainly GPIIb/IIIa and GPIb/IX/V, and less against GPIa/IIa, IV or VI (49-52). As a result, anti-platelet antibodies targeting GPIIb/IIIa participate in platelet destruction when the platelets are opsonized by the attachment of autoantibodies to the GP, then bound to FcγRs expressed on macrophages, and phagocytosed (43,44). Following the phagocytosis, these macrophages present a platelet-derived antigen that stimulates CD4+ T cells, which can contribute in the activation of B cells (53). This activation leads to the differentiation of auto-reactive B cells into plasma cells to produce anti-platelet antibodies (53,54). While autoantibodies against platelet GP remains a major mechanism in the ITP pathogenesis, it is important to mention that these autoantibodies are not detected in almost half of patients with ITP, which suggest the involvement of other mechanisms (55). For instances, it has been shown that the immune platelet destruction in ITP is also associated with wide range of B-cell and T-cell involvement (46,56,57). In addition to removal of platelets by FcγR-mediated mechanisms, anti-GP1b/IX has an unusual activity where the antibody binds to platelets and removes sialic acid (58,59). These desialylated platelets are then removed through interaction with the Ashwell-Morell receptor on hepatocytes in the liver (60). This interaction results in production of the platelet growth factor, thrombopoietin (TPO), likely as a feed-back mechanism in an effort to produce more platelets. CD8+ cytotoxic T lymphocytes (CTLs) also plays a role in ITP and can directly kill platelets and megakaryocytes and/or induce desialylated platelets (61,62) (Figure 1A).
IVIg has been used for more than 40 years to treat ITP, initially used to treat primary immunodeficient patients and then later approved to be used to treat several autoimmune diseases and other conditions, including ITP (127-133). In ITP, IVIg is generally considered an effective and safe treatment option as high-quality evidences showed its favorable immunomodulatory effects (134,135). Although the mechanisms of actions of IVIg are complex and still unclear, there are several mechanisms that have been proposed and extrapolated (discussed in further detail below); but most of these mechanisms are extrapolated based on animal models. Nevertheless, in humans, it has been revealed that IVIg plays a role in increasing the platelet lifespan in vivo by reducing the splenic clearance of platelets (136), via Fc-dependent mechanism (6,137).
J.B.B. reports the following disclosures: consultant at CSL Behring (intravenous immunoglobulin manufacturer), UCB, Argenx, Momenta/Janssen (manufacturers of neonatal Fc receptor [FcRn] inhibitors), and Rallybio (company interested in screening and prophylaxis of fetal and neonatal alloimmune thrombocytopenia [FNAIT]) and Data Safety Monitoring Board at CSL Behring. R.L.B. reports the following disclosures: Momenta/Janssen (manufacturers of FcRn inhibitors) and Rallybio (company interested in screening and prophylaxis of FNAIT). E.L.V.H. reports no conflict of interest. 2ff7e9595c
Comments