Abstract Number: VPB1217
Meeting: ISTH 2022 Congress
Theme: Platelet Disorders, von Willebrand Disease and Thrombotic Microangiopathies » Acquired Thrombocytopenias
Background: Thrombocytopenia is a multifactorial condition that frequently involves concomitant defects in platelet production and clearance. Sialylation on platelet membrane glycoprotein and follicular helper T cells (TFHs) are thought to be the novel platelet clearance pathways.
Aims: We aimed to evaluate the associations of platelet desialylation and circulating TFHs in the pathophysiology of immune thrombocytopenia (ITP) and non-ITP thrombocytopenia.
Methods: A cohort of 190 patients with ITP and 94 patients with non-ITP-related thrombocytopenia including case of aplastic anemia (AA) and myelodysplastic syndromes (MDS) were enrolled. Healthy volunteers were included as controls (n = 110). Desialylated platelets binding with Erythrina cristagalli lectin (ECL) and Ricinus communis agglutinin I (RCA-I), apoptotic platelets and circulating TFHs were measured. CXCL13 (a key chemokine produced by TFHs) and platelet autoantibodies were assessed.
Results: In comparison to healthy controls, we observed at least a 2.0-fold increase in desialylated platelet levels and circulating TFHs from patients with ITP or non-ITP-related thrombocytopenia in the AA and MDS cohorts. Desialylated platelets were negatively correlated with platelet count (r = -0.1867, P = 0.0267 vs. ECL; and r = -0.3587, P < 0.0001 vs. RCA-I, respectively), and positively correlated with TFHs proportion (r = 0.2184, P = 0.0161 for CD4+CXCR5+PD1+ TFHs vs. ECL; r = 0.2484, P = 0.0052 for CD4+CXCR5+ TFHs vs. ECL; r = 0.2281, P = 0.0122 for CD4+CXCR5+PD1+ TFHs vs. RCA-I). Patients bearing anti-platelet autoantibodies displayed 5.9-fold higher levels of TFHs than those without autoantibodies (P = 0.0385). Moreover, CXCL13 and apoptotic platelets were significantly upregulated, and pro-apoptotic proteins and MAPK/mTOR pathway were markedly activated. Responders after treatment presented significantly greater reduction in platelet desialylation levels than non-responders did (ECL: P = 0.0946; RCA-I: P = 0.0024).
Conclusion(s): Platelet desialylation and circulating TFHs may become the potential biomarkers and therapeutic targets for thrombocytopenia in patients with ITP and non-ITP.
To cite this abstract in AMA style:
Chen Y, Luo L, Zhen Q, Kalayu Yirga S, Shi Q, Hu J. Association of platelet desialylation and circulating follicular helper T cells in patients with thrombocytopenia [abstract]. https://abstracts.isth.org/abstract/association-of-platelet-desialylation-and-circulating-follicular-helper-t-cells-in-patients-with-thrombocytopenia/. Accessed September 29, 2023.« Back to ISTH 2022 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/association-of-platelet-desialylation-and-circulating-follicular-helper-t-cells-in-patients-with-thrombocytopenia/