Objective: To assess the clinical significance of detecting the immune markers in idiopathic thrombocytopenic purpura (ITP).
Methods: The frequencies of circulating B cells secreting platelet-specific antibody, platelet-specific antibody, the percentage of T lymphocyte subsets, the percentage of reticulated platelet and the level of thrombopoietin in 64 ITP patients and 31 healthy controls were measured with enzyme-linked immunospot assay (ELISPOT), modified monoclonal antibody immobilization of platelet antigens assay (MAIPA), flow cytometry and sandwich enzyme-linked immunosorbent assay respectively.
Results: Compared with the controls [1.3 ± 0.5/10(5) peripheral blood mononuclear cell (PBMC), (0.33 ± 0.06, 0.41 ± 0.03), (22.08 ± 4.54)% and (8.19 ± 2.46)%], the frequencies of circulating B cells secreting platelet-specific antibody (7.6 ± 4.6/10(5) PBMC in acute ITP group, 5.3 ± 3.0/10(5) PBMC in chronic ITP group), platelet-specific antibody (including the anti-GPIIb/IIIa antibody, anti-GPIb/IX antibody) (0.51 ± 0.11, 0.48 ± 0.06 in acute ITP group; 0.49 ± 0.10, 0.46 ± 0.09 in chronic ITP group), the percentage of CD(8)(+) T Lymphocyte (27.09 ± 9.86)%, the percentage of reticulated platelet in ITP patients [the megakaryocyte cytosis group (24.85 ± 19.18)%, the normal megakaryocyte group (23.89 ± 18.90)%] were significantly increased (all P < 0.05). The frequencies of circulating B cells secreting platelet-specific antibody in acute ITP patients were notably increased (P < 0.05) compared to the chronic ITP patients. In T lymphocyte subsets, the percentage of CD(3)(+) T lymphocyte and CD(4)(+) T lymphocyte and the ratio of CD(4)(+)/CD(8)(+) in the patients with ITP [(60.88 ± 14.59)%, (28.41 ± 10.55)%, 1.18 ± 0.59] were notably decreased than those in the healthy controls [(69.89 ± 6.43)%, (35.38 ± 5.05)%, 1.64 ± 0.29, P < 0.05]. There was no apparent difference of the level of thrombopoietin between ITP patients with megakaryocyte cytosis (72.09 ± 41.64) and health controls (75.37 ± 26.32, P > 0.05), however, the level of thrombopoietin of ITP patients with normal megakaryocyte apparently increased (118.60 ± 70.72, P < 0.05).
Conclusion: Detecting the frequencies of circulating B cells secreting platelet-specific antibody, platelet-specific antibody, the percentage of T lymphocyte subsets, the percentage of reticulated platelet and the level of thrombopoietin in the patients with ITP may improve the diagnosis and guide clinical therapy.