{'fraction_non_alphanumeric': 0.046948356807511735, 'fraction_numerical': 0.03338549817423057, 'mean_word_length': 4.99375, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Expression and significance of VLA-4 and CX3CR1 in aplastic anemia

Objective:To investigate the contribution of the expression of VLA-4 and CX3CR1 on T cells surface to the pathogenesis of acquired aplastic anemia (AA).Method:①The percentage of T cell subsets and the expression of VLA-4 and CX3CR1 on T cells from peripheral blood and bone marrow were analyzed by flow cytometry in 46 AA patients (20 with severe aplastic anemia and 26 with non-severe aplastic anemia). ②The levels of VCAM-1 (ligand of VLA-4) and Fractalkine (ligand of CX3CR1) were investigated in blood and bone marrow from AA patients and controls by Enzyme-linked immunosorbent assay.Result:①In peripheral blood,there was no significant difference of the percentage of CD3+ cells (P0.05). But increased CD8+ cells and reduced CD4+ cells were found in AA patients (P0.01). In bone marrow,both the percentage of CD3+ cells and CD8+ cells were increased in AA patients (P0.01). And significantly lower percentage of CD4+ cells was only found in SAA patients (P0.05). ②Both in blood and bone marrow,there was no statistically significant difference of the expression of VLA-4 on T cell subsets (P0.05). However,the percentage of CD3+/CX3CR1+ cells、CD3+/CD4+/CX3CR1+ cells,and especially CD3+/CD8+/CX3CR1+ cells were increased in AA patients compared with controls (P0.05). ③ There were no significant difference of the levels of VCAM-1 in blood or bone marrow plasma between AA patients and controls (P0.05),but the plasma levels of Fractalkine were significantly higher in SAA patients' blood and all the patients' bone marrow (P0.05).Conclusion:Acquired AA is a T-cell-media-ted immune disease,and presents abnormal T cell subsets. T cells appear to relocate from peripheral blood and accumulate in bone marrow to destruct hematopoietic stem and progenitor cells,probably due to elevated expression of surface CX3CR1 interacting with Fractalkine.