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Severe aplastic anemia (SAA) is a rare disease characterized by severe pancytopenia and bone marrow failure. Most patients with AA respond to immunosuppressive therapy (IST), usually as antithymocyte globulin (ATG) and cyclosporine (CsA), but some relapse on CsA withdrawal or require long-term administration of CsA to maintain blood counts. Recent research has found that rapamycin (Rapa) was an effective therapy in mouse models of immune-mediated bone marrow failure. However, it has not achieved a satisfactory effect in clinical application. At present, many studies have confirmed that eltrombopag (ELT) combined with IST can improve the curative effect of AA patients. Then, whether Rapa combined Elt in the treatment of AA will acquire better efficacy than a single drug application remains unclear. In this study, an immune attack-mediated AA mouse model was constructed by total body irradiation (TBI) and allo-lymphocyte infusion. In our study, we tested the efficacy of Rapa combined with Elt as a new treatment in mouse models of immune-mediated bone marrow failure. It showed that treatment with Rapa in combination Elt in the AA mouse model ameliorated pancytopenia and extended animal survival in a manner comparable to the standard dose of CsA and Rapa alone. However, there was no significant improvement effect on the number and function of NK cells and their subsets, mDCs, and CD4+/CD8+ ratio in AA mice after the therapy of Rapa combined with Elt compared with Rapa alone. Furthermore, the secretion of IL-10 of Tregs in AA mice increased significantly after the therapy of Rapa combined with Elt, but there was no significant difference in the number of Treg cells. We did not observe the difference in the curative effect of the Rapa group and CsA group, but for IL-10/Tregs ratio, the Rapa group was superior to the CsA group. And the IFN-r secretion of CD8+T cells in AA mice decreased significantly after the combination therapy of Rapa and Elt than Rapa alone. Compared with the AA group, the level of plasma IFN-γ, IL-2, and TNF-α decreased significantly (P < 0.05), but IL-10, IL-4, IL-5, and IL-1β increased significantly in the Rapa group (P < 0.05). As for IL-10, IL-12p70, IL-2, IL-6, KC/GRO, and TNF-α, the therapy of Rapa combined with Elt showed a more significant effect than Rapa alone in AA mice. To some extent, this study had shown a relatively better synergistic effect in murine models of immune-mediated bone marrow failure after the combination therapy of Rapa and Elt, which was a promising clinical utility in SAA treatment. [ABSTRACT FROM AUTHOR]

Objective. We studied bone marrow plasma (BMP) cytokines in severe aplastic anemia (SAA) patients and healthy volunteers to investigate differences in the cytokine profiles between them and propose a cytokine signature of SAA. Methods. A Bio-Plex suspension array system was used to measure 27 analytes in BMP samples from 47 SAA patients and 30 healthy donors. Results. Compared to healthy people, SAA patients had higher levels of tumor necrosis factor α (TNF-α), interferon-γ (IFN-γ), interleukin-2 (IL-2), monocyte chemoattractant protein 1 (MCP-1), and granulocyte colony-stimulating factor (G-CSF). They also had lower levels of interleukin-1 receptor antagonist (IL-1ra), interleukin-9 (IL-9), regulated upon activation normal T cell expressed and secreted (RANTES) factor, platelet-derived growth factor-BB (PDGF-BB), and macrophage inflammatory protein 1β (MIP-1β). Levels of interleukin-4 (IL-4), IL-1ra, macrophage inflammatory protein 1α (MIP-1α), and eotaxin were significantly higher in recovering SAA (RSAA) patients. Levels of IL-5, IL-6, IL-10, IL-12, IL-13, IL-15, granulocyte-macrophage colony-stimulating factor (GM-CSF), and vascular endothelial growth factor (VEGF) were undetectable. There were no significant differences in the levels of IL-1β, IL-4, IL-7, IL-8, IL-17, basic fibroblast growth factor (FGF-β), and IFN inducible protein-10 (IP-10) between patients and healthy controls (HCs). Eotaxin, IL-1ra, MCP-1, MIP-1β, and RANTES levels increased after IST, whereas IFN-γ, G-CSF, IL-2, IL-7, and TNF-α levels decreased after IST. Conclusions. The current study demonstrated distinct cytokine profiles among untreated SAA patients, recovering SAA (RSAA) patients, and healthy people. The cytokines of RSAA patients showed similar characteristics to those of untreated SAA patients and healthy people, respectively, which may reflect that the immune status of RSAA patients is in different stages of recovery after IST; thus, it may provide an important tool in diagnosing and evaluating or predicting curative effects in clinics. [ABSTRACT FROM AUTHOR]

Severe aplastic anemia (SAA) is characterized by pancytopenia and failure of hematopoietic function and is caused by excessive functioning of cytotoxic T lymphocytes (CTLs). EBNA-1, a nucleoprotein of the Epstein Barr virus (EBV), can influence the proliferation and function of lymphocytes. We therefore tested the number of EBV copies in the CD8+ T cells of 27 patients with SAA and 10 healthy control subjects and observed the influences of EBNA-1 upon the CD8+ T cells of patients with SAA. The results showed that more EBV copies were found in the CD8+ T cells of patients with untreated SAA than in patients with SAA in remission or in the healthy control subjects. Their copy number was positively correlated with the expression of granzyme B and perforin, the secretion level of interferon-γ in CD8+ T cells, and the viability of CD8+ T cells, whereas no correlation was seen between the copy number and the interleukin 4 secretion level or the apoptosis rate. Meanwhile, the expression of granzyme B and perforin was reduced after EBNA-1 gene knockdown, whereas the interferon-γ secretion level and cell viability declined. Therefore, we infer that EBV infection may be a factor in the activation of CTLs and in damaging the bone marrow hematopoietic function of patients with SAA. [ABSTRACT FROM AUTHOR]