Interleukin-7 is decreased and maybe plays a pro-inflammatory function in primary immune thrombocytopenia

Abstract

Primary immune thrombocytopenia (ITP) is an autoimmune disease with many immune dysfunctions, including over-proliferation and apoptosis resistance of auto-reactive lymphocytes. This study aimed to determine the effects of interleukin (IL)-7 on the cytokine production and survival of peripheral blood mononuclear cells and bone marrow mononuclear cells from ITP patients. We found that the plasma IL-7 levels in peripheral blood from ITP patients were lower than that of the normal controls, and it had positive correlation with platelet counts. However, the levels of IL-7 did not change in bone marrow serum of ITP patients compared with that of normal controls. The result of further stimulation experiments in vitro showed that IL-7 up-regulated the apoptosis of autologous platelets, promoted the proliferation and secretion of interferon-γ, tumor necrosis factor-α as well as IL-10 of lymphocyte both from peripheral blood and bone marrow. As the role of IL-7 in apoptosis-resistance and stimulation of pro-inflammatory cytokines, we speculated that decreased IL-7 in peripheral blood, maybe, is a consequence of the negative feedback of the pro-inflammatory function in ITP patients.

• Apoptosis
• cell activation
• interleukin 7
• primary immune thrombocytopenia

Acknowledgements

We are grateful to the patients and healthy individuals who made this study possible.

Declaration of interest

The authors report no declarations of interest. This work was supported in part by grants of National Natural Science Foundation of China (81070397), Ministry of Science and Technology (2011ZX09302-007-04), Ministry of Health (201202017) and Tianjin Municipal Science and Technology Commission (09JCYBJC10900, 10JCZDJC19700 and 12JCQNJC08000).