Relationship between Changes of Lymphocyte Subsets and Early Hematologic Response in Immunosuppressive Therapy of Severe Aplastic Anemia Patients

OBJECTIVE To explore the relationship between the change of lymphocyte subsets before and after immunosuppressive therapy (IST) with disease severity of severe aplastic anemia (SAA) and hematologic response to IST. METHODS The clinical data of 94 patients with SAA/VSAA treated by r-ATG and CsA in our hospital from December 2009 to October 2011 was analyzed retrospectively. Among them, 26 patients who had sequential data of lymphocyte subsets and cytokines before and after treatment were enrolled. The relationship between lymphocyte subsets, cytokine level before IST and disease severity, as well as the relationship between changes if lymphocyte subsets, changes of cytokine and the HR after IST for 6 months was analyzed. RESULTS There were no statistical differences in the ratio and absolute count of lymphocyte, the ratio and absolute count of each lymphocyte subsets, including CD3+T cells, CD3+CD4+T cells, CD3+CD8+T cells, CD3-CD16+1CD56+NK cells, and CD19+B cells, and the level of cytokines, such as IL-1, IL-2, IL-4, IL-6 and TNF-α before IST between SAA and VSAA groups. Also, there were no statistical difference in the levels of above-motional parameter at 3 and 6 months after IST. The ratio and absolute count of Lym, absolute count of CD3+T cells, absolute count of B cells and IL-2 level in response group after IST for 3 and 6 months was significant lower than those before IST. However, only ratio of Lym showed significant decrease after IST for 3 and 6 months in non-response group. After IST for 3 months, the absolute count of CD3+T and CD4+T cells in response group was significant higher than those in non-response group. CONCLUSION The hematopoietic recovery and early hematologic remission may be affected by the intensity of immune suppression reflected from the changes of lymphocyte subsets and the immune reconstruction reflected from the recovery of lymphocyte subsets. The immune reconstruction is most significant within 3 months after IST.