[Changes of lymphocyte subsets in autologous hemopoietic stem cell transplantation for severe/refractory autoimmune disease].

Objective: To investigate the dynamic changes of lymphocyte subsets before and after autologous hemopoietic stem cell transplantation (HSCT) in severe/refractory autoimmune disease (AID) and study the post-transplantation immunological reconstitution in AID.

Methods: Thirteen patients with severe/refractory AID who registered for HSCT from April 2003 to April 2005 in Peking Union Medical College Hospital, including 8 patients with systemic lupus erythematosus, 4 patients with rheumatoid arthritis, and 1 patient with primary Sjögren's syndrome (pSS) were enrolled in this study. Blood samples were collected before/after mobilization, before conditioning, and 2 weeks, 1 month, 3 months, 6 months, 12 months, and 18 months post-transplantation. Lymphocyte subsets were tested by flow cytometry as follows: T cell (CD3 +), B cell (CD19 +), natural killer (CD3-CD16 + CD56 +), Th (CD3 + CD4 +), Tc (CD3 + CD8 +), naïve T (CD4 + CD45RA), memory T (CD4 + CD45RO), and CD4/CD8 ratio.

Results: Lymphocyte subsets for SLE patients were severely abnormal compared to normal or RA patients (both P < 0.01). B cell reconstituted to normal level within 18 months, meanwhile NK and T cell remained low. The repopulations of Th and naive T cell were delayed, which caused the up-side-down of CD4/CD8 ratio and low level of naYve T cell percentage for a relatively long time.

Conclusions: Lymphocyte subsets abnormality in SLE patients are more severe than in RA patients. Although most autoimmune T/B cell in the grafts and patients can be effectively removed after transplantation, nonmyeloablative conditioning may be a risk for the relapse of AID. The long-term inhibition of CD4 + T cell may be related with the relief of AID after transplantation.