RESUMEN
Autologous hematopoietic stem cell transplantation (HSCT), a safer type of HSCT than allogeneic HSCT, is a promising therapy for patients with severe autoimmune diseases (ADs). Despite the long history of medical practice, structural changes in the adaptive immune system as a result of autologous HSCT in patients with various types of ADs remain poorly understood. In this study, we used high-throughput sequencing to investigate the structural changes in the peripheral blood T-cell repertoire in adult patients with ankylosing spondylitis (AS) during two years after autologous HSCT. The implementation of unique molecular identifiers allowed us to substantially reduce the impact of the biases occurring during the preparation of libraries, to carry out a comparative analysis of the various properties of the T-cell repertoire between different time points, and to track the dynamics of both distinct T-cell clonotypes and T-cell subpopulations. In the first year of the reconstitution, clonal diversity of the T-cell repertoire remained lower than the initial one in both patients. During the second year after HSCT, clonal diversity continued to increase and reached a normal value in one of the patients. The increase in the diversity was associated with the emergence of a large number of low-frequency clonotypes, which were not identified before HSCT. Efficiency of clonotypes detection after HSCT was dependent on their abundance in the initial repertoire. Almost all of the 100 most abundant clonotypes observed before HSCT were detected 2 years after transplantation and remained highly abundant irrespective of their CD4+ or CD8+ phenotype. A total of up to 25% of peripheral blood T cells 2 years after HSCT were represented by clonotypes from the initial repertoire.
RESUMEN
During the last several years high-dose chemotherapy (HDCT) with autologous stem cell transplantation (ASCT) has been established as a therapeutic option for multiple sclerosis (MS) patients. We report on the long-term effects of HDCT + ASCT in two female patients affected by secondary progressive and relapsing-remitting types of MS, respectively. As a result, disease stabilization was achieved in the first case and disease improvement in the second one. Both patients were off immunosuppressive or immunomodulating therapy throughout the post-transplant period. Notably, HDCT + ASCT resulted in an excellent quality of life (QoL) response in both cases. Our findings demonstrate that HDCT + ASCT could be considered as an effective treatment for MS patients. Moreover, QoL measurement seems to be an effective approach to assessment of treatment outcomes at long-term follow-up of patients with MS.