Lymphocyte subset analysis for the assessment of treatment-related complications after autologous stem cell transplantation in multiple myeloma

Abstract

Background aims. The aim of this study was to investigate the correlation between infused lymphocyte populations and lymphocyte subsets at engraftment, and the early clinical implications of lymphocyte subset recovery after autologous stem cell transplantation (ASCT) in multiple myeloma (MM). Methods. We examined the lymphocyte populations of infused autografts and the lymphocyte subsets of peripheral blood at engraftment from 50 patients using flow cytometry. Each subset was grouped as low (below median) and high (above median) to examine the correlation with mucositis of grade 3 or more and the occurrence of infections and cytomegalovirus (CMV) reactivation. Results. Using Spearman correlation coefficients, we found that cell doses of infused CD8⁺ (P = 0.042) and CD19⁺ cells (P = 0.044) were significantly associated with the absolute lymphocyte count (ALC) at engraftment. The dose of infused CD34⁺ cells was not associated with the change of lymphocyte subsets except for an inverse correlation with CD4⁺ cells (P = 0.006). After adjusting for potential variables in univariate analysis, multivariate analyzes revealed that the lower ratio of infused CD4⁺ to CD8⁺ cells (P = 0.030) was an independent factor for severe mucositis. Of lymphocyte subsets at engraftment, a higher frequency of CD3⁺ (P = 0.024) and a lower frequency of CD56⁺ (P = 0.020) were independent predictors for infections after engraftment. A higher frequency of CD8⁺ cells (P = 0.041) and a lower ratio of CD4⁺ to CD8⁺ (P = 0.021) were independent predictors for CMV reactivation. Conclusions. Our data suggest that lymphocyte subset analysis of infused autograft and peripheral blood at engraftment may provide new predictors for early complications after ASCT in patient with MM.

Key Words::

• autologous stem cell transplantation
• infection
• lymphocyte subset analysis
• mucositis
• multiple myeloma

Acknowledgments

The authors acknowledge all members at the Catholic Blood and Marrow Transplantation Center, particularly the house staff, for their excellent care of the patients. This study was supported by the Korea Healthcare Technology R&D Project, Ministry of Health, Welfare & Family Affairs, Republic of Korea (grant number A092258).

Conflict of interest: The authors declare that they have no Conflict of Interest.