VH3 and VH6 Immunoglobulin M Repertoire Reconstitution after Hematopoietic Stem-Cell Transplantation in Children

B Cell Reconstitution and Influencing Factors After Hematopoietic Stem Cell Transplantation in Children

B cell reconstitution after hematopoietic stem cell transplantation (HSCT) is variable and influenced by different patient, donor, and treatment related factors. In this review we describe B cell reconstitution after pediatric allogeneic HST, including the kinetics of reconstitution of the different B cell subsets and the development of the B cell repertoire, and discuss the influencing factors. Observational studies show important roles for stem cell source, conditioning regimen, and graft vs. host disease in B cell reconstitution. In addition, B cell recovery can play an important role in post-transplant infections and vaccine responses to encapsulated bacteria, such as pneumococcus. A substantial number of patients experience impaired B cell function and/or dependency on Ig substitution after allogeneic HSCT. The underlying mechanisms are largely unresolved. The integrated aspects of B cell recovery after HSCT, especially BCR repertoire reconstitution, are awaiting further investigation using modern techniques in order to gain more insight into B cell reconstitution and to develop strategies to improve humoral immunity after allogeneic HSCT.

An unusual pattern of B-cell immunological reconstitution after allogeneic stem cell transplantation: a possible correlation with CMV reactivation?

IR after HSCT is a slow process that involves several components of the immune response, and, in allogeneic setting, it can be delayed by GvHD and immuno-suppressive therapy. Our study on IR post-HSCT included a child with FA who underwent MUD transplantation. To evaluate B, T and NK cell reconstitution and to investigate the differentiation of B lymphocyte repertoire, this patient was carefully monitored at various time points by IgHCDR3 (third complementarity determining region of the immunoglobulin heavy chain) fingerprinting and by FACS analysis. IgHCDR3 fingerprinting showed a strong oligoclonality of IgM and IgG profiles from day +60 to +180 post-transplant. CMV reactivation was present at the same time points and overlapped the clonal pattern shown in IgHCDR3 fingerprinting. Immunophenotype analysis showed early repopulation of T and NK cells following HSCT, whereas B cells increased first at one yr post-transplant. The overlapping of virus reactivation and B-cell clonal expansion seems to suggest that B lymphocytes may be involved in the CMV immunological response, at least in the early time points after HSCT when the immune repertoire is still reconstituting.

Parental Experience of Family Stress During Hematopoietic Stem Cell Transplantation of Pediatric Patients in Germ-free Isolation in Taiwan

This qualitative inquiry study used convenience sampling through in-depth interviews to obtain life experiences and feelings of parents while their children underwent hematopoietic stem cell transplantation. Eleven parents of children younger than 18 years undergoing hematopoietic stem cell transplantation in a medical center in north Taiwan consented to participate in this study and provide oral and written responses in Mandarin or Taiwanese. Semistructured interviews lasting 60 minutes were conducted privately and audiotaped. Verbatim transcriptions of the interviews were examined by the content analysis method. The trustworthiness of the data was examined by Lincoln and Guba (Naturalistic Inquiry. Newbury Park, Calif: Sage; 1985) principles. Results indicated that family stress experiences of parents of children undergoing hematopoietic stem cell transplants include 4 themes: parental psychological distress, family lifestyle disturbances, parents' coping patterns, and family resources. The results of this study provide evidence of the nature of parents' experiences while their children undergo hematopoietic stem cell transplantation and provide guidelines for family-centered nursing care.