Reconstitution of the Ig Heavy Chain CDR3 Repertoire after Allogeneic Haematopoietic Stem Cell Transplantation with Myeloablative or Reduced‐Intensity Conditioning Regimens

• Published in: Scandinavian journal of immunology Vol. 61; no. 1; pp. 72 - 81
• Main Authors: Omazic, B., Hentschke, P., Näsman‐Björk, I., Mattsson, J., Oxelius, V.‐A., Ringdén, O., Barkholt, L., Permert, J., Lundkvist, I.
• Format: Journal Article
• Language: English
• Published: Oxford, UK; Malden, USA Blackwell Science Ltd 01-01-2005; Wiley Subscription Services, Inc
• Subjects: Acute Disease; Adult; B-Lymphocytes - immunology; Basic Medicine; Chimera - immunology; Chronic Disease; Complementarity Determining Regions - genetics; Cytomegalovirus; Female; Graft vs Host Disease - etiology; Hematopoietic Stem Cell Transplantation - adverse effects; Humans; Immunoglobulin Allotypes - blood; Immunoglobulin G - blood; Immunologi inom det medicinska området; Immunology in the medical area; Lymphocyte Subsets - immunology; Male; Medical and Health Sciences; Medicin och hälsovetenskap; Medicinska och farmaceutiska grundvetenskaper; Middle Aged; Time Factors; Transplantation Conditioning - methods; Transplantation, Homologous
• ISSN: 0300-9475; 1365-3083; 1365-3083
• DOI: 10.1111/j.0300-9475.2005.01528.x

The objective of this study was to investigate B‐lymphocyte reconstitution in patients undergoing allogeneic haematopoietic stem cell transplantation (HSCT) after myeloablative conditioning (MAC) or reduced‐intensity conditioning (RIC) regimens. B‐lymphocyte reconstitution was studied by monitoring the CDR3 repertoire with spectratyping. We demonstrate a delay in the recovery of the B‐lymphocyte repertoire, measured by variation in size distribution of the immunoglobulin H CDR3 in patients conditioned with RIC compared to MAC. We found no general explanation for this finding, but when clinical data for each patient were studied in detail, we could identify a cause for the oligoclonality of the B‐lymphocyte repertoire after HSCT with RIC for each of the patients. Older patients and donors, low cell dose at transplantation, relapse, graft‐versus‐host disease (GVHD) and its treatment as well as cytomegalovirus infection and its treatment are all possible causes for the restriction of the B‐lymphocyte repertoire observed in this study. Taken together, reconstitution of the B‐lymphocyte repertoire after HSCT is a process dependent on multiple factors and differs between patients. The conditioning regimen may be of importance, but data from this study suggest that individual factors and the various complications occurring after HSCT are more likely to determine the development of the B‐lymphocyte repertoire.