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.
Di Martino
Daniela
D
Department of Paediatric Haematology and Oncology, G. Gaslini Institute, Genova, Italy. danieladimartino@ospedale.gaslini.ge.it
Terranova
M Paola
MP
Valetto
Angelo
A
Scarso
Lucia
L
Faraci
Maura
M
Lanino
Edoardo
E
Morreale
Giuseppe
G
D001402:B-Lymphocytes / Q000276:immunology*; D002648:Child; D003586:Cytomegalovirus Infections / Q000276:immunology*; D005199:Fanconi Anemia / Q000276:immunology / Q000601:surgery*; D006084:Graft Rejection / Q000276:immunology; D006801:Humans; D016130:Immunophenotyping; D007694:Killer Cells, Natural / Q000276:immunology; D008297:Male; D033581:Stem Cell Transplantation; D013601:T-Lymphocytes / Q000276:immunology; D019172:Transplantation Conditioning / Q000379:methods; D014184:Transplantation, Homologous / Q000276:immunology