Immune reconstitution and outcome after unrelated cord blood transplantation: a single paediatric institution experience

Abstract

Summary:We report the outcome of 12 children who underwent unrelated cord blood transplant (U-CBT) in a single institution between February 1997 and July 1998. The 1 year event-free survival was 67% (95% CI of 26%). Four children died with infectious complication as cause of death in three cases. Immune reconstitution was studied during first year post transplant by assaying total lymphocyte counts, B cells, NK cells and T cell subsets in the eight disease-free surviving patients. We observed a prompt recovery of CD19 + cell number which was greater than 500/l at 9 months for all patients except the one with severe cGVHD. B cells constituted the predominant lymphocyte subset at 6 and 9 months post transplant with normal or elevated B cell numbers according to normal paediatric range. We noted normal serum immunoglobulin levels at 6 months post transplant for IgA and IgM and at 9 months for IgG. The CD3 + cell count and particularly the CD3 + CD8 + T cell subset remained depressed until 12 months post transplant. Six months after unrelated CBT, seven out of eight patients had less than 100 CD3 + CD8 + cells/l. CD3 + CD4 + cell recovery was less impaired with all children achieving an absolute count of CD3 + CD4 + cells greater than 200/l during the first year in a median of 5 months. The percentage of NK cells was elevated during the first 6 months after CBT but their absolute count remained within the normal range. Bone Marrow Transplantation (2000) 25, 53-57.

Reconstitution of maturating and regulatory lymphocyte subsets after cord blood and BMT in children

“…Indeed, B-cell number recovery was more rapid after CBT, but the proportion of CD27 þ memory B cells was identical at any time point, and still remains below the normal range for children at 1-year post transplant. Rapid recovery of B-cell numbers after CBT, already described by others, 2,6,8,9 can be attributed to a higher proportion of B-cell precursors in cord blood. 37 B-cell maturation after CBT remains suboptimal at 1-year post-transplant, as already described with other graft sources.…”

Unrelated cord blood transplantation for severe combined immunodeficiency and other primary immunodeficiencies

“…39 Our previously reported Omenn's syndrome patient is the first case successfully treated by UCB transplant. 22 Development of lymphocyte subpopulations and immunologic function in our SCID and non-SCID patients followed the pattern previously described, [34][35][36][37] with early recovery of normal NK cell values followed by CD19, CD3, CD4 and finally CD8. Response to mitogens and immunoglobulin production preceded the development of serologic responses to specific antigens.…”

“…19,20 The recovery period of myeloid and lymphoid activity is longer in UCB transplants, 13,17,18,20,[34][35][36][37] which raises the risk of severe infections. In contrast, advantages of UCB include easy availability and lower HLA-compatibility requirements.…”

Use of immunoglobulins in the prevention of GvHD in a xenogeneic NOD/SCID/γc− mouse model

“…The kinetics and the quality of immune reconstitution are crucial for preventing morbidity and mortality following HSCT. [69][70][71][72] IVIG are considered an immunomodulatory rather than an immunosuppressive drug and thus could be very useful following HSCT as they should not inhibit immune reconstitution. Nevertheless, it has never been demonstrated that IVIG do not inhibit immune reconstitution post-HSCT.…”