BACKGROUND: Immune reconstitution following unrelated cord blood transplantation (UCBT) in adult patients is of great concern because of immaturity of cord blood immunological cells.

STUDY DESIGN AND METHODS: Twenty-six adult patients (15 to 58 year-old) with hematological malignancies, who underwent UCBT and sustained engraftment were enrolled in this study. Infused number of immunological cells in thawed CB units including T cells (CD3+), B cells (CD19+), NK cells (CD3-CD56+), monocytes (CD14+) and also CD34 + cells was analysed using bead-contained TRUCOUNT tube (BD, CA). Dead cells after thawing were excluded by gating out with 7AAD dye. Immune reconstitution was analysed every 30 days by 120 days after CBT. Four-colour FACS Caliber and TRUCOUNT tube were utilized to calculate the absolute number of immune cells concentration in blood after UCBT. We put strict volume of 50μl fresh unmanipulated blood in each TRUCOUNT tube.

RESULTS: Thawed-transplanted NC 2.3±x107/kg, CD34 was 0.72±0.3x105/kg (4.1x106 total), T cells; 3.1±1.6x106/kg with CD4/8 ratio of 3.2±2.0, B cells; 1.2±0.5x106/kg, NK cells; 1.0±0.5x106/kg and monocytes; 1.6±0.6x106/kg. There were no correlations between infused CD34+ cells number and T, B, NK and monocytes numbers. Monocytes increased in blood rapidly after CBT at 30 days, then, declined to the normal value. NK cells was recovered in the early after CBT and then did not so change in number from 30 to 120 days after CBT, while T cells increased time dependent manner, and B cells appeared late but influenced by acute GVHD grade. Within 120 days after CBT, T cells showed also CD4+dominant in most cases with relatively high CD25+CD4+ regulatory T (rT) cells compared to normal control. The patients with grade II to IV aGVHD showed significantly higher number of rT cells on 30 days (P<0.05) compared to those with grade 0–I aGVHD. On day 30, the number of rT cells showed 7.7±5.9/μl in grade 0–I aGVHD and 19.4±13.3/ μl in grade II–IV. The patients with grade II to IV aGVHD showed significant delayed recovery of B cells on 90 days after CBT compared to those with 0–I aGVHD (P<0.001).

CONCLUSION: aGVHD in adult patients may influence on the number of regulatory T cells in the early period after UCBT and delayed recovery of B cells.

Topics:
graft-versus-host disease, acute, immune reconstitution, umbilical cord blood transplantation, radiation therapy, cd34 antigens, dyes, hematologic neoplasms, b-lymphocytes, monocytes, t-lymphocytes

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2005, The American Society of Hematology
2004
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