Helper T-lymphocyte precursor frequency predicts the occurrence of graft-versus-host disease and disease relapse after allogeneic bone marrow transplantation from HLA-identical siblings.

BACKGROUND AND

OBJECTIVES

Donor helper T-lymphocytes may be involved in graft-versus-host disease (GVHD) and a graft-versus-leukemia effect after bone marrow transplantation (BMT). We assayed donor helper T-lymphocyte precursor frequencies (HTLP(f)) to see whether they could predict the severity of GVHD and disease relapse after transplantation, thereby facilitating donor selection, pre-transplant counselling and modification of GVHD prophylaxis after BMT.

DESIGN AND

METHODS

Thirty-six consecutive adult BMT recipients and their HLA-identical sibling donors were recruited. HTLP((f)) was measured as a function of interleukin-2 secretion by alloreactive donor T-cells using a limiting dilution assay. Patients were followed prospectively to assess the severity of GVHD and the status of the primary disease after BMT.

RESULTS

Eight donors had HTLP((f)) less than or equal to 10(-6); no recipients of these grafts developed severe GVHD after transplantation. Twenty-eight donors had HTLP(f) greater than 10(-6) and 18 recipients of these grafts developed severe GVHD (> or = grade 2) (chi(2) test, p<0.01). Seven donors had HTLP(f) greater than 10(-5) and no recipient had disease relapse. Twenty-nine donors had HTLP(f) less than or equal to 10(-5), 11 recipients of these grafts developed disease relapse (chi(2) test, p=0.08).

INTERPRETATION AND

CONCLUSIONS

BMT recipients from HLA-identical sibling donors with low (<10(-6)) and high (>10(-5)) HTLP(f) may have a low risk of acute GVHD and disease relapse after transplantation.