Association with the presence of naive T cells in chronic myeloid leukemia patients after allogeneic human stem cell transplantation and the lower incidence of chronic graft-versus host disease and relapse.
BACKGROUND
Allotransplantation in chronic myeloid leukemia (CML) patients offers long-lasting remissions, which largely depend on immunologic surveillance of alloreactivity. Alloreactivity in CML patients has a durable potential. However a large proportion of relapsing patients, who have to undergo donor lymphocyte treatment is still abundant.


METHODS
We studied a group of 31 CML patients post allogeneic transplantation for their level of T-cell receptor excision circles (TREC) and proportion of naive and memory/effector T cells in the peripheral blood (PB). TREC numbers were determined by quantitative PCR (qPCR) and T-cell subsets CD4(+)CD27(+)CD45RO(-), CD4(+)CD27(-)CD24RO(+), CD4(+)CCR7(+), and CD4(+)CCR7(-) by flow cytometry. Patients were analyzed for posttransplant chimerism, type of bcr-abl transcripts, and number of TREC in association with the presence of chronic graft-versus-host disease (cGVHD) and relapse. CML patients with TREC+ in PB had a higher proportion of CD4(+)CD27(+)CD45RO(-) cells (3.54 vs 2.45%; P = .105) and CD4(+)CCR7(+) cells (4.85 vs 2.67%; P = .007), and a lower proportion of CD4(+)CD27(-)CD45RO(+) cells (5.55 vs 9.09%; P = .037). The incidence of cGvHD was reduced among TREC+ CML patients (3/14 vs 11/17; P = .006).


RESULTS
The 5 out of 31 CML patients who relapsed were characterized by the presence of b2a2, b3/a2 or both type of transcripts, a lack of TREC in the blood, and a lower proportion of naïve and effector/memory T cells. No association was observed between any of HLA specificities, type of bcr-abl transcripts and incidence of relapse.


CONCLUSIONS
The presence of TREC is affected by chronic GvHD; TREC negativity may constitute a risk of mixed chimerism and relapse.
Wysoczanska
B
B
L. Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wroclaw, Poland.
Bogunia-Kubik
K
K
Dlubek
D
D
Jaskula
E
E
Sok
A
A
Drabczak-Skrzypek
D
D
Sedzimirska
M
M
Lange
A
A
D000293:Adolescent; D000328:Adult; D015703:Antigens, CD / Q000097:blood; D016026:Bone Marrow Transplantation / Q000276:immunology; D002648:Child; D002908:Chronic Disease; D005260:Female; D005434:Flow Cytometry; D006086:Graft vs Host Disease / Q000276:immunology*; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects*; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000276:immunology* / Q000628:therapy*; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D013601:T-Lymphocytes / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D018183:Transplantation Chimera; D014184:Transplantation, Homologous / Q000276:immunology
D015703:Antigens, CD