Prevalence of chimerism after non-myeloablative hematopoietic stem cell transplantation.
OBJECTIVE
Non-myeloablative hematopoietic stem cell transplantation (NMA-HSCT) is performed in onco-hematological patients who cannot tolerate ablative conditioning because of older age or comorbidities. This approach does not completely eliminate host cells and initially results in mixed chimerism. Long-term persistence of mixed chimerism results in graft rejection and relapse. Involvement of graft-versus-host disease is concomitant with complete chimerism and graft-versus-tumor effect. The aim of this study was to evaluate the prevalence of chimerism in onco-hematological patients who underwent NMA-HSCT.


METHODS
Observational clinical study on chimerism status after human leukocyte antigen-identical NMA-HSCT at the Discipline of Hematology and Hemotherapy of Universidade Federal de São Paulo.


METHODS
We sequentially analyzed the amplification of APO-B, D1S80, DxS52, FVW, 33.6, YNZ-2 and H-ras primers using variable number of tandem repeats (VNTR) on 17 pairs and fluorescent in situ hybridization (FISH) with the XY probe and SRY primer on 13 sex-unmatched pairs.


RESULTS
The informativeness of the primers using VNTR was 60% for APO-B, 75% D1S80, 36% DxS52, 14% FVW, 40% YNZ-22 and 16% H-ras. The SRY primer was informative in female receptors with male donors. The XY-FISH method was informative in 100% of the sex-unmatched pairs.


CONCLUSIONS
These methods were sensitive and informative. In VNTR, the association of APO-B with D1S80 showed 88% informativeness. The quantitative FISH method was more sensitive, but had the disadvantage of only being used for sex-unmatched pairs.
Ruiz
Azulamara da Silva
Ada S
Division of Hematology and Transfusion Medicine, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil.
Chauffaille
Maria de Lourdes Ferrari
Mde L
Alves
Solivanda Trindade
ST
Oliveira
José Salvador Rodrigues de
JS
D000328:Adult; D004812:Epidemiologic Methods; D005260:Female; D005784:Gene Amplification / Q000235:genetics; D005819:Genetic Markers; D006086:Graft vs Host Disease / Q000235:genetics* / Q000517:prevention & control; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects / Q000379:methods; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D018598:Minisatellite Repeats; D009101:Multiple Myeloma / Q000601:surgery*; D018183:Transplantation Chimera / Q000235:genetics*
D005819:Genetic Markers