[The clinical significance of interphase fluorescence in situ hybridization monitoring chimeric status after sex-mismatched allogeneic hematopoietic stem cell transplantation for leukemia].
OBJECTIVE
To explore the association between chimerism, minimal residual disease (MRD) and relapse after sex-mismatched allogeneic hematopoietic stem cell transplantation (allo-HSCT) for leukemia.


METHODS
Fifty-seven patients with leukemia received allogeneic hematopoietic stem cell grafts from HLA-matched or partially matched, but sex-mismatched donors. Chimeric status and MRD were detected by dual-color interphase fluorescence in situ hybridization (I-FISH) using X/Y sex chromosome centromere DNA probe and bcr/abl dual fusion DNA probe, respectively, at different time points after transplantation. SPSS software was used to analyse the correlation between chimeric status, MRD and relapse.


RESULTS
In comparison with karyotype analysis, I-FISH was of higher sensitivity in detecting sex chromosome and bcr/abl fusion gene. Chimeric status was negatively correlated with MRD (r=-0.9690, P<0.01). In the early times of transplantation (within 3 months), mixed chimerism had higher relapse rate than did complete chimerism. Chimeric status and MRD were correlated with leukemic relapse (r=-8240, P<0.01; r=-0.9040, P<0.01). The decrease in chimeric status occurred before leukemic relapse in hematology.


CONCLUSIONS
I-FISH is a more specific and sensitive test for monitoring MRD after transplantation. The clinical value of sex chromosome is identical to that of the special tumor gene for monitoring MRD after transplantation. Chimeric status is negatively correlated with MRD. Chimeric status and MRD are associated with leukemic relapse. The decrease in chimeric status is considered a mark of leukemic relapse after transplantation.
Liu
Qifa
Q
Department of Hematology, Nanfang Hospital, First Military Medical University, Guangzhou, Guangdong,510515 P. R. China. liuqifa@fimmu.com
Song
Lanlin
L
Zhang
Yu
Y
Wei
Yongqiang
Y
Xu
Dan
D
Sun
Jing
J
Liu
Xiaoli
X
Xu
Bing
B
Meng
Fanyi
F
Zhou
Shuyun
S
D000293:Adolescent; D000328:Adult; D002648:Child; D041321:Chromosomes, Human, X / Q000235:genetics; D041322:Chromosomes, Human, Y / Q000235:genetics; D015342:DNA Probes / Q000235:genetics; D005260:Female; D016044:Fusion Proteins, bcr-abl / Q000235:genetics; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D007938:Leukemia / Q000235:genetics* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D018183:Transplantation Chimera / Q000235:genetics; D014184:Transplantation, Homologous; D055815:Young Adult
D015342:DNA Probes; D016044:Fusion Proteins, bcr-abl