Chimerism analysis in peripheral blood using indel quantitative real-time PCR is a useful tool to predict post-transplant relapse in acute leukemia.
Detection of increasing mixed chimerism (IMC) using standard PCR correlates with relapse after allo-SCT for acute leukemias (ALs). Quantitative real-time PCR of insertion/deletion polymorphism (indel qrtPCR) is a much more sensitive method, which can be performed on peripheral blood. We studied the significance of low increases of recipient cells (0.1%) detected by indel qrtPCR in a cohort of 89 transplants. We did not observe relapse among the 32 patients with no IMC. Fifty-seven patients presented a first IMC, which was followed by four different scenarios: a decreasing MC (26 cases, no relapse), a stable MC (1 case, 1 relapse), a second IMC (24 cases, 15 relapse) or no control of chimerism (6 cases, 5 relapses). In multivariate analysis, detection of two successive IMCs was strongly associated with relapse (hazard ratio (HR): 9.4, 95% confidence interval (CI): 3.8-23; P<0.0001). Among the 57 patients who presented at least one IMC, 27 underwent immunomodulation (tapering of immunosuppression or donor lymphocyte injection), leading to a 1-year relapse rate of 15.7% vs 57.6% in the 30 other patients (P=0.0007). Altogether, these results indicate that chimerism analysis using indel qrtPCR in peripheral blood is a useful tool for detection of relapse in patients transplanted for AL.
Hematology Department, Pitié-Salpêtrière Hospital, Paris, France.
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Jacque
Hematology Department, Pitié-Salpêtrière Hospital, Paris, France.
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Nguyen
Biostatistics Department, Pitié-Salpêtrière Hospital, Paris, France.
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JL
Golmard
Hematology Department, Pitié-Salpêtrière Hospital, Paris, France.
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Uzunov
Hematology Department, Pitié-Salpêtrière Hospital, Paris, France.
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Garnier
Hematology Department, Pitié-Salpêtrière Hospital, Paris, France.
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Leblond
Hematology Department, Pitié-Salpêtrière Hospital, Paris, France.
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Vernant
Molecular Hematology Unit, Henri Mondor Hospital, Créteil, France.
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Bories
1] Hematology Department, Pitié-Salpêtrière Hospital, Paris, France [2] Adolescent Young Adult Unit, Hematology Department, Saint Louis Hospital, Paris, France.
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Dhédin
D000293:Adolescent; D000328:Adult; D000368:Aged; D064591:Allografts; D005260:Female; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000097:blood / Q000628:therapy; D008297:Male; D008875:Middle Aged; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000097:blood / Q000628:therapy; D060888:Real-Time Polymerase Chain Reaction; D012008:Recurrence; D012189:Retrospective Studies; D033581:Stem Cell Transplantation; D018183:Transplantation Chimera / Q000097:blood*