Biol Blood Marrow Transplant 19 (2013) 1271-1273
Letters to the Editor
ASBMT
Letter-to-the Editor
American Society for Blood and Marrow Transplantation
Robert Peter Gale* From the Celgene Corporation
Two reports in a recent issue, by Arpinati et al. [1] and Goldman [2], touch on how to interpret results of highsensitivity PCR testing for BCR/ABL1 mRNA transcripts in persons with chronic myelogenous leukemia (CML). The authors sensibly argue that an occasional positive test should not be interpreted as indicating clinical relapse and should not precipitate an intervention. They then offer intriguing, sometimes complex, explanations of this observation. Might I add another? Ten years ago, in an interesting, dense, and completely ignored report by Butturini et al.[3] we showed, using mathematical modeling, that when there are few residual leukemia cells in a person, say 10E4, test sensitivity, rather than sampling error, predominates. Namely, because there are many residual leukemia cells in
the body, every sample is likely to contain 1 or more. An important corollary is that observations, such as a higher proportion of leukemia relapses in persons who are PCR-positive versus those who are PCR-negative, is fundamentally a self-fulfilling prophesy and does not prove the PCR test is a reliable surrogate for relapse in persons with few residual leukemia cells. This incorrect conclusion is common in interpreting results of MRD testing and not only in persons with CML. ACKNOWLEDGMENTS Conflict of interest statement: There are no conflicts of interest to report. Financial disclosure: The author has nothing to disclose.
* Correspondence and reprint requests: Robert Peter Gale, MD, PhD, Celgene Corporation. E-mail address:
[email protected]. http://dx.doi.org/10.1016/j.bbmt.2013.05.013
REFERENCES 1. Arpinati M, Tolomelli G, Bochicchio MT, et al. Molecular monitoring of BCR-ABL transcripts after allogeneic stem cell transplantation for chronic myeloid leukemia. Biol Blood Marrow Transplant. 2013;19:735-740. 2. Goldman JL. The significance of BCR-ABL transcripts after allogeneic stem cell transplantation for chronic myeloid leukemia. Biol Blood Marrow Transplant. 2013;19:679-680. 3. Butturini A, Klein J, Gale RP. Modeling minimal residual disease (MRD)-testing. Leuk Res. 2003;27:293-300.
Adoptive Transfer of Umbilical Cord Blood-Derived Regulatory T Cells and Early Viral Reactivation Claudio G. Brunstein 1, 2, *, Bruce R. Blazar 1, 3, Jeffrey S. Miller 1, 2, Qing Cao 1, Keli L. Hippen 1, 3, David H. McKenna 4, Julie Curtsinger 5, Philip B. McGlave 1, 2, John E. Wagner 1, 3 1
Blood and Marrow Transplant Program, University of Minnesota, Minneapolis, Minnesota Division of Medical Hematology, Oncology and Transplantation, University of Minnesota, Minneapolis, Minnesota Division of Pediatric Blood and Marrow Transplantation, University of Minnesota, Minneapolis, Minnesota 4 Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota 5 Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 2 3
We previously reported that the infusion of ex vivo expanded umbilical cord blood (UCB)-derived natural regulatory T cells (nTregs) infused immediately after UCB transplantation was associated with a reduced incidence of acute graft-versus-host disease (GVHD) relative to historical
control subjects [1]. We did not observe an increased incidence of opportunistic infections or relapse, suggesting the transient nature of nTreg provided sufficient immune suppression to control GVHD without long-term deleterious effects. However, we hypothesized that early side effects
1083-8791/$ e see front matter Ó 2013 American Society for Blood and Marrow Transplantation.
