METHODS FOR IDENTIFYING LEUKEMIA STEM CELLS AND DISTINGUISHING THEM FROM NORMAL HEMATOPIETIC STEM CELLS IN PATIENTS WITH ACUTE MYELOID LEUKEMIA: USES IN DIAGNOSIS, TREATMENT, AND RESEARCH

• US 20130079424A1
• Filed: 09/24/2012
• Published: 03/28/2013
• Est. Priority Date: 09/22/2011
• Status: Active Grant

• Current Assignee: Johns Hopkins University
• Original Assignee: Johns Hopkins University
• Inventors: Jones, Richard John, Gerber, Jonathan Michael
• Granted Patent: US 9,012,215 B2
• Time in Patent Office: Days
• US Class Current: 514/789
• CPC Class Codes: C12Q 1/32 involving dehydrogenase
• CPC Class Codes: G01N 2800/54 Determining the risk of relapse
• CPC Class Codes: G01N 33/57426 leukemia

Abstract

Using the methods of the present invention, intermediate (int) levels of aldehyde dehydrogenase (ALDH) activity reliably distinguished leukemic CD34⁺CD38⁻ cells capable of engrafting immunodeficient mice, from residual normal hematopoietic stem cells that exhibited relatively higher ALDH activity. Minimal residual disease (MRD) detected during complete remission was enriched for the CD34⁺CD38⁻ALDH^int leukemic cells, and the presence of these cells after therapy highly correlated with subsequent clinical relapse. The methods of the present invention can distinguish normal from leukemic CD34⁺CD38⁻ cells, and identifies those AML cells associated with relapse. Methods of prediction of relapse of AML patients and methods of treatment are also provided.

Claims

1. A method for identifying the presence of leukemic stem cells (LSC) in a sample from a subject suffering from AML comprising:

a) obtaining a biological sample from a subject;

b) isolating CD34⁺CD38⁻

mononuclear cells or population of cells from the sample;

c) measuring the ALDH activity of the cells or population of cells of b); and

d) identifying the cells from c) that have a intermediate level of ALDH activity (CD34⁺CD38⁻

ALDH^int) as being LSC.

2. A method for prediction of an increased risk of relapse after treatment in a subject suffering from AML comprising:

a) treating the subject suffering from AML with appropriate therapy;

b) obtaining a post-therapy biological sample from a subject;

c) isolating CD34⁺CD38⁻

mononuclear cells or population of cells from the sample;

d) measuring the ALDH activity of the cells or population of cells of c);

e) identifying the cells from c) that have a intermediate level of ALDH activity (CD34⁺CD38⁻

ALDH^int) as being LSC; and

f) determining that the subject has an increased risk for relapse of AML, and/or require further treatment, when the presence of LSC are detected.

3. In accordance with a further embodiment, the present invention provides a method for treatment of a subject suffering from AML comprising:

a) obtaining a pre- and/or post-therapy biological sample from a subject;

b) isolating CD34⁺CD38⁻

mononuclear cells or population of cells from the sample;

c) measuring the ALDH activity of the cells or population of cells of c);

d) identifying the cells from c) that have a intermediate level of ALDH activity (CD34⁺CD38⁻

ALDH^int) as being LSC;

e) treating the subject suffering from AML with appropriate therapy;

f) repeating steps a) to e); and

g) determining that the subject has completed treatment for AML when the presence of LSC are not detected.

4. The method of claim 3, wherein the method further comprises repeating steps a) to e) if the presence of LSC are detected.