MOLECULAR DETECTION OF ALL IN THE PERIPHERAL BLOOD IS MORE SENSITIVE THAN FLOW CYTOMETRIC ANALYSIS OF THE BONE MARROW IN PATIENTS WITH TREATMENT-RELATED HYPOCELLULARITY
(Abstract release date: 05/19/16)
EHA Library. Kirsch I. 06/09/16; 132403; E854
Dr. Ilan Kirsch
Contributions
Contributions
Abstract
Abstract: E854
Type: Eposter Presentation
Background
Minimal residual disease detection (MRD) is an important tool for early detection and monitoring relapse. Traditionally, bone marrow is collected and analyzed by flow cytometry (FC) to evaluate MRD status in acute lymphoblastic leukemia patients (ALL). More recently, highly sensitive molecular methods such as high throughput sequencing (HTS) allow for more sensitive detection of MRD below 1 in 10-5. Although the bone marrow is considered to be more representative of leukemic burden than sampling the blood, bone marrow collection is more invasive, traumatic, and costly than peripheral blood draws and therefore is performed only at specified and limited intervals. Paired bone marrow and blood samples from ALL patients can be assessed and compared for MRD at different time points in therapy.
Aims
In this study, we analyzed paired blood and bone marrow samples from the Adaptive Biotechnologies assay of IgH and TCRG in order to determine whether HTS performed on a peripheral blood sample is as informative as HTS and FC on a bone marrow sample in the assessment of MRD.
Methods
ALL patients enrolled in the Seattle Children’s Pediatric Leukemia Adoptive Therapy (PLAT-02) trial undergo MRD assessment pre and post CD19 CAR T cell infusion by FC of the bone marrow. We have used high throughput sequencing (HTS) in paired blood and bone marrow samples from these patients. Samples taken prior to therapy evaluate the complete B cell repertoire and detect any dominant sequences which may be used for subsequent tracking. Samples taken at intervals during therapy assess the levels of MRD up to 63 days post-infusion.
Results
We have obtained 38 paired bone marrow and peripheral blood samples to date. We have observed a significant correlation in both the frequency of total reads and the number of malignant cells per million in paired peripheral blood and bone marrow samples by HTS. Of these, 26/38 (68%) of bone marrow samples were determined either aparticulate or hypocellular. Importantly, 8/14 (57%) of patients who were MRD negative in the bone marrow by FC were MRD positive in the blood by HTS. While it may only be true of patients receiving this particular form of treatment, there were some samples assayed by immunosequencing in which peripheral blood was a more sensitive measure of tumor burden than simultaneously acquired bone marrow. These data suggest, that, in cases where the bone marrow is hypocellular or aparticulate, peripheral blood samples evaluated by HTS are more sensitive than traditional flow cytometric analysis in the bone marrow for detection of MRD.
Conclusion
The impact of B cell aplasia may be important in increasing the sensitivity of HTS in the detection of MRD. The ability to detect an ALL B cell clone in the blood through HTS has many clinical implications; blood can be sampled more often, is less of a burden to patients, and can provide earlier prediction of relapse.
Session topic: E-poster
Keyword(s): Acute lymphoblastic leukemia, Ig and TCR gene rearrangement, Monitor
Type: Eposter Presentation
Background
Minimal residual disease detection (MRD) is an important tool for early detection and monitoring relapse. Traditionally, bone marrow is collected and analyzed by flow cytometry (FC) to evaluate MRD status in acute lymphoblastic leukemia patients (ALL). More recently, highly sensitive molecular methods such as high throughput sequencing (HTS) allow for more sensitive detection of MRD below 1 in 10-5. Although the bone marrow is considered to be more representative of leukemic burden than sampling the blood, bone marrow collection is more invasive, traumatic, and costly than peripheral blood draws and therefore is performed only at specified and limited intervals. Paired bone marrow and blood samples from ALL patients can be assessed and compared for MRD at different time points in therapy.
Aims
In this study, we analyzed paired blood and bone marrow samples from the Adaptive Biotechnologies assay of IgH and TCRG in order to determine whether HTS performed on a peripheral blood sample is as informative as HTS and FC on a bone marrow sample in the assessment of MRD.
Methods
ALL patients enrolled in the Seattle Children’s Pediatric Leukemia Adoptive Therapy (PLAT-02) trial undergo MRD assessment pre and post CD19 CAR T cell infusion by FC of the bone marrow. We have used high throughput sequencing (HTS) in paired blood and bone marrow samples from these patients. Samples taken prior to therapy evaluate the complete B cell repertoire and detect any dominant sequences which may be used for subsequent tracking. Samples taken at intervals during therapy assess the levels of MRD up to 63 days post-infusion.
Results
We have obtained 38 paired bone marrow and peripheral blood samples to date. We have observed a significant correlation in both the frequency of total reads and the number of malignant cells per million in paired peripheral blood and bone marrow samples by HTS. Of these, 26/38 (68%) of bone marrow samples were determined either aparticulate or hypocellular. Importantly, 8/14 (57%) of patients who were MRD negative in the bone marrow by FC were MRD positive in the blood by HTS. While it may only be true of patients receiving this particular form of treatment, there were some samples assayed by immunosequencing in which peripheral blood was a more sensitive measure of tumor burden than simultaneously acquired bone marrow. These data suggest, that, in cases where the bone marrow is hypocellular or aparticulate, peripheral blood samples evaluated by HTS are more sensitive than traditional flow cytometric analysis in the bone marrow for detection of MRD.
Conclusion
The impact of B cell aplasia may be important in increasing the sensitivity of HTS in the detection of MRD. The ability to detect an ALL B cell clone in the blood through HTS has many clinical implications; blood can be sampled more often, is less of a burden to patients, and can provide earlier prediction of relapse.
Session topic: E-poster
Keyword(s): Acute lymphoblastic leukemia, Ig and TCR gene rearrangement, Monitor
Abstract: E854
Type: Eposter Presentation
Background
Minimal residual disease detection (MRD) is an important tool for early detection and monitoring relapse. Traditionally, bone marrow is collected and analyzed by flow cytometry (FC) to evaluate MRD status in acute lymphoblastic leukemia patients (ALL). More recently, highly sensitive molecular methods such as high throughput sequencing (HTS) allow for more sensitive detection of MRD below 1 in 10-5. Although the bone marrow is considered to be more representative of leukemic burden than sampling the blood, bone marrow collection is more invasive, traumatic, and costly than peripheral blood draws and therefore is performed only at specified and limited intervals. Paired bone marrow and blood samples from ALL patients can be assessed and compared for MRD at different time points in therapy.
Aims
In this study, we analyzed paired blood and bone marrow samples from the Adaptive Biotechnologies assay of IgH and TCRG in order to determine whether HTS performed on a peripheral blood sample is as informative as HTS and FC on a bone marrow sample in the assessment of MRD.
Methods
ALL patients enrolled in the Seattle Children’s Pediatric Leukemia Adoptive Therapy (PLAT-02) trial undergo MRD assessment pre and post CD19 CAR T cell infusion by FC of the bone marrow. We have used high throughput sequencing (HTS) in paired blood and bone marrow samples from these patients. Samples taken prior to therapy evaluate the complete B cell repertoire and detect any dominant sequences which may be used for subsequent tracking. Samples taken at intervals during therapy assess the levels of MRD up to 63 days post-infusion.
Results
We have obtained 38 paired bone marrow and peripheral blood samples to date. We have observed a significant correlation in both the frequency of total reads and the number of malignant cells per million in paired peripheral blood and bone marrow samples by HTS. Of these, 26/38 (68%) of bone marrow samples were determined either aparticulate or hypocellular. Importantly, 8/14 (57%) of patients who were MRD negative in the bone marrow by FC were MRD positive in the blood by HTS. While it may only be true of patients receiving this particular form of treatment, there were some samples assayed by immunosequencing in which peripheral blood was a more sensitive measure of tumor burden than simultaneously acquired bone marrow. These data suggest, that, in cases where the bone marrow is hypocellular or aparticulate, peripheral blood samples evaluated by HTS are more sensitive than traditional flow cytometric analysis in the bone marrow for detection of MRD.
Conclusion
The impact of B cell aplasia may be important in increasing the sensitivity of HTS in the detection of MRD. The ability to detect an ALL B cell clone in the blood through HTS has many clinical implications; blood can be sampled more often, is less of a burden to patients, and can provide earlier prediction of relapse.
Session topic: E-poster
Keyword(s): Acute lymphoblastic leukemia, Ig and TCR gene rearrangement, Monitor
Type: Eposter Presentation
Background
Minimal residual disease detection (MRD) is an important tool for early detection and monitoring relapse. Traditionally, bone marrow is collected and analyzed by flow cytometry (FC) to evaluate MRD status in acute lymphoblastic leukemia patients (ALL). More recently, highly sensitive molecular methods such as high throughput sequencing (HTS) allow for more sensitive detection of MRD below 1 in 10-5. Although the bone marrow is considered to be more representative of leukemic burden than sampling the blood, bone marrow collection is more invasive, traumatic, and costly than peripheral blood draws and therefore is performed only at specified and limited intervals. Paired bone marrow and blood samples from ALL patients can be assessed and compared for MRD at different time points in therapy.
Aims
In this study, we analyzed paired blood and bone marrow samples from the Adaptive Biotechnologies assay of IgH and TCRG in order to determine whether HTS performed on a peripheral blood sample is as informative as HTS and FC on a bone marrow sample in the assessment of MRD.
Methods
ALL patients enrolled in the Seattle Children’s Pediatric Leukemia Adoptive Therapy (PLAT-02) trial undergo MRD assessment pre and post CD19 CAR T cell infusion by FC of the bone marrow. We have used high throughput sequencing (HTS) in paired blood and bone marrow samples from these patients. Samples taken prior to therapy evaluate the complete B cell repertoire and detect any dominant sequences which may be used for subsequent tracking. Samples taken at intervals during therapy assess the levels of MRD up to 63 days post-infusion.
Results
We have obtained 38 paired bone marrow and peripheral blood samples to date. We have observed a significant correlation in both the frequency of total reads and the number of malignant cells per million in paired peripheral blood and bone marrow samples by HTS. Of these, 26/38 (68%) of bone marrow samples were determined either aparticulate or hypocellular. Importantly, 8/14 (57%) of patients who were MRD negative in the bone marrow by FC were MRD positive in the blood by HTS. While it may only be true of patients receiving this particular form of treatment, there were some samples assayed by immunosequencing in which peripheral blood was a more sensitive measure of tumor burden than simultaneously acquired bone marrow. These data suggest, that, in cases where the bone marrow is hypocellular or aparticulate, peripheral blood samples evaluated by HTS are more sensitive than traditional flow cytometric analysis in the bone marrow for detection of MRD.
Conclusion
The impact of B cell aplasia may be important in increasing the sensitivity of HTS in the detection of MRD. The ability to detect an ALL B cell clone in the blood through HTS has many clinical implications; blood can be sampled more often, is less of a burden to patients, and can provide earlier prediction of relapse.
Session topic: E-poster
Keyword(s): Acute lymphoblastic leukemia, Ig and TCR gene rearrangement, Monitor
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