title: Detection of minimal residual disease in B lymphoblastic leukemia by high-throughput sequencing of IGH.
abstract: OBJECTIVE
  High-throughput sequencing (HTS) of immunoglobulin heavy-chain genes (IGH) in unselected clinical samples for minimal residual disease (MRD) in B lymphoblastic leukemia (B-ALL) has not been tested. As current MRD-detecting methods such as flow cytometry or patient-specific qPCR are complex or difficult to standardize in the clinical laboratory, sequencing may enhance clinical prognostication.
  
  
  METHODS
  We sequenced IGH in paired pretreatment and day 29 post-treatment samples using residual material from consecutive, unselected samples from the Children's Oncology Group AALL0932 trial to measure MRD as compared with flow cytometry. We assessed the impact of ongoing recombination at IGH on MRD detection in post-treatment samples. Finally, we evaluated a subset of cases with discordant MRD results between flow cytometry and sequencing.
  
  
  RESULTS
  We found clonal IGH rearrangements in 92 of 98 pretreatment patient samples. Furthermore, while ongoing recombination of IGH was evident, index clones typically prevailed in MRD-positive post-treatment samples, suggesting that clonal evolution at IGH does not contribute substantively to tumor fitness. MRD was detected by sequencing in all flow cytometry-positive cases with no false-negative results. In addition, in a subset of patients, MRD was detected by sequencing, but not by flow cytometry, including a fraction with MRD levels within the sensitivity of flow cytometry. We provide data that suggest that this discordance in some patients may be due to the phenotypic maturation of the transformed cell.
  
  
  CONCLUSIONS
  Our results provide strong support for HTS of IGH to enhance clinical prognostication in B-ALL.
authors: Department of Laboratory Medicine, University of Washington, Seattle, Washington.
authors: David
authors: D
authors: Wu
authors: Adaptive Biotechnologies, Seattle, Washington.
authors: Ryan O
authors: RO
authors: Emerson
authors: Adaptive Biotechnologies, Seattle, Washington.
authors: Anna
authors: A
authors: Sherwood
authors: Pediatric Hematology/Oncology, University of California, San Francisco, San Francisco, California.
authors: Mignon L
authors: ML
authors: Loh
authors: Children's National Medical Center, The George Washington University of Medicine, Washington, DC.
authors: Anne
authors: A
authors: Angiolillo
authors: Adaptive Biotechnologies, Seattle, Washington.
authors: Bryan
authors: B
authors: Howie
authors: Adaptive Biotechnologies, Seattle, Washington.
authors: Jennifer
authors: J
authors: Vogt
authors: Adaptive Biotechnologies, Seattle, Washington.
authors: Mark
authors: M
authors: Rieder
authors: Adaptive Biotechnologies, Seattle, Washington.
authors: Ilan
authors: I
authors: Kirsch
authors: Adaptive Biotechnologies, Seattle, Washington.
authors: Christopher
authors: C
authors: Carlson
authors: Adaptive Biotechnologies, Seattle, Washington.
authors: David
authors: D
authors: Williamson
authors: Department of Laboratory Medicine, University of Washington, Seattle, Washington.
authors: Brent L
authors: BL
authors: Wood
authors: Fred Hutchinson Cancer Research Center, Seattle, Washington. hrobins@fhcrc.org.
authors: Harlan
authors: H
authors: Robins
mesh_terms: D018572:Disease-Free Survival; D005434:Flow Cytometry; D015326:Gene Rearrangement, B-Lymphocyte, Heavy Chain / Q000235:genetics; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D015448:Leukemia, B-Cell / Q000150:complications / Q000235:genetics* / Q000473:pathology; D018365:Neoplasm, Residual / Q000209:etiology / Q000235:genetics* / Q000473:pathology; D011379:Prognosis
chemical_list: D007143:Immunoglobulin Heavy Chains