LILRB1: A Novel Diagnostic B-Cell Marker to Distinguish Neoplastic B Lymphoblasts From Hematogones

Am J Clin Pathol. 2021 Nov 8;156(6):941-949. doi: 10.1093/ajcp/aqab057.

Abstract

Objectives: New B-cell markers are needed for monitoring B lymphoblastic leukemia (B-ALL) in the era of immunotherapies directed against CD19 and CD22. The expression of leukocyte immunoglobulin-like receptor subfamily B member 1 (LILRB1) on hematogones in bone marrow (BM) and neoplastic B lymphoblasts has not yet been systematically investigated.

Methods: We assessed LILRB1 expression pattern on B cells in 19 control BMs and 22 B-ALL cases by flow cytometry.

Results: In all cases, mature B cells and hematogones exhibited a consistent pattern of LILRB1 expression with variable intensity over different stages of maturation, including a characteristic V-shaped pattern on hematogones. While neoplastic B lymphoblasts in all cases expressed LILRB1, the pattern of expression was distinctly abnormal relative to hematogones (loss of the dynamic pattern in all cases and abnormal expression levels in 83% of cases).

Conclusions: LILRB1 is a novel diagnostic B-cell marker to aid in distinguishing neoplastic B lymphoblasts from hematogones.

Keywords: Anti-CD22; B-lymphoblastic leukemia; Flow cytometry; LILRB1; Minimal residual disease.

MeSH terms

  • Antigens, CD*
  • B-Lymphocytes / immunology
  • B-Lymphocytes / pathology
  • Flow Cytometry
  • Humans
  • Immunophenotyping
  • Leukocyte Immunoglobulin-like Receptor B1*
  • Lymphocytes
  • Precursor B-Cell Lymphoblastic Leukemia-Lymphoma* / immunology
  • Precursor B-Cell Lymphoblastic Leukemia-Lymphoma* / pathology
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma*

Substances

  • Antigens, CD
  • LILRB1 protein, human
  • Leukocyte Immunoglobulin-like Receptor B1