Immunohistochemical analysis of the novel marginal zone B-cell marker IRTA1 in malignant lymphoma

Hum Pathol. 2017 Jan:59:70-79. doi: 10.1016/j.humpath.2016.09.011. Epub 2016 Sep 22.

Abstract

Marginal zone lymphoma (MZL) is a low-grade B-cell lymphoma derived from marginal zone B cells. Because of a lack of specific immunohistochemical markers, MZL is mainly diagnosed based on the cytological appearance and growth pattern of the tumor. Marginal zone B cells were recently shown to selectively express immunoglobulin superfamily receptor translocation-associated 1 (IRTA1), but the antibody used in that study is not commercially available. We therefore investigated the IRTA1 expression in nonneoplastic lymphoid tissues and 261 malignant lymphomas, examining the ability of a commercially available antibody to accurately diagnose MZL. Among 37 MZLs, 23 of 25 extranodal MZLs of mucosa-associated lymphoid tissue (MALT lymphomas), 3 of 6 splenic MZLs and 3 of 6 nodal MZLs were positive for IRTA1. Among the 98 diffuse large B-cell lymphomas, 33 were positive for IRTA1, including 1 of 38 follicular lymphomas, and all precursor B-lymphoblastic (2/2) and T-lymphoblastic (7/7) leukemia/lymphomas. Other mature B-cell and T-cell lymphomas, and Hodgkin lymphoma were negative for IRTA1. In MALT lymphoma, positive cells were detected mainly in intraepithelial and subepithelial marginal zone B cells. In 1 case of grade 3 follicular lymphoma, IRTA1 was also expressed in the area of large cell transformation. When tumors were classified as germinal center B cell-like (GCB) or non-GCB using the algorithm of Hans, positive expression of IRTA1 was correlated significantly with non-GCB diffuse large B-cell lymphomas (P < .05). These results demonstrated the ability of the commercially available IRTA1 antibody to distinguish MALT lymphoma from other low-grade B-cell lymphomas.

Keywords: IRTA1; Immunohistochemistry; MALT lymphoma; Malignant lymphoma; Marginal zone B cell.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies
  • Biomarkers, Tumor / analysis*
  • Biopsy
  • Diagnosis, Differential
  • Humans
  • Immunohistochemistry*
  • Lymphoma, B-Cell, Marginal Zone / chemistry*
  • Lymphoma, B-Cell, Marginal Zone / pathology
  • Neoplasm Grading
  • Predictive Value of Tests
  • Receptors, Fc / analysis*

Substances

  • Antibodies
  • Biomarkers, Tumor
  • FCRL4 protein, human
  • Receptors, Fc