Immunohistochemical analysis of the novel marginal zone B-cell marker IRTA1 in malignant lymphoma.
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.
Department of Pathology, Osaka University Graduate School of Medicine, Suita 565-0871, Japan.
Jun-Ichiro
JI
Ikeda
Department of Pathology, Osaka University Graduate School of Medicine, Suita 565-0871, Japan.
Masaharu
M
Kohara
Department of Pathology, Osaka University Graduate School of Medicine, Suita 565-0871, Japan.
Yoko
Y
Tsuruta
Department of Pathology, Osaka University Graduate School of Medicine, Suita 565-0871, Japan.
Satoshi
S
Nojima
Department of Pathology, Osaka University Graduate School of Medicine, Suita 565-0871, Japan.
Shinichiro
S
Tahara
Department of Pathology, Osaka University Graduate School of Medicine, Suita 565-0871, Japan.
Kenji
K
Ohshima
Department of Pathology, Osaka University Graduate School of Medicine, Suita 565-0871, Japan.
Masako
M
Kurashige
Department of Pathology, Osaka University Graduate School of Medicine, Suita 565-0871, Japan.
Naoki
N
Wada
Department of Pathology, Osaka University Graduate School of Medicine, Suita 565-0871, Japan. Electronic address: morii@molpath.med.osaka-u.ac.jp.
Eiichi
E
Morii
D000906:Antibodies; D014408:Biomarkers, Tumor / Q000032:analysis*; D001706:Biopsy; D003937:Diagnosis, Differential; D006801:Humans; D007150:Immunohistochemistry; D018442:Lymphoma, B-Cell, Marginal Zone / Q000737:chemistry* / Q000473:pathology; D060787:Neoplasm Grading; D011237:Predictive Value of Tests; D011961:Receptors, Fc / Q000032:analysis*
D000906:Antibodies; D014408:Biomarkers, Tumor; C423544:FCRL4 protein, human; D011961:Receptors, Fc
IRTA1; Immunohistochemistry; MALT lymphoma; Malignant lymphoma; Marginal zone B cell