Associations of Aberrant T Cell Antigen Expression on B Cells of Diffuse Large B Cell Lymphoma Patients with Their Background and Prognosis

With the exception of CD5, the clinical implications of aberrant T-cell antigen expression on B cells in diffuse large B cell lymphoma (DLBCL) have not been well studied. The present retrospective study aimed to determine associations between T cell antigen expression and patients′ characteristics and prognosis

Patients, Material and Methods: 249 cases with B-cell lymphoma (BCL) newly-diagnosed in our Institute between January 2002 and August 2009 were biopsied and also analyzed by flow cytometry. Biopsy specimens were fixed in formalin, stained with Hematoxylin-Eosin, and also immunostained. Histological subtypes were defined according to the World Health Organization Classification Version 3. Flow cytometric (F/C) analysis was performed following standard methods.

The aberrant expression of one or more T cell surface antigens on B cells (CD2, 3, 4, 7, 8) was assessed. Statistical analysis was conducted to seek associations between aberrant positive and negative cases and patients′ background laboratory data, and prognosis.

This study was approved by the Ethics Committee of Kitasato University School of Medicine.

150 DLBCL, 68 Follicular lymphoma (FL), 17 Marginal zone lymphoma (MZL), 6 MCL and 4 CLL patients were tested. Of the DLBCL cases, 12 (8%) showed aberrant T cell antigen expression with 4, 1, 5, 1 and 1 patients′ B cells positive for CD2, CD4, CD7, CD8 and CD7 + 8 respectively. Aberrant expression among the FL, MCL, MZL and CLL cases was seen in 0, 1, 1 and 1 patient, respectively.

Among the DLBCL patients, T antigen-negative cases tended to have higher WBC counts and greater CD20 expression by F/C analysis. No statistically significant associations with gender, age, IPI, clinical stage, laboratory data, expression of CD5 and other markers, ABC/GCB, or karyotype were observed between the positive and negative groups.

96 of the 150 DLBCL patients received rituximab-chemotherapy. Again, there were no statistically significant differences between the two groups in overall survival and response to treatment.

1) CD2 and CD7 are relatively common among aberrant T cell antigen- positive DLBCL. 2) No statistically significant differences were observed between the two groups in terms of background and prognosis. 3) Both CD8-positive DLBCL patients experienced a very aggressive clinical course and rapidly succumbed to their disease. CD8-positive DLBCL cases may in general have poorer survival. 4) Further analysis will be necessary to confirm these results.

No relevant conflicts of interest to declare.