ABSTRACT
<p><b>OBJECTIVE</b>To analyze CD21 expression in diffuse large B cell lymphoma (DLBCL) and to explore its relationship with the clinicopathological characteristics and prognosis.</p><p><b>METHODS</b>The clinical data from 80 DLBCL patients who were treated in First Hospital of Jilin University from June 2005 to September 2011 were retrospectively analyzed. The cases were subjected to immunohistochemical staining (SP method) for Ki-67, CD20, CD79a, CD3, CD43, CD5, cyclin D1, bcl-2, CD10, bcl-6, GCET-1, FOXP-1 and MUM-1 protein expression in the tumor tissue. Immunohistochemistry was also used to detect CD21 expression in the tumor tissue. SPSS 18.0 was used to analyze the relationship between CD21 expression and various clinical factors, and the relationship between various clinical factors including CD21 and overall survival.</p><p><b>RESULTS</b>In the patients aged under 60 years, the incidence of CD21(+) lymphoma (64.0%, 16/25) was significantly higher than that of CD21(-) lymphoma (38.2%, 21/55). There were more CD21(+) lymphoma patients who were at clinical stages I-II (52.0%, 13/25) than patients with CD21(-)lymphomas (23.6%, 13/55). There were also more CD21(+) lymphoma patients (68.0%, 17/25) having less than two extranodal sites involvement than CD21(-)lymphoma patients (41.8%, 23/55). In addition, there were more CD21(+) lymphoma patients with IPI 0-2 (68.0%, 17/25) than CD21(-)lymphoma patients (41.8%, 23/55). There were more CD21(+) lymphoma patients with GCB subtype (60.0%, 15/25) than CD21(-)lymphoma patients (23.6%, 13/55). Death related to DLBCL was less in CD21(+) lymphoma patients (32.0%, 8/25) than CD21(-) lymphoma patients (56.4%, 31/55). Univariate analysis showed that these clinical pathological characteristics affected the overall survival of DLBCL patients, including age, ECOG score, LDH, extranodal involvement, IPI index, CD21 expression, treatment option and efficacy (P < 0.05) . Cox multivariate analysis showed that ECOG score, LDH, extranodal involvement, CD21 expression were closely related to prognosis, and the difference was statistically significant (P < 0.05). Among the 80 patients, the overall survival (OS) of CD21(+) lymphoma patients was significantly higher than that of CD21(-) lymphoma patients.</p><p><b>CONCLUSIONS</b>The expression of CD21 is associated with young age at onset, early clinical stage, small number of involvement and low IPI index. The OS and median overall survival of CD21(+) lymphoma patients are significantly higher than those of CD21(-) patients. CD21 expression, ECOG score, LDH, extranodal involvement are independent prognostic factors in DLBCL, and in particular, the expression of CD21 is more significant in the prognosis of DLBCL patients.</p>