Clinical relevance of immunologic phenotype in diffuse large cell lymphoma

The immunologic phenotypes of 78 diffuse large cell lymphomas were determined by an immunoperoxidase technique using a panel of monoclonal antibodies. The phenotypes were correlated with clinical and morphological parameters by univariate and multivariate analysis. Forty-one lymphomas (53%) expressed immunoglobulin (Ig+). Of the 37 cases that did not express immunoglobulin (Ig-), 9 expressed T cell antigens. Although the T cell phenotypes were antigenically heterogeneous, all cases represented mature T cell phenotypes. The majority of the remaining 28 cases expressed the B cell-associated antigen, B1. At 5 yr, actuarial survival for the Ig- patients was 63%, compared with 15% for the Ig+ patients. A significantly greater proportion of patients with Ig+ lymphomas were over the age of 65 at diagnosis. All of the 9 patients with marrow involvement were Ig+. Multiple factors were analyzed by the Cox regression procedure for their impact on survival, including antigenic profile, histologic grade, morphological classification, and numerous clinical parameters previously recognized to be of prognostic significance. In this analysis, stage, age greater than 65 yr, systemic symptoms, and marrow involvement had the greatest influence on survival. The survival difference between Ig- and Ig+ patients is explained by a higher proportion of Ig+ patients with these unfavorable prognostic factors. With our current immunologic methods, retrospective cell phenotyping analysis has not provided independent prognostic significance in diffuse large cell lymphoma. A prospective evaluation of similarly treated patients is needed to characterize the influence of phenotype fully and to determine its potential usefulness for therapy.