The use of serum interleukin-2 receptor value for diagnosis of malignant lymphoma.

Abstract

e19507 Background: Serum soluble interleukin-2 receptor (sIL2R) has been anecdotally used for diagnosis of malignant lymphoma (ML). However, sensitivity and specificity have not been evaluated; therefore, there is no consensus for the appropriate cut-off value for diagnosis of ML. Methods: We retrospectively analyzed sIL2R values at initial presentation in the patients who were diagnosed with ML. We compared them with the sIL2R values in the patients who presented with lymphadenopathy but were not diagnosed with ML. Results: In 496 patients with ML, 232 patients were diagnosed with diffuse large B-cell lymphoma (DLBCL), 109 with follicular lymphoma (FL), 40 with T-cell lymphoma (TCL), 39 with Hodgkin lymphoma (HL), 16 with marginal zone B-cell lymphoma (MZBCL), 12 with mantle cell lymphoma (MCL) and 21 with others. In the 69 control patients who did not have ML, 22 patients were diagnosed with metastatic lymph nodes of cancer, 14 with reactive lymph nodes, 12 with Kikuchi’s disease (histiocytic necrotizing lymphadenitis), 6 with granulomatous lymphadenitis (including mycobacterial infection), 3 with sarcoidosis, 2 with infectious mononucleosis (in combination with clinical diagnosis), 1 with Castleman’s disease and 9 with others. Mean value of sIL2R in the patients with ML was 4223U/ml (95% confidence interval, CI: 3251-5196). It was significantly higher than that in patients not having ML (mean: 1072U/ml, 95%CI: 788-1356, p<0.0001, t-test). The sensitivity and specificity were calculated based on our results. When the cut-off value was set at 1000U/ml, sensitivity for diagnosis of ML was 64% and specificity was 68%. When the cut-off value was set at 2000U/ml, sensitivity was 41% and specificity was 86%. According to histologic subtypes, mean sIL2R values were 4592U/ml (95%CI: 3690-6088) in DLBCL, 2166U/ml (95%CI: 1669-2664) in FL, 6510U/ml (95%CI: 3692-9329) in TCL, 1395U/ml (95%CI: 550-2240) in MZBCL, 2956U/ml (95%CI: 1736-4175) in HL and 3264U/ml (95%CI: 1734-4795) in MCL. Mean sIL2R value in each histologic subtype, except for MZBCL, was significantly higher than that in patients not having ML. Conclusions: Our study suggests that sIL2R value is useful for diagnosis of ML other than MZBCL.