Performance of serum soluble interleukin-2 receptor as a diagnostic marker for lymphoma in patients with fever

Abstract

Abstract There have been few reports on the diagnostic performance of soluble interleukin-2 receptor (sIL-2R) for lymphoma. A cross-sectional study was conducted at an university hospital. All patients who were admitted to the Division of General Internal Medicine and underwent serum sIL-2R testing were included. Patients were divided into two groups based on the presence of fever (≥ 38.0oC). Among 602 patients, 421 had fever and 80 were diagnosed with lymphoma (52 of the 80 were in the febrile group). In all patients, the area under the receiver operating characteristic curve (AUROC) of sIL-2R for the diagnosis of lymphoma was 0.82 (95% confidence interval [CI], 0.76–0.87). The AUROC was significantly higher in the febrile group (0.88; 95% CI, 0.83–0.94) than in the afebrile group (0.75; 95% CI, 0.65–0.85). In the febrile group, the sensitivity and specificity were 82.7% and 83.5%, respectively, with an optimal cutoff value of 3,250 U/mL. In the afebrile group, they were 89.3% and 55.6%, respectively, with a value of 868 U/mL. Serum sIL-2R showed high performance as an adjunctive diagnostic marker for lymphoma, particularly among febrile patients. Different cutoff values should be used for patients with and without fever to maximize the diagnostic performance.