Impact of the soluble interleukin-2 receptor level in the relapsed or refractory phase on the clinical outcome of patients with diffuse large B-cell lymphoma

Predictive impact of soluble interleukin‐2 receptor and number of extranodal sites for identification of patients at very high risk of CNS relapse in diffuse large B‐cell lymphoma

There remains an unmet clinical need to identify which patients with diffuse large B‐cell lymphoma (DLBCL) would benefit from central nervous system (CNS) prophylaxis, due to the low positive predictive value (PPV; 10%–15%) of the currently available predictive models. To stratify patients at high risk of developing CNS relapse, we retrospectively analyzed 182 patients with DLBCL initially treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R‐CHOP), or a R‐CHOP‐like regimen. Among them, 17 patients relapsed with CNS involvement, and the 2‐year rate of CNS relapse was 7.9%. Upon carrying out multivariate analysis, ≥3 extranodal sites and elevated soluble interleukin‐2 receptor (sIL‐2R) levels at diagnosis were identified as independent risk factors for CNS relapse. The 2‐year and 3.5‐year rates of CNS relapse were 57.1% and 78.6%, respectively, in patients with both elevated sIL‐2R and ≥3 extranodal sites. Furthermore, combined use of these risk factors of both elevated sIL‐2R and ≥3 extranodal sites resulted in a high PPV (71.4%), negative predictive value (93.1%), and overall accuracy (92.3%) for undergoing CNS relapse. In conclusion, we propose a simple and valuable tool to predict patients with DLBCL at very high risk of CNS relapse.

Measurement of the concentration of serum soluble interleukin-2 receptor alpha chain in dogs with lymphoma

Soluble interleukin-2 receptor (sIL-2r) is released directly from the surface of lymphocytes expressing interleukin-2 receptor alpha chain (CD25), and its serum concentration has been found to reflect the prognosis of human lymphoproliferative malignancies. In this study, we demonstrated the presence of sIL-2r in canine serum and developed a specific sandwich enzyme-linked immunosorbent assay (ELISA) to quantify the concentration of canine serum sIL-2r. In the immunoprecipitation (IP) assay, CD25 protein weighing approximately 45 kDa was detected in canine serum, smaller than the membrane-bound CD25 (approximately 55 kDa). To measure the concentration of serum sIL-2r in dogs, an ELISA system was developed. Serum sIL-2r levels were significantly higher in dogs with multicentric high-grade B-cell lymphoma before therapy than that in healthy dogs. Serum sIL-2r concentration was also found to be elevated in a proportion of dogs with other types of lymphoma. Changes in serum sIL-2r levels generally paralleled the changes in mass and lymph node size in dogs with high-grade B-cell lymphoma. This study demonstrated that serum sIL-2r level would be a marker to monitor tumour growth and regression in canine lymphoma.

Insignificance of surveillance imaging in patients with diffuse large B-cell lymphoma who achieved first complete remission: a retrospective cohort study

The aim of this study was to evaluate the value of scheduled imaging for patients who achieved first complete remission after CHOP-like chemotherapy plus rituximab. In this retrospective cohort study, we included 759 patients newly diagnosed with de novo diffuse large B-cell lymphoma (DLBCL) at the Cancer Institute, Japanese Foundation for Cancer Research. Relapsed patients were divided into two groups based on method of diagnosis: clinical symptoms (symptom group, n = 57) or scheduled imaging (imaging group, n = 27). Our primary goal was to compare overall survival and relapse-free survival between the two groups. No significant difference in outcomes was found between the symptom and imaging groups. Median overall survival [7.5 years; 95% confidence interval (CI) 4.0-9.7 vs. 9.1 years; 95% CI 2.7 to not reached; P = 0.747), and median relapse-free survival (1.8 years; 95% CI 1.4-2.5 vs. 2.4 years; 95% CI 1.2-4.4; P = 0.108). Surveillance imaging in patients with DLBCL who achieved first complete remission did not demonstrate an advantage in terms of overall survival or relapse-free survival.