Clinicopathologic characteristics of patients with kidney-involved diffuse large B-cell lymphoma

Objective·To analyze the clinicopathologic characteristics of patients with kidney-involved diffuse large B-cell lymphoma (DLBCL), including clinical characteristics, pathological characteristics, gene mutation profiles, and prognostic factors.Methods·One hundred and forty-nine patients with kidney-involved DLBCL, admitted to Ruijin Hospital, Shanghai Jiao Tong University School of Medicine from July 2005 to November 2021, were retrospectively analyzed for their clinicopathological data, survival and prognostic factors, which included therapeutic methods, clinical outcomes, staging, etc. Gene mutation profiles were evaluated by targeted sequencing of 54 lymphoma-related genes. Prognostic factors were also analyzed based on the information mentioned above.Results·A total of 149 kidney-involved DLBCL cases were included, of which 89 patients (58.4%) were aged over sixty, 121 patients (81.2%) were staged Ann Arbor Ⅲ‒Ⅳ, 27 patients (18.1%) had an Eastern Cooperative Oncology Group (ECOG) performance status of two or more, 121 patients (81.2%) had elevated serum lactate dehydrogenase (LDH) level, 111 patients (74.5%) had extranodal invasion in at least two organs and 131 patients (87.9%) scored over 2 points on the international prognosis index (IPI). The estimated 5-year overall survival (OS) rate and progression-free survival (PFS) rate of kidney-involved DLBCL patients were 52.2% and 50.4% respectively. Univariate analysis revealed that elevated serum LDH levels were an adverse prognostic factor for both OS (P=0.048) and PFS (P=0.033). In pathological characteristics, 145 patients (97.3%) belonged to DLBCL, not otherwise specified (NOS) and 39 patients (26.3%) belonged to germinal center B-cell (GCB) according to Hans classification. Among 144 patients who could be evaluated for clinical outcomes, 87 patients (60.4%) got complete response (CR). Targeted sequencing data from 75 kidney-involved DLBCL patients showed high mutation frequency in PIM1 (n=23, 31%), MYD88 (n=22, 29%), CD79B (n=21, 28%) and KMT2D (n=18, 24%), with CD79B mutation indentified as an adverse prognostic factor for OS in patients with kidney-involved DLBCL (P=0.034).Conclusion·Elevated serum LDH level is an adverse prognostic factor in patients with kidney-involved DLBCL. The prognosis of patients with CD79B mutations is poor.