Serum Soluble CD163 Levels as a Prognostic Biomarker in Patients with Diffuse Large B-Cell Lymphoma Treated with Chemoimmunotherapy

Soluble CD163 (sCD163) functions as a scavenger receptor for haptoglobin-hemoglobin complexes, and is mostly expressed by monocytes and macrophages. The level of soluble CD163 has been used to determine macrophage activation. Our goal was to determine whether the loading of M2 CD163 positive tumor-associated macrophages (TAMs) through the secretion of sCD163 affects overall survival in patients with DLBCL and eventually discriminates subgroups of patients with different prognosis. sCD163 levels were measured in 40 frozen serum samples from patients diagnosed with DLBCL and 30 healthy individuals (HI) using an enzyme-linked immunosorbent assay (ELISA). Statistical analyses were performed using SPSS version 28. The results showed that patients who achieved complete response after standard-of-care immuno-chemotherapy and were alive and disease-free after 12 months of follow-up, but had elevated sCD163 levels (above median) at diagnosis, presented a significantly worse overall survival compared to those with initial serum sCD163 levels below median (p=0.03). Consequently, serum sCD163 level in DLBCL patients may constitute a marker of long-term response to chemo-immunotherapy.