CD163+ Tumor Associated Macrophages Predict Inferior Outcome in Patients with Diffuse Large B-Cell Lymphoma Treated with R-CHOP

Tumor-associated macrophages (TAMs), as the major component in tumor microenvironment, have been reported to correlate with the prognosis in diffuse large B-cell lymphoma (DLBCL). However due to the different subtypes of TAMs and the given therapy regimen, the prognostic value of TAMs in DLBCL patients remains controversial. To explore the prognostic significance of different TAMs subtypes in DLBCL patients treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone), we retrospectively analyzed 77 de novo DLBCL patients in present study.

TAM markers including CD68 and CD163 were evaluated by immunohistochemistry. The cutoff value of CD68, CD163 and CD163/CD68 ratio was determined by receiver operating characteristic curve. In a total of 77 patients, CD68 high expression was found in71.4 %( 55/77) DLBCL patients and CD163 high expression in 51.4 %( 40/77 patients. Patients with high CD163 expression were more present with extranodal sites (P =0.049). However other clinical parameters including age, gender, Ann Arbor stage, performance stage, B symptoms, LDH and international prognostic index (IPI) showed no difference in patients with high and low CD68 or CD163 expression (P >0.05). CD68 expression has less effect on overall survival (OS) and event-free survival (EFS) (P =0.852, 0.782). However, high CD163 expression showed poor OS and EFS in DLBCL patients (P =0.006, 0.004) and also high CD163/CD68 ratio (P <0.001, 0.001). The multivariate analysis revealed that the high CD163 expression and CD163/CD68 ratio remained unfavorable factors for both OS (P =0.094, 0.002) and EFS (P =0.044, 0.016) independent of IPI. In conclusion, our date suggest that high CD163+ TAMs in tumor microenvironment may imply poor outcome in DLBCL patients treated with R-CHOP, but not CD68+ TAMs.