Dendritic cells (DCs) are known to be major antigen-presenting cells, and lymph nodes (LNs) play an important role in DC-mediated immune response. CD1a is known as a marker of monocyte-derived DCs. The present study focused on the infiltration of CD1a-positive DCs (CD1a-DCs) into regional LNs in 70 cases of gallbladder cancer (GBC). After univariate analyses, the results showed that LN infiltration by CD1a-DCs was associated with unfavorable clinical outcomes in patients with GBC, with all cases categorized in the CD1a-DCs high group had nodal metastasis. LN infiltration by CD1a-DCs was not an independent prognostic factor identified by multivariate analyses. After subgroup analyses of cases with LN metastasis (n = 32), no significant impacts of CD1a-DCs infiltration into metastatic LNs were observed. In contrast, CD1a-DCs infiltration into primary tumors had a significant impact on surgical outcomes. The results of strong confounding between CD1a-DCs and LN metastasis support the theory that CD1a-DCs are developed from monocytes at tumor sites. As the results of previous research focused on CD1a-DCs infiltration into regional LNs of other organs varied, the role and significance of CD1a-DCs infiltration in regional LNs may be different according to the tumor histology or its primary site. Thus, further studies are needed to clarify the role and significance of CD1a-DCs infiltration into regional LNs of solid cancers.
Keywords: CD1a; dendritic cell; gallbladder cancer; lymph node; monocyte.