Human hepatic lymph nodes contain normal numbers of mature myeloid dendritic cells but few plasmacytoid dendritic cells

We investigated whether the hyporesponsiveness of the adaptive arm of the liver immune system is related to the composition of the dendritic cell (DC) population in hepatic lymph nodes. Noninflamed human hepatic lymph nodes (LN) were obtained from multiorgan donors, inflamed hepatic LN from liver transplant recipients with autoimmune cholestatic liver diseases, and inguinal LN from kidney transplant recipients. Quantitative immunohistochemistry showed that all three types of LN contained comparable numbers of mature and immature myeloid DC, but that noninflamed and inflamed hepatic LN contained significantly fewer plasmacytoid DC as compared to inguinal LN. Likewise, DC-enriched cell preparations from hepatic LN contained relatively few plasmacytoid DC. The difference in numbers of plasmacytoid DC was confirmed in comparisons of hepatic LN and ileacal LN from the same organ-donors. Myeloid DC from hepatic LN showed similar expressions of HLA-DR, CD83, and CD86, and higher expression of CD80 compared to myeloid DC from inguinal LN. In conclusion, hepatic LN contain similar numbers of myeloid DC as muscle/skin lymph-draining LN, with no signs of immaturity, but relatively few plasmacytoid DC.