Increased levels of immune inhibitory CD34 + progenitor cells in the peripheral blood of patients with node positive head and neck squamous cell carcinomas and the ability of these CD34 + cells to differentiate into immune stimulatory dendritic cells

Objectives: This study determined whether mobilization of immune inhibitory CD34 + cells by head and neck squamous cell carcinomas (HNSCC) is most prominent in patients who are node positive and whether these CD34 + cells could differentiate into immune stimulatory dendritic cells. Study Design and Setting: Peripheral blood from patients with head and neck cancer was used to measure the frequency of CD34 + cells and their capacity to differentiate into immune stimulatory dendritic cells. Results: This study demonstrated that increased CD34 + cell levels were most prominent in patients who were node positive and patients with recurrent disease. These CD34 + cells differentiated into dendritic cells that were able to present tetanus toxoid to autologous T-cells. Conclusions: Immune suppressive CD34 + cells that are prominent in patients with HNSCC who are node positive are able to develop into immune stimulatory dendritic cells. Significance: Differentiation of tumor-mobilized CD34 + cells into dendritic cells may be an immunotherapeutic approach to stimulate antitumor reactivity. (Otolaryngol Head Neck Surg 2001;125:205-12.)