[Immunosuppression caused by head and neck surgery]

The immunomodulating effect of primary surgical intervention was investigated in 33 patients with squamous cell carcinomas of the oral cavity, pharynx and larynx. An operation time longer than 7 h was significantly associated with a decrease in lymphocytes, CD4(+) T-lymphocytes and CD8(+) T-lymphocytes. The CD4/CD8-ratio as a marker for the down-regulation of the cellular immune response was slightly decreased but was still in the normal range. CD4-lymphocyte counts increased 7 days after operation while CD8 lymphocytes were found elevated 4 weeks after surgery. The in vitro stimulation of the lymphocytes was impaired for 1 to 4 weeks. Interleukins, interferon-gamma and tumor necrosis factor did not show any changes after surgery. Decreases of lymphocytes, especially CD4(+) and CD8(+) lymphocytes, were significantly associated with the time of operation and the volume of blood loss. Extensive trauma, age, different kinds of anesthesia and intensive care interventions were not associated with specific immunomodulating effects, although these factors might be responsible for suppressing cytokine responses.