Interleukin-6 production in lung tissue after transthoracic esophagectomy.

Abstract

The mechanisms of the reported high increase in interleukin-6 (IL-6) levels after esophagectomy are unclear. We investigated the influence of an intrathoracic procedure, esophagectomy, on IL-6 production in lung tissue. Fourteen paired lung tissue samples were obtained from patients before and after they underwent transthoracic esophagectomy for esophageal cancer. IL-6 levels in the lung were measured with enzyme-linked immunosorbent assay, and IL-6 mRNA expression was determined with real-time quantitative reverse transcription-polymerase chain reaction. Immunohistochemical staining was used to localize IL-6, and circulating levels were also measured. IL-6 protein and mRNA were significantly increased in lung tissue after this intrathoracic procedure (p < 0.05). Peak levels of plasma IL-6 after surgery were correlated with IL-6 levels in lung tissues obtained after the procedure (p < 0.05). Immunohistochemical staining revealed IL-6 production from alveolar and bronchial epithelial cells but not from alveolar macrophages. Transthoracic esophagectomy causes an increase in IL-6 production from airway epithelial cells, secondary to increased expression of IL-6 mRNA. Local response of lung tissue may be one source of increased serum IL-6 after this procedure.