Elevated expression of inducible nitric oxide synthase and inflammatory cytokines in the alveolar macrophages after esophagectomy

Objective: To evaluate the role of inducible nitric oxide (NO) synthase (iNOS) and inflammatory cytokines in alveolar macrophages (AMs) after esophagectomy in the pathogenesis of acute lung injury. Design: Prospective, exploratory, open-labeled clinical study. Setting: Intensive care unit and operating room in a university hospital. Patients: Thirteen patients receiving esophagectomy with carcinoma of the esophagus (postesophagectomy group), ten patients just before the surgery (preoperation group), and seven patients receiving surgery less invasive than esophagectomy (other surgery group) were selected. Interventions: Bronchoalveolar lavage fluid (BALF) and blood samples were obtained from study groups. Measurements and Main Results: The AMs in the BALF collected from each group were stained immunohistochemically with antibodies against iNOS, interleukin (IL)-6, and IL-8. The intensities of these expressions were determined by semiquantitative cytofluorometric system. NOx (NO2-+NO3-), IL-6, and IL-8 levels in the BALF and plasma were measured concurrently. The expressional intensities of NOS, IL-6, and IL-8 in AMs obtained from the postesophagectomy group were maximal 24 hrs after the skin incision and significantly more evident than those from other groups. The IL-6, IL-8, and NOx levels in BALF and IL-6 and IL-8 levels in plasma in the postesophagectomy patients were also elevated. The intensifies of iNOS and inflammatory cytokines expressions in AMs were closely related to postoperative respiratory failure. Conclusions: The activation of topical alveolar macrophages may be involved in the pathogenesis of pulmonary complications in the postoperative period after esophagectomy.