Inhaled vasoactive intestinal peptide exerts immunoregulatory effects in sarcoidosis.

Rationale: Previous studies suggest an important immunoregulatory role of vasoactive intestinal peptide (VIP) in experimental models of chronic noninfectious inflammation. Sarcoidosis is characterized by noncaseating epitheloid cell granulomas, where excessive tumor necrosis factor-alpha production by pulmonary macrophages plays a critical role in granuloma formation and disease progression, which may lead to fatal organ dysfunction.

Objectives: To test whether inhaled VIP has an immunoregulatory role.