Elevated serum levels of CXCL9/monokine induced by interferon-γ and CXCL10/interferon-γ-inducible protein-10 in ocular sarcoidosis

PURPOSE. Sarcoidosis is a chronic multisystem granulomatous disorder characterized by an accumulation of activated CD4(+) T cells and monocytes/macrophages in involved organs. Chemokines are required for the extravasation of leukocytes to the inflammation site. This study was undertaken to determine which chemokines are augmented in the serum of patients with active ocular sarcoidosis. METHODS. Seventeen patients with diagnosed ocular sarcoidosis, 28 with suspected ocular sarcoidosis, 16 with Behcet's disease, 17 with Vogt-Koyanagi-Harada disease, and 18 healthy subjects were studied. Serum levels of CCL2, CCL5, CXCL8, CXCL9, and CXCL10 were simultaneously measured by cytometric bead array using flow cytometer. In addition, serum CXCL9 and CXCL10 levels in the patients with diagnosed or suspected ocular sarcoidosis were compared with respect to ocular disease activity, the presence of bilateral hilar lymphadenopathy (BHL), and laboratory data. RESULTs. Serum levels of both CXCL9 and CXCL10 were markedly elevated in the patients with diagnosed or suspected ocular sarcoidosis compared with patients with other types of uveitis and healthy subjects. Although CCL2 and CXCL8 were detected in the serum of all subjects, the levels were extremely low with no significant differences between groups. Elevation of serum CXCL9 and CXCL10 in ocular sarcoidosis correlated significantly with ocular disease activity and ACE (angiotensin converting enzyme) levels and was Unrelated to the presence of BHL, erythrocyte sedimentation rate, white blood cell count, serum IgG, or serum lysozyme. CONCLUSIONS. The results demonstrated that serum levels of CXCL9 and CXCL10 were elevated markedly in the patients with ocular sarcoidosis and correlated with ocular disease activity and ACE level.