Measurement of serum monocyte chemoattractant protein-1 and its clinical application for estimating the activity of granuloma formation in sarcoidosis.

BACKGROUND AND AIM OF THE WORK: The role of monocyte chemoattractant protein-1 (MCP-1) in bronchoalveolar lavage fluids from sarcoidosis patients was previously reported. To study the role of MCP-1, we evaluated the serum MCP-1 and its clinical significance in sarcoidosis.

METHODS

The serum MCP-1 level was measured in 47 patients with sarcoidosis and 10 normal healthy controls with the use of an enzyme-linked immunosorbent assay. The localization and mRNA expression of MCP-1 in sarcoid lymph nodes were evaluated by an immunohistochemical method using an anti-MCP-1 monoclonal antibody and an in situ hybridization technique to determine the cellular source(s) of MCP-1.

RESULTS

Serum MCP-1 levels were significantly elevated in the sarcoidosis patients compared with the healthy controls (698.3 +/- 101.9 vs. less than 39 pg/ml, p < 0.001). A comparison of the patients' serum MCP-1 levels among standard radiographic stages revealed that the serum MCP-1 was significantly higher in early stages: stage 0 vs. III, and stage I vs. II. In addition, the serum MCP-1 levels were significantly correlated with the serum angiotensin converting enzyme levels (r = 0.539, p = 0.0006). MCP-1 expression was detected in macrophages peripheral to the epithelioid granuloma in sarcoid lymph nodes, by both immunohistochemistry and in situ hybridization.

CONCLUSIONS

These data suggest that MCP-1 may be expressed by the macrophages in the granuloma throughout the body, and that the measurement of serum MCP-1 levels may have clinical value as an indicator in estimating the activity of granuloma formation throughout the body in sarcoidosis.