Elevated serum concentrations of triggering receptor expressed on myeloid cells-1 in diffuse cutaneous systemic sclerosis: association with severity of pulmonary fibrosis.

OBJECTIVE

To determine serum concentrations and clinical association of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) in patients with systemic sclerosis (SSc).

METHODS

Serum sTREM-1 levels from 17 patients with limited cutaneous SSc (lSSc), 24 patients with diffuse cutaneous SSc (dSSc), and 29 healthy control individuals were examined by ELISA.

RESULTS

Total SSc patients exhibited significantly elevated serum sTREM-1 levels relative to controls (p < 0.01). Serum sTREM-1 levels were significantly elevated in patients with dSSc compared to controls (p < 0.005) and lSSc patients (p < 0.05). By contrast, sTREM-1 levels in lSSc were similar to those in controls. Serum sTREM-1 levels were significantly elevated in SSc patients with decreased percentage vital capacity (%VC). Consistent with this, serum sTREM-1 levels in SSc patients correlated negatively with %VC (r = -0.24, p < 0.005). Among SSc patients with pulmonary fibrosis, sTREM-1 levels were significantly increased in patients with decreased %VC or decreased percentage of diffusion capacity for carbon monoxide relative to those with normal values (p < 0.05).

CONCLUSION

Serum sTREM-1 levels were elevated in dSSc patients and correlated with severity of pulmonary fibrosis, suggesting that serum sTREM-1 is a novel serological marker for the disease severity of SSc.