Serum concentrations of the CXC chemokines interleukin 8 and growth-regulated oncogene-alpha are elevated in patients with systemic sclerosis

Abstract

Objective: To determine whether serum concentrations of 2 CXC chemokines, interleukin 8 (IL-8) and growth-regulated oncogene-alpha (GRO-alpha), which are potent chemoattractants and activators for neutrophils, are elevated and whether they correlate with clinical features in patients with systemic sclerosis (SSc).

Methods: Serum samples from patients with diffuse cutaneous SSc (dSSc; n = 36), limited cutaneous SSc (lSSc; n = 42), systemic lupus erythematosus (SLE; n = 15), dermatomyositis (DM; n = 15), and healthy controls (n = 35) were examined by ELISA.

Results: Serum IL-8 was detected significantly more frequently in patients with dSSc (61%) and lSSc (55%) relative to healthy controls (6%), patients with SLE (7%), and those with DM (13%). Similarly, serum GRO-alpha concentrations in SSc patients were significantly increased compared with controls, patients with SLE, or those with DM. Elevated IL-8 concentrations significantly correlated with decreased % DLCO and rheumatoid factor positivity, while increased GRO-alpha levels were significantly associated with decreased % DLCO and % vital capacity, involvement of kidney and muscle, the presence of anti-topoisomerase I antibody, and increased serum IgG levels.

Conclusion: Our results suggest that the elevation of serum levels of the CXC chemokines IL-8 and GRO-alpha is specific to SSc and that the elevation of CXC chemokines, particularly GRO-alpha, correlates with the involvement of internal organs, especially pulmonary damage.