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

Abstract

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). 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. 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. 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.