Serum levels of macrophage-derived protein MRP-8/14 are elevated in active multiple sclerosis

Serum concentrations of two macrophage-derived calcium-binding proteins, MRP-8 and MRP-8/14, were studied in 28 patients with relapsing multiple sclerosis (MS). Serum levels were determined with a commercially available sandwich ELISA and the one-tailed Mann-Whitney U test was used for statistical analysis. Median serum levels of MRP-8/14 were significantly higher in MS patients (5150 ng/ml) compared to 26 healthy controls (1482 ng/ml) and significantly higher in MS patients within an acute relapse (6690 ng/ml) compared to MS patients with stable disease (3050 ng/ml). MRP-8 levels were not elevated in MS patients. These results may indicate an early activation of macrophages in the formation of demyelinating MS plaques. In addition, increased serum levels of MRP-8/14 may prove to be a useful paraclinical disease activity parameter in MS patients. (C) 1998 Elsevier Science Ireland Ltd.