Soluble intercellular adhesion molecule-1 (sICAM-1) in patients with systemic lupus erythematosus

Circulating sICAM-1 is known to be elevated in various inflammatory disorders. It is further suggested that elevated levels correlate well with disease activity in several autoimmune disorders. The objectives of this study are to determine the serum sICAM-1 levels in patients with systemic lupus erythematosus (SLE) and correlate sICAM-1 levels with clinical and laboratory (ESR, CRP, anti-dsDNA) measures of disease activity. Forty-one patients (34 female, 7 male) all fulfilling 1982 ARA classification criteria for SLE and 16 healthy controls (8 female, 8 male) were included in the study. Disease activity was measured according to SLEDAI. sICAM-1 was determined by ELISA. Mean sICAM-1 in SLE patients (339 +/- 161 ng/ml) were significantly higher than in the controls (216 +/- 85 ng/ml) (p < 0.005). Although slightly elevated in active patients, there was no statistically significant difference between mean sICAM-1 levels of active and inactive SLE patients (349 +/- 183 ng/ml and 316 +/- 103 ng/ml respectively) (p > 0.05). We could not find a correlation between sICAM-1 levels and any organ involvements. Similarly, no significant correlation was found between ESR, CRP, anti-ds-DNA and sICAM-1. These results suggest that although higher than normal, sICAM-1 levels in SLE do not provide additional information over conventional activity markers.