Serum β₂-Microglobulin as a Marker of Activity in Systemic Lupus Erythematosus

Abstract

A prospective study of 62 patients with systemic lupus erythematosus (SLE) was performed in order to establish whether serum β₂m could be a good marker of clinical activity. β₂m was determined by radio-immunoassay and the values compared with a control group of healthy individuals. The mean value of β₂m in the control group was 1.480.52 mg/l and 2.87$2.19 mg/l (p< 0.001) in the SLE group, 4.53$2.89 mg/l in the 22 patients with active disease and 2.40$1.80 mg/l (p< 0.001) in the 40 patients with inactive disease. High β₂m values ($3 mg/l) were observed in 64% of the patients with active SLE, VS. only 12% of the patients with inactive disease (p< 0.001). Significant differences were also observed when β₂m of the patients with inactive SLE was compared with the control group (p< 0.001). The β₂m with a sensitivity of 64%, a specificity of 87%, and an efficiency of 79% could be a good parameter to detect SLE clinical activity.