Beta2-Microglobulin Can Be a Disease Activity Marker in Systemic Lupus Erythematosus

To investigate the clinical significance of beta2-microglobulin in Korean patients with systemic lupus erythematosus (SLE).Blood samples were collected from patients with SLE (n = 100) and normal healthy controls (n = 50). The level of beta2-microglobulin was investigated by enzyme-linked immunosorbent assay. Serial samples from SLE patients were collected at 4.2 +/- 2.6 months after first sampling.The beta2-microglobulin levels of the SLE patients (2.64 +/- 0.11 microg/mL) were higher than the normal controls (2.14 +/- 0.04 microg/mL, P0.001). The patients with SLE with serositis, oral ulcer, or lupus nephritis had significantly higher beta2-microglobulin levels than those without, respectively. A significant correlation was found between the beta2-microglobulin level and each of anti-dsDNA antibody, hemoglobin, complement, and SLE Disease Activity Index. In sequential sampling of patients with SLE, a positive correlation was found between the change of the SLE Disease Activity Index and the change of the beta2-microglobulin levels.These data suggest that the measurement of beta2-microglobulin seem to be a useful addition to the laboratory tests that can help in assessment of disease activity of SLE.