Background Estimating of Systemic Lupus Erythematosus (SLE) activity is necessary for the choice of correct treatment and for monitoring its results. There are many tools for assessment of SLE activity. Clinical methods including the assessment of numerous organs' involvement and concentration of marker proteins are useful.

There are ongoing studies concerning the usefulness of new biochemical markers which correlate with the clinical symptoms and other disease activity indicators. It has been suggested recently in the literature, that such role could be played by β2-microglobulin (β2M) serum concentration.

Objectives The aim of this study was to investigate the relationship between serum levels of β2M and clinical, immunological markers of disease activity in SLE patients (pts).

Methods Sixty-nine SLE pts (62 female; 7 men), aged 34.5±11.5 years (range 19-69) with duration of the disease of 5.8±4.8 years (0.5-19) were included. The level of β2M was investigated by enzyme-linked immunosorbent assay. Disease activity was assessed by: SLEDAI-2K, circulating levels of complement C3, C4, anti-double-stranded DNA (anti-DNA) and serum levels of β2M. We also estimated the relationship between serum levels of β2M and clinical manifestations of SLE.

Results Median serum levels of β2M were 3.0±1.2 μg/ml (1.8-8.6) in SLE pts. Serum levels of β2MG were positive in 24 SLE pts (34.8%). The significant correlations were found between serum levels of β2M and of anti-dsDNA (p=0.04; r=0.26), C3 complement (p=0.02; r= -0.3) and SLEDAI-2K (p=0.0005; r=0.64). The SLE pts with arthritis, vasculitis and hematologic symptoms had significantly higher β2M levels than those without, respectively.

Conclusions Serum level of β2M can be a good biochemical marker of the activity of SLE, positively correlated with clinical activity of the disease.

References

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2. Hermansen ML, Hummelshøj L, Lundsgaard D, Hornum L, Keller P, Fleckner J, Fox B, Poulsen LK, Jacobsen S. Increased serum β2-microglobulin is associated with clinical and immunological markers of disease activity in systemic lupus erythematosus. Lupus.(2012) 21,1098-1104.

3. Wakabayashi K, Inokuma S, Matsubara E, Onishi K, Asashima H, Nakachi S, Hagiwara K. Serum β2-microglobulin level is a useful indicator of disease activity and hemophagocytic syndrome complication in systemic lupus erythematosus and adult-onset Still's disease. Clin Rheumatol. 2013 Jul;32(7):999-1005.

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Disclosure of Interest None declared