Elevated serum MFG‐E8 level is possibly associated with the presence of high‐intensity cerebral lesions on magnetic resonance imaging in patients with systemic lupus erythematosus

Human milk fat globule‐EGF factor 8 (MFG‐E8), also known as lactadherin, is a secreted glycoprotein that plays essential roles in the clearance of apoptotic cells and angiogenesis. It has been reported that serum MFG‐E8 levels are higher in systemic lupus erythematosus (SLE) patients compared with in healthy controls; however, a previous study reported no correlation between serum MFG‐E8 levels and SLE disease activity. The objective of this study was to assess serum MFG‐E8 levels and their clinical associations in patients with SLE. Serum MFG‐E8 levels in 49 Japanese patients with SLE, eight with cutaneous LE, and 28 healthy controls were examined. Serum MFG‐E8 levels in SLE patients were significantly higher than those in cutaneous LE patients and healthy individuals. In addition, serum MFG‐E8 levels were positively correlated with the SLE Disease Activity Index score, which reflects the disease activity of SLE. Notably, the frequency of the presence of high‐intensity cerebral lesions on MRI in the SLE patients with elevated serum MFG‐E8 levels was significantly higher than that in SLE patients with normal serum MFG‐E8 levels. These findings suggest that elevated serum MFG‐E8 levels may be associated with cerebrovascular diseases or neuropsychiatric SLE in patients with SLE, and that the measurement of serum MFG‐E8 levels in SLE patients is useful for risk stratification of cerebrovascular disease or cerebrovascular disease‐related neuropsychiatric SLE.