Background Sphingolipids involved in regulating signal pathways in cell growth, differentiation, and apoptosis are increasingly recognized as playing an important role in the pathophysiology of chronic inflammatory diseases. This study aimed to evaluate the serum profile of sphingolipids in systemic lupus erythematosus (SLE) and to investigate the association between serum sphingolipids and disease activity.

Methods Levels of sphingolipids in plasma of women with SLE were assessed by liquid chromatography tandem mass spectrometry. The diagnostic value of plasma sphingolipids was analyzed using the area under the receiver operating characteristic curve (ROC). Pearson’s correlation coefficient was used to analyze the relationship with disease activity markers.

Results Serum samples were collected from 38 women with SLE, including 11 lupus nephritis, and 30 controls. There were increases in concentration ceramide (Cer) and Cer to sphingosine-1-phosphate (S1P) ratio subspecies in patients with SLE, while the levels of sphingomyelins were decreased compared to the controls. The ratio of Cer16:0 to S1P showed a particularly strong increase in patients with lupus nephritis, with an area under the curve 0.739 (95% confidence interval, 0.581–0.898) to discriminate lupus nephritis in the control group. Furthermore, Cer16/S1P levels were correlated with disease duration, anti-double stranded DNA antibody, SLE disease activity index 2000, and Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index.

Conclusions Our data indicate that serum sphingolipids can be a good candidate for SLE diagnostic markers. In particular, we identified that Cer16 to S1P could be useful for diagnosing lupus nephritis.