Serum Autotaxin as a Potential Biomarker in Systemic Lupus Erythematosus Patients and Its Relation to Disease Activity.

Systemic lupus erythematosus (SLE) is a chronic multisystem autoimmune inflammatory disease with unknown etiology . However, several genetic, immunological and environmental factors play a role in the etiopathogenesis of SLE . During the disease course, patients may be presented with diverse clinical manifestations (mucocutaneous, articular, neurological, or renal manifestations) . Anti-nuclear antibodies(ANA), anti- double stranded DNA (ds-DNA)and anti smith(SM) antibodies are common biomarkers of SLE. However the sensitivity and specificity of the current biomarkers are not ideal that the diagnosis of SLE can be missed .

Lysophospholipids are phospholipids with only one fatty acid chain, such as lysophosphatidic acid (LPA) and lysophosphatidylserine. Autotaxin (ATX), one of the enzymes that catalyze the formation of Lysophospholipid, is mainly responsible for the production of LPA in blood . Tumor necrosis factor (TNF), interleukin-6 (IL-6), and type I interferons, have been reported to induce the expression of ATX . ATX was reported recently as potential biomarkers of various diseases (serum ATX in malignancy and chronic hepatitis C, while in acute myocardial infarction ATX was overexpressed in cardiac tissue and in the synovium of rheumatoid arthritis patients) . Several studies have reported that serum ATX concentrations were higher in females than in males . The mRNA expression of ATX was found to be significantly induced by estrogen . There is growing evidence that ATX may play a role in the pathogenesis of SLE. Few recent studies have reported that serum ATX level can be a possible novel biomarker and key molecule in SLE .