Semaphorin 5A, Anti-Nucleosome Antibodies and Ferritin: Disease Activity Markers in Patients with Systemic Lupus Erythematosus

Background: Systemic Lupus Erythematosus (SLE) is a multi-factorial, chronic autoimmune disorder characterized by dysfunction of T and B lymphocytes. Although the prognosis of SLE has improved in the past few decades, the absence of biomarkers for residual activity in various organs and the early detection of disease flares hamper further management. Conventional serologic markers of SLE, such as anti-dsDNA and complement levels, are not ideal, as they are not sufficiently sensitive and specific for the diagnosis of the disease and monitoring of disease activity. Thus, novel biomarkers for SLE activity have to be developed. Semaphorin 5A (Sema 5A), antinuclosome antibody (Anu A) and ferritin may fall into this category of novel bio markers.Objective: To evaluate the role of serum Sema 5A, Anu A and ferritin in detection of SLE activity.Methods: The present study included 40 patients with SLE divided according to Systemic Lupus Erythematous Disease Activity Index (SLEDAI) into two groups: 20 active SLE and 20 inactive SLE patients. They were compared with 20, sex and age matched healthy individuals for control. Levels of Sema 5A, Anu A were measured by Enzyme- Linked Immunosorbent Assay (ELISA) and serum ferritin levels were measured by Electrochemiluminescence immunoassay (ECLIA).Results: There was highly significant increase in Sema 5A, Anu A and ferritin levels inactive when compared within active SLE patients and control subjects (P=0.000 and P=0.000 and P=0.000 respectively). There was a significant increase in ferritin level in inactive SLE patients when compared with control subjects (P=0.045) with no significant difference regarding Sema 5A, Anu A (P3=0.089 and 0.225 respectively). There were positive correlations between Sema 5A, Anu A, ferritin and each of SLEDAI, and CRP. Positive correlation also found between Sema 5A and each of Anu A and ferritin and between AnuA and ferritin. Negative correlation was found between Sema 5A and C3 and between Anu A, ferritin and C4. Significant relation was found between Sema 5A, Anu A, ferritin and each of ANA and anti-dsDNA in active SLE patients. Area under the curve (AUC) for ferritin, Sema 5A and Anu A were (0.861, 1.0 and 1.0 respectively).Conclusion: Our study showed that the serum proteins semaphorin 5A, antinuclosome antibodies and ferritin may be useful markers in monitoring disease activity in patients with SLE. Regarding area under the curve (AUC), these serum protein markers result in even better sensitivity and specificity profiles in picking up early relapse of SLE.