Abstract

Prognostic role of plasma cell free DNA in a cohort of Egyptian systemic lupus erythematosus patients

Author(s): Neama M Lotfy, Noran O El-Azizi, Marwa A Nassef, Yasser Zeitoun, Dina El Shennawy & Kareem Mohamed Saeed

Background: Cell death has an important event in lupus pathogenesis as it leads to release of antigens as nucleic acids for immune complex formation. DNA-antibody complexes in the circulation are one of the hallmarks of Systemic Lupus Erythematosus (SLE) that leads to the clinical manifestations of SLE. Fluctuation in circulating DNA level might be one of the driving factors behind flare-ups. The objective of this study is to estimate the prevalence of plasma circulating cell-free deoxyribonucleic acid (cf DNA) in SLE patients and evaluate it as a prognostic marker in SLE and its relation to drug therapy. Methods: A case control study conducted on 75 Egyptian SLE patients divided into 2 groups; 45 SLE patients on therapy and 30 SLE patients recently diagnosed (without therapy) and 25 matched healthy control group. All patients are subjected to detailed medical history and clinical examination. Disease activity was done using SLEDAI-2k, related laboratory investigations in addition to estimation of cf-DNA concentration by real-time PCR technique. Findings: On comparing the 2 SLE groups, there was significant increase in nephritis, neuropsychiatric manifestations, vasculitis, fever, SLEDAI -2k, ESR, ANA, Anti-DNA titre and cf-DNA concentration and significant decrease in TLC, Hb, PLT, C3 and C4 in SLE without therapy than those on therapy (P<0.001). On comparing the 3 studied groups there was significant increase in cf-DNA concentration in SLE patients without therapy than those on therapy than in the control group (p <0.001). There was a significant correlation between cf-DNA concentration and neuropsychiatric manifestations, nephritis, fever, ESR, lymphopenia, anemia, thrombocytopenia, ANA titre, Anti-DNA titre, C3, C4 levels and SLEDAI -2k in all SLE patients (p <0.001). Conclusion: Plasma level of cf-DNA is significantly increased in SLE patients especially before starting therapy, so cf-DNA can be used as a marker of disease activity and treatment follow-up.