Plasma and Urinary Level of High Mobility Group Box 1, Early Marker in Systemic Lupus Erythematosis Activity

Introduction: Systemic Lupus Erythematosis (SLE) is a systemic autoimmune disease characterised by involvement of multiple organ systems. Its aetiology is largely unknown; however, genetic and environmental factors are proposed to contribute to breaking tolerance, resulting in the production of a variety of antibodies directed to self-components [1],Aim of Work: We aim to study the potential role of HMGB1 in SLE and whether plasma and urinary levels correlate withMethods: In a case control study, 61 systemic lupus patients and 18 healthy volunteers, were divided in 4 groups. Group 1: 21 patients with lupus nephritis. Group 2: 21 patients with lupus activity without nephritis. Group 3: 19 patients without activity. Group 4: 18 healthy volunteers, age and sex matched. Participants were subjected to history taking, physical examination, activity scoring using SLEDAI, complete blood count, kidney function tests, ESR, ANA, Anti dsDNA, C3 C4 level, plasma and urinary levels of HMGB1 by ELISA.Results: Plasma and urinary HMGB1 levels were significantly increased in patients with active LN compared to patients without active LN and control (p 0.001), suggesting active release of HMGB1. Plasma and urinary levels in patients without active LN were also significantly higher compared to control group (p 0.001). Plasma and urinary HMGB1 levels and renal tissue extranuclear expression pattern of HMGB1 levels were significantly correlated with SLEDAI.Conclusion: HMGB1 plays an important role in patho-genesis of lupus nephritis and reflects disease activity. Thus, HMGB1 can be utilized as a biomarker for renal disease activity in patients with lupus and the therapeutic value of HMGB1 blocking agents must be investigated.