the study explores the potential role of chronic H. pylori infection as a trigger or aggravating factor in SLE, an autoimmune disorder characterized by overactive immune responses that cause multisystem organ damage . The rationale is based on recent findings suggesting that chronic infections may worsen autoimmune disease activity by persistent immune stimulation and production of cross-reactive autoantibodies . SLE patients attending clinics at Assiut University Hospital will be assessed over one year; inclusion requires confirmed SLE diagnosis per established criteria, absence of recent antibiotics/PPIs, and consent. Clinical data, disease activity (via SLEDAI-2K), and socio-demographic information will be collected through detailed medical interviews and laboratory investigations, particularly focusing on stool-based antigen tests for H. pylori. All data will be securely recorded for statistical analysis assessing the bidirectional impact of infection status and SLE severity .