Lupus mesenteric vasculitis with gastrointestinal bleeding as the primary manifestation: a case report.

Systemic lupus erythematosus (SLE) is a complex autoimmune disease where the body loses tolerance to its own antigens, particularly nuclear antigens. Abnormal responses from T and B cells lead to the production of autoantibodies and the formation of immune complexes in tissues, triggering complement activation, inflammation, and irreversible organ damage. SLE can affect any part of the body, resulting in diverse clinical symptoms. One rare manifestation of SLE is lupus mesenteric vasculitis (LMV), which presents with vague symptoms, abnormal laboratory findings, and specific imaging features. LMV, although uncommon, can progress to severe complications such as bowel perforation, haemorrhage, and even mortality. Here, we report a case of LMV with the involvement of multiple organ systems (including mucocutaneous, musculoskeletal, serosal cavities, and haematological systems), presenting initially with life-threatening intractable gastrointestinal bleeding, and complicated by severe pulmonary infection. By sharing this case, we aim to enhance clinicians' confidence in managing critical SLE cases and raise awareness about disease surveillance.