Abstract
We present the first case of enthesitis in the lumbar spine in a woman with systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS). Enthesopathy is defined as pathological alterations at the site of insertion of a tendon, ligament, joint capsule, or fascia to bone. In particular, enthesitis is the universal hallmark of seronegative spondyloarthropathies (SpA), including ankylosing spondylitis, reactive arthritis, psoriatic arthritis, and spondyloarthropathies associated with inflammatory bowel diseases. A 36-year-old female SLE patient with a history of lupus nephritis and thrombosis from APS presented with low back pain that had been gradually worsening for several months. She reported no previous episodes of trauma. Plain radiography indicated sclerosis at the anterior superior bodies of L3 and L5. Magnetic resonance imaging (MRI) showed low-intensity lesions on T1-weighted images and high-intensity lesions on T2-weighted images at the anterior superior bodies of L3, L4, and L5, consistent with osteitis or enthesitis. A nonsteroidal antiinflammatory drug (NSAID) was used as the first-line therapy in this patient, which improved her symptoms. This is the first report of enthesitis in the context of SLE. Although the possibility of coincidental occurrence of SpA and SLE cannot be excluded, the observations in this case suggest that enthesitis may be one of the manifestations of SLE. Enthesitis, which is a well-recognized manifestation of SpA, has not been reported previously in association with SLE. However, unexplained low back pain should raise the possibility of enthesitis in patients with SLE or coexistent SpA and SLE, despite the lack of clinical evidence of SpA. The diagnosis can be confirmed based on the results of imaging studies. Regardless of its cause, enthesitis shows a favorable response to conventional NSAID therapy.