SAPHO syndrome with bone destruction in the lumbar vertebral endplates: A case report

SAPHO syndrome is a rare inflammatory osteoarticular disorder, which includes autoimmune diseases such as pustulotic arthro-osteitis, inflammatory bowel disease-associated spondyloarthritis, and psoriatic arthritis. There are few reports on the treatment of SAPHO syndrome that presents with bone destruction in the spine. We present a case in which adalimumab (ADA) was administered to treat destruction of the lumbar vertebral endplates caused by SAPHO syndrome. The patient was a woman in her 20s who was referred to Toho University Sakura Medical Center with complaints of low back pain; acne on the face, anterior chest, and back; and sternoclavicular joint pain. Blood tests showed a mild increase in C-reactive protein but negative results for rheumatoid factor and anti-cyclic citrullinated peptide antibody. Radiographs and computed tomography images demonstrated destruction with surrounding bone sclerosis in the cranial endplates of the L4 and L5 vertebrae and the left sternoclavicular joint. The Ankylosing Spondylitis Disease Activity Score was 2.05, and the Bath Ankylosing Spondylitis Functional Index was 3.00. Despite the use of the maximum dose of nonsteroidal anti-inflammatory drugs, her symptoms did not improve, and ADA was administered at a dose of 40 mg every 2 weeks. After ADA administration, both the Ankylosing Spondylitis Disease Activity Score and the Bath Ankylosing Spondylitis Functional Index were immediately reduced and low disease activity or remission was maintained thereafter. After 3 years, the computed tomography images showed no progression of bone destruction in the lumbar vertebrae and sternoclavicular joint, and the patient was completely free from low back pain and was able to run normally.