Colchicine-resistant sacroiliitis in a Japanese patient with familial Mediterranean fever.

The articular involvement in patients with familial Mediterranean fever (FMF) represents a clinical characteristic of acute monoarthritis with pain and hydrarthrosis, which always resolves spontaneously. Colchicine prevents painful arthritis attacks in most FMF cases. Spondyloarthritis is rarely associated with Japanese patients with FMF. Here, we report a Japanese male patient with FMF-related axial joint involvement. A 43-year-old male Japanese patient who presented with recurrent febrile episodes with hip joint and back pain was referred to our hospital. He carried heterozygous variants in exon 2 (L110P/E148Q) of the MEFV gene. FMF was suspected, and oral administration of colchicine (1 mg/day) was initiated. Colchicine treatment improved his febrile attack with hip joint pain. He was diagnosed as having FMF based on the Tel-Hashomer diagnostic criteria for FMF since he fulfilled one major criterion (repeated febrile attack accompanied by hip joint pain) and one minor criterion (improvement with colchicine treatment). Although the human leucocyte antigen-B27 allele was not detected, sacroiliitis-related symptoms progressed despite the ongoing colchicine treatment. Salazosulphapyridine and methotrexate were administered in addition to colchicine; however, these treatments were not effective. Canakinumab treatment successfully resolved this unique aspect of sacroiliitis, and the patient was finally diagnosed with FMF-associated axial joint involvement.