Hideto Kameda1, Mitsumasa Kishimoto2, Shigeto Kobayashi3, Tetsuya Tomita4, Akimichi Morita5, Masahiro Yamamura6. 1. Division of Rheumatology, Department of Internal Medicine, Faculty of Medicine, Toho University (Ohashi Medical Center), 2-22-36 Ohashi, Meguro-ku, Tokyo, Japan. hideto.kameda@med.toho-u.ac.jp. 2. Department of Nephrology and Rheumatology, Kyorin University School of Medicine, Tokyo, Japan. 3. Department of Internal Medicine and Rheumatology, Juntendo University Koshigaya Hospital, Saitama, Japan. 4. Department of Orthopedic Biomaterial Science, Osaka University Graduate School of Medicine, Osaka, Japan. 5. Department of Geriatric and Environmental Dermatology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan. 6. Center for Rheumatology, Okayama Saiseikai General Hospital, Okayama, Japan.
Abstract
PURPOSE OF REVIEW: The differences in the epidemiology and management of patients with axial spondyloarthritis (axSpA) among regions and countries largely depend on the positivity of human leukocyte antigen (HLA)-B27 and the health care system. This review article focused on axSpA in Japan, where the prevalence of HLA-B27 is extremely low (0.3%) and the universal health insurance system typically provides a 70% or more copayment by the government. RECENT FINDINGS: A nationwide survey was conducted in Japan in 2018, which estimated that there were 3200 patients (95% confidence interval [CI]: 2400-3900) with ankylosing spondylitis (AS), a term interchangeable with radiographic axSpA (r-axSpA), and 800 patients (95% CI: 530-1100) had non-radiographic (nr)-axSpA. These data indicate a prevalence of 2.6/100,000 or 0.0026% for AS and 0.6/100,000 or 0.0006% for nr-axSpA. Patients with AS, but not those with nr-axSpA, are designated as suffering from intractable diseases in Japan; thus, their medical expenses are reduced by grant under the Act on Medical Care for Patients with Intractable Diseases. As of February 2022, infliximab, adalimumab, secukinumab, ixekizumab, and brodalumab have been approved for AS, and secukinumab, ixekizumab, and brodalumab have been approved for nr-axSpA. An algorithm for nr-axSpA in Japan has been developed for the proper diagnosis and use of these therapeutic agents. A low prevalence of axSpA, especially that of nr-axSpA, was found in Japan. Early referral and the resultant diagnosis and appropriate treatment of these patients by rheumatologists are crucial issues in Japan, as in other countries.
PURPOSE OF REVIEW: The differences in the epidemiology and management of patients with axial spondyloarthritis (axSpA) among regions and countries largely depend on the positivity of human leukocyte antigen (HLA)-B27 and the health care system. This review article focused on axSpA in Japan, where the prevalence of HLA-B27 is extremely low (0.3%) and the universal health insurance system typically provides a 70% or more copayment by the government. RECENT FINDINGS: A nationwide survey was conducted in Japan in 2018, which estimated that there were 3200 patients (95% confidence interval [CI]: 2400-3900) with ankylosing spondylitis (AS), a term interchangeable with radiographic axSpA (r-axSpA), and 800 patients (95% CI: 530-1100) had non-radiographic (nr)-axSpA. These data indicate a prevalence of 2.6/100,000 or 0.0026% for AS and 0.6/100,000 or 0.0006% for nr-axSpA. Patients with AS, but not those with nr-axSpA, are designated as suffering from intractable diseases in Japan; thus, their medical expenses are reduced by grant under the Act on Medical Care for Patients with Intractable Diseases. As of February 2022, infliximab, adalimumab, secukinumab, ixekizumab, and brodalumab have been approved for AS, and secukinumab, ixekizumab, and brodalumab have been approved for nr-axSpA. An algorithm for nr-axSpA in Japan has been developed for the proper diagnosis and use of these therapeutic agents. A low prevalence of axSpA, especially that of nr-axSpA, was found in Japan. Early referral and the resultant diagnosis and appropriate treatment of these patients by rheumatologists are crucial issues in Japan, as in other countries.
Authors: Anne Boel; Anna Molto; Désirée van der Heijde; Adrian Ciurea; Maxime Dougados; Lianne S Gensler; Maria-José Santos; Eugenio De Miguel; Denis Poddubnyy; Martin Rudwaleit; Astrid van Tubergen; Floris A van Gaalen; Sofia Ramiro Journal: Ann Rheum Dis Date: 2019-07-30 Impact factor: 19.103
Authors: S Hukuda; M Minami; T Saito; H Mitsui; N Matsui; Y Komatsubara; H Makino; T Shibata; M Shingu; T Sakou; K Shichikawa Journal: J Rheumatol Date: 2001-03 Impact factor: 4.666