University of Leeds, Leeds Institute of Rheumatic and Musculosckeletal Medicine, Leeds, United Kingdom.
Rheumatology Unit, Department of Medicine DIMED, University of Padova, Padova, Italy.
Autoimmun Rev. 2024 Jan;23(1):103405. doi: 10.1016/j.autrev.2023.103405. Epub 2023 Aug 3.
Axial spondyloarthritis (axSpA) encompasses radiographic axial SpA (r-axSpA), formally designated as ankylosing spondylitis (AS) and non-radiographic axial SpA (nr-axSpA). The advent of MRI permitted the description of the "pre-radiographic" (nr-AxSpA) stage characterized by bone marrow oedema lesions, histologically an osteitis, not yet visible on X-rays. Most subjects with a diagnosis of nr-axSpA do not progress to r-axSpA and the risk of misdiagnosis of nr-axSpA is considerable because back pain related to malalignment, degenerative conditions or biomechanical stress including intense exercise may lead to positive MRI scans. Even when nr-axSpA or r-axSpA are accurately diagnosed only about 40-50% achieve the ASAS40 responses with licensed therapies. It is likely that spinal enthesitis/osteitis leading to structural damage and associated damage contributes to post inflammatory disc territory secondary pain responses. Things are complicated as the concept of refractory axSpA itself is not well defined since there is no gold standard test to capture the full burden of inflammatory disease and, in any event, MRI has not been systematically applied. Nevertheless, there is sufficient evidence to borrow from the refractory rheumatoid arthritis field to propose two types of refractory axial SpA- a persistent inflammatory refractory ax-SpA (PIRaxSpA) and non-inflammatory refractory ax-SpA (NIRaxSpA). Both axSpA refractoriness and misdiagnosis need careful considerations when evaluating treatment failure. The immunological basis for axSpA immunotherapeutics non-responses is still rudimentary beyond the knowledge of HLA-B27 positivity status, CRP elevation, and MRI bone oedema that represents osteitis being equated with responder status.
中轴型脊柱关节炎（axSpA）包括放射学中轴型脊柱关节炎（r-axSpA），其正式名称为强直性脊柱炎（AS）和非放射学中轴型脊柱关节炎（nr-axSpA）。磁共振成像（MRI）的出现使得“放射前”（nr-AxSpA）阶段的描述成为可能，其特征是骨髓水肿病变，组织学上是骨炎，在 X 光片上还不可见。大多数被诊断为 nr-axSpA 的患者不会进展为 r-axSpA，nr-axSpA 的误诊风险相当大，因为与错位、退行性疾病或生物力学应激相关的背痛，包括剧烈运动，可能导致 MRI 扫描呈阳性。即使 nr-axSpA 或 r-axSpA 得到准确诊断，只有约 40-50%的患者在使用许可治疗后达到 ASAS40 反应。很可能是脊柱附着点炎/骨炎导致结构损伤和相关损伤导致炎症后椎间盘区域的继发性疼痛反应。情况变得复杂，因为难治性 axSpA 本身的概念尚未得到很好的定义，因为没有黄金标准测试来捕捉炎症性疾病的全部负担，而且无论如何，MRI 尚未得到系统应用。然而，有足够的证据可以借鉴难治性类风湿关节炎领域，提出两种类型的难治性中轴型脊柱关节炎——持续性炎症性难治性 axSpA（PIRaxSpA）和非炎症性难治性 axSpA（NIRaxSpA）。在评估治疗失败时，需要仔细考虑 axSpA 难治性和误诊。除了 HLA-B27 阳性状态、CRP 升高和代表骨炎的 MRI 骨水肿与应答者状态等同之外，axSpA 免疫治疗无反应的免疫学基础仍然很基础。
