Key publications: diagnosis within rheumatology

The diagnosis of axial SpA is complex, whereby individual symptoms or tests in isolation are insufficient to either diagnose or rule out axial SpA. We have curated a summary of key publications related to the diagnosis of axial SpA in rheumatology.

ACT ON AXIAL SpA:

A Gold Standard time to diagnosis

The current time to diagnosis of axial SpA in the UK averages approximately 8.5 years from symptom onset. This delay is unacceptable and has serious consequences for the patient. Our act on axial SpA campaign sets out a roadmap for reducing the time from symptom onset to diagnosis to just one year. 

British Society of Spondyloarthritis (BRITSpA) Papers

Keat A, Bennett AN, Gaffney K, Jones GT, Martindale J, Sengupta R, et al. BRITSpA at five. Rheumatology. 2020;59(4):699-701. https://doi.org/10.1093/rheumatology/kez523

The British Society for Spondyloarthritis (BRITSpA) (https://britspa.co.uk/) was conceived to facilitate the sharing of information and networking among members of the various medical and scientific disciplines associated with SpA; to enhance research, diagnosis and treatment of these conditions and, importantly, to engage UK clinicians and scientists in achieving this. British clinicians and scientists have done much over the years to put SpA on the world map. The once flickering flame of ankylosing spondylitis has become an inferno of energetic and productive research. Recent developments in understanding of the disease thanks partly to the availability of MRI have even led to changed terminology for axial SpA to encompass the spectrum of inflammatory spinal disease. Combined efforts led by clinicians, academics, the pharmaceutical industry and patient organizations such as NASS have applied pressure, support and encouragement to foster better services and new knowledge. This publication introduces BRITSpA as a mechanism for mobilizing and supporting talent, ability, motivation and expertise within the UK to achieve a better future for people with SpA. In a world where substantial expertise, both pharmaceutical and academic, is being brought to bear in the field of SpA, British rheumatologists are stepping up to the mark.

Bennett AN, Marzo-Ortega H, Kaur-Papadakis D, Rehman A. The Use of Magnetic Resonance Imaging in Axial Spondyloarthritis: Time to Bridge the Gap Between Radiologists and Rheumatologists. J Rheumatol. 2017;44(6):780-5. https://www.jrheum.org/content/44/6/780.long

Two-hundred sixty-nine radiologists from 131 acute UK National Health Service trusts/health boards responded to an online survey. Awareness of axial SpA was reported by 75% of radiologists, and awareness of definitions for positive MRI of sacroiliac joints (SIJ) and spine by 31% and 25%, respectively. These data highlight the need for better rheumatology-radiology collaboration on the identification of diagnostic axial SpA MRI lesions and support the need for a UK-based consensus on the most appropriate MRI protocols for the assessment of axial SpA (see publication below). MRI waiting times < 2 months were reported by 90% of radiologists and mean scan times were suggested at 34 minutes. However, despite internationally published consensus recommendations by The European Society of Skeletal Radiology (ESSR), the current study indicates that only 30% of radiologists scanned the whole spine and SIJ as recommended by ESSR. These modified whole-spine and SIJ protocols are cost-and time-effective, and can be performed in a standard 30-min MRI slot. Indeed, methods for using MRI in the diagnosis of axial SpA across the United Kingdom were diverse and generally did not follow the ESSR protocol. Twenty-nine radiologists (11%) used contrast as standard, 256 (91%) used T1 and short-tau inversion recovery, and 172 (64%) also used T2 sequences. Eighteen percent did not use the subchondral bone marrow edema of the SIJ to help diagnose axial SpA and 18% did not use the inflammatory vertebral corner lesions to assist diagnosis.

Bray TJP, Jones A, Bennett AN, Conaghan PG, Grainger A, Hodgson R, et al. Recommendations for acquisition and interpretation of MRI of the spine and sacroiliac joints in the diagnosis of axial spondyloarthritis in the UK. Rheumatology (Oxford). 2019;58(10):1831-8. https://doi.org/10.1093/rheumatology/kez173

A working group comprising nine rheumatologists and nine musculoskeletal radiologists with an interest in axial SpA was established, with support from BRITSpA. Two meetings were held. In the first meeting, research questions were formulated. In the second meeting, the results of a systematic literature review designed to inform the recommendations were reviewed. An anonymized Delphi process was used to formulate the final set of recommendations. Two overarching principles were formulated, as follows: The diagnosis of axial SpA is based on clinical, laboratory and imaging features (overarching principle 1), and patients with axial SpA can have isolated inflammation of either the sacroiliac joints or the spine (overarching principle 2). Seven recommendations addressing the use of MRI in the assessment of patients with suspected axial SpA were formulated (see table below), covering topics including recommended sequences, anatomical coverage, acquisition parameters and interpretation of active and structural MRI lesions. The level of agreement for each recommendation was very high (range 8.8–9.8). A joint rheumatology and radiology consensus on the acquisition and interpretation of MRI in axial SpA diagnosis was achieved, and a research agenda formulated. This consensus should help standardize practice around MRI and ensure a more informed, consistent approach to the diagnosis of axial SpA.

Rec1

When requesting an MRI for suspected axial SpA, imaging of both the SIJs and the spine is recommended

Rec2

T1-weighted and fat-suppressed, fluid-sensitive sequences (including STIR, fat-saturated T2 or Dixon methods) are recommended for suspected axial SpA

Rec3

The minimum protocol when requesting an MRI for suspected axial SpA should include sagittal images of the spine with extended lateral coverage and images of the SIJs that are in an oblique coronal plane to the joint

Rec4

In the SIJs, the presence of bone marrow oedema, fatty infiltration or erosion is suggestive of the diagnosis of axial SpA. The presence of more than one of these features increases the diagnostic confidence of axial SpA

Rec5

In the spine, the presence of multiple corner inflammatory lesions and/or multiple corner fatty lesions increases the diagnostic confidence of axial SpA

Rec6

In the SIJs and/or spine the presence of characteristic new bone formation increases the diagnostic confidence of axial SpA

Rec7

The full range and combination of active and structural lesions of the SIJs and spine should be taken into account when deciding if the MRI scan is suggestive of axial SpA or not

October 2020 Rheumatology supplement

https://academic.oup.com/rheumatology/issue/59/Supplement_4
Marzo-Ortega H. Axial spondyloarthritis: coming of age. Rheumatology. 2020;59(Supplement_4):iv1-iv5. https://doi.org/10.1093/rheumatology/keaa437

The last two decades have seen major advances in the understanding of axial SpA – a chronic, heterogeneous, inflammatory syndrome that primarily affects axial entheses and joints, especially the fibro-cartilagenous bone. This issue of Rheumatology appraises the literature on the axial SpA spectrum, discusses the ongoing challenges in diagnosis, the impact of sex and co-morbidities, and summarizes recent findings in pathogenesis and treatment strategies. We have picked out some of the key papers relevant to diagnosis and summarised them on this page.

Poddubnyy D. Classification vs diagnostic criteria: the challenge of diagnosing axial spondyloarthritis. Rheumatology. 2020;59(Supplement_4):iv6-iv17. https://doi.org/10.1093/rheumatology/keaa250

In recent years, significant progress has been made in improving the early diagnosis of spondyloarthritides (SpA), including axial SpA. Nonetheless, there are still issues related to the application of classification criteria for making the primary diagnosis of SpA in the daily practice. There are substantial conceptional and operational differences between the diagnostic vs classification approach. Although it is not possible to develop true diagnostic criteria for natural reasons as discussed in this review, the main principles of the diagnostic approach can be clearly defined: consider the pre-test probability of the disease, evaluate positive and negative results of the diagnostic test, exclude other entities, and estimate the probability of the disease at the end. Denis Poddubnyy describes the diagnostic process as a “diagnostic scale”, whereby one should weigh positive test results and present clinical features against negative test results and the presence of an alternative explanation for the symptoms. Even when all tests have been conducted, a diagnosis of axial SpA may remain uncertain. However, we know that these conditions change and evolve over time. If a diagnosis of axial SpA cannot be confirmed but clinical suspicion remains high, consider a follow‑up MRI to monitor for any potential future inflammatory changes. Classification criteria should only be applied to patients with an established diagnosis and aimed at the identification of a homogeneous group of patients for the conduction of clinical research.

Michelena X, López-Medina C, Marzo-Ortega H. Non-radiographic versus radiographic axial SpA: what’s in a name? Rheumatology. 2020;59(Supplement_4):iv18-iv24. https://doi.org/10.1093/rheumatology/keaa422

Axial spondyloarthritis is a heterogeneous inflammatory condition with variable clinical presentations and outcomes. The complexity of its diagnosis and absence of biomarkers hamper the development of diagnostic criteria with the risk of misuse of the available classification criteria in clinical practice and its consequences. Axial spondyloarthritis should be regarded as a continuum in which some patients, but not all, will have a more severe phenotype characterized by progression into new bone formation and joint fusion. Growing understanding of the factors that might drive disease progression and treatment response will allow for better characterization of treatment options and outcome for each affected individual. The aim of this review is to update the current evidence of what is axial spondyloarthritis and to highlight the need to focus on the concept rather than its classification.

Barnett R, Ingram T, Sengupta R. Axial spondyloarthritis 10 years on: still looking for the lost tribe. Rheumatology. 2020;59(Supplement_4):iv25-iv37. https://doi.org/10.1093/rheumatology/keaa472

Despite the publication of various recommendations, quality standards and referral strategies to promote early diagnosis in axial SpA over the last decade, there remains a significant delay to diagnosis, leading to a lost tribe of undiagnosed, untreated patients with persistent back pain and axial SpA symptoms. This review discusses the various factors contributing to diagnostic delay in axial SpA, while providing recommendations to improve the diagnostic pathway, for example use of the online Spondyloarthritis Diagnosis Evaluation (SPADE) tool (http://www.spadetool.co.uk/). Significant shortcomings exist at both the primary and secondary care level, with healthcare professionals often lacking knowledge and awareness of axial SpA. Myths regarding the classical signs and symptoms still prevail, including the perception of axial SpA as a male disease, only occurring in individuals who are HLA-B27 positive with raised inflammatory markers. Individuals within this lost tribe of undiagnosed patients are likely lacking adequate treatment and are thereby at risk of worse clinical outcomes. It is therefore vital that public health initiatives are implemented to improve education of healthcare professionals and to ensure early specialist referral, to ultimately improve the lives of patients with axial SpA.

Additional papers of interest

Rudwaleit M, van der Heijde D, Landewe R, Listing J, Akkoc N, Brandt J, et al. The development of Assessment of SpondyloArthritis international Society classification criteria for axial spondyloarthritis (part II): validation and final selection. Ann Rheum Dis. 2009;68(6):777-83. https://ard.bmj.com/content/68/6/777

It is important to note that, as discussed above, such classification criteria are not intended for use in diagnosis – the primary objective of classification criteria is to identify a homogenous population for clinical trials and research, whereby patients are similar in terms of clinical characteristics. However, the 2009 Assessment of Spondyloarthritis International Society (ASAS) classification criteria were seminal in that they formally recognised the concept of nr-axial SpA – placing emphasis on early disease and use of MRI to identify early inflammatory changes, to allow for earlier detection of patients with the condition and inclusion of patients with nr-axial SpA in clinical trials.

Symptoms starting slowly

Pain in the lower back

Improves with movement

Night time waking

Early onset (under 40)