Clinical Evolution in Patients With New-Onset Inflammatory Back Pain: A Population-Based Cohort Study

Factors predicting axial spondyloarthritis among first-degree relatives of probands with ankylosing spondylitis: a family study spanning 35 years

Objective

Factors predicting axial spondyloarthritis (axSpA) among first-degree relatives (FDRs) of ankylosing spondylitis (AS) patients need to be defined. We investigated the predictive value of the probands’ HLA-B27 and radiographic sacroiliitis status on disease occurrence among their FDR. We also assessed the predictive value of features of the clinical history, including chronic inflammatory back pain (CIBP) and acute anterior uveitis (AAU), among the FDR and how they can be used to improve classification and diagnosis of axSpA.

Methods

In 1985, we studied 363 AS probands and 806 FDR who underwent rheumatologic examination, completed questionnaires, provided blood samples for HLA-typing and underwent radiography of sacroiliac joints. At follow-up in 2018–2019, 125 patients and 360 FDR were available for study, and completed a postal questionnaire about axSpA features. FDRs were asked to report whether after 1985 they had been diagnosed by Swiss rheumatologists as having axSpA.

Results

Among HLA-B27(+) FDR, axSpA occurred in 25.4%–26.3%, independent of the radiographic sacroiliitis status of the proband. AAU occurred in 13/34 (38.2%) FDR with axSpA vs 29/251 (11.6%) FDR without axSpA (p=0.00004, OR=4.74 95% CI 2.15 to 10.47). The presence of CIBP at baseline did not predict later occurrence of axSpA but combining CIBP and pain/discomfort at the thoracic spine and at anterior (ventral) chest wall ever, assessed at follow-up in 2018–2019, provided 83.1% sensitivity and 87.2% specificity for current axSpA.

Conclusion

Occurrence of AAU among FDR of axSpA probands should prompt screening for axSpA. Moreover, co-occurrence of CIBP and pain/discomfort in the thoracic spine and at anterior chest wall as a three-question tool may further enhance clinical suspicion of axSpA among these FDR.

Axial spondyloarthritis

Axial spondyloarthritis (axSpA) encompasses both radiographic and non-radiographic axSpA. It is a chronic inflammatory disease with a predilection for involving the axial skeleton. The most common presenting symptoms are chronic back pain and spinal stiffness but peripheral and extra-musculoskeletal manifestations occur also frequently. The diagnosis of axSpA relies on the recognition of a clinical pattern of the disease, based on clinical, laboratory and imaging features. The Assessment in SpondyloArthritis international Society classification criteria for axSpA are valid and well implemented for research purposes. Sustained disease activity, measured by validated tools such as the Ankylosing Spondylitis Disease Activity Score, leads to irreversible structural damage and poor functioning and therefore should be abrogated. As part of the management algorithm, non-steroidal anti-inflammatory drugs remain as the first line of pharmacological treatment besides physiotherapy. As a second line, tumour necrosis factor inhibitor and interleukin-17 inhibitor are available but recently Janus kinase inhibitors have also shown efficacy in improving symptoms of the disease.

Diagnosing axial spondyloarthritis by multidiciplinary team conference at 3.5 years' follow-up in a cohort of patients with disease features according to the ASAS criteria

OBJECTIVES

During the past two decades, magnetic resonance imaging (MRI) has increasingly been used diagnostically in axial spondyloarthritis (axSpA), and in 2009 MRI was introduced in the Assessment of SpondyloArthritis Society (ASAS) classification criteria. In clinical practice, there is a risk of overdiagnosis if MRI findings are not related to clinical and biochemical findings. The aim of this study was to provide an estimate of the prevalence of axSpA in a cohort of clinical patients with low back pain and findings suggestive of axSpA according to ASAS through consensus diagnosis at a multi-disciplinary team (MDT) conference, and to describe the performance of the features included in the ASAS criteria.

METHOD

Consensus diagnoses of axSpA at MDT conferences were retrospectively established at 3.5 years' follow-up in a cohort of 84 patients, initially referred with disease features according to the ASAS criteria. Patients were examined clinically regarding spondyloarthritis features, and biochemical tests and MRI of the sacroiliac joints and entire spine were performed at baseline and after a mean of 3.5 years.

RESULTS

According to the MDT consensus, 25 patients (30%) of the total cohort had axSpA at follow-up; 40% of individuals who fulfilled the ASAS criteria at baseline had axSpA, and 37% at follow-up; 96% of axSpA patients according to the MDT consensus met the ASAS criteria at baseline and 92% at follow-up.

CONCLUSION

Approximately one-third of the included patients had axSpA when evaluated at the MDT conference. The ASAS criteria had low predictive value, but high sensitivity at both baseline and follow-up.

Imaging in Axial Spondyloarthritis: What is Relevant for Diagnosis in Daily Practice?

PURPOSE OF REVIEW

To explore how imaging may assist diagnosing axial spondyloarthritis in rheumatology practice.

RECENT FINDINGS

A diagnosis of axial spondyloarthritis is based on pattern recognition by synthesizing clinical, laboratory, and imaging findings. In health care settings providing low threshold access to advanced imaging, sacroiliac joint MRI is the preferred imaging modality in clinically suspected axial spondyloarthritis. In daily routine, the optimum protocol to assess suspected inflammatory back pain combines sacroiliac joint and spine MRI fitting a 30-min slot. Contextual assessment of concomitant structural and active MRI lesions is key to enhance diagnostic utility. In women with postpartum back pain suggestive of axial spondyloarthritis, recent reports advocate waiting 6-12 months after delivery before acquiring sacroiliac joint MRI. Major unmet needs are consistent MRI protocols, standardized training modules on how to evaluate axial MRI, and timely dissemination of imaging advances into mainstream practice both in rheumatology and in radiology. In rheumatology practice, MRI has become indispensable to help diagnose early axial spondyloarthritis. However, major gaps in training and knowledge transfer to daily care need to be closed.

Inflammatory back pain: a concept, not a diagnosis

PURPOSE OF REVIEW

The concept of inflammatory back pain (IBP) describes a cohort of patients with chronic back pain (CBP) who have distinct clinical characteristics, rather than being a diagnosis in and of itself. IBP is a common and important feature of axial spondyloarthritis (axSpA) but this is not the only differential. This review examines the utility of IBP in both primary and secondary care settings.

RECENT FINDINGS

There are a number of suggested referral strategies for patients with suspected axSpA that include IBP. These strategies attempt to strike a balance between ensuring potential axSpA patients are not overlooked, whilst simultaneously not overwhelming secondary care services. Their success relies on the clinicians who first encounter these patients being familiar with IBP as a concept; however, it is still poorly recognized by many healthcare professionals. IBP may be helpful as part of a referral strategy; however, other clinical features, laboratory investigations and radiology must be incorporated for the final diagnostic outcome in axSpA.

SUMMARY

Delayed diagnosis is a major clinical problem in axSpA and is associated with worse clinical outcomes. When recognized and utilized correctly, IBP can be a useful tool to promote prompt referral to rheumatology services.

Additive values of pelvic tomosynthesis in comparison to pelvic radiography alone for the diagnosis of sacroiliitis in patients with suspected axial spondyloarthritis

OBJECTIVES

To compare inter-reader agreement and diagnostic confidence in detecting sacroiliitis by the modified New York criteria (mNY) on digital radiography (DR) versus digital pelvic tomosynthesis assisted DR (DR+DPT), and to evaluate changes in the presence of axial spondyloarthritis (axSpA) according to the Assessment of Spondyloarthritis International Society (ASAS) criteria.

METHODS

One hundred and thirty-eight patients who underwent both DR and DPT with suspicious axSpA in our rheumatologic clinic were included from February 2017 to February 2018. Three radiologists independently graded sacroiliitis and confidence level on DR first and then re-graded them on DPT in a paired manner. Agreement, confidence, and diagnostic accuracy were evaluated for readers. Changes in the presence of disease by mNY and ASAS criteria were assessed between DR alone and DR+DPT.

RESULTS

On DR alone, 73 patients were assessed with radiographic sacroiliitis, and 85 were classified into axSpA by the ASAS criteria; however, 78 and 85, respectively, were classified on DR+DPT. With the assistance of DPT, 17 and 12 patients changed to the disease positivity according to the mNY and ASAS criteria, respectively; the negative results changed to positive in 11 and six patients, respectively. For all readers, agreement improved with DPT (0.79 to 0.89). DR+DPT achieved higher diagnostic accuracy (AUC, P < 0.05).

CONCLUSION

The combination of DR and DPT achieved a higher diagnostic performance than that of DR alone, with better agreement. On DR+DPT, the diagnoses of 9.0% of patients with suspicious axSpA (12 of 134) were changed to the status of disease by the ASAS criteria.

Axial spondyloarthritis: new advances in diagnosis and management

Axial spondyloarthritis (axSpA) is an inflammatory disease of the axial skeleton associated with significant pain and disability. Previously, the diagnosis of ankylosing spondylitis required advanced changes on plain radiographs of the sacroiliac joints. Classification criteria released in 2009, however, identified a subset of patients, under the age of 45, with back pain for more than three months in the absence of radiographic sacroiliitis who were classified as axSpA based on a positive magnetic resonance imaging or HLAB27 positivity and specific clinical features. This subgroup was labeled non-radiographic (nr)-axSpA. These patients, compared with those identified by the older New York criteria, contained a larger percentage of women and demonstrated less structural damage. However, their clinical manifestations and response to biologics were similar to radiographic axSpA. The discovery of the interleukin (IL) IL-23/IL-17 pathway revealed key molecules involved in the pathophysiology of axSpA. This discovery propelled the generation of antibodies directed toward IL-17A, which are highly effective and demonstrate treatment responses in axSpA that are similar to those observed with anti-TNF agents. The finding that agents that block IL-23 were not effective in axSpA came as a surprise and the potential underlying mechanisms underlying this lack of response are discussed. New agents with dual inhibition of the IL-17A and F isoforms and some oral small molecule agents that target the Jak-STAT pathway, have also shown efficacy in axSpA.

How to investigate: Early axial spondyloarthritis

Axial spondyloarthritis (axSpA) is a chronic inflammatory condition of the axial skeleton that encompasses radiographic and non-radiographic axSpA and that can lead to chronic pain, structural damage, disability, and loss of quality of life. Scientific advances, including the role of MRI assessment, have led to new diagnostic insights and the creation of a new set of classification criteria for axial and peripheral SpA. New criteria allow the identification of SpA patients with early disease and their enrolment in clinical studies. In this chapter, we discuss the difference between diagnostic and classification criteria, the diagnostic approach to patients with suspected axSpA, the limitations of MRI assessment, and the importance of early identification of this condition. A practical algorithm to investigate axSpA, based on the current evidence, is also proposed. Clinical judgement should always be kept as the mainstay in the diagnosis of axSpA.

A referable clinical pattern of spondyloarthritis-associated uveitis

Objective. The aim of the study was to identify a clinical pattern of spondyloarthritis (SpA)-associated uveitis in order to facilitate proper rheumatologic referral by ophthalmologists. Methods. Demographic data were recorded and acute phase reactants were measured using standard methods between May and August 2017, for all adult patients (age > 18 years) presenting with acute uveitis (standardization of uveitis nomenclature). Afterwards, they were referred to a rheumatology clinic to be screened for the 2009 Assessment of SpondyloArthritis International Society (ASAS) classification criteria of SpA. SpA and non-SpA patients were then compared using appropriate statistical tests (significant if p < 0.05). All the patients offered a written informed consent and the study was approved by the local ethics committee. Results. The sample included 67 subjects, of whom 32 (47.8%) were classified with SpA, of whom 21 were known with this diagnosis (median disease duration of 13.6 years), while 11 (34.4% of the SpA subgroup) fulfilled the ASAS classification criteria for SpA without a prior diagnosis. Compared to non-SpA patients, SpA patients were more frequently male urban dwellers, they were significantly younger, they had a higher prevalence of HLA-B27 and recurrent uveitis, and they had higher median of C-reactive protein and lower median of white blood counts. Conclusions. Uveitis is an important revelatory manifestation of SpA. Young men presenting in an ophthalmology department with acute anterior uveitis and inflammatory back pain should be referred to a rheumatology unit. Abbreviations: AAU = Acute Anterior Uveitis, AS = Ankylosing Spondylitis, ASAS = Assessment Of Spondyloarthritis International Society, CRP = C-Reactive Protein, ESR = Erythrocyte Sedimentation Rate, HLA = Human Leukocyte Antigen, IBP = Inflammatory Back Pain, IBD = Inflammatory Bowel Disease, IL = Interleukin, MRI = Magnetic Resonance Imaging, Nsaids = Non-Steroidal Anti-Inflammatory Drugs, SD = Standard Deviation, Spa = Spondyloarthritis, Tnfα = Tumour Necrosis Factor Alpha, WBC = White Blood Count.