HLA-B27 prevalence in axial spondyloarthritis patients and in blood donors in a Lebanese population: Results from a nationwide study

What is the best referral strategy for axial spondyloarthritis? A prospective multicenter study in patients with suspicious chronic low back pain

OBJECTIVE

To assess the value of referral strategies for axial spondyloarthritis (axSpA) in patients with suspicious chronic inflammatory low back pain (LBP), to estimate the value of inflammatory back pain (IBP) for referral, and to identify the predictive factors of the final diagnosis of axSpA in Middle Eastern Arab countries.

METHODS

The study was multicentric, prospective, and conducted in LBP first-line clinics (rheumatology, internal, family medicine, orthopedic surgery, neurosurgery, and neurology). Consecutive adult patients aged under 45years were included in case of LBP suspicious of inflammatory nature according to the first-line physician. The rheumatologist's final diagnosis was the gold standard. The diagnostic properties of ten referral strategies (Brandt I, II, III, Hermann, RADAR, RADAR 2/3, MASTER, Braun, CAFASPA, and ASAS) and of IBP were calculated. A multivariable logistic regression identified the clinical predictive factors of axSpA.

RESULTS

In 515 referred patients, axSpA was confirmed in 48%, refuted in 43%, and diagnosis remained inconclusive in 9%. The optimal referral strategy was the MASTER (PLR 3.3), which comprises IBP, good response to NSAIDs, positive HLA-B27, and SpA family history. Considering strategies without HLA-B27, the RADAR 2/3 had a PLR of 2.9 (IBP, good response to NSAIDs, any extra-musculoskeletal manifestation). The predictive factors for axSpA were MRI sacroiliitis, positive HLA-B27, high CRP, psoriasis, IBP, and longer symptom duration. Of all patients, 35% were self-referred, 16% were referred by primary care physicians, and 15% by neuro/orthopedic surgeons.

CONCLUSION

Optimizing physicians' awareness of these clinical features may enhance referral in axSpA.

Peptide-based vaccine targeting IL17A attenuates experimental spondyloarthritis in HLA-B27 transgenic rats

OBJECTIVES

Spondyloarthritis (SpA) is known as series of immune-mediated inflammatory disease of the axial and peripheral joints. Human leucocyte antigen (HLA)-B27 is a genetic risk factor for SpA. Recent evidence suggests that the interleukin -17 (IL17) axis strongly contributes to SpA. This study aimed to assess the efficacy of an IL17A peptide-based vaccine on SpA manifestations in model rats.

METHODS

HLA-B27/human β₂-microglobulin (hβ₂M) transgenic rats were immunised with heat-inactivated Mycobacterium tuberculosis (MT) to develop spondylitis and arthritis as an experimental SpA model after immunisation with a keyhole limpet hemocyanin-conjugated IL17A peptide-based vaccine with an alum adjuvant three times. The IL17A antibody titre was assessed using ELISA, and arthritis score and joint thickness were monitored two times a week. Enzyme-linked immunospot (ELISpot) assays for IL4- and interferon-γ-secreting splenocytes were conducted to evaluate IL17A-specific T cell activation. We also evaluated the effect of IL17A vaccine in SpA therapeutic model.

RESULTS

The IL17A peptide-based vaccine with alum adjuvant successfully induced antibody production and suppressed the arthritis score and joint thickness. X-ray and histological analyses showed that enthesitis, bone destruction and new bone formation were inhibited by the IL17A vaccine. The ELISpot assay showed that the IL17A peptide-based vaccine did not elicit any IL17A-reactive T cell responses. IL17A vaccine tends to mitigate, but not significant, in SpA treatment model. These data showed that the peptide-based vaccine targeting IL17A alleviated the SpA phenotype in a heat-inactivated MT-induced SpA model in HLA-B27/hβ₂M transgenic rats.

CONCLUSIONS

IL17A peptide-based vaccine may be a therapeutic option for SpA treatment.

Practical Significance of Biomarkers in Axial Spondyloarthritis: Updates on Diagnosis, Disease Activity, and Prognosis

Axial spondyloarthritis (axSpA) is a chronic inflammatory disease that can lead to ankylosis by secondary ossification of inflammatory lesions, with progressive disability and a significant impact on quality of life. It is also a risk factor for the occurrence of comorbidities, especially cardiovascular diseases (CVDs), mood disorders, osteoporosis, and malignancies. Early diagnosis and treatment are needed to prevent or decrease functional decline and to improve the patient's prognosis. In respect of axSpA, there is an unmet need for biomarkers that can help to diagnose the disease, define disease activity and prognosis, and establish personalized treatment approaches. The aim of this review was to summarize the available information regarding the most promising biomarkers for axSpA. We classified and identified six core categories of biomarkers: (i) systemic markers of inflammation; (ii) molecules involved in bone homeostasis; (iii) HLA-B27 and newer genetic biomarkers; (iv) antibody-based biomarkers; (v) microbiome biomarkers; and (vi) miscellaneous biomarkers. Unfortunately, despite efforts to validate new biomarkers, few of them are used in clinical practice; however, we believe that these studies provide useful data that could aid in better disease management.

The Risk of Major Adverse Cardiovascular Events in Ankylosing Spondylitis Patients With a History of Acute Anterior Uveitis: A Nationwide, Population Based Cohort Study

Background

To investigate the association between a history of acute anterior uveitis (AAU) and the risk of major adverse cardiovascular events (MACE) among patients with ankylosing spondylitis (AS).

Methods

We identified 38,691 newly diagnosed AS patients between 2003 and 2013 from the Taiwan National Health Insurance Research Database. The exposure group was defined as people with uveitis diagnosis by ophthalmologist before AS diagnosis date. The incidence of MACE in patients with AS according to the International Classification of Diseases, Ninth Revision. We randomly selected a comparison group without a history of AAU at a 1:4 ratio matched by age, sex, and index year in relation to the risk of developing MACE. We used cox proportional hazard regression model to compare the risk of MACE between groups, shown as adjusted hazard ratios (aHRs) with 95% confidence intervals (CI). Further subgroup analysis and sensitivity tests were also performed.

Results

There were 3,544 patients in the AAU group and 14,176 patients in the non-AAU group. The aHR of MACE for the AAU group was 0.79 (95% CI = 0.57–1.10) at a 1:4 ratio for age, sex and index year. Sensitivity analyses using various adjustment variables showed consistent results. Cox proportional hazard regression model demonstrated that use of non-steroidal anti-inflammatory drugs (NSAIDs) was associated with an increased risk of MACE in this cohort (HR = 3.44; 95% CI = 2.25–5.25).

Conclusion

This cohort study showed that subjects with AAU was not associated with the risk of MACE among AS patients, compared to non-AAU controls.

Where we are in treat to target era? Predictive factors for remission and drug switching in patients with axial spondyloarthritis: a real-life evidence from BioStaR nationwide registry

OBJECTIVES

Factors associated with disease activity of axial spondyloarthritis (axSpA) and switching of biologic disease-modifying anti-rheumatic drugs have not been clearly defined. We aimed to evaluate clinical characteristics of patients with axSpA, factors related to remission in treat to target era and predictive factors for biologic disease-modifying anti-rheumatic drug switching.

METHOD

A multicenter, observational cross-sectional study was performed between February 2019 and August 2019. We included all consecutive patients ≥ 18 years with axSpA. Demographic and clinical variables were prospectively recorded. Clinical tools included Ankylosing Spondylitis Disease Activity Score with C-reactive protein (ASDAS-CRP), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Metrology Index (BASMI), and Maastricht Ankylosing Spondylitis Enthesitis Score (MASES).

RESULTS

There were 969 patients with a mean age of 43.4 ± 10.8 years. There were 143 patients (14.8%) with remission and 223 (23.1%) patients with low disease activity. Male sex (p = 0.021), positive family history (p = 0.036), and human leukocyte antigen-B27 (p = 0.011) were predictors of remission by ASDAS-CRP. There were 654 patients (67.5%) who did not switch to another drug. The highest BASMI and MASES scores were calculated in patients with very high disease activity (p < 0.05). In patients with drug switching, the disease duration was significantly higher (p < 0.001) and the age at diagnosis was significantly lower (p = 0.016). There were significantly more patients with uveitis and higher scores of MASES and BASMI in patients who switch to another biologic disease-modifying anti-rheumatic drugs (p = 0.003, p = 0.009, and p = 0.004, respectively).

CONCLUSIONS

In patients with axSpA, male sex, younger age, and HLA-B27 positivity are associated with remission, while longer disease duration and accompanied uveitis appear to be related with drug switching.

CLINICAL TRIAL REGISTRATION NUMBER AND DATE

NCT04139954/25.10.2019.

Geographical prevalence of family history in patients with axial spondyloarthritis and its association with HLA-B27 in the ASAS-PerSpA study

BACKGROUND

A positive family history (PFH) of spondyloarthritis (SpA) consists of five SpA-related entities, of which a PFH of axial spondyloarthritis (axSpA) is most common in European patients with axSpA. Moreover, a PFH of axSpA is associated with human leucocyte antigen B27 (HLA-B27) positivity in these patients. It is unknown if this holds true in patients with axSpA in other parts of the world.

OBJECTIVE

To investigate the geographical prevalence of a PFH of SpA and its association with HLA-B27 positivity in patients with axSpA worldwide.

METHODS

Cross-sectional analyses included patients from the ASAS peripheral involvement in Spondyloarthritis (PerSpA) study from 24 countries worldwide with an axSpA diagnosis, known HLA-B27 status and family history. Logistic regression models were built to assess the effect of HLA-B27 status on the occurrence of PFH. This was repeated for each of the five SpA entities in a PFH.

RESULTS

Among 2048 patients, axSpA was the most common SpA entity in a PFH in all geographical regions (Asia 28%, Europe and North America 27%, Latin America 20%, Middle East and North Africa 41%). A PFH of axSpA was associated with HLA-B27 positivity in Asia (OR 4.19), Europe and North America (OR 2.09) and Latin America (OR 3.95), but not in the Middle East and North Africa (OR 0.98), which has a lower prevalence of HLA-B27 positivity. A PFH of other SpA entities was less prevalent and not consistently associated with HLA-B27 positivity.

CONCLUSION

In patients with axSpA worldwide, axSpA was consistently the most common SpA entity in a family history and was associated with HLA-B27 positivity in all geographical regions but one.

The Role of HLA-B27 in Argentinian Axial Spondyloarthritis Patients

BACKGROUND

The prevalence of human leukocyte antigen B27 (HLA-B27) is variable around the world. Our objectives were to estimate the frequency of HLA-B27 in an Argentinian cohort of axial spondyloarthritis (axSpA), to evaluate the differences between HLA-B27-positive and HLA-B27-negative patients, and to analyze its performance as a diagnostic biomarker.

METHODS

Observational study including patients older than 18 years, with axSpA diagnosis assessed in a fast track program (Reuma-Check SpA). All patients underwent the following: blood tests, HLA-B27, sacroiliac images, and enthesitis ultrasound. Sociodemographic data and SpA symptoms were also collected. The clinical assessor was blinded to complementary studies. For the sensitivity and specificity analysis, patients with chronic low back pain without axSpA who performed the same circuit in the same period were used as control, paired 1:1 (sex and age).

RESULTS

One hundred fifty patients were included, 75 axSpA and 75 controls. The frequency of HLA-B27 was 43% (95% confidence interval [CI], 30-53). The differences between HLA-B27-positive and HLA-B27-negative patients were observed in age of low back pain onset (36 vs 46 years), BASFI (Bath Ankylosing Spondylitis Functional Index) (4 vs 5), and extra-articular SpA features such as uveitis and inflammatory bowel disease (29% vs 50%). When this frequency was compared (low back pain control group), the difference was 43% versus 9% (odds ratio, 7.7; 95% CI, 2.8-24), and HLA-B27 had a sensitivity of 43%, specificity of 91%, positive predictive value of 85%, negative predictive value of 58%, and likelihood ratio of 4.9 (95% CI, 3-8).

CONCLUSIONS

The frequency of HLA-B27 in axSpA was 43%; positive patients had an earlier age of onset (36), a higher BASFI, and more SpA features. For the diagnosis of SpA, HLA-B27 had a good specificity but low sensitivity.

Australian Consensus Statements for the Assessment and Management of Non-radiographic Axial Spondyloarthritis

Background

The understanding of non-radiographic axial spondyloarthritis (nr-axSpA) has accelerated over the last decade, producing a number of practice-changing developments. Diagnosis is challenging. No diagnostic criteria exist, no single finding is diagnostic, and other causes of back pain may act as confounders.

Aim

To update and expand the 2014 consensus statement on the investigation and management of non‐radiographic axial spondyloarthritis (nr-axSpA).

Methods

We created search questions based on our previous statements and four new topics then searched the MEDLINE and Cochrane databases. We assessed relevant publications by full-text review and rated their level of evidence using the GRADE system. We compiled a GRADE evidence summary then produced and voted on consensus statements.

Results

We identified 5145 relevant publications, full-text reviewed 504, and included 176 in the evidence summary. We developed and voted on 22 consensus statements. All had high agreement. Diagnosis of nr-axSpA should be made by experienced clinicians, considering clinical features of spondyloarthritis, blood tests, and imaging. History and examination should also assess alternative causes of back pain and related conditions including non-specific back pain and fibromyalgia. Initial investigations should include CRP, HLA-B27, and AP pelvic radiography. Further imaging by T1 and STIR MRI of the sacroiliac joints is useful if radiography does not show definite changes. MRI provides moderate-to-high sensitivity and high specificity for nr-axSpA. Acute signs of sacroiliitis on MRI are not specific and have been observed in the absence of spondyloarthritis. Initial management should involve NSAIDs and a regular exercise program, while TNF and IL-17 inhibitors can be used for high disease activity unresponsive to these interventions. Goals of treatment include improving the frequent impairment of social and occupational function that occurs in nr-axSpA.

Conclusions

We provide 22 evidence-based consensus statements to provide practical guidance in the assessment and management of nr-axSpA.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40744-021-00416-7.

Worldwide Differences in Clinical Phenotype of Axial Spondyloarthritis

PURPOSE OF REVIEW

This review aims to describe the variations in the clinical presentation of axial spondyloarthritis (axSpA) across the globe.

RECENT FINDINGS

We searched the PubMed database and screened more than 1360 articles; 60 of them were selected based on relevance to the topic being discussed and the goals of the review. Most of the clinical manifestations, including IBP, peripheral arthritis, and extra-articular involvement are seen in different regions of the world, but with appreciable clinical heterogeneity, possibly related to a smaller number of patients from some countries, and global variation in the prevalence of HLA-B27. For example, HLA-B27-positive patients have an earlier age of onset, higher prevalence of acute anterior uveitis, and greater familial occurrence. Peripheral arthritis and enthesitis are most commonly seen among axSpA patients from Latin America and Asia, whereas IBD appears to be slightly more common among Middle Eastern and North African patients. The main weakness encountered while reviewing these data is that some studies were small, and others were cross-sectional and retrospective; hence the inferences may have a selection bias. AxSpA is a very heterogenous disease with varied presentation across the globe, in part related to HLA-B27 positivity. It is imperative to further investigate the key regional differences as they impact timely disease recognition and initiation of early treatment. Therefore, there is a need for a large worldwide systematic study to capture the clinical picture of AxSpA in a more uniform manner.

Younger age of onset and uveitis associated with HLA-B27 and delayed diagnosis in Thai patients with axial spondyloarthritis

To identify characteristics associated with HLA-B27, and to identify factors associated with delayed diagnosis in Thai patients with axial spondyloarthritis (axSpA). This cross-sectional study included Thai patients were diagnosed with axSpA by a rheumatologist at Siriraj Hospital. Clinical data were collected. Regression analyses were employed to identify factors associated with study outcomes. Of total 177 patients, 127 (72%) were positive HLA-B27. Uveitis [Odds ratio (OR) 4.0], age at onset of the first musculoskeletal symptom of ≤ 28 years [OR 3.5], female [OR 0.4], and psoriasis [OR 0.4] were significantly associated with HLA-B27 in multiple regression analysis. Those with positive HLA-B27 had less spinal flexibility. Elevated C-reactive protein (p = 0.012) was associated with shorter delay in diagnosis, while uveitis (p < 0.001) and younger age at onset of the first symptom (p = 0.002) were associated with longer delay in diagnosis in multiple regression analysis. Younger age at onset of the first musculoskeletal symptom and uveitis were associated with HLA-B27 and delayed diagnosis in axSpA patients. Young people with musculoskeletal symptom and uveitis should be referred to a rheumatologist to rule out or make a timely diagnosis of axSpA.

Comparison of Clinical Features in HLA-B27 Positive and Negative Patients With Axial Spondyloarthritis: Results From a Cohort of 4,131 Patients

Objective: The aim of our study was to assess the influence of the HLA-B27 status on axial spondyloarthritis (axSpA) in the largest cohort in China.

Methods: An observational, cross-sectional, and analytic study of axSpA patients from the China axSpA database was performed. Demographic and clinical data were compared in terms of the HLA-B27 status. Univariate and multivariate analyses were performed to identify variables related to HLA-B27 presence.

Results: We enrolled 4,131 patients in this study; of those, 36,95 (89.4%) were HLA-B27 positive. In the multivariate analysis, male gender (p < 0.001), younger age (p < 0.001), a disease duration of more than 3 years (p < 0.001), a family history of SpA (p < 0.001), uveitis (p < 0.001), ASDAS-CRP (p < 0.001), and biologic treatment (p < 0.001) were the main variables that were independently related to HLA-B27 presence, whereas a diagnosis delay time >36 months (p < 0.001) and psoriasis (p < 0.001) were independently related to HLA-B27 absence.

Conclusion: In Chinese axial SpA patients, presence of HLA-B27 is associated with the male sex, younger age, longer disease duration, greater family aggregation, and higher frequency of uveitis; absence of HLA-B27 is associated with longer diagnosis delay time and higher frequency of psoriasis.

The treatment journey for patients with axial spondyloarthritis in North Africa and the Middle East: From diagnosis to management

The management of axial spondyloarthritis (axSpA) is challenging worldwide, and the particular challenges shared by North Africa and the Middle East are mainly related to early diagnosis and standardized management. We believe there are several reasons for these challenges, including: (a) limited awareness of the disease manifestations and prevalence in the region among physicians; (b) the concept of nonradiographic axSpA, while accepted with some difficulty by the rheumatology community, may not be well understood by the referring primary care physicians; (c) access to, and training in magnetic resonance imaging varies greatly between countries in the North Africa and Middle East region, and this may have a large impact on early diagnosis; (d) country‐specific treatment guidelines are unavailable; and (e) economic and cultural factors influence patients’ attempts to seek and continue treatment. In this review, we will discuss the prevalence of axSpA in North Africa and the Middle East, as well as the challenges to diagnose and treat patients in this region. As rheumatologists practicing in North Africa and the Middle East, we also provide suggestions to assist physicians, other healthcare professionals, and researchers in facilitating early, accurate diagnosis and treatment of axSpA.

What Does Human Leukocyte Antigen B27 Have to Do with Spondyloarthritis?

Human leukocyte antigen (HLA) B27 is the key laboratory parameter for axial spondyloarthritis (axSpA). Its prevalence is variable across different geographic zones and ethnicities, and often mirrors the prevalence of axSpA. HLA-B27 plays a role in axSpA physiopathology. It is correlated with spondyloarthritis phenotype with a consistent positive association with family history, early disease onset, shorter diagnostic delay, hip involvement, and acute anterior uveitis. HLA-B27 has a pivotal role in many referral strategies. However, these strategies were developed in European populations and need to be evaluated in populations with lower HLA-B27 background prevalence, and where additional parameters might be needed.