Gender differences among patients with primary ankylosing spondylitis and spondylitis associated with psoriasis and inflammatory bowel disease in an iberoamerican spondyloarthritis cohort

Greater magnitude of entheseal microdamage and repair in psoriatic arthritis compared with ankylosing spondylitis on ultrasound

Objectives

AS and PsA share clinical and immunological features centred on enthesitis. However, a strong association between PsA and preceding injury has been recognized. The aim of this study was to test the hypothesis that the entheseal damage seen by US is commoner in PsA patients than in AS patients.

Methods

Seventy-nine AS and 85 PsA patients had US scans of 1640 entheses to calculate entheseal inflammation (hypoechogenicity, thickening and Doppler) and damage scores (calcifications, enthesophytes and erosions). Regression modelling was done to evaluate the effect of diagnoses on outcomes, controlling for age, gender, BMI, clinical enthesitis, HLA-B27, and anti-TNF use.

Results

Both inflammation and damage scores on US were correlated with BMI (r = 0.392; r = 0.320) and age (r = 0.308; r = 0.538) (P < 0.001), and men had higher inflammation scores than women [12.3 (7.5) vs 8.9 (7.3), P = 0.001]. In multivariate analysis, despite similar (anti-TNF-treated patients) or slightly less inflammation (anti-TNF-naïve patients) in the PsA group, they had 4.22 times more US damage than their counterparts with AS. The difference was even higher in the anti-TNF-naïve patients (5.6 times).

Conclusion

On US assessment, PsA patients have greater entheseal insertion damage scores compared with AS, suggesting potential differences in tissue repair, immunobiology or response to injury at insertions.

Axial disease in psoriatic arthritis and ankylosing spondylitis: a critical comparison

Ankylosing spondylitis (AS) was first identified in the late 17th century. 250 years later, inflammatory spine disease was recognized to be one of the patterns of psoriatic arthritis (PsA). Isolated spondylitis is rare among patients with PsA, occurring in less than 5% of patients; however, many patients with PsA have axial disease that is concurrent with peripheral arthritis. At the other end of the spondyloarthritis spectrum, psoriasis is observed in 10% of patients with AS. Although axial involvement in PsA can be indistinguishable from axial disease in AS, it can also differ in several respects, raising the question of whether axial PsA and AS (with or without psoriasis) are different clinical presentations of the same disease, or whether they are separate diseases that have overlapping features. In this Review, the clinical presentation, metrology, radiographic characteristics, genetic factors, treatment options and axial prognosis of the two diseases are addressed. The aim of this Review is to capture all available comparisons made to date, to highlight the similarities and differences between AS and axial PsA and to propose a research agenda.

Real-World Patient Experience on the Path to Diagnosis of Ankylosing Spondylitis

Introduction

We describe the journey to diagnosis of ankylosing spondylitis (AS) from the patient perspective and examine differences in this journey by sex.

Methods

US adults aged ≥ 18 years with a self-reported AS diagnosis were recruited online through CreakyJoints, a patient support community, and ArthritisPower, a patient research registry. Respondents completed a web-based survey on sociodemographics, disease burden, and diagnosis history. Results were stratified by sex and time to diagnosis using two-sample t tests and χ² tests, respectively, to observe differences across the groups; P < 0.05 was considered statistically significant.

Results

Among 235 respondents, 174 (74.0%) were female. Mean (SD) ages of female and male respondents were 48.6 (10.6) and 53.1 (10.3) years, respectively. From the time respondents began seeking medical attention, 87 were diagnosed within ≤ 1 year, 71 in 2–9 years, and 77 after ≥ 10 years. Symptoms that led respondents to seek treatment were back pain (73.2%) and joint pain (63.8%); fatigue and difficulty sleeping were more common among respondents with longer times to diagnosis. During the diagnosis process, men with AS tended to receive quicker AS diagnosis compared with women. Overall, commonly reported initial diagnoses among respondents with longer time to AS diagnosis included back problems and psychosomatic disorders. Significantly more women reported misdiagnoses of fibromyalgia (20.7 vs. 6.6%) and psychosomatic disorders (40.8 vs. 23.0%) compared with men.

Conclusions

Diagnosis delays and misdiagnoses were common among respondents with AS. Increasing awareness about AS among referring providers may minimize diagnosis delay.

Funding

Novartis Pharmaceuticals Corporation.

Plain Language Summary

Plain language summary available for this article.

Electronic Supplementary Material

The online version of this article (10.1007/s40744-019-0153-7) contains supplementary material, which is available to authorized users.

GC-MS-based fecal metabolomics reveals gender-attributed fecal signatures in ankylosing spondylitis

Ankylosing spondylitis (AS) has different clinical features in males and females. Fecal metabolites play significant roles in AS disorders. This study aimed to reveal gender-attributed fecal signatures of AS. Fecal samples from 87 cross-sectional individuals (healthy controls: 20 males, 18 females; AS patients: 26 males, 23 females) were analyzed by gas chromatography-mass spectroscopy (GC-MS). Partial least squares discriminant analysis (PLS-DA) was used to reveal differences in the fecal signatures of AS between males and females. Fecal signatures were defined by the significantly different fecal metabolites between AS patients and healthy individuals. Therefore, different fecal signatures of male and female AS patients were defined as gender-attributed fecal signatures. Male-specific fecal signatures in AS patients were steroid compounds, including cholestan-3-ol, tocopherol, stigmastan-3,5-diene, cholest-3-ene, cholest-4-en-6-one and 1-heptatriacotanol. Female-specific fecal signatures were ergost-5-en-3-ol, acetate and D-myo-Inositol. Gender-attributed fecal signatures of AS further reveal differences between males and females in terms of AS features.

Can the Second to Fourth Digit Ratio (2D : 4D) Be a Marker to Determine Ankylosing Spondylitis Disease Activity?

Objective

The length ratio of the index finger (2D) to the ring finger (4D) (2D : 4D ratio) is considered a biomarker of prenatal sex hormone exposure. The 2D : 4D ratio is influenced by prenatal androgen and estrogen levels. Because ankylosing spondylitis (AS) influences men more frequently and severely than women, androgens are proposed to be related to AS pathogenesis. Estrogens have immune-modulating effects and reduce AS disease activity. The aim of this study was to assess the relationship between 2D : 4D ratio and AS disease activity.

Material and Methods

In this study, 167 (43 female) patients diagnosed with AS were studied. The lengths of the second and fourth fingers were measured using a digital caliper. The 2D : 4D ratio was found by dividing the length of the second finger by the length of the fourth finger. AS disease activity was assessed with the Turkish version of the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). AS functional status was assessed with Bath Ankylosing Spondylitis Functional Index (BASFI). L-Schober, tragus to wall distance, finger to floor distance, and chest expansion were used to evaluate mobility.

Results

In female patients, the right hand 2D : 4D ratios were higher than those in male patients. Biologic drug use was more frequent in males. The BASDAI scores were higher in female patients than in male patients. There were significant negative correlations between right and left hand 2D : 4D ratio and BASFI and BASDAI in female patients. There was no significant correlation between the 2D : 4D ratio and BASFI or BASDAI in male patients. We found a positive correlation between L-Schober and right hand 2D : 4D and a negative correlation between the left hand 2D : 4D ratio and finger to floor distance in female patients with AS.

Conclusion

The 2D : 4D ratio of the right and left hand was low in female patients with high BASFI and BASDAI and low spinal mobility (L-Schober) was also linked to low female 2D : 4D. The lack of strong associations between 2D : 4D and AS in male patients may have resulted from their higher use of biologics.

Are gender-specific approaches needed in diagnosing early axial spondyloarthritis? Data from the SPondyloArthritis Caught Early cohort

Background

Although gender differences have been observed in the severity of axial spondyloarthritis (axSpA), gender differences in disease presentation of early axSpA have not been thoroughly investigated. In particular, their impact on the diagnostic process is unknown.

Methods

Baseline data from the SPondyloArthritis Caught Early cohort, which includes patients with chronic back pain (CBP; duration ≥ 3 months and ≤ 2 years, age of onset < 45 years), were analysed. Patients underwent a full diagnostic work-up, including MRI and radiograph of the sacroiliac joints (MRI-SIJ and X-SIJ), to establish a diagnosis of axSpA. Characteristics of male and female patients with a certain diagnosis of axSpA (confidence level by the physician ≥ 7 on a 0–10 rating scale) were compared. Regression models were built for: the whole CBP cohort stratified by gender, to study which SpA features were associated most with diagnosis in each gender; and for axSpA patients, to test whether gender was associated with imaging positivity (MRI-SIJ⁺ and/or X-SIJ⁺).

Results

Of the 719 CBP patients, 275 were male. With 146/275 males and 155/444 females diagnosed as axSpA, males were more likely to be diagnosed with axSpA (OR 2.1, 95% CI 1.5–2.9). Despite similar symptom duration, male axSpA patients were younger at diagnosis (27.4 ± 7.5 vs 29.5 ± 7.8 years; p = 0.02). Presence of SpA features was similar in male and female axSpA patients, except for HLA-B27 and imaging positivity that were more common in male axSpA patients (80% vs 60%; p < 0.01 and 78% vs 64%; p = 0.01). Nevertheless, these SpA features were still more prevalent in female axSpA patients than in no-axSpA patients, both females (HLA-B27⁺ 23%, positive imaging 7%) and males (HLAB27⁺ 34%, positive imaging 11%) (all p < 0.01). Moreover, in multivariable models with diagnosis of axSpA as outcome, HLA-B27 and imaging positivity were associated with the diagnosis in both sexes. In models with imaging positivity as outcome, male gender and HLA-B27 were both independently associated with MRI⁺ and/or X-SI⁺.

Conclusions

While our data show clear gender differences in early axSpA, they highlight that HLA-B27 and imaging are still key elements for diagnosis in both genders. Our study does not suggest that separate diagnostic strategies for men and women are required.

Electronic supplementary material

The online version of this article (10.1186/s13075-018-1705-x) contains supplementary material, which is available to authorized users.

Recent advances in ankylosing spondylitis: understanding the disease and management

The term spondyloarthritis refers to a group of immune-mediated diseases characterised by inflammation of the axial skeleton, peripheral joints, and entheses. Ankylosing spondylitis (AS) is the most common and characteristic of these entities and even though it was first described over two centuries ago, the understanding of the underlying disease mechanism remains incomplete. It is known that around 40% of patients with AS have subclinical bowel inflammation, suggesting that the origin of the disease could be in the gut. Also, more genes and new molecules have demonstrated a role in the pathogenesis of AS. In this review, we analyse the latest therapies for spondyloarthritis and the most relevant discoveries over the last three years, together with their implications for different aspects of the disease.

Nature versus nurture in the spectrum of rheumatic diseases: Classification of spondyloarthritis as autoimmune or autoinflammatory

Spondyloarthritides (SpA) include inflammatory joint diseases with various clinical phenotypes that may also include the axial skeleton and/or entheses. SpA include psoriatic arthritis, reactive arthritis, enteropathic arthritis and ankylosing spondylitis; the latter is frequently associated with extra-articular manifestations, such as uveitis, psoriasis, and inflammatory bowel disease. SpA are associated with the HLA-B27 allele and recognize T cells as key pathogenetic players. In contrast to other rheumatic diseases, SpA affect women and men equally and are not associated with detectable serum autoantibodies. In addition, but opposite to rheumatoid arthritis, SpA are responsive to treatment regimens including IL-23 or IL-17-targeting biologics, yet are virtually unresponsive to steroid treatment. Based on these differences with prototypical autoimmune diseases, such as rheumatoid arthritis or connective tissue diseases, SpA may be better classified among autoinflammatory diseases, with a predominant innate immunity involvement. This would rank SpA closer to gouty arthritis and periodic fevers in the spectrum of rheumatic diseases, as opposed to autoimmune-predominant diseases. We herein provide available literature on risk factors associated with SpA in support of this hypothesis with a specific focus on genetic and environmental factors.

The Importance of Sex Stratification in Autoimmune Disease Biomarker Research: A Systematic Review

The immune system is highly dynamic and regulated by many baseline characteristic factors. As such, significant variability may exist among different patient groups suffering from the same autoimmune disease (AD). However, contemporary research practices tend to take the reductionist aggregate approach: they do not segment AD patients before embarking on biomarker discovery. This approach has been productive: many novel AD biomarkers have recently been discovered. Yet, subsequent validation studies of these biomarkers tend to suffer from a lack of specificity, sensitivity, and reproducibility which hamper their translation for clinical use. To enhance reproducibility in validation studies, an optimal discovery-phase study design is paramount: one which takes into account different parameters affecting the immune system biology. In this systematic review, we highlight need for stratification in one such parameter, i.e., sex stratification. We will first explore sex differences in immune system biology and AD prevalence, followed by reported sex-bias in the clinical phenotypes of two ADs—one which more commonly affects females: systemic lupus erythematosus, and one which more commonly affects males: ankylosing spondylitis. The practice of sex stratification in biomarker research may not only advance the discovery of sex-specific AD biomarkers but more importantly, promote reproducibility in subsequent validation studies, thus easing the translation of these novel biomarkers from bench to bedside to improve AD diagnosis. In addition, such practice will also promote deeper understanding for differential AD pathophysiology in males and females, which will be useful for the development of more effective interventions for each sex type.

Gender Differences in Axial Spondyloarthritis: Women Are Not So Lucky

PURPOSE OF REVIEW

Ankylosing spondylitis (AS) was historically seen as a predominantly male disease. However, more recent data showed a more homogenous sex prevalence. Unfortunately, in many studies in axial spondyloarthritis (axSpA), the number of women included is low and the analyses are often not stratified for gender distribution. The purpose of this review is to aggregate the existing data on gender differences in axSpA in order to increase the awareness that female axSpA patients are still under-recognized.

RECENT FINDINGS

Several studies considering gender differences revealed that female axSpA patients had different disease manifestations due to different immunological, hormonal, and genetic responses. For instance, allelic frequencies of the AHNK-gene and tissue non-specific alkaline phosphatase (TNAP) haplotypes differed between men and women with ankylosing spondylitis (AS). In addition, different levels of tumor necrosis factor (TNF), interleukins IL-6, IL-17, and IL-18, were found between the two sexes. Furthermore, female patients show a higher diagnostic delay compared to males. Several studies indicate a higher frequency of extra-articular manifestations (EAM) in female axSpA patients, such as enthesitis, psoriasis, and inflammatory bowel disease (IBD), whereas acute anterior uveitis is more prevalent in male patients. Male AS patients more frequently show a higher Bath Ankylosing Spondylitis Radiology Index (BASRI) scores and modified Stoke Ankylosing Spondylitis Spine Scores (mSASSS) than females, which indicates that males have higher radiological damage and radiographic progression. However, disease activity (BASDAI) and quality of life (AsQol) scores are significantly higher in women, and more importantly, they have significantly lower response rates to treatment with TNF inhibitors (TNFi) and a significantly lower drug adherence. Despite the fact that men with axial SpA have a worse radiologic prognosis, women have a high disease burden, in part because they have a longer delay in diagnosis, higher disease activity, and significantly less responsiveness to treatment with TNFi.

The Sex Influence on Response to Tumor Necrosis Factor-α Inhibitors and Remission in Axial Spondyloarthritis

OBJECTIVE

The aim of this study was to evaluate the influence of sex on response to treatment and disease remission in patients with axial spondyloarthritis (axSpA).

METHODS

In this retrospective multicenter study, patients with axSpA, according to the Assessment of Spondyloarthritis international Society (ASAS) criteria for axSpA, and treated with adalimumab, etanercept, golimumab, or infliximab, were studied. We compared clinical characteristics, patient-reported outcomes, disease activity, function, and response to treatment in male and female patients with this disease.

RESULTS

Three hundred forty patients with axSpA (270 with ankylosing spondylitis, 19 with psoriatic arthritis with axial involvement, and 51 with nonradiographic axSpA) were studied. Male subjects had a significantly higher prevalence of grade IV sacroiliitis, higher levels of serum C-reactive protein, lower Maastricht Ankylosing Spondylitis Enthesitis Score, and fatigue when compared with females. Further, Kaplan-Meier survival curves showed that the rate of partial remission, ASAS40 response, and Ankylosing Spondylitis Disease Activity Score (ASDAS) major improvement, but not ASDAS inactive disease, were significantly lower in female patients.

CONCLUSION

Our data suggest that female sex was associated with a lower rate of response to treatment and of disease remission in patients with axSpA treated with antitumor necrosis factor-α drugs.

Erratum: Gender differences among patients with primary ankylosing spondylitis and spondylitis associated with psoriasis and inflammatory bowel disease in an iberoamerican spondyloarthritis cohort: Erratum

[This corrects the article DOI: 10.1097/MD.0000000000005652.].