Incidence and prevalence of psoriatic arthritis, ankylosing spondylitis, and reactive arthritis in the first descriptive population-based study in the Czech Republic

A population-based projection of psoriatic arthritis in Germany until 2050: analysis of national statutory health insurance data of 65 million German population

The population-based prevalence of psoriatic arthritis (PsA) is still unclear and not well described globally. The aim of this study was to conduct a population-based prevalence projection and provide long-term future estimations of PsA patients in Germany until 2050, using the illness-death model and based on historical data. We analyzed the national statutory health insurance data of 65 million population in the German Institute for Medical Documentation and Information between January 2009 and December 2012. We constructed an estimation of the PsA burden among the German population using the relevant epidemiological parameters to project the numbers of patients with PsA in Germany until 2050 under five possible scenarios by varying the incidence and mortality. The overall conservatively estimated prevalence of PsA in Germany in 2019 was 0.31% (95% CI 0.28-0.36%). Women contribute a higher prevalence than men in all five scenarios. In the assumed scenarios with increased incidence, the prevalence of PsA at 60 years of age could rise from 1% in 2019 to more than 3% in 2050 for both genders, with the increase particularly pronounced for women, reaching around 3.5%. However, in the assumed scenarios with decreasing incidence, the prevalence curve may flatten and begin a decreasing trend from 2035 to 2050 for both genders, achieving a prevalence of less than 1% in 2050. Our research is to generate assumed population-based data on PsA in Germany that can serve as a reference for public health stakeholders to prepare an optional intervention. We would expect worryingly high numbers in the coming decades if preventive strategies are not implemented. In the long term, it will be necessary to implement preventive strategies to identify predictors and treat psoriasis symptoms early in order to delay or even prevent the transition of psoriasis to PsA.

Psoriatic arthritis and its special features predispose not only for osteoporosis but also for fractures and falls

Limited data are available on the predisposing factors to fractures and falls of patients with psoriatic arthritis (PsA). Our study intended to explore the differences between PsA patients and controls, concerning bone mineral density (BMD), the 10-year fracture risk, the number of prevalent fractures, the frequency of falls and to investigate the association of the same factors with PsA disease characteristics within the PsA group. Medical reports of 61 PsA patients and 69 consecutive, age-matched controls were analyzed, physical examination and bone mineral density (BMD, and T-score) were performed, and the 10-year fracture risk was calculated. The results were subjected to statistical analysis. Femoral neck BMD, as well as vertebral and femoral neck T-scores were lower, the odds ratio (OR) for low BMD and the 10-year risk of hip fracture was higher (p = 0.0029; 0.0002, p < 0.0001, OR = 21,9, p = 0.014) in the PsA group. The PsA patients were more predisposed to prevalent fractures, including peripheral fractures, and vertebral fractures as well as falls (OR 3.42; 2.26; 13.33; 3.95, respectively), compared to controls. Within the PsA group (beyond the age) scalp psoriasis and late-onset psoriasis, were significantly associated with a greater number of prevalent fractures (p = 0.0049; 0.029), while the number of falls per year correlated with late-onset psoriasis and the flexural psoriasis (p = 0.007; 0.023). Our results suggest that PsA is an independent risk factor for reduced bone density and falls hence to related bone fractures. Patients with late-onset psoriasis are more likely to suffer falls and related fractures, especially if their disease is characterized by the involvement of the hairy scalp and body folds.

Reactive, infectious, or postinfectious arthritis?

The issue of reactive arthritis belongs to one of the most complex problems in rheumatology. Although the original concept of reactive arthritis as a „sterile arthritis“ has already been overcome, much remains unclear. Non-uniform terminology, classification and diagnostic criteria as well as treatment guidelines leave room for different interpretations of this issue. Therefore it is difficult for non-rheumatologists (internal medicine physicians and general practitioners) to find their way around this topic. Our comprehensive report discusses the latest findings from etiology to treatment of reactive arthritis. It also addresses the aforementioned controversies from terminology to the latest list of causative pathogens, including viruses, parasites and vaccines.

[Ankylosing spondylitis in Senegal: epidemiological, diagnostic, therapeutic and evolutionary features at the Hospital Center University Aristide Le Dantec, Dakar]

Introduction

la spondylarthrite ankylosante (SA) est une maladie évolutive, pouvant s'aggraver par une invalidité. Le but de notre étude est de décrire les aspects épidémiologiques, diagnostiques, thérapeutiques et évolutifs de la SA dans le service de rhumatologie du Centre Hospitalier Universitaire Aristide LeDantec à Dakar.

Méthodes

il s´agissait d´une étude transversale descriptive et analytique, avec un recueil de données à la fois prospectif et rétrospectif sur une période de 8 ans, entre janvier 2012 et décembre 2020, sur des patients atteints de SA de diagnostic établi en accord avec les critères diagnostiques d´Amor, de l´ESSG (European Seronegative Spondylarthropathy Group), d´ASAS (Assessment of Spondyloarthritis International Society) et les critères de New York modifié pour la SA. Les données ont été recueillies par le biais d'un questionnaire structuré et analysées à l´aide du logiciel SPSS25 (Statistical Package for the Social Sciences).

Résultats

six cent quarante-sept (647) patients ont répondu aux critères d´inclusions; 414 femmes et 233 hommes soit un sex ratio de 1,77F/1H. Différentes formes symptomatiques étaient obtenues: les formes axiales (55,65%), les formes mixtes (44,35%) et les formes systémiques avec manifestation extra-articulaires: uvéites (12,21%), insuffisance aortique (5,71%) et maladie fibrobulleuse des poumons (3,86%). Soixante pourcent (60%) des patients étaient sous antiinflammatoires non stéroïdiens (AINS), 47% sous méthotrexate et 0,92% sous biothérapie. Les indices d´activité de la maladie, les indices fonctionnels et les indices de la qualité de vie ont permis le suivi de la maladie.

Conclusion

nos résultats ont montré une prédominance féminine. Les formes axiales étaient les plus représentées. Plus de la moitié de nos patients étaient sous antiinflammatoires, 47% sous méthotrexate et 0,92% sous biothérapie. Cette étude a permis de comprendre le poids de la SA dans les spondyloarthrites et son évolution dans le temps.

The Epidemiology of Psoriatic Arthritis Over Five Decades: A Population-Based Study

OBJECTIVE

To determine the incidence of psoriatic arthritis (PsA) in a US population and describe trends in incidence and mortality over 5 decades.

METHODS

The previously identified population-based cohort that included Olmsted County, Minnesota residents ≥18 years of age who fulfilled PsA criteria during 1970-1999 was extended to include patients with incident PsA during 2000-2017. Age- and sex-specific incidence rates and point prevalence, adjusted to the 2010 US White population, were reported.

RESULTS

There were 164 incident cases of PsA in 2000-2017 (mean ± SD age 46.4 ± 12.0 years; 47% female). The overall age- and sex-adjusted annual incidence of PsA per 100,000 population was 8.5 (95% confidence interval [95% CI] 7.2-9.8) and was higher in men (9.3 [95% CI 7.4-11.3]) than women (7.7 [95% CI 5.9-9.4]) in 2000-2017. Overall incidence was highest in the 40-59 years age group. The incidence rate was relatively stable during 2000-2017, with no evidence of an overall increase or an increase in men only (but a modest increase of 3% per year in women), compared to 1970-1999 when a 4%-per-year increase in incidence was observed. Point prevalence was 181.8 per 100,000 population (95% CI 156.5-207.1) in 2015. The percentage of women among those with PsA increased from 39% in 1970-1999 and 41% in 2000-2009 to 54% in 2010-2017 (P = 0.08). Overall survival in PsA did not differ from the general population (standardized mortality ratio 0.85 [95% CI 0.61-1.15]).

CONCLUSION

The incidence of PsA in this predominantly White US population was stable in 2000-2017, in contrast to previous years. However, an increasing proportion of women with PsA was found in this study.

Characteristics Associated with the Occurrence and Development of Acute Anterior Uveitis, Inflammatory Bowel Disease, and Psoriasis in Patients with Ankylosing Spondylitis: Data from the Chinese Ankylosing Spondylitis Prospective Imaging Cohort

Introduction

This study aimed to determine the association between extra-articular manifestations (EAMs) and baseline characteristics of patients with ankylosing spondylitis (AS) and identify their potential risk factors in an observational cohort.

Methods

We analyzed the data of consecutive patients with AS obtained between April 2016 and May 2019 from the ongoing Chinese Ankylosing Spondylitis Prospective Imaging Cohort.

Results

Among the 1414 patients with AS, 23.1% had experienced EAMs at baseline. The prevalence rates of acute anterior uveitis (AAU), inflammatory bowel disease, and psoriasis among patients with AS were 16.7, 6.9, and 2.6%, respectively, and the prevalence of AAU increased significantly with the disease duration. Patients with comorbidity of AAU and psoriasis had Ankylosing Spondylitis Disease Activity Score (ASDAS) than patients without EAMs (2.16 ± 0.984 vs. 1.99 ± 0.956 [p = 0.025] and 2.36 ± 1.01 vs. 1.99 ± 0.96 [p = 0.025]). Among the 1087 patients with AS without EAMs at baseline, 98 developed EAMs during follow-up. Long disease duration (> 10 years) and high disease activity at baseline (ASDAS > 2.1) were associated with the risk of new-onset EAMs (hazard ratio [HR] [95% confidence interval, CI], 2.150 [1.229–3.762] and 2.896 [1.509–5.561], respectively) and new-onset AAU (HR [95% CI], 2.197 [1.325–3.642] and 3.717 [1.611–8.574], respectively).

Conclusions

In Chinese patients with AS, patients with comorbidity of AAU and psoriasis had higher disease activity scores than patients without EAMs. Furthermore, the risk of AAU or combined EAMs increases with the duration of AS and appears to be associated with higher cumulative exposure to inflammation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40744-021-00293-0.

Is Axial Spondyloarthritis More Common Than Rheumatoid Arthritis?

PURPOSE OF REVIEW

To discuss the disease incidence and prevalence rates of axial spondyloarthritis (axSpA) and ankylosing spondylitis (AS) relative to those of rheumatoid arthritis (RA).

RECENT FINDINGS

According to the most recently published systematic reviews, pooled prevalence estimates for RA are 0.38% in North America, and 0.21 to 0.25% in European subregions, while that of AS is 0.20% in North America and 0.25% in Europe. The estimated prevalence of axSpA has been reported to be approximately twice as common as AS in a study from the USA. This finding has also been supported by studies from northern Norway, central Italy, western Turkey, northern and southern regions of China, and rural Taiwan. These data suggest that axSpA, that encompasses AS, may be more prevalent than RA, at least in some countries. In general, higher occurrences of RA relative to AS have been noted worldwide, both in terms of incidence and prevalence. But axSpA, that encompasses AS, may be more prevalent than RA, at least in some countries. There is a need for concurrently run studies in the same population for a reliable comparison to establish occurrence of RA, AS, and axSpA. It is hoped that the implementation of the ICD-11 codes for axSpA will be helpful in determining a more accurate estimate of its incidence and prevalence.

Skin inflammation associated with arthritis, synovitis and enthesitis. Part 2: rheumatoid arthritis, reactive arthritis, Reiter's syndrome, Lyme borreliosis, dermatomyositis and lupus erythematosus

Syndromes associated with concurrent skin and joint inflammation frequently pose a therapeutic challenge for both dermatologists and rheumatologists. In part 1 of this review, we discussed psoriatic arthritis as well as the autoinflammatory disorders SAPHO syndrome, Still's disease and Behçet's disease. Part 2 will address rheumatoid arthritis, reactive arthritis, Reiter's syndrome and Lyme borreliosis. In addition, we will discuss dermatomyositis and lupus erythematosus, two common autoimmune disorders that frequently present with both cutaneous and joint involvement. For each of the aforementioned disorders, we will highlight aspects of epidemiology, pathogenesis, clinical presentation, diagnosis and treatment.

Add-On Effects of Conventional Synthetic Disease-Modifying Anti-Rheumatic Drugs in Ankylosing Spondylitis: Data from a Real-World Registered Study in China

Background

The aim of this study was to investigate the effects of conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) on patients with ankylosing spondylitis (AS) using real-world data, and to analyze patients’ choices of csDMARDs and reasons for discontinuation.

Material/Methods

This observational study included 320 patients satisfying the modified New York criteria for AS. Patients were grouped according to medication: Group 1: 122 patients receiving non-steroidal anti-inflammatory drug (NSAID) monotherapy; Group 2: 198 patients receiving csDMARDs and NSAIDs. Patients were followed for 18 months at 6-month intervals. The change in AS Disease Activity Score and C-reactive protein (ASDAS-CRP) at each visit was the primary outcome. Secondary outcomes were based on validated disease activity questionnaires, clinical assessment, and acute-phase biomarkers (CRP and erythrocyte sedimentation rate [ESR]). Inter-group relationships were assessed across the 18-month follow-up period using generalized additive mixed models.

Results

Sulfasalazine and thalidomide were the most commonly used csDMARDs, with cumulative use times of 8.9±4.1 months and 9.1±4.7 months, respectively. In Group 2, 56 patients discontinued or switched csDMARDs during the follow-up period, with lack of efficacy being the primary reason. The ASDAS-CRP was found to decrease significantly in both groups; however, improvements in many parameters (including ASDAS-CRP, disease activity questionnaires and ESR) were greater in Group 2.

Conclusions

Use of csDMARDs can improve disease activity in terms of ASDAS-CRP. The addition of csDMARDs may provide increased benefits compared with NSAID monotherapy, particularly in the reduction of AS disease activity, in the Chinese population.

Validation of claims-based algorithms for psoriatic arthritis

PURPOSE

An increasing number of new medications are being developed and approved for psoriatic arthritis (PsA). To generate real-world evidence on comparative safety and effectiveness of these drugs, a claims-based algorithm that can accurately identify PsA is greatly needed.

METHODS

To identify patients with PsA, we developed seven claims-based algorithms based on a combination of diagnosis codes and medication dispensing using the claims data from Medicare parts A/B/D linked to electronic medical records (2012-2014). Two physicians independently conducted a chart review using the treating physician's diagnosis of PsA as the gold standard. We calculated the positive predictive value (PPV) and 95% confidence intervals of each algorithm.

RESULTS

Of the total 2157 records identified by the seven algorithms, 45% of the records had relevant clinical data to determine the presence of PsA. The PPV of the algorithms ranged from 75.2% (algorithm 1: ≥2 diagnosis codes for PsA and ≥1 diagnosis code for psoriasis) to 88.6% (algorithm 7: ≥2 diagnosis codes for PsA with ≥1 code by rheumatologist and ≥1 dispensing for PsA medication). Having ≥2 diagnosis codes and ≥1 dispensing for PsA medications (algorithm 6) also had PPV of 82.4%.

CONCLUSIONS

All seven claims-based algorithms demonstrated a moderately high PPV of 75% to 89% in identifying PsA. The use of ≥2 diagnosis codes plus ≥1 prescription claim for PsA appears to be a valid and efficient tool in identifying PsA patients in the claims data, while broader algorithms based on diagnoses without a prescription claim also have reasonably good PPVs.

Reactive arthritis induced by active extra-articular tuberculosis: A case report

RATIONALE

Rare cases of reactive arthritis induced by active extra-articular tuberculosis (Poncet disease) have been reported. Complete response to antitubercular treatment and evidence of active extra-articular tuberculosis are the most important clinical features of Poncet disease. We report the case of successfully treated a patient with reactive arthritis induced by active extra-articular tuberculosis with a TNF inhibitor after sufficient antitubercular treatment.

PATIENT CONCERNS

A 56-year-old Japanese man was admitted to our department with polyarthralgia, low back pain, and high fever. The results of rheumatoid factor, anti-citrullinated protein antibody, human leukocyte antigen B27, and the assays for the detection of infections (with an exception of T-SPOT.TB) were all negative. Fluoro-deoxy-D-glucose-positron emission tomography with CT (PET/CT) showed moderate uptake in the right cervical, right supraclavicular, mediastinal, and abdominal lymph nodes. As magnetic resonance imaging and power Doppler ultrasonography showed peripheral inflammation (tendinitis, tenosynovitis, ligamentitis, and enthesitis in the limbs).

DIAGNOSIS

A diagnosis of tuberculous lymphadenitis was eventually established on the basis of lymph node biopsy results. There was no evidence of a bacterial infection including acid-fast bacteria in his joints, and the symptoms of polyarthralgia and low back pain were improved but not completely resolved with NSAID therapy; in addition, a diagnosis of reactive arthritis induced by active extraarticular tuberculosis was made.

INTERVENTIONS

The patient experienced persistent peripheral inflammation despite antitubercular treatment for more than nine months and was then successfully treated with a tumor necrosis factor inhibitor (adalimumab 40 mg every 2 weeks).

OUTCOMES

Finally, the patient responded to the treatment and has been in remission for over 4 months as of this writing.

LESSONS

In patients who present with symptoms associated with spondyloarthritis, it is important to distinguish between classic reactive arthritis and reactive arthritis induced by extra-articular tuberculosis infection. Introduction of biological agents should be carefully considered in settings where reactive arthritis induced by active extra-articular tuberculosis shows progression to chronicity despite sufficient antitubercular treatment.

Incidence of ankylosing spondylitis and spondyloarthritis in 2000-2013: a nationwide Danish cohort study

Objective: To describe the incidence of ankylosing spondylitis (AS) and spondyloarthritis (SpA) in the Danish population in 2000-2013, at national and regional level, and to investigate any trends in incidence over time.Methods: From the Danish National Patient Registry (NPR), we identified patients diagnosed with AS (International Classification of Diseases, 10th revision: M45) or SpA (M46) from 1 January 2000 to 31 December 2013. Patients without a relevant contact in NPR at 12-24 months after initial diagnosis were excluded. Incidence rate ratios (IRRs) were calculated using the background population of men and women aged 18-45 years in 2000-2013 as a comparator. Variations in incidence between periods and the five Danish regions were evaluated.Results: In total, 3042 incident cases were identified (AS: 1849; SpA: 1193). AS incidence increased from 476 in 2000-2004 to 660 in 2010-2013; the IRR (95% confidence interval) increased from 1.49 (1.33-1.67) in 2005-2009 to 1.74 (1.53-1.97) in 2010-2013. SpA incidence increased from 156 in 2000-2004 to 707 in 2010-2013; the IRR increased from 2.45 (2.03-2.94) in 2005-2009 to 6.31 (5.27-7.55) in 2010-2013. The incidence of both AS and SpA increased in all five regions.Conclusion: The incidence of both AS and SpA in Denmark increased from 2000 to 2013. However, the proportion of patients diagnosed with SpA rather than AS was significantly higher in 2010-2013. This may be due to increased awareness of SpA and new treatment options, but possibly also misclassification of patients with SpA.

Peripheral spondyloarthritis: Concept, diagnosis and treatment

Peripheral spondyloarthritis refers to spondyloarthritis with predominant peripheral (arthritis, enthesitis or dactylitis) involvement. Diagnosis can be challenging, particularly in the absence of SpA extra-articular manifestations such as uveitis, psoriasis or inflammatory bowel disease. Evaluation of disease activity should always include assessment of objective signs of inflammation, particularly in the presence of enthesitis as the sole peripheral manifestation, mainly due to the potential misdiagnosis with fibromyalgia tender points. Several recommendations for management/treatment of psoriatic arthritis have been published by EULAR and GRAPPA but none for peripheral SpA in general. NSAIDs and glucocorticoids are recommended as the first step of treatment in all peripheral manifestations, while conventional synthetic (cs) DMARDs seem only efficacious in arthritis. Several biologics and targeted synthetic (ts) DMARDs (TNFi, anti-IL17 and JAK-inhibitors) have been proven to be efficacious in peripheral involvement in PsA (arthritis and enthesitis), but studies on peripheral SpA are lacking.

Evolving patterns of reactive arthritis

OBJECTIVE

To characterize rheumatologists' perspectives on evolving trends of reactive arthritis (ReA).

METHODS

After ethics approval, 548 members of the Canadian Rheumatology Association were surveyed with 37 questions covering their demographic information, subspecialty, level of experience, practice setting and opinions on prevalence, treatment, and causes of ReA. Results were analyzed with descriptive statistics.

RESULTS

Ninety-seven responded to the survey (18% response rate); 66 fully completed it. Nearly half of respondents believed that the incidence of ReA is declining and causes of ReA may be changing. Physicians reported that most of the ReA cases in their practices were caused by an unknown organism, sexually transmitted, or gastrointestinal infection. Full triad ReA increased the chance of recurrence according to their impressions. Common investigations in ReA included inflammatory markers, HLA-B27, chlamydia and gonorrhea testing, stool cultures, synovial fluid analyses, SI joint imaging. ReA treatment included NSAIDs, intra-articular corticosteroid injections, and DMARDs. Two-thirds said they used TNF alpha inhibitors in chronic ReA occasionally or more frequently.

CONCLUSION

ReA may be decreasing in frequency and severity in Canada. Changes could be due to less food borne illness, cleaner water, or more rapid treatment of sexually transmitted infections. The cause is often unknown in clinical practice.Key Points• Reactive arthritis (ReA) is likely decreasing in prevalence and severity.• Patients with classic trial of arthritis, urethritis, and conjunctivitis are more likely to have recurrent and/or chronic ReA.• The causal organisms are often not detected and seem to be changing over time.

Update on the epidemiology, risk factors, and disease outcomes of psoriatic arthritis

Psoriatic arthritis (PsA) is a chronic inflammatory disease that affects different structures of the musculoskeletal system in addition to the skin and the nail. The complexity of the disease had been a barrier to understand the pathogenesis and define valid outcome tools; however, our understanding about the disease has considerably increased with time mainly because of the advances in imaging, new discoveries in genetics and underlying inflammatory pathways, and better understanding of the epidemiology of the disease and environmental risk factors. The purpose of this review is to summarize developments and changes in epidemiology, risk factors for developing PsA, and outcome measures with a focus on data obtained in the last 10 years.

Increasing incidence and shifting profile of idiopathic inflammatory rheumatic diseases in adults during this millennium

To explore the trends in the incidence of idiopathic inflammatory rheumatic diseases (IIRDs) after the turn of the millennium. From a nationwide register maintained by the Social Insurance Institution of Finland, we collected all adult patients with IIRDs granted a new special reimbursement for anti-rheumatic drugs between 2000 and 2014. Temporal trends in the incidences of various IIRDs were estimated in three 5-year intervals. A total of 58,405 adult patients were identified. Between 2000-2004 and 2010-2014, the age-adjusted incidence rate of IIRDs increased from 114 to 116/100000 [incidence rate ratio (IRR) 1.03 (95% CI 1.01 to 1.06)] in women and from 67 to 69/100,000 [IRR 1.10 (95% CI 1.06-1.14)] in men. The incidence of seropositive rheumatoid arthritis (RA) remained stable while that of seronegative RA decreased. For other diagnoses, the incidences either increased (unspecified arthritis, psoriatic arthritis, spondyloarthritis), remained stable (reactive arthritis), or decreased (SLE and the group of diseases with the ICD-10 code M35). The gender difference in spondyloarthritis leveled as the incidence in women increased at a higher rate than in men. Mean age at IIRD diagnosis decreased among women. The total age-adjusted incidence of IIRDs has gradually increased, due to the increase in unspecified arthritis, psoriatic arthritis, and spondyloarthritis. This, in addition to the ascending number of individuals at risk in the population, translates into a growing burden to the health care system.

Trends in the prevalence and incidence of ankylosing spondylitis in South Korea, 2010-2015 and estimated differences according to income status

The aim of this study is to determine the prevalence and incidence of ankylosing spondylitis (AS) in South Korea, 2010–2015. This study was conducted using the Health Insurance Review Agency (HIRA) database, which includes information on every patient diagnosed with AS. The incidence and prevalence of AS were evaluated by age, sex, and income status. The prevalence increased linearly by 7.7% annually, i.e., 31.62 in 2010 to 52.30 in 2015 (per 100,000 persons). During the study period, the incidence was 6.34 per 100,000 person-years. The prevalence peaked for both men and women in the age range 30–39 years. Incidence peaked for men in the age range 20–29 years, but peaked for women between ages 70 and 89. AS was 3.6 times more prevalent in men than in women, and the incidence in men was 2.1 times greater than in women. With respect to income status, the prevalence and incidence of AS were 3 times greater and 5 times greater, respectively, in medical aid recipients compared to individuals with other income levels. The trend of increasing AS prevalence and the observation that 14.3% of all patients newly diagnosed with AS are medical aid recipients have significant implications for healthcare planning.

Role of inflammasomes in inflammatory autoimmune rheumatic diseases

Inflammasomes are intracellular multiprotein complexes that coordinate anti-pathogenic host defense during inflammatory responses in myeloid cells, especially macrophages. Inflammasome activation leads to activation of caspase-1, resulting in the induction of pyroptosis and the secretion of pro-inflammatory cytokines including interleukin (IL)-1β and IL-18. Although the inflammatory response is an innate host defense mechanism, chronic inflammation is the main cause of rheumatic diseases, such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), ankylosing spondylitis (AS), and Sjögren's syndrome (SS). Since rheumatic diseases are inflammatory/autoimmune disorders, it is reasonable to hypothesize that inflammasomes activated during the inflammatory response play a pivotal role in development and progression of these diseases. Indeed, previous studies have provided important observations that inflammasomes are actively involved in the pathogenesis of inflammatory/autoimmune rheumatic diseases. In this review, we summarize the current knowledge on several types of inflammasomes during macrophage-mediated inflammatory responses and discuss recent research regarding the role of inflammasomes in the pathogenesis of inflammatory/autoimmune rheumatic diseases. This avenue of research could provide new insights for the development of promising therapeutics to treat inflammatory/autoimmune rheumatic diseases.

The potent suppressive effect of β-d-mannuronic acid (M2000) on molecular expression of the TLR/NF-kB Signaling Pathway in ankylosing spondylitis patients

Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease characterized by the inflammation of sacroiliac joints and axial skeleton. A combination of genetic, environmental and immunological factors are involved in AS's pathogenesis. TLRs are type I transmembrane glycoproteins that play a crucial role in the innate immune responses against invading pathogens. Observational studies have demonstrated a possible association between TLR dysregulation and AS. The β-d-mannuronic acid (M2000), as a novel NSAID with immunosuppressive property, has shown an inhibitory effect on Toll-like receptor (TLR) 2, 4 signaling in HEK293 cells. In the present study, we investigated the gene expression of Myd88, IKB-alpha, NF-kB and MAPK14 (genes of the TLR/NF-kB Signaling Pathway) in AS patients in comparison to healthy subjects and also the effect of β-d-mannuronic acid on disease activity and mRNA expression of these molecules in affected patients. We showed for the first time that the gene expression level of Myd88, IKB-alpha, NF-kB and MAPK14 was higher in AS patients in comparison to healthy subjects. Moreover we confirmed that the β-d-mannuronic acid not just reduced significantly the disease activity of AS individuals compared to placebo, but also it could significantly decrease the expression level of genes associated with TLR/NF-kB Signaling Pathway in treated patients with M2000. These results may provide a new therapeutic approach to attenuate inflammatory responses in AS patients, (Identified; IRCT 2013062213739N1).

Incidence and prevalence of psoriatic arthritis in Denmark: a nationwide register linkage study

Objectives

To examine the incidence and temporal trends of psoriatic arthritis (PsA) in the general population in Denmark.

Methods

Using nationwide registry data, we estimated the number of patients with incident PsA within each 1-year period between 1997 and 2011 and calculated the rate of PsA cases within gender and age subgroups. Incidence rates were presented per 100 000 person-years.

Results

There was a female predominance ranging from 50.3% (1998) to 59.2% (2010), and the mean age at time of diagnosis was 47–50 years. We identified a total of 12 719 patients with PsA (prevalence=0.22%), including 9034 patients where the PsA diagnosis was made by a rheumatologist (prevalence=0.16%). Incidence rates of PsA (per 100 000 person-years) increased from 7.3 in 1997 to a peak incidence of 27.3 in 2010. Incidence rates were highest for women and patients aged 50–59 years, respectively. The use of systemic non-biologic agents, that is, methotrexate, leflunomide, ciclosporin or sulfasalazine increased over the 15-year study course and were used in 66.3% of all patients. Biologic agents (etanercept, infliximab, adalimumab, certolizumab pegol, golimumab or ustekinumab) were used in 17.7% of patients with PsA.

Conclusions

We found a clear trend of rising PsA incidence on a national level. While the cause remains unclear, our findings might be explained by increased attention by patients and physicians.

Self-reported Diagnosis of Rheumatoid Arthritis or Ankylosing Spondylitis Has Low Accuracy: Data from the Nord-Trøndelag Health Study

OBJECTIVE

Self-reported diagnoses of inflammatory arthritis are not accurate. The primary study aim was to ascertain self-reported diagnoses of rheumatoid arthritis (RA) and ankylosing spondylitis (AS) in the Norwegian population-based Nord-Trøndelag Health Study (HUNT) using hospital case files. The secondary aim was to provide updated estimates of the prevalence and incidence of RA and AS.

METHODS

All inhabitants ≥ 20 years old from the county of Nord-Trøndelag were invited. Data from 70,805 unique participants from HUNT2 (1995-1997) and HUNT3 (2006-2008) were included. For participants who self-reported RA or AS, case files from all 3 hospitals in the catchment area were evaluated using standardized diagnostic criteria.

RESULTS

Of 2703 self-reported cases of RA, 19.1% were verified in hospital files. Of 1064 self-reported cases of AS, 15.8% were verified. Of 259 cases self-reporting both RA and AS, 8.1% had RA and 5.4% had AS. Overall, a self-report of 1 or both diagnoses could not be verified in 82.1%, including 22.8% with insufficient information or no case file. The prevalence of RA was 768 (95% CI 705-835) per 100,000. The incidence of RA from HUNT2 to HUNT3 was 0.48 (0.41-0.56) per 1000 per year. The prevalence of AS was 264 (228-305) per 100,000. The incidence of AS from HUNT2 to HUNT3 was 0.19 (0.15-0.24) per 1000 per year.

CONCLUSION

Self-reported diagnoses of RA and AS are often false-positive. The prevalence and incidence of RA were comparable to reports from similar populations. The incidence of AS was higher than previously reported in a mixed population from Norway.

Screening of Patients with Psoriasis for Psoriatic Arthritis in the Slovak Republic

Global prevalence of psoriasis is ranging from 0.91 % to 8.5 % [1]. Exact numbers are missing for Slovakia. 1-5% range is the most probable while 2 % is also mentioned as an average prevalence for the European population. There is approximately 110 thousand patients suffering from psoriasis when extrapolating from total population of 5.5 million [2]. Extracutaneous manifestation is observed in 11–30 % of patients after years of solely skin symptoms presentation [3, 4, 5, 6].

Objective: To estimate prevalence of psoriatic arthritis among psoriatic patients population visiting dermatology out-patient irrelevant of the disease duration and the treatment regimen. To compare the sensitivity of both tests (ToPAS and PASE) used, evaluate possible PsA risk factors.

Methods: This was a prospective, non-interventional, epidemiological, observational study conducted using a survey administered to psoriatic patients by their dermatologists. 10–20 consequent outpatients with psoriasis in each center in 43 regional dermatology officies were screened for the presence of extra-cutaneous symptoms (i.e. joint pain, enthesitis, dactylitis, nail involvement) using questionnaire, developed specificaly for this study, and by the PASE and ToPAS questionnaires. Patients without personal history of PsA and „positivity“ of PASE and/or ToPAS were sent to the center for confirmation / exclusion of the diagnosis by applying CASPAR criteria. Outcomes were statistically processed.

Results: 177 (21.8 %) of total of 831 psoriatic patients had PsA. 9 of 177 (5.35 %) has been newly diagnosed. There was almost equal number of men (50.5 %) and women (49.5 %).

Plaque psoriasis has been most frequent type – 76.9 %. 43.2 % of PsA patients reported the onset of the disease after 40 years of life. Time interval between onset of psoriasis and PsA has been less than 10 years in 20.2 %, 10–20 years in 20.8 % and more than 20 years in 16.1 %. Most frequent co-morbidity in the study population was hypertension 23.2 %, asthma 3 % and diabetes 2.4 %. Average value of BSA and PASI was higher in PsA vs. non-PsA group: 24 vs. 20 and 10 vs 9, respectively. The sensitivity (72.6 % vs 58.9 %, P=0.01) and specificity (81.3 % vs 80.5 %) of ToPAS was higher compared to PASE.

Conclusion: 21.8 % PsA prevalence in psoriatic population in Slovakia is within the range observed in other studies. ToPAS test showed comparable results in terms of specificity, but significantly better results in terms of sensitivity and its early application should be of major importance because of the diagnostic process acceleration. The effect of an early diagnosis on the total patient outcome should be an objective of further research. This project was supported from educational grant of Pfizer Inc.

Prevalence of Skin and Skin-Related Diseases in the Rochester Epidemiology Project and a Comparison with Other Published Prevalence Studies

In Olmsted County, Minn., USA, reliable, population-based epidemiologic research studies can be performed because of a unique medical records linkage system, the Rochester Epidemiology Project (REP). Our objective was to summarize the epidemiologic data describing the prevalence of skin and skin-related diseases derived from the REP and to compare the findings with those from other studies worldwide. Retrospectively, we reviewed the results of population-based REP studies reporting the prevalence of skin and skin-related diseases over more than 4 decades and compared them to other published prevalences globally. Prevalences from the REP reported per 100,000 persons were as follows: hidradenitis suppurativa, 130.0; psoriasis, 700.0; psoriatic arthritis in 1992, 100.0, and in 2000, 160.0; Behçet disease, 5.2; scleroderma, 13.8; dermatomyositis, 21.42; systemic lupus erythematosus (SLE), from 30.5 to 122.0 suspected SLE, 32.8; combined SLE, 41.8; discoid lupus erythematosus, 27.6, and cutaneous lupus erythematosus, 70.4 and 73.2 (from 2 studies). Many of the population-based prevalences of specific skin and skin-related diseases derived from the REP are different from those estimated globally. Suggested reasons for disparity in the prevalences globally may include differences in the type of reported prevalence, study methodology, geographic areas, ethnic groups, age distribution, and socioeconomic status.

The Epidemiology of Psoriatic Arthritis

Psoriatic arthritis (PsA) is a chronic systemic inflammatory disorder characterized by joint and entheseal inflammation with a prevalence of 0.05% to 0.25% of the population and 6% to 41% of patients with psoriasis. PsA is a highly heterogeneous inflammatory arthritis. In this review, current knowledge is discussed regarding the epidemiology of PsA, including disease manifestations, classification criteria for adult and juvenile PsA, methods for recognizing early PsA, including use of screening tools and knowledge of risk factors for PsA, and medical comorbidities associated with PsA.

The prevalence of clinically diagnosed ankylosing spondylitis and its clinical manifestations: a nationwide register study

INTRODUCTION

Prevalence estimates of ankylosing spondylitis vary considerably, and there are few nationwide estimates. The present study aimed to describe the national prevalence of clinically diagnosed ankylosing spondylitis in Sweden, stratified according to age, sex, geographical, and socio-economic factors, and according to subgroups with ankylosing spondylitis-related clinical manifestations and pharmacological treatment.

METHODS

All individuals diagnosed with ankylosing spondylitis according to the World Health Organization International Classification of Disease codes, between 1967 and 2009, were identified from the National Patient Register. Data regarding disease manifestations, patient demographics, level of education, pharmacological treatment, and geographical region were retrieved from the National Patient Register and other national registers.

RESULTS

A total of 11,030 cases with an ankylosing spondylitis diagnosis (alive, living in Sweden, and 16 to 64 years old in December 2009) were identified in the National Patient Register, giving a point prevalence of 0.18% in 2009. The prevalence was higher in northern Sweden, and lower in those with a higher level of education. Men had a higher prevalence of ankylosing spondylitis (0.23% versus 0.14%, P < 0.001), a higher frequency of anterior uveitis (25.5% versus 20.0%, P < 0.001) and were more likely to receive tumor necrosis factor inhibitors than women (15.6% versus 11.8% in 2009, P < 0.001). Women were more likely than men to have peripheral arthritis (21.7% versus 15.3%, P < 0.001), psoriasis (8.0% versus 6.9%, P = 0.03), and treatment with oral corticosteroids (14.0% versus 10.4% in 2009, P < 0.001).

CONCLUSION

This nationwide, register-based study demonstrated a prevalence of clinically diagnosed ankylosing spondylitis of 0.18%. It revealed phenotypical and treatment differences between the sexes, as well as geographical and socio-economic differences in disease prevalence.

Modes of presentation of reactive arthritis based on the affected joints

Introduction:

Reactive arthritis is an autoimmune condition that occurs as a reaction against an infection site elsewhere in the body. Reactive arthritis affects mostly young ages, mainly group age 20-40 y.o., mostly males with ratio 2:1 against females, sometimes 3:1, and even 14:1. The purpose of the study was to observe the mode of illness presentation based on the number of affected joints.

Material and Methods:

During the 01.03.2012 – 01.03.2014 in the Clinic for Rheumatology and O.S.I.R. “Vendenisi – AL” in Besiana have been examined, elaborated and hospitalized 100 patients with reactive arthritis, out of them 66 males and 34 females. Patients underwent necessary laboratory, hematological, biochemical, and immunological examinations. Subsequently each affected joint has been examined based on the propedeutics rules (inspection, palpation and assessment of the level of motility), as well as x ray examination.

Results:

From 100 examined patients 66% were males and 34% females respectively. 11% of them were in the 10-20y.o. group age, 30% belonged to group age 21-30 y.o., 24% of patients to 31-40 y.o. group age, 30% to 41-50 y.o. group age, and 5% of patients to the group age over the 51 year old. Regarding the affected articulations and modes of illness presentation, we‘ve obtained the following results: Knee was affected in 64.7% female and 52,12% male patients respectively, T/C joint in 50% female and 57.57% male patients, MTPH joint in 41.11% female and 48.48% male patients respectively, and R/C joint in 44.11% female and 48.48% male patients respectively. Oligoarticular type is seen in 73% male and 70% female patients. Monoarticular type is seen in 14% male and 13% female patients, and poliarticular type is seen in 10% male and 14% female patients respectively. Results from our study have revealed that: reactive arthritis is more frequent in males than females in ratio 2:1 in the infections of urogenital infection, 3:1 in nasopharyngeal infections, and similar in infections of enteral origin.

Conclusion:

Reactive arthritis mostly attacks young ages 20-40 y.o., while over the age of 50 and below the age of 20 is rarely seen. First reactive arthritis attack in males occurs earlier than in females. Most affected joints are: knee, talocrural joint, metatarsophalangeal (MTPH) joint, radiocarpal (R/C) joint, and proximal interphalanteal (PIPH) joint. Oligoarticular mode of illness presentation is 2.5 more frequent than mono and poliarticular mode of illness presentation.

Increasing proportion of female patients with ankylosing spondylitis: a population-based study of trends in the incidence and prevalence of AS

OBJECTIVE

With the introduction of MRI in diagnosis and tumour necrosis factor inhibitors for treatment, the field of ankylosing spondylitis (AS) has undergone significant changes. We carried out a population-based study of the trends in incidence and prevalence of AS over the past 15 years.

METHODS

This is a retrospective analysis of provincial health administrative databases. Residents of Ontario, Canada aged 15 years or older diagnosed with AS between 1995 and 2010 were included in the study. Crude as well as age-standardised and sex-standardised incidence and prevalence of AS between 1995 and 2010 were calculated. Trends in prevalence and incidence of male and female patients with AS were separately analysed.

RESULTS

We identified 24,976 Ontarians with AS. Age/sex-standardised AS prevalence increased from 79/100,000 in 1995 to 213/100,000 in 2010. Men had higher prevalence than women, but the male/female prevalence ratio decreased from 1.70 in 1995 to 1.21 by 2010. A higher proportion of male compared with female patients with AS were diagnosed in the 15-45 age group. Annual incidence rates revealed increasing diagnosis of AS among women after 2003.

CONCLUSIONS

The prevalence of AS in Ontario has nearly tripled over the past two decades. The proportion of women with new diagnosis of AS is increasing, a trend that began around the year 2003. A higher proportion of male compared with female patients with AS are diagnosed at an earlier age.

Reactive arthritis

Reactive arthritis (ReA) is an immune-mediated seronegative arthritis that belongs to the group of spondyloarthropathies and develops after a gastrointestinal or genitourinary system infection. The condition is considered to be characterized by a triad of symptoms (conjunctivitis, arthritis and urethritis) although a constellation of other manifestations may also be present. ReA is characterized by psoriasiform dermatological manifestations that may resemble those of pustular psoriasis and, similar to guttate psoriasis, is a post-infectious entity. Also, the articular manifestations of the disorder are similar to those of psoriatic arthritis and both conditions show a correlation with HLA-B27. These facts have led several authors to suggest that there is a connection between ReA and psoriasis, listing ReA among the disorders related to psoriasis. However, the pathogenetic mechanism behind the condition is complex and poorly understood. Bacterial antigenicity, the type of host response (i.e. Th1/Th2 imbalance) and various genetic factors (i.e. HLA-B27 etc.) play an important role in the development of the disorder. It is unknown whether all the aforementioned factors are part of a mechanism that could be similar to, or share basic aspects with known psoriasis pathogenesis mechanisms.

Biological therapy in inflammatory rheumatic diseases: issues in Central and Eastern European countries

Biological drugs revolutionized the treatment of inflammatory rheumatic diseases. Access to treatment presents substantial variability across Europe. The economic level of a particular country as well as administrative restrictions have been proved as determining factors of biological drug uptake. The objective of this paper was to provide an overview of biological treatment in six selected Central and Eastern European (CEE) countries, namely in the Bulgaria, Czech Republic, Hungary, Poland, Romania and Slovakia. The literature is summarized with regard to the epidemiology, disease burden and use of biological agents in rheumatoid arthritis, psoriatic arthritis and ankylosing spondylitis. Moreover, an estimate is provided on the prevalence and number of patients with biological treatment based on international and local sources. In view of the limited availability of information and uncertainty in data, there is an urgent need for development of systematic and comprehensive data collection in inflammatory rheumatic diseases in CEE countries.

The epidemiology of extra-articular manifestations in ankylosing spondylitis: a population-based matched cohort study

OBJECTIVE

To assess the incidence and risks of common extra-articular manifestations (EAMs), that is, acute anterior uveitis (AAU), psoriasis and inflammatory bowel disease (IBD), in patients with ankylosing spondylitis (AS) compared with population-based controls.

METHODS

All incident patients with AS (n=4101) from the UK Clinical Practice Research Datalink (1987-2012) were matched with up to seven control subjects without AS by year of birth, sex and practice (n=28,591). Incidence rates, cumulative incidence rates and adjusted (adj) HRs for the development of EAMs were calculated, with time-dependent adjustments for age, sex, comorbidity and medication use.

RESULTS

At diagnosis of AS, the proportion of patients with an EAM was 11.4% for AAU, 4.4% for psoriasis and 3.7% for IBD. Incidence rates of EAMs were 8.9/1000 person-years for AAU, 3.4/1000 person-years for psoriasis and 2.4 /1000 person-years for IBD in AS. The 20-year cumulative incidence was 24.5%, 10.1% and 7.5%, respectively. Risks of EAMs were 1.5-fold to 16-fold increased versus controls, with an adj HR of 15.5 (95% CI 11.6 to 20.7) for AAU, adj HR of 1.5 (95% CI 1.1 to 1.9) for psoriasis and adj HR of 3.3 (95% CI 2.3 to 4.8) for IBD. For psoriasis and IBD, the highest risks were found in the 1st years after diagnosis, while developing AAU continued to be increased also 10 years after diagnosis of AS.

CONCLUSIONS

The risk of, in particular AAU, but also of psoriasis and IBD, is significantly increased in patients with AS compared with controls. Hazard patterns are different for each of the EAMs.

Epidemiology of spondyloarthritis: a review

The classification of Spondyloarthritis (SpA) has been revised with the introduction of the ASAS classification criteria. Although this has best been described in ankylosing spondylitis and psoriatic arthritis, there are population studies evaluating the epidemiology of the different subgroups of SpA. In this paper, we present data on the incidence and prevalence of the subgroups of SpA in different populations, and point to data indicating how the introduction of new classification criteria, with the altered perception of the SpA entity, might impact on the epidemiology.

The prevalence of moderate to severe radiographic sacroiliitis and the correlation with health status in elderly Swedish men--the MrOS study

BACKGROUND

Ankylosing Spondylitis (AS) is a chronic inflammatory disease with onset in young adults, but little is known about the prevalence in older age groups. Furthermore, there is very limited information of health status of elderly patients with AS. Our objective was to estimate the prevalence of moderate to severe radiographic sacroiliitis in elderly men and its impact on health.

METHODS

A cross-sectional, population-based survey, that included 1005 men aged 69-81 years old, with the primary aim to study risk factors for osteoporosis (MrOS), was used. X-rays of the pelvis and spine were done for the whole population and then examined by two readers. The prevalences of grade 3-4 sacroiliitis, syndesmophytes and spondylophytes were ascertained. Using a self-administered questionnaire, information was obtained on physical activity (PASE), functional status (IADL items), health related quality of life - QoL (SF-12) and back pain (pain question, Quebec Pain Disability Scale items).

RESULTS

Fourteen cases with grade 3-4 sacroiliitis were identified, corresponding to a prevalence of 1.4% (95%CI: 0.7-2.4). Eight of the patients with sacroiliitis had both AS-typical and degenerative changes in the spine, 4 had only degenerative changes and 2 had only AS-related changes. There were no statistically significant differences between those with and without radiographic sacroiliitis regarding demographics, anthropometric measures, smoking status or health status, reflected by measures on physical activity, functional status, health related QoL and back pain.

CONCLUSIONS

The prevalence of moderate to severe radiographic sacroiliitis was estimated to be 1.4% among elderly men in Sweden. Self-reported health was only slightly different in those with sacroiliitis, suggesting that the relative impact of AS is modest in this age group.

Global prevalence of ankylosing spondylitis

OBJECTIVES

For effective health care provision, knowledge of disease prevalence is paramount. There has been no systematic endeavour to establish continent-based AS estimates, however, prevalence is thought to vary by country and background HLA-B27 prevalence. This study aimed to estimate AS prevalence worldwide and to calculate the expected number of cases.

METHODS

A systematic literature search was conducted. Prevalence data were extracted and used to calculate the mean prevalence by continent and the expected number of cases based on country-specific prevalence (or, if missing, the prevalence from neighbouring countries). A second estimate was made using the prevalence from countries with similar HLA-B27 prevalences if a country-specific prevalence estimate was not available.

RESULTS

The mean AS prevalence per 10,000 (from 36 eligible studies) was 23.8 in Europe, 16.7 in Asia, 31.9 in North America, 10.2 in Latin America and 7.4 in Africa. Additional estimates, weighted by study size, were calculated as 18.6, 18.0 and 12.2 for Europe, Asia and Latin America, respectively. There were sufficient studies to estimate the number of cases in Europe and Asia, calculated to be 1.30-1.56 million and 4.63-4.98 million, respectively.

CONCLUSION

This study represents the first systematic attempt to collate estimates of AS prevalence into a single continent-based estimate. In addition, the number of expected cases in Europe and Asia was estimated. Through reviewing the current literature, it is apparent that the continuing conduct of epidemiological studies of AS prevalence is of great importance, particularly as diagnostic capabilities improve and with the recent development of the criteria for axial SpA.

Validity of diagnostic codes and prevalence of psoriasis and psoriatic arthritis in a managed care population, 1996-2009

BACKGROUND

Few population-based studies have reported the prevalence of psoriatic disease.

OBJECTIVE

We validated computerized diagnoses to estimate the prevalence of psoriasis and psoriatic arthritis.

METHOD

We identified adults with ≥1 ICD-9 diagnosis codes of 696.0 (psoriatic arthritis) or 696.1 (psoriasis) in clinical encounter data during 1996-2009 and used chart review to confirm the diagnoses in random samples of patients. We then used the best performing case-finding algorithms to estimate the point prevalence of psoriasis and psoriatic arthritis.

RESULTS

The number of persons with a diagnosis for psoriasis (ICD-9 code 696.1) was 87 827. Chart review of a random sample of 101 cases with at least one dermatologist-rendered psoriasis code revealed a positive predictive value (PPV) of 90% (95% CI, 83-95) with sensitivity of 88% (95% CI, 80-93). Psoriatic arthritis (code 696.0) was recorded for 5187 patients, with the best performing algorithm requiring ≥2 diagnoses recorded by a rheumatologist or ≥1 diagnosis recorded by a rheumatologist together with ≥1 psoriasis diagnoses recorded by a dermatologist; the PPV was 80% (95% CI, 70-88) with sensitivity 73% (95% CI, 63-82). Among KPNC adults, the point prevalence of psoriasis, with or without psoriatic arthritis, was 939 (95% CI, 765-1142) per 100 000, and the overall prevalence of psoriatic arthritis, with or without psoriasis, was 68 (95% CI, 54-84) per 100 000.

CONCLUSION

Within an integrated health care delivery system, the use of computerized diagnoses rendered by relevant disease specialists is a valid method for identifying individuals with psoriatic disease.

The economic burden of the ankylosing spondylitis in the Czech Republic: comparison between 2005 and 2008

To investigate the burden of ankylosing spondylitis in the Czech Republic as a baseline for future health economic evaluations. Data were obtained from two cross-sectional studies Beda I (2005) and Beda II (2008), performed in 1,008 and 509 patients, respectively. Methodology used was Cost-of-Illness prevalence-based analysis bottom-up approach. Analysis was performed from payer (health insurance companies) and societal perspective (including productivity costs using friction cost approach). Mean age of sample in Beda I and Beda II was 50.2 and 52.5 years, male were present by 61.0 and 62.7 %; average disease duration was 23.0 and 26.4 years, respectively. Mean total annual costs per patient in the sample were €4,782 in Beda I and €5806 in Beda II. Average direct costs per patient in the sample per year are estimated at €1,812 (Beda I) and €2,588 (Beda II) with the average productivity costs €2,970 (Beda I) and €3,218 (Beda II). We observed a small decrement in percentage (6.7 %) of productivity costs for Beda II as an influence of higher consumption of biologic drugs, hence higher direct costs and possible productivity preservation. The largest direct cost burdens were spa procedures (45.3 %, Beda I) and biological drugs (52.8 %, Beda II). Unique analysis of the burden of the AS in the Central-Eastern Europe presents health care resource and cost consumption by comparing two cross-sectional prevalence-based studies. Further analysis should be carried to obtain data connecting health status with costs consumption in order to analyse the AS from this perspective.

Epidemiology of spondyloarthritis

Spondyloarthritis (SpA) represents a group of interrelated diseases with common clinical features and a close association with HLA-B27. Reports of incidence and prevalence of diseases vary depending on methodological differences between studies, the case definition used to classify disease, and the prevalence of HLA-B27 in the population studied. Newly proposed criteria for axial SpA and peripheral SpA present a new approach to facilitate classification of the SpA into 2 main subtypes and the criteria allow earlier detection of patents with inflammatory back pain. These criteria were developed for use in a (specialized) clinical setting and not for large epidemiologic studies.

Association of the ANTXR2 gene polymorphism and ankylosing spondylitis in Chinese Han

OBJECTIVE

Ankylosing spondylitis (AS) is an inflammatory disease of unknown origin. Both genetic and environmental factors are involved. A recent genome-wide association study (GWAS) found anthrax toxin receptor 2 (ANTXR2) to be associated with AS in Caucasians. We aimed to investigate whether the ANTXR2 polymorphism is also associated with AS in a Chinese Shandong Han population.

METHODS

From 2008 to 2009, we recruited 309 patients with AS and 384 age- and sex-matched controls of Han nationality. We selected six single nucleotide polymorphisms (SNPs) of ANTXR2 (rs4333130, rs6534708, rs6818557, rs12646132, rs12509658, and rs13140055) and genotyped them by polymerase chain reaction restriction fragment-length polymorphism (PCR-RFLP) and Taqman methods. We analysed linkage disequilibrium and constructed haplotypes.

RESULTS

Cases and controls did not differ in the frequency of ANTXR2 alleles, genotypes, or haplotypes. Thus, the six SNPs of ANTXR2 are not associated with AS in our Chinese Shandong Han population.

CONCLUSIONS

ANTXR2 might not be a susceptibility gene of AS in Chinese Han.

Seronegative spondyloarthritis

Seronegative spondyloarthritis (SpA) is a group of inflammatory rheumatic diseases with common clinical and aetiological features, including axial and peripheral inflammatory arthritis, enthesitis, extra-articular manifestations and a close link to the presence of the human leucocyte antigen (HLA)-B27 epitope. Ankylosing spondylitis is the most common of the SpA diseases, with prevalence in the Caucasian population ranging between 0.15% and 1.8%, generally higher in populations with a higher background prevalence of HLA-B27 positivity. Incidence has been estimated between 0.49 (Japan) and 10 (Norway) per 100,000. The prevalence of psoriatic arthritis ranges from 0.02% to 0.2%, and the incidence in the normal population is 7.2 per 100,000 per year. In patients with existing psoriasis, the prevalence of psoriatic arthritis rises to 6-42%. The prevalence of reactive arthritis is dependent on the background incidence of gastrointestinal or genitourinary infections; incidence has been described as up to 30-40 per 100,000. SpA symptoms are present in up to 50% of patients with inflammatory bowel disease.

Clinical features of axial undifferentiated spondyloarthritis (USpA) in China: HLA-B27 is more useful for classification than MRI of the sacroiliac joint

OBJECTIVES

To analyse the clinical features of Chinese undifferentiated spondyloarthritis (USpA) patients with predominantly axial involvement, and in particular the influence of human leucocyte antigen (HLA)-B27 and magnetic resonance imaging (MRI) of the sacroiliac joint (SIJ) on the classification of axial USpA.

METHODS

Patients with low back pain for ≥ 3 months and no definite radiographic sacroiliitis were enrolled in this study. They were diagnosed as USpA based on rheumatologists' findings. Correlations between clinical features and HLA-B27 status or MRI manifestations were analysed.

RESULTS

A total of 197 USpA patients were recruited, of whom 135 (70.3%) were positive for HLA-B27. Acute inflammation, structural damage lesions, and normal findings on SIJ MRI were recorded in 64.5, 13.2 and 22.3% of patients, respectively. Classification criteria for axial SpA according to the European Spondylarthropathy Study Group (ESSG), Amor, and the Assessment of SpondyloArthritis International Society (ASAS) were fulfilled by 63.5, 64.5 and 83.2% patients, respectively. Cross-validation showed significant correlation among these three criteria. Patients positive for HLA-B27 included more males, with earlier onset age, better response to non-steroidal anti-inflammatory drugs (NSAIDs), and higher erythrocyte sedimentation rate (ESR)/C-reactive protein (CRP) levels. In addition, more HLA-B27-positive than HLA-B27-negative patients fulfilled the ESSG, Amor, and ASAS criteria. Patients with acute inflammation on SIJ MRI had a higher level of ESR/CRP, and a greater proportion of them fulfilled the Amor and ASAS criteria. However, the proportion of those fulfilling the ESSG criteria did not differ with different MRI manifestations.

CONCLUSION

Both HLA-B27 status and SIJ MRI findings influence the classification of Chinese axial USpA patients, but HLA-B27 seems of more value.

Reactive arthritis

Reactive arthritis (ReA) can be defined as the development of sterile inflammatory arthritis as a sequel to remote infection, often in the gastrointestinal or urogenital tract. Although no generally agreed-upon diagnostic criteria exist, the diagnosis is mainly clinical, and based on acute oligoarticular arthritis of larger joints developing within 2-4 weeks of the preceding infection. According to population-based studies, the annual incidence of ReA is 0.6-27/100,000. In addition to the typical clinical picture, the diagnosis of ReA relies on the diagnosis of the triggering infection. Human leucocyte antigen (HLA)-B27 should not be used as a diagnostic tool for a diagnosis of acute ReA. In the case of established ReA, prolonged treatment of Chlamydia-induced ReA may be of benefit, not only in the case of acute ReA but also in those with chronic ReA or spondylarthropathy with evidence of persisting chlamydia antigens in the body. In other forms of ReA, there is no confirmed evidence in favour of antibiotic therapy to shorten the duration of acute arthritis. The outcome and prognosis of ReA are best known for enteric ReA, whereas studies dealing with the long-term outcome of ReA attributable to Chlamydia trachomatis are lacking.