Seronegative spondyloarthropathies in Greece: a population-based study of prevalence, clinical pattern, and management. The ESORDIG study

Recurrence of axial spondyloarthritis among first-degree relatives in a prospective 35-year-follow-up family study

Objective

The lifetime recurrence rate (RR) of axial spondyloarthritis (axSpA) among first-degree relatives (FDR) and the effect of proband’s gender, HLA-B27 and radiographic status is unclear. Our 35-year-follow-up family study has enabled these issues to be addressed.

Methods

In 1985, 363 ankylosing spondylitis (AS) probands (members of the Swiss AS Patient Society) and 806 FDR recruited into the study, completed questionnaires regarding axSpA manifestations, underwent a physical examination and most also underwent pelvic radiography and HLA-B27 typing. At follow-up in 2018–2019, of the former participants whose current addresses could be retrieved, 162 had died and 485 (125 patients with AS plus 360 FDR) completed a postal questionnaire.

Results

At follow-up, 48 of 177 HLA-B27(+) FDR had developed axSpA, an RR of 27.1% (95% CI 20.6% to 33.7%). 27/148 (18.2%) children of AS probands (modified New York (mNY) criteria) were affected versus 2/50 (4.0%) children of non-radiographic axSpA probands (p=0.0138, OR=5.36; 95% CI 1.23 to 23.40). Children of female probands were more often affected (12/22; 54.5%) than of male probands (15/78; 19.2%) (p=0.0003; OR=4.89; 95% CI 1.96 to 12.23). This increased risk applies equally to sons and daughters.

Conclusion

The lifetime RR of axSpA for HLA-B27(+) FDR is substantial (27.1%), and disease severity (as defined by radiographic sacroiliitis by the mNY criteria) is an additional risk factor. Affected mothers pass on the disease significantly more often to their offspring than do affected fathers. These findings may lead to better assessment of lifetime risk for axSpA in the offspring. Moreover, investigation of this gender effect may uncover additional putative disease susceptibility factors.

Heterogeneity of axial spondyloarthritis: genetics, sex and structural damage matter

OBJECTIVE

Axial spondyloarthritis (axSpA) comprises both radiographic and non-radiographic disease. However, the paucity of specific objective measures for the disease and current classification criteria showing suboptimal specificity contribute to disease heterogeneity observed in clinical practice and research. We used a historical cohort of patients with axSpA to assess sources of heterogeneity.

METHODS

The study involved 363 axSpA probands recruited from membership of the Swiss Ankylosing Spondylitis Patient Society. Participants underwent examination by a rheumatologist, completed questionnaires and provided blood samples for HLA typing. Patients underwent radiography of sacroiliac joints and were categorised according to the New York (NY) criteria (ankylosing spondylitis (AS) or non-radiographic axSpA (nr-axSpA)) and HLA-B27 status. Genetic characterisation by single nucleotide polymorphism microarray was performed and AS polygenic risk scores (PRS) were calculated.

RESULTS

Considerable heterogeneity was observed. The male to female ratio for AS (NY+) was 3:1, but 1:1 for nr-axSpA. For HLA-27(+) AS, the ratio was 2.5:1, but nearly 1:1 for HLA-B27(-) disease. Women with nr-axSpA had strikingly lower mean PRS and lower HLA-B27 prevalence than men with nr-axSpA or NY(+) male and female patients with AS. PRS was able to distinguish male but not female patients with nr-axSpA from related healthy first-degree relatives. Radiographic sacroiliitis was strongly associated with HLA-B27, especially in men.

CONCLUSION

Women clinically diagnosed with axSpA but without radiographic sacroiliitis as a group have a disease that is distinct from AS by the modified New York criteria overall and from nr-axSpA in men. Given the high degree of heterogeneity, stratified or adjusted analysis of effectiveness studies is indicated, taking genetics, sex and radiographic damage (sacroiliitis) into account.

Uveitis as a Risk Factor for Developing Acute Myocardial Infarction in Ankylosing Spondylitis: A National Population-Based Longitudinal Cohort Study

Background

Ankylosing spondylitis (AS) is a chronic inflammatory disease. Excess cardiovascular risks were well recognized in patients with AS and were attributed to prolonged systemic inflammation. Uveitis is one of the most common extra-articular symptoms of AS and is also considered an indicator of systemic inflammation. This study aimed to investigate whether uveitis was a risk factor for developing acute myocardial infarction (AMI) in patients with AS using the National Health Insurance Research Database (NHIRD).

Methods

Data were collected from the NHIRD over a fifteen-year period. Variables were analyzed using the Pearson chi-square test and Fisher’s exact test. Risk factors for the occurrence of AMI were examined by calculating hazard ratio. Kaplan-Meier analysis was performed to compare the cumulative incidence of AMI in the uveitis and non-uveitis cohorts.

Results

A total of 5905 patients with AS were enrolled, including 1181 patients with uveitis (20%) and 4724 patients without uveitis (80%). The Kaplan–Meier method with the log-rank test showed that the uveitis group had a significantly higher cumulative hazard for patients with AMI than the non-uveitis group (p < 0.001). The adjusted hazard ratio (aHR) of AMI was higher in the uveitis group than in the non-uveitis group (aHR = 1.653, p < 0.001). Stratified analysis revealed that patients with uveitis had an increased risk of developing AMI regardless of their sex (male/female aHR = 1.688/1.608, p < 0.001). Patients with uveitis in all age groups were independently associated with an increased risk of developing AMI compared to those without uveitis (20–39 years/40–59 years/≥ 60 years, aHR = 1.550, 1.579, 3.240, p < 0.001). Patients with uveitis had a higher probability of developing AMI regardless of comorbidities. Uveitis patients with comorbidities had a higher risk of developing AMI compared to uveitis patients without comorbidities.

Conclusion

Uveitis is a significant risk factor for developing AMI in patients with AS. Physicians should be aware of the potential cardiovascular risk in AS patients with uveitis, especially simultaneously with other traditional risk factors of AMI. Further prospective studies are needed to elucidate the underlying mechanism between uveitis and AMI in patients with AS.

Sex-specific differences and how to handle them in early psoriatic arthritis

Objectives

The prevalence of psoriatic arthritis (PsA) is the same in men and women; however, the latter experience a higher burden of disease and are affected more frequently by polyarthritis. Here, we performed an early PsA cohort analysis to assess sex-related differences in demographics, disease characteristics, and evolution over 1 year including applied treatment strategies.

Methods

Our study is embedded in the Dutch south-west Early Psoriatic Arthritis cohoRt. We described patient characteristics and treatment decisions. For the comparison across sexes and baseline and 1 year follow-up, appropriate tests depending on the distribution were used.

Results

Two hundred seventy-three men and 294 women with no significant differences in age and ethnicity were included. Women reported significantly longer duration of symptoms before diagnosis and significantly higher tender joint count, a higher disease activity, higher levels of pain, and lower functional capacity. Although minimal disease activity (MDA) rates increased over time for both sexes, MDA remained significantly more prevalent among men at 1 year (58.1% vs 35.7%, p < 0.00).

Initially, treatment strategies were similar in both sexes with methotrexate being the most frequently used drug during the first year. Women received methotrexate for a shorter period [196 (93–364) vs 306 (157–365), p < 0.00] and therefore received a lower cumulative dose compared to men. Retention time was shorter for all DMARDs, and women had a delayed start on b-DMARDs.

Conclusion

After 1 year of standard-of-care treatment, women did not surpass their baseline disadvantages. Despite the overall improvement, they still presented higher disease activity, higher levels of pain, and lower functional capacity score than men. The nature of these findings may advocate a need for sex specific adjustment of treatment strategies and evaluation in early PsA patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02680-y.

Spondyloarthritis in Senegal: a study of 770 cases

BACKGROUND

Very few studies have focused on spondyloarthritis (SpA) in sub-Saharan Africa. The majority of these studies have focused on series of HLA B27-negative SpA.

OBJECTIVE

To determine the epidemiological, diagnostic, therapeutic and evolutionary aspects of SpA in the rheumatology department of the CHU Aristide LeDantec in Dakar, Senegal.

METHODS

We conducted a retrospective, descriptive, analytical study from January 1, 2012 to December 31, 2020, of patients with spondyloarthritis diagnosed according to the ESSG (54.5%), Amor (52.5%), modified New York criteria (48.3%) and ASAS (23%). For each patient, the following information was collected: sex, age, occupation, family history of spondyloarthritis in the parents, time to diagnosis, type of SpA.

RESULTS

770 observations were collected from 273 men (35.5%) and 497 women (64.5%). Ankylosing spondylitis (AS) was the most frequent type of SpA in our series with 84% of cases. A biological inflammatory syndrome was present in 77.27% of our patients. HLA B27 phenotyping was performed in 437 patients, of which 225 were HLA B27 positive (51.48%). The majority of our patients were under conventional treatment due to the high cost of biotherapies which limits their prescription.

CONCLUSION

The profile of SpA patients in our series was characterised by : the predominance of females, the later age of onset, the frequency of radiographic axial forms of SpA and the biological inflammatory syndrome. HLA B27 was present in one patient out of two, as in the North African series.

Familial aggregation and heritability of ankylosing spondylitis - a Swedish nested case-control study

OBJECTIVES

AS is known to be a highly heritable disease, but previous studies on the magnitude of the familial aggregation and heritability of AS have been small and inconclusive, with familial relative risks ranging from 17 to 94. We aimed to improve estimates of these factors by studying families of all subjects diagnosed with AS in Sweden over a period of 16 years and to investigate if familial risks vary by sex or type of relative.

METHODS

In a nested case-control study, we identified AS index patients from the National Patient Register (NPR) and the Swedish Rheumatology Quality Register (SRQ) between 2001 and 2016. Each index patient was matched on age and sex to up to 50 general population controls. First-degree relatives of index patients and controls were identified through the Multi-Generation Register, with disease status ascertained in the NPR and SRQ. Familial risks were defined as odds ratios (ORs) of having AS when exposed to a first-degree relative with AS, using conditional logistic regression.

RESULTS

The overall familial OR for AS was 19.4 (95% CI 18.1, 20.8). Estimates were similar for different relative types and by sex, but having more than one affected relative resulted in a higher risk [OR 68.0 (95% CI 51.3, 90.1)]. Heritability, estimated by assuming sibling risks were completely due to genetics, was 77% (95% CI 73, 80).

CONCLUSION

Although the familial risk and heritability of AS are higher than for most other diseases, we report estimates that are substantially lower than commonly referenced numbers for AS from other populations.

The effect of gender on disease activity and clinical characteristics in patients with axial psoriatic arthritis

OBJECTIVES

In this study, we aimed to evaluate the effect of gender on clinical findings, disease activity, functional status and quality of life in patients with axial involvement in Turkey.

METHODS

Patients with PsA who met the CASPAR classification criteria were enrolled consequently in this cohort. Turkish League Against Rheumatism (TLAR)-Network was formed with the participation of 25 centres. The demographic variables, fatigue, diagnostic delay, the beginning of peripheral arthritis, enthesitis, dactylitis and spine involvement, inflammatory low back pain, BASFI, HAQ, HAQ-s, visual analogue scale-pain (VAS-pain), anxiety, depression and disease activity parameters (ESR, DAS28, BASDAI) were recorded. Axial involvement was assessed according to clinical and radiological data according to modified New York (MNYC) or Assessment of SpondyloArthritis international Society (ASAS) criteria.

RESULTS

A total of 1018 patients with PsA were included in this study. Of the 373 patients with axial involvement, 150 were male (40.2%) and 223 (59.8%) were female. Spondylitis was detected in 14,7% of men and 21,9% of women in all patients. Pain score (VAS) (p < .002), fatigue (p < .001), ESR (p < .001), DAS28 (p < .001), BASDAI score (p < .001), PsAQoL (p < .001), HAQ score (p < ,01), HAQ-S score (p < .001), anxiety (p < .001), depression (p < .024), FACIT (p < .001) and FiRST (p < .001) scores were statistically significantly worse in women than males with axial PsA. However, quality of life was better (p < .001) and PASI score (p < .005) were statistically worse in male patients than in female patients with axial involvement.

CONCLUSION

This study has shown that the burden of disease in axial PsA has significant difference between genders. Disease activity, physical disability, functional limitation, depression and anxiety scores were higher in female patients, while quality of life were better and PASI score were higher in male patients. Therefore, we suggest that new strategies should be developed for more effective treatment of axial PsA in female patients.

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.

Prevalence of ankylosing spondylitis in a Chinese population: a systematic review and meta-analysis

Ankylosing spondylitis (AS) is a common inflammatory rheumatic disease that affects the axial skeleton. In this study, we systematically reviewed Chinese AS epidemiological studies from the past 15 years to elucidate its prevalence and provide scientific data for China's health care system. AS epidemiological research in China was summarized by conducting a literature review. A review and statistical analysis of the literature on the epidemiology of AS in mainland China published from May 2005 to May 2019 were performed via a meta-analysis. We calculated the prevalence of AS and analysed differences by sex, region, and population source using STATA12.0 software. Eleven papers including 122,558 subjects from mainland China were included. Over the past 15 years, the total prevalence of AS in mainland China was 0.29% (95% CI 0.22-0.35%), ranging from 0.42% (95% CI 0.31-0.52%) in males to 0.15% (95% CI 0.13-0.18%) in females; the difference in the prevalence of AS by sex was statistically significant (P < 0.001). The prevalence of AS in both southern and northern China was 0.31% (95% CI 0.21-0.42% and 0.21-0.40%, respectively), with no significant difference noted (P = 0.816 > 0.005). The prevalence of AS in Chinese military populations was 0.27% (95% CI 0.09-0.45%), and in community populations, it was 0.29% (95% CI 0.23-0.35%). There was no statistically significant difference in the prevalence of AS by sampling resource (P = 0.115 > 0.005). The prevalence of AS in China was 0.29% and continues to increase. Sex differences in its prevalence were identified; the prevalence rate was 2.8 times higher in males than in females. Epidemiologists in China should formulate precise scientific investigations to provide additional authoritative epidemiological data for the prevention and treatment of AS.

Serum Interleukin 23 in Psoriatic Arthritis Patients: Relation to disease activity, physical function and health related quality of life

Objective To assess interleukin 23 (IL-23) levels in the sera of psoriatic arthritis (PsA) patients and to determine the relationship of IL-23 with different disease activity indices, physical function and quality of life (QoL).

Methods Fifty PsA patients and 46 matched healthy controls were included in this study. Data including a detailed history, a thorough clinical examination, skin severity based on the Psoriasis Area and Severity Index (PASI), the Disease Activity index for Psoriatic Arthritis (DAPSA) and the Composite Psoriatic Disease Activity Index (CPDAI) were obtained for all patients. Physical function was assessed by the Health Assessment Questionnaire Disability Index (HAQ-DI) and health-related QoL was assessed using the Short Form Health Survey (SF-36), Psoriatic Arthritis Quality of Life (PsAQoL) and the Dermatology Life Quality Index (DLQI) were also assessed. Serum IL-23 levels were measured in the studied groups.

Results The study included 23(46%) females and 27 (54%) males with a mean age of 42.78±12.33 years. The mean serum IL-23 level was significantly higher in PsA patients (50.89±13.86 pg/ml) than in controls (43.88±6.34 pg/ml) (p=0.006). There were significant correlations between serum IL-23 levels and different grades of DAPSA activity (p=0.007) and PASI (p=0.015). No significant correlations could be detected between serum IL-23 levels and (HAQ-DI, DLQI, SF-36 or PsAQoL). CPDAI and DAPSA were significantly correlated with DLQI, SF-36 and PsAQoL.

Conclusion IL-23 is a useful biomarker for identifying joint activity or skin severity but not QoL or physical function.

Prevalence of ankylosing spondylitis in Spain: EPISER2016 Study

Objective: The aim of this study was to estimate the prevalence of ankylosing spondylitis (AS) in Spain.Method: This is a cross-sectional, population-based study of people aged 20 years or older in Spain. Randomly selected individuals were contacted by telephone and rheumatic disease screening was performed. If the first screening was positive, medical records were then reviewed and/or a telephone questionnaire was conducted by a rheumatologist, followed by an appointment if necessary. Cases had to fulfil the modified New York (mNY) criteria.Results: In total, 4916 individuals were included, of whom 355 had a positive screening result for AS. Of these, 11 were classified as AS. An additional individual who reported a prior diagnosis of rheumatoid arthritis had a diagnosis of AS confirmed on review of the medical records. Estimated prevalence was 0.26% (95% CI 0.14-0.49).Conclusion: EPISER2016 is the first population-based study to estimate the prevalence of AS in Spain, which has been estimated as being similar to that in other European countries.

Sensitivity and Specificity of Autoantibodies Against CD74 in Nonradiographic Axial Spondyloarthritis

OBJECTIVE

Autoantibodies against CD74 (anti-CD74) are associated with ankylosing spondylitis (AS). The present multicenter study, the International Spondyloarthritis Autoantibody (InterSpA) trial, was undertaken to compare the sensitivity and specificity of anti-CD74 and HLA-B27 in identifying patients with nonradiographic axial spondyloarthritis (axSpA).

METHODS

Patients ages 18-45 years with inflammatory back pain of ≤2 years' duration and a clinical suspicion of axSpA were recruited. HLA-B27 genotyping and magnetic resonance imaging of sacroiliac joints were performed in all patients. One hundred forty-nine patients with chronic inflammatory back pain (IBP) not caused by axSpA served as controls, and additional controls included 50 AS patients and 100 blood donors whose specimens were analyzed.

RESULTS

One hundred patients with inflammatory back pain received a diagnosis of nonradiographic axSpA from the investigators and fulfilled the Assessment of SpondyloArthritis international Society (ASAS) criteria. The mean age was 29 years, and the mean symptom duration was 12.5 months. The sensitivity of IgA anti-CD74 and IgG anti-CD74 for identifying the 100 axSpA patients was 47% and 17%, respectively. The specificity of both IgA anti-CD74 and IgG anti-CD74 was 95.3%. The sensitivity of HLA-B27 was 81%. The positive likelihood ratios were 10.0 (IgA anti-CD74), 3.6 (IgG anti-CD74), and 8.1 (HLA-B27). Assuming a 5% pretest probability of axSpA in chronic back pain patients, the posttest probability, after consideration of the respective positive test results, was 33.3% for IgA anti-CD74, 15.3% for IgG anti-CD74, and 28.8% for HLA-B27. A combination of IgA anti-CD74 and HLA-B27 results in a posttest probability of 80.2%.

CONCLUSION

IgA anti-CD74 may be a useful tool for identifying axSpA. The diagnostic value of the test in daily practice requires further confirmation.

The Greek (Hellenic) rheumatology over the years: from ancient to modern times

Rheumatology has its roots in ancient Greece. Hippocrates and other prominent Greek (Hellenes) physicians in ancient times, Hellenistic, Roman, and Byzantine period were acute observers of disease course and of patients and were able to define many disorders. They wrote books on various aspects of medicine and these writings were the basis of medical practice and education in Europe and the Arabic world well into the seventeenth century. In 1821, Greece emerged from a long occupation by the Turks. In 1930, Adamantiades, a Greek Ophthalmologist, before Behcet of Turkey, described what is known as (Adamantiades)-Behcet disease. The first scientific Hellenic Society for Rheumatology (ERE) was established in 1960 and today ERE having been merged with the Professional Union of Greek rheumatologists (EPERE) is known as ERE-EPERE. Rheumatology is a strong specialty with 348 rheumatologists for a population of around 11 million. Greek rheumatologists have contributed to rheumatology science and practice, and are active physicians participating in the American College of Rheumatology and the EULAR annual congresses and in many educational postgraduate courses. ERE-EPERE formed therapeutic protocols for inflammatory and autoimmune rheumatic diseases which were incorporated in the electronic National prescription system. Rheumatologists are authorized to use this platform to prescribe biologicals free of charge for patients. ERE-EPERE publishes a peer-reviewed English language journal, the Mediterranean Journal of Rheumatology (MJR), an open access journal with no publication fees. MJR is a quarterly journal with international Editorial Board.

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.

Evaluation of the comorbidity burden in patients with ankylosing spondylitis using a large US administrative claims data set

Comorbidities among US patients with ankylosing spondylitis (AS) are inadequately understood. This study compared the prevalence and incidence of comorbidities between patients with AS and matched controls using national claims databases. Adults enrolled in the MarketScan Commercial and Medicare databases with ≥ 1 inpatient or ≥ 2 non-rule-out outpatient diagnoses of AS between January 1, 2012 and December 31, 2014 were included. Patients had to have ≥ 1 AS diagnosis in 2013; the first AS diagnosis in 2013 was assigned as the index date. Control patients without AS were matched to AS patients on age, geographic region, index calendar year, and sex. Comorbidities were evaluated in AS patients and matched controls during the baseline and follow-up periods (before and after the index date, respectively). Hazard ratios of developing new comorbidities were estimated using Cox proportional hazard models adjusted for patients’ characteristics. A total of 6679 patients with AS were matched to 19,951 control patients. In addition to extra-articular manifestations of AS (inflammatory bowel disease [IBD], psoriasis, uveitis), a higher proportion of AS patients had asthma, cardiovascular disease, depression, dyslipidemia, gastrointestinal ulcers, malignancies, multiple sclerosis, osteoporosis, sleep apnea, and spinal fractures during the baseline period than matched controls. After AS diagnosis, a higher proportion of patients developed newly diagnosed cases of cardiovascular diseases, depression, osteoporosis, spinal fracture, IBD, psoriasis, and uveitis than matched controls. In this real-world, US claims-based study, patients with AS were shown to have significantly more comorbidities than matched controls.

Evaluation of the comorbidity burden in patients with ankylosing spondylitis treated with tumour necrosis factor inhibitors using a large administrative claims data set

Objectives

Comorbidity incidence rates among US patients with ankylosing spondylitis (AS) treated with tumour necrosis factor inhibitors (TNFis) are inadequately understood. This study compared the relative occurrence of comorbidities between patients with AS treated with TNFis and those not treated with TNFis.

Methods

Adults aged ≥18 years enrolled in the MarketScan Commercial and Medicare Supplemental databases with a diagnosis of AS between 1 January 2008 and 30 June 2015 were eligible. Patients were divided into two groups, those treated with TNFis (TNFi users) and those not treated with TNFis (TNFi nonusers) during the 12 months after the index date, defined as the date of first TNFi treatment or a randomly assigned date for TNFi nonusers. Patients had to have continuous enrolment for 24 months with no AS diagnosis or TNFi therapy pre‐index and a follow‐up period of ≥12 months postindex. The incidence of new comorbidities was evaluated in patients and adjusted for baseline characteristics.

Key findings

A total of 3077 TNFi users and 3830 TNFi nonusers were included. A higher proportion of TNFi users had a new diagnosis of inflammatory bowel disease (hazard ratio [HR], 2.00), including Crohn's disease (HR, 2.45) and ulcerative colitis (HR, 1.65), as well as uveitis (HR, 1.68) and sleep apnoea (HR, 1.21) after initiation of TNFi therapy than TNFi nonusers.

Conclusions

Patients with AS treated with TNFis had higher incidence rates of IBD, uveitis and sleep apnoea after initiation of TNFi therapy than patients not treated with TNFi therapy.

The epidemiology of psoriatic arthritis in Israel - a population-based study

BACKGROUND

There is limited information on the epidemiology of psoriatic arthritis (PsA) in general and in Middle Eastern populations in particular. The aims of this study were to estimate the prevalence and incidence rates of PsA and their temporal trends in the general population in Israel.

METHODS

In this study, a cohort of adult patients with PsA was derived from the database of Clalit Health Services (CHS), Israel's largest health fund, with over 4.4 million members. The crude and age- and sex-standardized prevalence and incidence rates of PsA from 2006 to 2015 in the general population were calculated. The variation in PsA prevalence was assessed in relation to several demographic factors.

RESULTS

Among the 2,931,199 individuals aged 18 years and older registered in the CHS database in 2015, 4490 patients had a diagnosis of PsA (322 incident cases), resulting in overall crude prevalence and incidence rates of 0.153% (95% CI 0.149%, 0.158%) and 10.9 (95% CI 9.8, 12.3) per 100,000 population, respectively. The reported prevalence of PsA in Israel has doubled between 2006 and 2015 (from 0.073% to 0.153%). In contrast, the global incidence rate remained stable, with a gradual increase in incidence among individuals aged 51 to 70 years. PsA is associated with Jewish ethnicity, high socioeconomic status, and higher body mass index.

CONCLUSIONS

The prevalence and incidence of PsA in Israel are within the range of previous estimates from Southern European populations. An increase in the reported prevalence of PsA was observed over the past decade in the general population in Israel.

Spanish Cultural Adaptation of the Questionnaire Early Arthritis for Psoriatic Patients

INTRODUCTION AND OBJECTIVES

The Early Arthritis for Psoriatic patients (EARP) questionnaire is a screening tool for psoriatic arthritis. The original Italian version has good measurement properties but the EARP required translation and adaptation for use in Spain. This article describes the cultural adaptation process as a step prior to validation.

MATERIAL AND METHODS

We used the principles of good practice for the cross-cultural adaptation of patient-reported outcomes measurement established by the International Society Pharmacoeconomics and Outcome Research. The steps in this process were preparation, forward translation, reconciliation, back-translation and review, harmonization, cognitive debriefing and review, and proofreading. During preparation the developers of the original questionnaire were asked for their permission to adapt the EARP for use in Spain and to act as consultants during the process.

RESULTS

The original questionnaire was translated into Spanish by native Spanish translators, who made slight changes that were approved by the questionnaire's developers. The Spanish version was then back-translated into Italian; that version was reviewed to confirm equivalence with the original Italian text. The reconciled Spanish EARP was then tested for comprehensibility and interpretation in a group of 35 patients. All the patients answered all items without making additional comments.

CONCLUSION

This cultural adaptation of the EARP questionnaire for Spanish populations is the first step towards its later use in routine clinical practice. The application of a cross-cultural adaptation method ensured equivalence between the original and Spanish versions of the EARP. The Spanish questionnaire will be validated in a second stage.

The prevalence of spondyloarthropathy in fibromyalgia patients

OBJECTIVE

To document the prevalence of Spondyloarthropathy (SpA) with an evaluation of patients previously diagnosed with fibromyalgia syndrome (FMS).

METHODS

The patients diagnosed with FMS before telephoned and asked three questions to determine for inflammatory back pain. American College of Rheumatology (ACR) Fibromyalgia criteria 1990 and ACR 2010 and for diagnosing patients with SpA; criteria from the European Spondyloarthropathy Study Group (ESSG), and Amor were applied.

RESULTS

FMS was diagnosed according to 1990 ACR criteria in 14 (60.8%) SpA patients who were diagnosed with SpA according to the Amor criteria alone and in 10 (43.4%) patients who were diagnosed according to ESSG criteria alone, while it was diagnosed in 9 (33.3%) patients who were diagnosed with SpA according to Amor and ESSG criteria together and in 15 (65.2%) patients diagnosed with SpA according to Amor and/or ESSG criteria. The most tenderness was experienced in the bilateral shoulder supraspinatus tendon insertion region (57.7%) and in the sacroiliac joint (40.8%). Fourteen (60.8%) patients diagnosed according to ACR 1990 and 17 (51.6%) patients diagnosed according to ACR 2010 had plantar fasciitis and/or Achilles enthesopathy on foot radiography.

CONCLUSIONS

There is a meaningful section of patients who are SpA or FMS and SpA are together in the patients thought to be FMS or the patients diagnosed with FMS according to ACR's criteria can be said.

Diagnostic Prevalence of Ankylosing Spondylitis Using Computerized Health Care Data, 1996 to 2009: Underrecognition in a US Health Care Setting

INTRODUCTION

Few studies have assessed the prevalence and features of axial spondyloarthritis (axSpA) and ankylosing spondylitis in diverse, population-based, community settings.

OBJECTIVES

We used computerized diagnoses to estimate the prevalence of axSpA and ankylosing spondylitis in Kaiser Permanente Northern California (KPNC).

METHODS

We identified persons aged 18 years or older with 1 or more International Classification of Diseases, Ninth Revision (ICD-9) diagnosis Code 720.X (ankylosing spondylitis and other inflammatory spondylopathies) in clinical encounter data from 1996 through 2009 to estimate the prevalence of axSpA and ankylosing spondylitis. We reviewed medical records to confirm the diagnosis in a random sample and estimated the positive predictive value of computerized data to identify confirmed cases using various case definitions.

RESULTS

In the computerized data, 5568 adults had diagnostic codes indicating axSpA. On the basis of our case-finding approach using a single physician diagnosis code for ICD-9 720.X, the point prevalence of these conditions, standardized to the 2000 US Census, was 2.26 per 1000 persons for axSpA and 1.07 per 1000 for ankylosing spondylitis. Less than half of suspected cases saw a rheumatologist. The most specific algorithm for confirmed ankylosing spondylitis required 2 or more computerized diagnoses assigned by a rheumatologist, with 67% sensitivity (95% confidence interval, 64%-69%) and 81% positive predictive value (95% confidence interval, 79%-83%).

CONCLUSIONS

Observed prevalence in the KPNC population, compared with national estimates for axSpA and ankylosing spondylitis, suggests there is substantial underrecognition of these conditions in routine clinical practice. However, use of computerized data is able to identify true cases of ankylosing spondylitis, facilitating population-based research.

Challenges of diagnosis and management of axial spondyloarthritis in North Africa and the Middle East: An expert consensus

Axial spondyloarthritis (SpA) is a spectrum of inflammatory disease with stages characterized by both nonradiographic and radiographic sacroiliitis. Nonradiographic axial SpA is associated with health-related quality-of-life impairment and may progress to ankylosing spondylitis. Axial SpA has a low prevalence in some countries in North Africa and the Middle East, and pooling of data and resources is needed to increase understanding of the regional picture. Early diagnosis and effective treatment are required to reduce disease burden and prevent progression. Anti-TNF therapy is recommended for patients with persistently high disease activity despite conventional treatment, and has been shown to be effective in patients without radiographic damage. Diagnostic delays can be an obstacle to early treatment and appropriate referral strategies are needed. In some countries, restricted access to magnetic resonance imaging and anti-TNF agents presents a challenge. In this article, a group of experts from North Africa and the Middle East evaluated the diagnosis and management of axial SpA with particular reference to this region.

Clinical Assessment and Management of Spondyloarthritides in the Middle East: A Multinational Investigation

Data on spondyloarthritis (SpA) from the Middle East are sparse and the management of these diseases in this area of the world faces a number of challenges, including the relevant resources to enable early diagnosis and referral and sufficient funds to aid the most appropriate treatment strategy. The objective was to report on the characteristics, disease burden, and treatment of SpA in the Middle East region and to highlight where management strategies could be improved, with the overall aim of achieving better patient outcomes. This multicenter, observational, cross-sectional study collected demographic, clinical, laboratory, and treatment data on 169 consecutive SpA patients at four centers (Egypt, Kuwait, Qatar, and Saudi Arabia). The data collected presents the average time from symptom onset to diagnosis along with the presence of comorbidities in the region and comparisons between treatment with NSAIDs and biologics. In the absence of regional registries of SpA patients, the data presented here provide a rare snapshot of the characteristics, disease burden, and treatment of these patients, highlighting the management challenges in the region.

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.

[Effects of an exercise and relaxation aquatic program in patients with spondyloarthritis: A randomized trial]

BACKGROUND AND OBJECTIVE

Spondyloarthritis is a general term referring to a group of chronic rheumatic illnesses that share clinical, genetic, radiological and epidemiological features. The clinical presentation of spondyloarthritis is characterized by the compromise of both the axial and peripheral articular skeleton. We aimed to evaluate the efficacy of an aquatic exercise plus relaxation program in patients with spondyloarthritis.

PATIENTS AND METHOD

This was a randomized single blind study including 30 patients with spondylitis who were randomly assigned to an experimental or control group. For 2 months, the experimental group underwent an aquatic fitness plus relaxation program (3 sessions per week). Evaluations were also performed in the control group the same days as the experimental group but they did not participate in any supervised exercise program. The following data were obtained at baseline and immediately after application of the last session: Bath Ankylosing Spondylitis Functional Index, Bath Ankylosing Spondylitis Disease Activity Index, Health Questionnaire SF-12 and Sigma PC3(®) (Sigma-Elektro GmbH, Neustadt, Germany) Heart Rate Monitor.

RESULTS

The Mann-Whitney test showed statistically significant differences in the quality of life (physical function [P=.05]), Bath Ankylosing Spondylitis Functional Index (P=.015), Bath Ankylosing Spondylitis Disease Activity Index (fatigue [P=.032], neck pain, back and hips [P=.045], pain or swelling in other joints [P=.032] and in waking morning stiffness [P=.019]).

CONCLUSIONS

The results of the present study suggest that therapy with physical exercise plus relaxation provides benefits to spondyloarthritis patients and these are advised as a part of their usual treatment.

Psoriatic arthritis: Epidemiology, diagnosis, and treatment

Our understanding of psoriatic arthritis has evolved as new knowledge of the disease has emerged. However, the exact prevalence of psoriatic arthritis is unknown, and its pathogenesis has not been fully elucidated. Genetic, environmental, and immunologic factors have all been implicated in disease development. Early diagnosis and treatment have become primary objectives in clinical rheumatology. Psoriatic arthritis not only causes functional impairment, but also increases mortality risk of patients. The advent of new therapeutic agents capable of arresting the progression of joint damage is expected. However, early psoriatic arthritis assessment remains limited. The objectives of this article are to outline the epidemiology, diagnosis, and treatment of psoriatic arthritis and to suggest a paradigm for identifying early psoriatic arthritis patients.

Prevalence and clinical manifestations of ankylosing spondylitis in young Greek males

Increased awareness and sensitivity of general physicians have increased the early diagnoses of seronegative arthritis in young patients, while new agents such as anti-TNF blockers have significantly changed the treatment of the disease. To investigate the prevalence, the clinical manifestations, and the ability for military service of young Greek males (18-30 years old) with ankylosing spondylitis (AS) in the pre-anti-TNF era. We retrospectively studied the AS cases recorded from 1989 to 1995 of the rheumatology department of the largest General Military Hospital in Greece; the diagnosis was based on the modified New York criteria for AS. A total of 285 AS cases were diagnosed among 357,184 young men. The overall prevalence of AS on December 1995 was estimated at 8.2 cases per 10,000 young men (95 % C.I. 7.2-9.2). All the patients had chronic back pain. Two hundred forty (84 %, 95 % C.I. 79-88 %) patients presented sacroiliitis of whom 163 (68 %, 95 % C.I. 62-73 %) were bilateral. Two hundred five patients (72 %, 95 % C.I. 66-77 %) had peripheral joint involvement. Thirty-one patients presented with anterior uveitis (11 %, 95 % C.I. 8-15 %). One patient had IgA nephropathy. None had gut involvement. HLA-B27 antigen was found in 257 patients (90 %, 95 % C.I. 86-93 %). Ninety-one patients (32 %, 95 % C.I. 27-38 %) had permanent discharge from the military service, while 128 (45 %, 95 % C.I. 39-51 %) were able for auxiliaries attendances. The prevalence of AS for the age group 18-30 years old in this young Greek men cohort was significantly lower than in other Caucasian European populations, and the clinical manifestations were considered as mild.

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.

The epidemiology of back pain, axial spondyloarthritis and HLA-B27 in the United States

The concept of inflammatory back pain (IBP) evolved in the 1970s, coincident with the discovery of the HLA-B27 association with ankylosing spondylitis (AS), leading to the development of criteria to determine the presence of IBP. The concept of IBP and it relationship with AS and axial spondyloarthritis (AxSpA) has further evolved, and an instrument developed (the Spondylitis Association of America Back Pain Tool), which was further modified and field tested for use in the 2009 to 2010 National Health and Nutrition Examination Survey (NHANES). This has shown the frequency of chronic back pain to have risen to 19.4%, with nearly one third having IBP. The prevalence of AxSpA has been defined at 1.0% to 1.4% and AS at 0.52% to 0.55%. The national prevalence of HLA-B27 in the United States is 6.1%, and intriguing data from NHANES 2009 suggest a decreasing frequency with increasing age. From this arise new questions and a work agenda ahead.

High prevalence of anti-CD74 antibodies specific for the HLA class II-associated invariant chain peptide (CLIP) in patients with axial spondyloarthritis

OBJECTIVES

The pathogenesis of axial spondyloarthritis (axSpA) is still unclear. There is a strong association with HLA-B27 and other genes. Recently, anti-CD74 antibodies with specificity to a class II-associated invariant chain peptide (anti-CLIP-ABs) were found in axSpA patients. We examined the prevalence, sensitivity and specificity of anti-CLIP-ABs in axSpA in comparison with controls.

METHODS

Sera of axSpA and non-SpA patients were analysed for IgG-antibodies against CD74 by ELISA with specificity for CLIP developed in cooperation with AESKU Diagnostics (Germany). A cut-off of ≥4 SDs of arbitrary units (AU) from mean serum levels was used to differentiate the results. The laboratory workers were completely blinded for clinical data.

RESULTS

We analysed 145 sera from 94 axSpA and 51 non-SpA patients. AxSpA patients were more often male and younger. HLA-B27 status was available in 72 patients. Anti-CLIP-ABs were detected in 85.1% in axSpA but in only 7.8% in non-SpA patients (p≤0.0001). AxSpA patients showed higher levels of anti-CLIP-ABs versus non-SpA: mean 14.5 versus 0.8 AU (p≤0.0001). The sensitivity of anti-CLIP-ABs for diagnosing axSpA was 85.1%, specificity 92.2%, likelihood ratio (LR) LR+ was 10.8 and LR- was 0.08. Anti-CLIP-ABs and HLA-B27 were positive in 87.5% patients with axSpA, but only 14.9% were anti-CLIP-negative, while 23.6% were HLA-B27-negative.

CONCLUSIONS

Anti-CLIP antibodies were strongly associated with axSpA. The LR for confirming axSpA by using anti-CLIP was even higher than by using HLA-B27. More studies using this promising new method in patients with non-radiographic axial SpA or peripheral SpA are needed to establish its usefulness in clinical practice.

Psoriatic arthritis in patients with psoriasis: evaluation of clinical and epidemiological features in 133 patients followed at the University Hospital of Brasília

BACKGROUND

Psoriatic arthritis is an inflammatory arthritis associated with psoriasis. Its prevalence in patients with psoriasis varies from 7 to 42% but its exact prevalence is unknown.

OBJECTIVES

Considering the lack of national data related to its diagnosis in patients with psoriasis, this study aims to describe the clinical, laboratorial and radiological manifestations of psoriatic arthritis in these patients.

METHODS

We evaluated 133 patients with psoriasis, treated as outpatients. These patients were asked to fill in the forms with data about the disease and were submitted to a clinical evaluation by a dermatologist and a rheumatologist. Suspected cases of arthritis were referred for further investigation and were classified according to presence or absence of psoriatic arthritis according to CASPAR criteria.

RESULTS

The number of patients with psoriatic arthritis was 47 (35%), 17 of them were new cases. There was no difference between the groups regarding the type of psoriasis, nail involvement, presence of scalp lesions and psoriatic arthritis. Patients with psoriatic arthritis had more enthesitis and dactylitis (46.7%) than those without arthritis.

CONCLUSIONS

Despite the high prevalence of arthritis found, we know that results from epidemiological studies are variable, which limits their use and interpretation. We conclude that more studies are needed to draw a profile of rheumatic manifestations in our population of psoriasis patients.

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.

Early psoriatic arthritis

Psoriatic arthritis is an inflammatory musculoskeletal disease associated with psoriasis that is usually seronegative for rheumatoid factor. Psoriatic arthritis affects men and women equally, usually during the fourth decade, although it may affect children and octogenarians. Psoriatic arthritis may lead to deformities, joint damage, reduced quality of life and function. Early detection and treatment may prevent untoward outcomes.

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.

Psoriatic arthritis: a systematic review

Psoriatic arthritis is an inflammatory rheumatic disorder of unknown etiology occurring in patients with psoriasis. The Classification Criteria for Psoriatic Arthritis study group has recently developed a validated set of classification criteria for psoriatic arthritis with a sensitivity of 91.4% and a specificity of 98.7%. Three main clinical patterns have been identified: oligoarticular (≤ 4 involved joints) or polyarticular (≥ 5 involved joints) peripheral disease and axial disease with or without associated peripheral arthritis. In this context distal interphalangeal arthritis and arthritis mutilans may occur. According to other reports, also in our centre, asymmetric oligoarthritis is the most frequent pattern at onset. Axial disease has been estimated between 5% and 36% of patients. It is characterized by an irregular involvement of the axial skeleton with a predilection for the cervical spine. Recurrent episodes of enthesitis and dactylitis represent a hallmark of psoriatic arthritis. In around 20% of cases distal extremity swelling with pitting edema of the hands or feet is observed. Unilateral acute iridocyclitis, usually recurrent in alternate fashion, is the most frequent extra-articular manifestation, and accelerated atherosclerosis is the prominent comorbidity. The clinical course of peripheral and axial psoriatic arthritis is usually less severe than rheumatoid arthritis and ankylosing spondylitis, respectively. Local corticosteroid injections and non-steroidal anti-inflammatory drugs are recommended in milder forms. Sulphasalazine and methotrexate are effective in peripheral psoriatic arthritis. Recent studies have provided evidence on the efficacy of anti-tumor necrosis factor-α drugs to control symptoms and to slow or arrest radiological disease progression.