Low grade radiographic sacroiliitis as prognostic factor in patients with undifferentiated spondyloarthritis fulfilling diagnostic criteria for ankylosing spondylitis throughout follow up

Differences between radiographic and non-radiographic axial spondyloarthritis patients in a Mexican cohort

To compare the demographic, clinical, and laboratory characteristics, disease onset, and clinical features of radiographic axial Spondyloarthritis (r-axSpA) and non-radiographic axial Spondyloarthritis (nr-axSpA) patients. All patients who attended outpatient spondylarthritis (SpA) clinics at Hospital General de Mexico and the Instituto Nacional de la Nutrición from 1998 to 2005 and met the rheumatologist diagnostic criteria for SpA were selected. Then the SpA patients were classified by European Spondyloarthropathy Study Group criteria (ESSG). We selected SpA patients with axial presentation as axial SpA (axSpA), and they were classified as r-axSpA if they met modified New York (mNY) criteria for sacroiliitis and as nr-axSpA if they did not meet mNY criteria; to compared clinical, demographic, and laboratory test between the subgroups. It included 148 SpA patients; 55 (37.2%) patients had r-axSpA, and 70 (47.3%) had nr-axSpA. The nr-axSpA patients had a lower proportion of males (58.6% vs 78.2%, P < 0.05), lower HLA-B27 frequency (54.3%. vs. 92.7%, P < 0.05), were older at disease onset (21 vs 16 years; P < 0.01) and had a higher frequency of infections at disease onset (9.1% vs 32.9, P < 0.05) than r-axSpA. BASFI (2.9 vs 4.8; P < 0.0001), Dougados functional index (7 vs. 14; P < 0.05), and BASDAI (4.1 vs. 5.2; P < 0.001) were lower in patients with nr-axSpA than r-axSpA, respectively. The factors that most influenced the presentation of r-axSpA were history of uveitis (OR 14, 95% CI 2.3-85), HLA-B27 (OR 7.97, 95% CI, 2.96-122), male sex (OR 6.16, 95% CI, 1.47-25.7), axial enthesopathy count (OR 1.17 95% CI, 1.03-1.33). This study provides insight into the differences between nr-axSpA and r-axSpA in Mexico. Patients with r-axSpA were mainly male, with a younger presentation age, a higher prevalence of HLA-B27, more history of uveitis, fewer episodes of dactylitis, more axial enthesopathy, and higher disease activity than nr-axSpA.

Radiographic Progression in Sacroiliac Joints in Patients With Axial Spondyloarthritis: Results From a Five-Year International Observational Study

OBJECTIVE

To evaluate progression from nonradiographic (nr-) to radiographic axial spondyloarthritis (r-axSpA) over 5 years in patients with recently diagnosed (≤1 year) axSpA fulfilling the Assessment of SpondyloArthritis international Society (ASAS) classification criteria.

METHODS

A prospsective, observational study (Patients with Axial Spondyloarthritis: Multi-Country Registry of Clinical Characteristics) was conducted in rheumatology practices in 29 countries. Baseline and follow-up radiographs of sacroiliac joints were centrally evaluated by three readers according to the grading system of the modified New York criteria for patients initially classified as nr-axSpA. Radiographic progression from nr-axSpA to r-axSpA was evaluated by Kaplan-Meier analysis. Cox proportional regression analyses for progression from nr-axSpA to r-axSpA were also conducted.

RESULTS

Among 2,165 patients with axSpA, 1,612 (74%) were classified as having r-axSpA (1,050 [65%]) or nr-axSpA (562 [35%]) by central reading. Of 246 patients with nr-axSpA (mean [SD] symptom duration: 4.4 [6.2] years) who had at least one follow-up sacroiliac joint radiograph, progression from nr-axSpA to r-axSpA at any follow-up visit was observed in 40 patients (16%) over 5 years. Mean time to radiographic progression was 2.4 years (ranging from 0.9 to 5.1 years). Progression to r-axSpA was associated with male sex (hazard ratio [HR] 3.16 [95% CI 1.22-8.17]), fulfillment of the imaging arm of the ASAS classification criteria (HR 6.64 [1.37-32.25]), and good response to nonsteroidal anti-inflammatory drugs (HR 4.66 [1.23-17.71]).

CONCLUSION

16% of patients with nr-axSpA progressed to r-axSpA within 5 years. Male sex, fulfillment of the imaging arm of the ASAS criteria, and good response to nonsteroidal anti-inflammatory drugs were predictors of radiographic progression in patients with recently diagnosed axSpA.

The Increasing Level of DKK-1 as a New Bone Formation Factor in Patients with Early Spondyloarthritis

The role of dickkopf-related protein 1 (DKK-1) in radiographic development may become a robust marker for early spondyloarthritis (SpA) diagnosis. This study aimed at determining the serum DKK-1 profile in patients with SpA and investigating its relationship with SpA progression. Supported by analyzing the BMD data which aims to affirm the potential of DKK-1 as a biomarker for early diagnosis of SpA, this research may become the early study to produce a robust tool to diminish the fatal impacts in SpA. This cross-sectional study included patients with SpA using ASAS 2010 criteria from Dr. Soetomo General Hospital, Indonesia. Collected data included patients' general characteristics, disease duration, disease activity using ASDAS-CRP and ASDAS-ESR, serum DKK-1 levels, and BMD. The patients were classified as early SpA if the disease duration was ≤5 years and established SpA if the disease duration was >5 years, while the low BMD was indicated by Z score ≤ -2.00. The correlation was tested using the Spearman or Pearson test. The differences in patients' characteristics among early and established SpA and also between low and normal BMD were tested using the unpaired T-test or the Mann-Whitney test. The serum DKK-1 levels in early SpA (7365 ± 2067 pg/dL) were significantly higher than those in established SpA (5360 ± 1054 pg/dL). Serum DKK-1 levels were also associated with disease duration (r = -0.370, p = 0.040) and BMD at the total hip (r = 0.467, p = 0.028). The differences in all patients' clinical parameters were not found between patients with low BMD at any site and patients with normal BMD unless in the BMI (p = 0.019). Our findings found DKK-1 as a potential diagnostic marker for early SpA. Early diagnosis may lead to rapid treatment to delay disease progression and prevent future impairment.

Occurrence of human leukocyte antigen B51-related ankylosing spondylitis in a family: Two case reports

BACKGROUND

Ankylosing spondylitis (AS) is strongly associated with the human leukocyte antigen (HLA) B27 haplotype. In regions where conventional polymerase chain reaction for HLA typing is available for antigens such as HLA B27 or HLA B51, it is common to perform the HLA B27 test for evaluation of AS. While HLA B27-associated clustered occurrences of AS have been reported in families, we report the first case series of HLA B51-related occurrences of AS in a family.

CASE SUMMARY

A father and his daughters were diagnosed with AS and did not have the HLA B27 haplotype. Although they were positive for HLA B51, they exhibited no signs of Behçet’s disease (BD). Of the five daughters, one had AS, and three, including the daughter with AS, were positive for HLA B51. The two daughters with the HLA B51 haplotype (excluding the daughter with AS) exhibited bilateral grade 1 sacroiliitis, whereas the daughters without the HLA B51 haplotype did not have sacroiliitis. Thus, this Korean family exhibited a strong association with the HLA B51 haplotype and clinical sacroiliitis, irrespective of the symptoms of BD.

CONCLUSION

It is advisable to check for HLA B51 positivity in patients with AS/spondyloarthropathy who test negative for HLA B27.

Inflammatory Foot Involvement in Spondyloarthritis: From Tarsitis to Ankylosing Tarsitis

Spondyloarthritis (SpA) is a group that includes a wide spectrum of clinically similar diseases manifested by oligoarticular arthritis and axial or peripheral ankylosis. Although axial SpA is predominant in Caucasians and adult-onset patients, juvenile-onset and Latin American patients are characterized by severe peripheral arthritis and particularly foot involvement. The peripheral involvement of SpA can vary from tarsal arthritis to the most severe form named ankylosing tarsitis (AT). Although the cause and etiopathogenesis of axSpA are often studied, the specific characteristics of pSpA are unknown. Several animal models of SpA develop initial tarsitis and foot ankylosis as the main signs, emphasizing the role of foot inflammation in the overall SpA spectrum. In this review, we attempt to highlight the clinical characteristics of foot involvement in SpA and update the knowledge regarding its pathogenesis, focusing on animal models and the role of mechanical forces in inflammation.

Evaluation of the early cervical structural change in patients with non-radiographic axial spondyloarthropathy

In this double-blind, controlled, cross-sectional study, we compared structural changes in the cervical vertebrae of patients with nonradiographic axial spondyloarthropathy (nr-axSpA), patients with ankylosing spondylitis (AS), and a control group. We used the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) to determine whether the involvement of the cervical spine occurs earlier and is more severe than that of the lumbar spine in axial spondyloarthropathy (axSpA). A statistically significant difference was found in the total mSASSS between the AS and nr-axSpA groups (p = 0.038), but not in the cervical and lumbar mSASSS. Although the duration of the symptoms was shorter in the nr-axSpA group than in the AS group, no statistically significant difference was found in the cervical mSASSS between the AS and nr-axSpA groups. In both the AS and nr-axSpA groups, the cervical mSASSS values were found to be higher than the lumbar mSASSS values for the majority of the patients (82.8 and 89.5%, respectively). This may indicate that structural changes in the cervical spine occur during an early period of axSpA.

Nonradiographic axial spondyloarthritis

Non-radiographic axial spondyloarthritis (nr-axSpA) is a complex disease process that is part of the spectrum of axial spondyloarthritis (axSpA). This article reviews the current state of the literature as the understanding of this disease spectrum expands. The conceptual history and terminology, genetics, and epidemiology are reviewed. The clinical manifestations, diagnostic approach, and measures of disease activity are examined. Finally the current treatment modalities and recommendations and the research agenda for nr-axSpA are reviewed. With the advent of new criteria, the disease spectrum can be studied in a systematic manner. These data have enriched our knowledge that reflects an earlier or milder form of disease on a spectrum same as that of ankylosing spondylitis (or radiographic axSpA). We learned how patients present in this stage and that despite an unacceptable delay in diagnosis (regardless of the stage), the burden of disease is high and unremitting. nr-axSpA clinical trials have been somewhat heterogeneous (with variable inclusion criteria) but have nevertheless shown considerable efficacy with tumor necrosis factor inhibitors and flare on withdrawal of therapy.

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

OBJECTIVE

Inflammatory back pain (IBP) is often an early manifestation of spondyloarthritis (SpA), but the prognosis of patients with incident IBP is unknown. This study was undertaken to investigate long-term outcomes in patients with IBP, and predictors of progression to SpA, in a population-based cohort.

METHODS

We conducted a retrospective, longitudinal study using the Rochester Epidemiology Project, a longstanding population-based cohort of residents of Olmsted County, MN. Patients ages 16-35 years with clinical visits for back pain from 1999 to 2003 were identified, and we screened these patients for the presence of new-onset IBP and performed medical record reviews to collect data on clinical, laboratory, and imaging features of SpA. Outcomes in these patients were followed up until July 2016. We used survival analysis for competing risks to examine progression to either SpA, a non-SpA diagnosis, or resolution of back pain. Recursive partitioning was used to identify predictors of progression to SpA.

RESULTS

Among 5,304 patients with back pain, we identified 124 patients with new-onset IBP. After a median follow-up of 13.2 years, IBP had progressed to SpA in 39 patients, 15 patients developed a non-SpA diagnosis, and 58 patients had resolution of IBP. At 10 years, the probability of having SpA was 30%, while the probability of resolution of IBP was 43%. The most important predictors for progression to SpA were uveitis, male sex, and family history of SpA.

CONCLUSION

In a minority of patients, new-onset IBP progresses to SpA, while IBP resolves in many. That IBP often resolves may explain the difference between the prevalence of IBP (3-6%) and the prevalence of SpA (0.4-1.3%).

Radiographic progression in non-radiographic axial spondyloarthritis

INTRODUCTION

Non-radiographic axial spondyloarthritis (nr-axSpA) represents a subtype of axial spondyloarthritis (axSpA) with no significant structural damage in sacroiliac joints and spine. In addition, patients with nr-axSpA demonstrate a substantial burden of illness, and a considerable share of them might progress to radiographic axSpA (r-axSpA) over time. The amount and quality of published data allows crude estimation of progression rate and factors related to a higher risk of progression. Areas covered: This review discusses the available data reporting the rates and predictors of radiographic progression in the sacroiliac joints and in the spine in patients with nr-axSpA as well as predisposing factors for such a progression. Expert commentary: Most of the studies report about 10-40% of patients with nr-axSpA to progress to r-axSpA over a period of 2-10 years. Multiple risk factors for the radiographic sacroiliitis progression are outlined and explored. There are not enough data to presume that any treatment modality may influence progression from nr-axSpA to r-axSpA, with TNFi showing some promising results. Radiographic progression in the spine is in general low in nr-axSpA; thus, long-term studies are required to investigate the natural course of the progression and possible treatment effects.

Progression of Nonradiographic Axial Spondyloarthritis to Ankylosing Spondylitis: A Population-Based Cohort Study

OBJECTIVE

The long-term outcome of patients with nonradiographic axial spondyloarthritis (SpA) is unclear, particularly whether few or most progress to ankylosing spondylitis (AS). Our objective was to examine the progression to AS in a population-based inception cohort of patients with nonradiographic axial SpA.

METHODS

The Rochester Epidemiology Project (REP) is a longstanding population-based study of health in the residents of Olmsted County, Minnesota. We searched the REP from 1985 to 2010 using diagnostic and procedural codes for back pain, HLA-B27, and magnetic resonance imaging of the pelvis, and we performed detailed chart reviews to identify subjects who fulfilled the Assessment of SpondyloArthritis international Society classification criteria for axial SpA but did not have AS. We followed these subjects from disease onset to March 15, 2015, and used survival analysis to measure the time to progression to AS.

RESULTS

After screening 2,151 patients, we identified 83 subjects with new-onset nonradiographic axial SpA. Over a mean follow-up of 10.6 years, progression to AS occurred in 16 patients. The probability that the condition would remain as nonradiographic axial SpA at 5, 10, and 15 years was 93.6%, 82.7%, and 73.6%, respectively. There was more frequent and more rapid progression among subjects in the imaging arm (n = 18) than among those in the clinical arm (n = 65) (28% versus 17%; hazard ratio 3.50 [95% confidence interval 1.15-10.6], P = 0.02).

CONCLUSION

Progression to AS occurred in a minority (26%) of patients with nonradiographic axial SpA over as long as 15 years of follow-up. This suggests that the classification criteria for nonradiographic axial SpA identifies many patients in whom the condition is unlikely to progress to AS or that nonradiographic axial SpA represents a prolonged prodromal state that takes longer to evolve to AS and thus requires longer follow-up.

Progression rate of ankylosing spondylitis in patients with undifferentiated spondyloarthritis: A systematic review and meta-analysis

BACKGROUND

The idea that undifferentiated spondyloarthritis (uSpA) represents the early undifferentiated stage of ankylosing spondylitis (AS) and other well-defined SpA subtypes is well known. The gist of this study is to assess the rate estimate of patients with uSpA evolved to AS during long-term follow-up.

METHODS

A systematic search was implemented to identify pertinent articles. The primary outcome was the rate estimate that patients with uSpA fulfilling the diagnosis of AS according to the modified New York criteria during follow-up. The rate estimate and corresponding 95% confidence interval (95%CI) were pooled by the random-effects model in STATA 11.0 software. Meta-regression analyses were adopted to explore the sources of heterogeneity. The quality assessment was conducted by the National Institutes of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies and the Begg test and the Egger test were applied to assess publication bias.

RESULTS

Sixteen papers were finally included in this study after screening 1299 citations. The pooled rate of patients with uSpA progression to AS synthesized from the 16 papers was 0.323 (95%CI 0.257-0.389). Subgroup analysis based on the length of follow-up showed that the rate at the time-point of 5, 8, and 10 years follow-up was 0.220 (95%CI 0.110-0.330), 0.291 (95%CI 0.257-0.325), and 0.399 (95%CI 0.190-0.608), respectively; while the rate in Asia, Europe, and Latin America was 0.367 (95%CI 0.282-0.452), 0.228 (95%CI 0.066-0.390), and 0.269 (95%CI 0.209-0.329), respectively. Meta-regression analysis indicated that the length of follow-up alone accounts for 45.23% of the total heterogeneity. Nearly half of the papers scored fair quality and none publication bias was identified based on the Begg test and the Egger test. Further, line chart describes an obviously increased trend for the patients with uSpA fulfilling the diagnosis of AS over time.

CONCLUSION

The progression rate of patients with uSpA evolved into AS was variable in different time-point, this variation can mostly be explained by the length of follow-up. Thus, more studies with similar time point of follow-up are needed to clarify the full spectrum of uSpA.

Prevalence of peripheral and extra-articular disease in ankylosing spondylitis versus non-radiographic axial spondyloarthritis: a meta-analysis

Background

Peripheral disease (arthritis, enthesitis and dactylitis) and extra-articular disease (uveitis, psoriasis and inflammatory bowel disease) is common in ankylosing spondylitis (AS) and non-radiographic axial spondyloarthritis (nr-axSpA). So far, however, summary data on the prevalence are lacking. The objective of this meta-analysis was to assess the prevalence of peripheral and extra-articular manifestations in ankylosing spondylitis (AS) and nr-axSpA.

Methods

We performed a systematic literature search to identify publications describing the prevalence of peripheral and extra-articular disease manifestations in patients with AS and nr-axSpA. We assessed the risk of bias and between-study heterogeneity, and extracted data. Pooled prevalence and prevalence differences were calculated.

Results

Eight studies comprising 2236 patients with AS and 1242 with nr-axSpA were included: 7 of the studies were longitudinal cohort studies. There was male predominance in AS (70.4 %, 95 % CI 64.4, 76.0 %) but not in nr-axSpA (46.8 %, 95 % CI 41.7, 51.9), which was independent of the prevalence of human leukocyte antigen (HLA)-B27. The prevalence of HLA-B27 was similar in AS (78.0 % (95 % CI 73.9, 81.9 %) and nr-axSpA (77.4 %, 95 % CI 68.9, 84.9 %)). The pooled prevalence of arthritis (29.7 % (95 % CI 22.4, 37.4 %) versus 27.9 % (95 % CI 16.0, 41.6 %)), enthesitis (28.8 % (95 % CI 2.6, 64.8) versus 35.4 % (95 % CI 6.1, 71.2)). dactylitis (6.0 % (95 % CI 4.7, 7.5 %) versus 6.0 % (95 % CI 1.9, 12.0 %)), psoriasis (10.2 % (95 % CI 7.5, 13.2 %) versus 10.9 % (95 % CI 9.1, 13.0 %)) and inflammatory bowel disease (4.1 % (95 % CI 2.3, 6.5 %) versus 6.4 % (95 % CI 3.6, 9.7 %)) were similar in AS and nr-axSpA. The pooled prevalence of uveitis was higher in AS (23.0 % (95 % CI 19.2, 27.1 %)) than in nr-axSpA (15.9 % (95 % CI 11.8, 20.4 %)).

Conclusion

Peripheral and extra-articular manifestations are equally prevalent in AS and nr-axSpA, except for uveitis, which is slightly more prevalent in AS. These data provide evidence for the largely equal nature of disease manifestations in nr-axSpA and AS.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-016-1093-z) contains supplementary material, which is available to authorized users.

The prevalence and clinical characteristics of nonradiographic axial spondyloarthritis among patients with inflammatory back pain in rheumatology practices: a multinational, multicenter study

BACKGROUND

Patients with ankylosing spondylitis (AS), who by definition have radiographic sacroiliitis, typically experience symptoms for a decade or more before being diagnosed. Yet, even patients without radiographic sacroiliitis (i.e., nonradiographic axial spondyloarthritis [nr-axSpA]) report a significant disease burden. The primary objective of this study was to estimate the prevalence and clinical characteristics of nr-axSpA among patients with inflammatory back pain (IBP) in rheumatology clinics in a number of countries across the world. A secondary objective was to estimate the prevalence of IBP among patients with chronic low back pain (CLBP).

METHODS

Data were collected from 51 rheumatology outpatient clinics in 19 countries in Latin America, Africa, Europe, and Asia. As consecutive patients with CLBP (N = 2517) were seen by physicians at the sites, their clinical histories were evaluated to determine whether they met the new Assessment of SpondyloArthritis international Society criteria for IBP. For those who did, their available clinical history (e.g., family history, C-reactive protein [CRP] levels) was documented in a case report form to establish whether they met criteria for nr-axSpA, AS, or other IBP. Patients diagnosed with nr-axSpA or AS completed patient-reported outcome measures to assess disease activity and functional limitations.

RESULTS

A total of 2517 patients with CLBP were identified across all sites. Of these, 974 (38.70 %) fulfilled the criteria for IBP. Among IBP patients, 29.10 % met criteria for nr-axSpA, and 53.72 % met criteria for AS. The prevalence of nr-axSpA varied significantly by region (p < 0.05), with the highest prevalence reported in Asia (36.46 %) and the lowest reported in Africa (16.02 %). Patients with nr-axSpA reported mean ± SD Ankylosing Spondylitis Disease Activity Scores based on erythrocyte sedimentation rate and CRP of 2.62 ± 1.17 and 2.52 ± 1.21, respectively, indicating high levels of disease activity (patients with AS reported corresponding scores of 2.97 ± 1.13 and 2.93 ± 1.18). Similarly, the overall Bath Ankylosing Spondylitis Disease Activity Index score of 4.03 ± 2.23 for patients with nr-axSpA (4.56 ± 2.17 for patients with AS) suggested suboptimal disease control.

CONCLUSIONS

These results suggest that, in the centers that participated in the study, 29 % of patients with IBP met the criteria for nr-axSpA and 39 % of patients with CLBP had IBP. The disease burden in nr-axSpA is substantial and similar to that of AS, with both groups of patients experiencing inadequate disease control. These findings suggest the need for early detection of nr-axSpA and initiation of available treatment options to slow disease progression and improve patient well-being.

Looking into the new ASAS classification criteria for axial spondyloarthritis through the other side of the glass

The new concept of axial spondylitis (axSpA) and the Assessment of Spondyloarthritis International Society (ASAS) classification criteria for axSpA have induced new clinical research that has broadened our understanding of spondyloarthritis (SpA) and has had indeed a positive impact on earlier diagnosis and treatment of patients with axSpA who have not yet developed radiographic sacroiliitis. The primary goal of any valid classification criteria for any disease is to provide a homogeneous study population with a common etiopathogenesis, similar prognosis, and similar response to identical treatment. Without such a homogeneous study population, robust clinical and basic science research in any subtype of SpA is not possible. All criteria are dynamic concepts that need updating as our knowledge advances and our review of the ASAS classification criteria of axSpA indicates that complex multi-selection design and unclear (not mutually exclusive) definitions of the imaging and clinical arms of the criteria results in patient heterogeneity across study populations. Therefore, there is a need to improve the validity of the ASAS criteria for axSpA. It is our opinion that in the meantime, the clinically well-established entity of AS, as defined by the modified New York (mNY) criteria, should be preserved for the most accurate comparison of the new research studies with those conducted over the last three decades, and that the use of the ASAS criteria should be restricted to patients with nr-axSpA, who are not recognized by the mNY criteria.

Ankylosing spondylitis: A state of the art factual backbone

Ankylosing spondylitis (AS) is a chronic inflammatory disease that affects 1% of the general population. As one of the most severe types of spondyloarthropathy, AS affects the spinal vertebrae and sacroiliac joints, causing debilitating pain and loss of mobility. The goal of this review is to provide an overview of AS, from the pathophysiological changes that occur as the disease progresses, to genetic factors that are involved with its onset. Considering the high prevalence in the population, and the debilitating life changes that occur as a result of the disease, a strong emphasis is placed on the diagnostic imaging methods that are used to detect this condition, as well as several treatment methods that could improve the health of individuals diagnosed with AS.

Occult spondyloarthritis in inflammatory bowel disease

Spondyloarthritis (SpA) is a frequent extra-intestinal manifestation in patients with inflammatory bowel disease (IBD), although its real diffusion is commonly considered underestimated. Abnormalities in the microbioma and genetic predisposition have been implicated in the link between bowel and joint inflammation. Otherwise, up to date, pathogenetic mechanisms are still largely unknown and the exact influence of the bowel activity on rheumatic manifestations is not clearly explained. Due to evidence-based results of clinical studies, the interest on clinically asymptomatic SpA in IBD patients increased in the last few years. Actually, occult enthesitis and sacroiliitis are discovered in high percentages of IBD patients by different imaging techniques, mainly enthesis ultrasound (US) and sacroiliac joint X-ray examinations. Several diagnostic approaches and biomarkers have been proposed in an attempt to correctly classify and diagnose clinically occult joint manifestations and to define clusters of risk for patient screening, although definitive results are still lacking. The correct recognition of occult SpA in IBD requires an integrated multidisciplinary approach in order to identify common diagnostic and therapeutic strategies. The use of inexpensive and rapid imaging techniques, such as US and X-ray, should be routinely included in daily clinical practice and trials to correctly evaluate occult SpA, thus preventing future disability and worsening of quality of life in IBD patients.

Similarities and differences between nonradiographic and radiographic axial spondyloarthritis: a clinical, epidemiological and therapeutic assessment

PURPOSE OF REVIEW

The concept of axial spondyloarthritis with two forms or subtypes (nonradiographic and radiographic) has been established over the last few years. However, debates concerning especially the nonradiographic form of the disease are still ongoing. Here we summarise recent data on similarities and differences (and their possible explanations) between nonradiographic axial spondyloarthritis and radiographic axial spondyloarthritis (ankylosing spondylitis).

RECENT FINDINGS

Nonradiographic and radiographic forms are about equally frequent among patients first diagnosed with axial spondyloarthritis and have in general similar clinical characteristics, especially related to clinical signs of disease activity and similar rates of treatment response. Nonradiographic axial spondyloarthritis is characterised by a higher prevalence of females and lower percentage of patients with elevated C-reactive protein that might reflect the presence of a certain proportion of patients who develop structural damage in the axial skeleton very slowly or do not develop it at all. Elevated C-reactive protein and active sacroiliitis on magnetic resonance imaging are strongest predictors of structural damage development in the sacroiliac joints and, therefore, of progression from nonradiographic to radiographic stage. The same parameters predict a good clinical response to therapy with tumour necrosis factor alpha blocking agent in axial spondyloarthritis, but especially if used in nonradiographic disease.

SUMMARY

Currently available data support the concept of axial spondyloarthritis as one entity. Nonradiographic axial spondyloarthritis seems to be, however, more heterogeneous than ankylosing spondylitis because of the presence of patients with a self-limiting disease or a slow disease course.

Seronegative arthritis in Latin America: a current review

In many Latin American countries seronegative arthritis, especially the spondyloarthritides (SpA), is commonly characterized by associated axial and peripheral involvement. In this article, the authors review the ethnic distribution of the population and the different SpA in 10 Latin American countries, and the main characteristics of the Ibero-American Registry of Spondyloarthropathies (RESPONDIA) compared with other international registries. The peripheral component of SpA is more frequent in mixed-race populations, whereas psoriatic arthritis is significantly more frequent in countries with predominantly white populations.

The presence of peripheral arthritis delays spinal radiographic progression in ankylosing spondylitis: Observation Study of the Korean Spondyloarthropathy Registry

OBJECTIVES

The aim of this study was to determine whether the presence of peripheral arthritis can affect radiographic structural damage in patients with AS.

METHODS

A total of 915 subjects comprising 363 patients with a history of peripheral arthritis and 552 patients without a history of peripheral arthritis obtained from the Observation Study of the Korean SpA Registry (OSKAR) were analysed looking at the relationship of peripheral arthritis history in a cross-sectional survey as well as the radiographic damage score according to the presence or absence of peripheral arthritis. Radiographs and clinical information were available for 501 subjects (205 peripheral arthritis patients and 296 without peripheral arthritis) at a mean follow-up of 2.7 years. The modified Stoke AS Spinal Score (mSASSS) was examined by two experienced radiologists to validate the results. Reliability was evaluated using the intraclass correlation coefficient for each radiograph.

RESULTS

The agreement between the two readers regarding the mSASSS was good. On simple comparison there was a significant difference in the mSASSS between patients with a history of peripheral arthritis and those without [mean 14.62 (s.e.m. 0.83) vs 18.78 (0.79), P < 0.001]. The mSASSS change was stratified according to the presence or absence of peripheral arthritis at baseline. After adjusting for multiple comparisons by Bonferroni correction, the patients with peripheral arthritis had less mSASSS change than those without peripheral arthritis [3.08 (s.e.m. 0.61) vs 5.18 (0.47), P = 0.008].

CONCLUSION

The presence of peripheral arthritis delays spinal radiographic progression in AS.

Tumor necrosis factor α inhibition in radiographic and nonradiographic axial spondyloarthritis: results from a large observational cohort

OBJECTIVE

To evaluate the baseline characteristics of patients with radiographic axial spondyloarthritis (SpA; ankylosing spondylitis [AS]) and patients with nonradiographic axial SpA, to investigate determinants of anti-tumor necrosis factor (anti-TNF) agent prescription on the background of a nonrestrictive reimbursement policy, and to assess the response to TNF inhibition.

METHODS

We compared the characteristics of radiographic axial SpA and nonradiographic axial SpA in 1,070 patients from the Swiss Clinical Quality Management (SCQM) Cohort who fulfilled the Assessment of SpondyloArthritis international Society (ASAS) classification criteria for axial SpA. By taking advantage of the situation that patients who are eligible for anti-TNF treatment are preferentially enrolled in the SCQM Cohort for patients with AS/axial SpA, we explored parameters leading to the initiation of anti-TNF treatment in single and multiple regression models and assessed treatment responses.

RESULTS

We confirmed a similar burden of disease (as determined by self-reported disease activity, impaired function, and quality of life) in patients with nonradiographic axial SpA (n = 232) and those with radiographic axial SpA (n = 838). Patients with radiographic axial SpA had higher median levels of acute-phase reactants and higher median AS Disease Activity Scores (ASDAS; 3.2 versus 3.0). Anti-TNF treatment was initiated in 363 patients with radiographic axial SpA and 102 patients with nonradiographic axial SpA, preferentially in those with sacroiliitis on magnetic resonance imaging, peripheral arthritis, a higher C-reactive protein (CRP) level, a higher ASDAS, and a higher Bath Ankylosing Spondylitis Disease Activity Index level. The ASAS criteria for 40% improvement responses at 1 year were higher in patients with radiographic axial SpA compared with those with nonradiographic axial SpA (48.1% versus 29.6%; odds ratio [OR] 2.2, 95% confidence interval [95% CI] 1.12-4.46, P = 0.02). The difference was smaller in the subgroups of patients with elevated baseline CRP levels (51.6% in patients with radiographic axial SpA versus 38.5% in those with nonradiographic axial SpA; OR 1.7, 95% CI 0.68-4.48, P = 0.29).

CONCLUSION

The indications for treatment with anti-TNF agents were comparable for patients with radiographic axial SpA and those with nonradiographic axial SpA. With the exception of patients with elevated CRP levels at baseline, higher rates of response to TNF inhibition were achieved in the group of patients with radiographic axial SpA than in the group with nonradiographic axial SpA.

Undifferentiated spondyloarthritis vs ankylosing spondylitis and psoriatic arthritis: a real-life prospective cohort study of clinical presentation and response to treatment

OBJECTIVE

SpA is a phenotypically heterogeneous disease, with AS and PsA as its best studied subtypes. This study aimed to investigate whether, despite a different phenotypic presentation, patients with undifferentiated SpA (uSpA) have similar disease activity and response to treatment to those with AS and PsA.

METHODS

175 patients presenting at a dedicated SpA outpatient clinic were recruited in a real-life prospective cohort with follow-up every 3 months. Clinical characteristics, disease activity at presentation and response to treatment of uSpA were compared with AS and PsA.

RESULTS

Twenty-three per cent (n = 40) of the patients were classified as uSpA. These patients were younger and tended to have a shorter disease duration than AS and PsA patients. uSpA patients exhibited a mixed axial (inflammatory back pain in 87.5%) and peripheral (peripheral arthritis in 62.5%) phenotype, with almost half of the patients having low-grade sacroiliitis on conventional X-ray. The overall disease activity in uSpA was similar to AS and higher than in PsA, also when analysing only anti-TNF naive patients. Initiation of TNF blockade significantly decreased disease activity in uSpA, with a similar amplitude to that in AS and PsA.

CONCLUSION

uSpA is a frequent, severe and anti-TNF-responsive phenotypic subtype of SpA. In agreement with the new ASAS classification criteria for axial and peripheral SpA and emerging data on TNF blockade in non-radiographic axial SpA and peripheral uSpA, these data emphasize the need for early diagnosis and optimal treatment of not only AS and PsA but also other SpA subforms.

Diagnostic imaging of sacroiliac joints and the spine in the course of spondyloarthropathies

Spondyloarthropathies belong to a group of rheumatic diseases, in which inflammatory changes affect mainly the sacroiliac joints, spine, peripheral joints, tendon, ligaments and capsule attachments (entheses). This group includes 6 entities: ankylosing spondylitis, arthritis associated with inflammatory bowel disease, reactive arthritis, undifferentiated spondyloarthropathy, psoriatic arthritis and juvenile spondyloarthropathy. In 2009, ASAS (Assessment in SpondyloArthritis international Society) association, published classification criteria for spondyloarthropathies, which propose standardization of clinical-diagnostic approach in the case of sacroiliitis, spondylitis and arthritis. Radiological diagnosis of inflammatory changes of sacroiliac joints is based on a 4 step radiographic grading method from 1966. According to modified New York criteria, the diagnosis of ankylosing spondylitis is made based on the presence of advanced lesions, sacroiliitis of at least 2 grade bilaterally or 3-4 unilaterally. In case of other types of spondyloarthropathies diagnosis is made based on presence of at least grade 1 changes. In MRI, active inflammation of sacroiliac joints is indicated by the presence of subchondral bone marrow edema, synovitis, bursitis, or enthesitis. ASAS discusses only the classic form of axial spondyloarthropathies, which is ankylosing spondylitis. To quantify radiological inflammatory changes in the course of the disease, Stoke Ankylosing spondylitis classification Spinal Score (SASSS) is recommended. The signs of inflammation and scarrying of the spinal cord in the course of ankylosing spondylitis, present in MRI include: bone marrow edema, sclerosis, fat metaplasia, formation of syndesmophytes, and ankylosis.

Undifferentiated spondyloarthritis in a heterogeneous Brazilian population: an eight-year follow-up study

The aim of the present study was to describe the outcomes of Brazilian patients with undifferentiated spondyloarthritis during an eight-year follow-up period. Patients fulfilling the European Spondyloarthritis (SpA) Study Group Classification Criteria were enrolled. Forty patients were seen at baseline, and 36 participated in the follow-up study. Twenty-three (58%) were female, and there were 24 (60%) African Brazilians enrolled. HLA-B27 was positive in 18 (45%) patients. At disease onset, the first presenting symptoms were pure peripheral manifestations in 26 (72.2%) patients. After the study period, mixed disease (axial + peripheral) predominated occurring in 25 (69.4%) patients. The Assessment of SpA International society (ASAS) classification criteria for axial SpA were fulfilled by 77% of patients, and the ASAS criteria for peripheral SpA were fulfilled by 59% of patients. After 2.5 years, 6 (16.7%) of the 36 patients fulfilled the modified New York Criteria for ankylosing spondylitis and 1 (2.7%) progressed to psoriatic arthritis. A total of 10 (27.8%) patients progressed to definite SpA during the eight-year study period. Buttock pain (p = 0.006, OR 10.55; 95% CI 2.00-65.90) and low-grade radiographic sacroiliitis (p = 0.025, OR = 11.50; 95% CI 1.33-83.39) at baseline were associated with definite SpA. Thus, in this Brazilian cohort, which had a predominance of female African-Brazilian patients, prevalent peripheral onset symptoms were followed by a high frequency of axial manifestations during the follow-up period. Evidence of clinical or radiological sacroiliitis was associated with progression to definite SpA.

Do patients with non-radiographic axial spondylarthritis differ from patients with ankylosing spondylitis?

OBJECTIVE

Patients with axial spondylarthritis (SpA) who have structural changes in the sacroiliac joints and/or the spine have been classified as having ankylosing spondylitis (AS), while those without such changes are now classified as having nonradiographic axial SpA (nr-axSpA). The differentiating features are incompletely understood.

METHODS

Data from 100 consecutive patients with axial SpA not treated with tumor necrosis factor antagonists were compared clinically and with laboratory parameters, spinal radiographs, and magnetic resonance imaging (MRI) of the spine. Standardized clinical assessment tools were used to assess health status.

RESULTS

AS was diagnosed in 56 patients and nr-axSpA in 44 patients. Signs of inflammation were significantly higher in patients with AS than in patients with nr-axSpA, with a median C-reactive protein level of 8.0 versus 3.8 mg/liter, a median Ankylosing Spondylitis Disease Activity Score of 2.2 versus 2.8, respectively, and a median amount of spinal inflammatory lesions on MRI of 2.0 versus 0.0, respectively. Significant differences between these 2 groups were seen in sex (76.8% male AS patients versus 31.8% male nr-axSpA patients). Clinical variables did not differ between patients with AS and nr-axSpA (Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis Functional Index, Ankylosing Spondylitis Quality of Life questionnaire, Short Form 36 health survey).

CONCLUSION

Patients with nr-axSpA were characterized by the low proportion of male patients and the low burden of inflammation compared to patients with AS. While both groups did not differ regarding health status, disease activity, and physical function, they did differ in signs of inflammation; all were higher in patients with AS. Since many patients with nr-axSpA had not developed structural changes after years of symptoms, we propose that those patients should not be regarded as having preradiographic AS but rather as having nr-axSpA.

Radiographic progression in ankylosing spondylitis/axial spondyloarthritis: how fast and how clinically meaningful?

PURPOSE OF REVIEW

Radiographic progression in the axial skeleton is considered as an important outcome in ankylosing spondylitis (AS) and in the whole group of axial spondyloarthritis (SpA). Recently new data on the rates and predictors of radiographic progression from observational cohorts have become available. Here we summarize recent data and discuss their clinical relevance and directions for further investigations.

RECENT FINDINGS

Nonradiographic axial SpA progresses to AS with a rate of about 12% over 2 years; elevated C-reactive protein (CRP) is an important predictor of such a progression. The rate of radiographic progression in the spine is strongly dependent on the presence of the following risk factors: syndesmophytes at baseline, elevated acute phase reactants (CRP and/or erythrocyte sedimentation rate) and smoking. The presence of radiographic damage in the spine has a strong impact on spinal mobility and functional status, although the association of radiographic sacroiliitis progression with the functional status remains unclear.

SUMMARY

Radiographic progression in the spine and, to a lesser extent, in the sacroiliac joint represents a clinically relevant clinical outcome and treatment target in AS/axial SpA.

Imaging in ankylosing spondylitis

Imaging is an integral part of the management of patients with ankylosing spondylitis and axial spondyloarthritis. Characteristic radiographic and/or magnetic resonance imaging (MRI) findings are key in the diagnosis. Radiography and MRI are also useful in monitoring the disease. Radiography is the conventional, albeit quite insensitive, gold standard method for assessment of structural damage in spine and sacroiliac joints, whereas MRI has gained a decisive role in monitoring disease activity in clinical trials and practice. MRI may also, if ongoing research demonstrates a sufficient reliability and sensitivity to change, become a new standard method for assessment of structural damage. Ultrasonography allows visualization of peripheral arthritis and enthesitis, but has no role in the assessment of axial manifestations. Computed tomography is a sensitive method for assessment of structural changes in the spine and sacroiliac joints, but its clinical utility is limited due to its use of ionizing radiation and lack of ability to assess the soft tissues. It is exciting that with continued dedicated research and the rapid technical development it is likely that even larger improvements in the use of imaging may occur in the decade to come, for the benefit of our patients.

The assessment of the spondyloarthritis international society concept and criteria for the classification of axial spondyloarthritis and peripheral spondyloarthritis: A critical appraisal for the pediatric rheumatologist

This review refers to the origin and current state of the assessment of the SpondyloArthritis International Society (ASAS) criteria for the classification of axial and peripheral spondyloarthritis (SpA) and the possible implications in the pediatric population. The ASAS criteria evolved from the idea that the earlier the recognition of patients with ankylosing spondylitis, the better the efficacy of tumor necrosis factor blockers. Strategies included the development of new concepts, definitions, and techniques for the study of clinical signs and symptoms. Of relevance, the new definition of inflammatory back pain (IBP) and the introduction of sacroiliitis by magnetic resonance imaging represented the most important advance in the early identification of AS in the "pre-radiographic stage" of the disease. AS is considered in this paper as a disease continuum with symptoms depending on age at onset. The application of those specific strategies in children and adolescents with SpA seems limited because the most important manifestation in the early stage of disease is not IBP, but peripheral arthritis and enthesitis. In this instance, the logical approach to juvenile onset SpA according to ASAS criteria should not be through the axial criteria but rather the peripheral set of criteria.

The eye in rheumatology

Rheumatic conditions affect a wide variety of tissues, including the eye, and can cause significant visual loss. Early diagnosis coupled with appropriate management, using immunosuppression where necessary, can significantly improve the outcome. This article reviews the most common manifestations seen in clinical practice.

Neck pain from a rheumatologic perspective

This article provides a comprehensive review of rheumatologic considerations for a clinician when evaluating a patient with neck pain. Clearly, anatomic derangements of the cervical spine should be considered when a patient complains of cervicalgia. However, one must also entertain the possibility of a systemic illness as the cause of the pain. Examples of diseases that may present with a prominent feature of neck pain are discussed, including rheumatoid arthritis, ankylosing spondylitis, diffuse idiopathic skeletal hyperostosis, myositis, and fibromyalgia. Evidence of an underlying rheumatic illness may guide the clinician in a different therapeutic direction.

Ankylosing spondylitis in a patient referred to physical therapy with low back pain

Low back pain (LBP) is one of the most common and costly medical conditions in the United States; various studies have reported up to 80% of the adult population will experience a significant episode of LBP sometime within their lifetime. Although many cases of LBP are related to the musculoskeletal system and appropriate for the care of the physical therapist (PT), some episodes of LBP have a systemic cause. Thus, it is the role of the PT to ensure each patient is appropriate for physical therapy intervention throughout the episode of care. When the patient's condition is not appropriate for physical therapy intervention, it is the PT's responsibility to refer the patient to other medical professions to ensure optimal patient care. The purpose of this case report is to describe a patient referred to PT who was diagnosed with ankylosing spondylitis. The patient presented initially to physical therapy with a diagnosis of LBP. However, after several visits her symptoms were inconsistent with mechanical LBP and thus required further medical consultation.

Epidemiology of spondyloarthritis in México

Spondyloarthritis (SpA) is an important group of rheumatic diseases in specialized Mexican clinics. Their most common pattern includes the involvement of both axial and peripheral sites, and their consequences have an important impact on functioning, health-related quality of life and direct and indirect costs. In México, the prevalence of SpAs in the community is 0.6% and that of ankylosing spondylitis is 0.09%. However, along with the limited awareness of SpAs, the facts are that rheumatic diseases are not a priority for the state, university curricula do not provide enough information to students and the number of board-certified rheumatologists in México is approximately 500 for 110 million people. Delayed referrals to a specialist are common and, treatment, in consequence, becomes difficult.

Spondyloarthritis in a pediatric population: risk factors for sacroiliitis

OBJECTIVE

Pediatric rheumatologists may have an opportunity to diagnose sacroiliitis in its early stages, prior to the development of irreversible radiographic changes. Early diagnosis frequently requires magnetic resonance imaging (MRI), the use of which is limited by expense and requirement for sedation. We set out to identify features of juvenile spondyloarthritis (SpA) associated with the highest risk of sacroiliitis, to identify patients who may be candidates for routine MRI-based screening.

METHODS

We reviewed the charts of 143 children seen at Texas Scottish Rite Hospital for Children diagnosed with SpA based on the International League of Associations for Rheumatology criteria for enthesitis-related arthritis or the Amor criteria for SpA. We performed logistic regression analysis to identify risk factors for sacroiliitis.

RESULTS

A group of 143 children were diagnosed with SpA. Consistent with the diagnosis of SpA, 16% had psoriasis, 43% had enthesitis, 9.8% had acute anterior uveitis, and 70% were HLA-B27+. Fifty-three children had sacroiliitis, of which 11 cases were identified by imaging studies in the absence of suggestive symptoms or physical examination findings. Logistic regression analysis revealed that hip arthritis was a positive predictor of sacroiliitis, while dactylitis was a negative predictor.

CONCLUSION

Children with SpA are at risk for sacroiliitis, which may be present in the absence of suggestive symptoms or physical examination findings. The major risk factor for sacroiliitis is hip arthritis, while dactylitis may be protective. Routine screening by MRI should be considered in patients at high risk of developing sacroiliitis.

Undifferentiated Spondyloarthritis: A Longterm Followup

Objective.

To analyze the longterm followup of a series of Brazilian patients with undifferentiated spondyloarthritis (uSpA).

Methods.

Prospective study analyzing a group of 111 patients with the diagnosis of uSpA, fulfilling the European Spondylarthropathy Study Group and the Amor criteria, who were followed for 5 to 10 years in a single university referral center. Patients had their outcome analyzed at 5, 7, and 10 years.

Results.

There was a predominance of men (81.1%), white ethnicity (78.4%), and positive HLA-B27 (61.3%), with a mean age at onset of 27.2 years. Twenty-seven patients presented development to ankylosing spondylitis (AS; 24.3%) and 3 to psoriatic arthritis (PsA; 2.7%), while 25 patients (22.5%) went into remission during the followup. Univariate logistic regression analysis revealed that ethnicity, HLA-B27, buttock pain, inflammatory low back pain, ankle involvement, grade I sacroiliitis at the beginning of the study, and the use of sulfasalazine were statistically associated with progression to AS. Multivariate logistic regression analysis revealed that HLA-B27 (p = 0.035, OR 6.720, 95% CI 11.45–39.43) and buttock pain (p = 0.009, OR 6.211, 95% CI 1.591–24.25) were statistically associated with progression to AS.

Conclusion.

In a longterm followup of 111 Brazilian patients with uSpA, HLA-B27 and buttock pain were significant predictors of progression to a definite disease.

Risk Factors for Axial Inflammatory Arthritis in Patients with Psoriatic Arthritis

Objective.

Axial involvement is an important manifestation of psoriatic arthritis (PsA). We aimed to identify risk factors associated with the presence of axial PsA (AxPsA) in patients with PsA.

Methods.

Patients with AxPsA (bilateral sacroiliitis ≥ grade 2/unilateral sacroiliitis ≥ 3 and inflammatory neck/back pain or limited spinal mobility) at first clinic visit were identified from the University of Toronto PsA clinic database. Risk factors associated with the presence of AxPsA were determined. Subsequently, patients without AxPsA at first clinic visit were identified. Under a multistate framework, the proportion of patients with PsA who subsequently developed AxPsA was estimated robustly using marginal methods and a Markov model. Risk factors at baseline that were associated with future development of AxPsA were identified through multiplicative time-homogeneous Markov models.

Results.

Our study included 206 patients. Fifty patients had AxPsA at first clinic visit. HLA-B*27, radiographic damage to peripheral joints, and elevated erythrocyte sedimentation rate (ESR) increased odds of having AxPsA, while family history of PsA decreased the odds. One hundred fifty-six patients did not have AxPsA at first clinic visit. On followup, 28 developed AxPsA, and 11 died. We estimated that after 10 years of followup, 15% would develop AxPsA. Nail dystrophy, number of radiographically damaged joints, periostitis, and elevated ESR increased the risk of developing AxPsA, while swollen joints decreased the risk.

Conclusion.

These results suggest that severe peripheral arthritis and HLA-B*27 are risk factors for AxPsA.

Articular manifestations in inflammatory bowel disease patients: a prospective study

BACKGROUND AND AIMS

Rheumatic manifestations are frequent in inflammatory bowel disease (IBD) and are associated with a wide range of clinical patterns.

METHODS

Articular symptoms and signs were investigated by questionnaire in a cohort of 651 pts, mean age 42+/-14 years, followed at two referral hospitals over a 12-month period.

RESULTS

142 ulcerative colitis (UC) and 120 Crohn's disease (CD) patients referred articular pain during their IBD history: in 46% this was associated with active IBD, in 56% symptoms were intermittent and in 19% symptoms preceded IBD diagnosis. 62 pts (28 UC, 34 CD) complaining of articular symptoms at the time of the interview, were investigated by the rheumatologist: arthropathy was axial in 52%, oligoarticular in 16% and polyarticular in 23%. Oligoarthritis commonly involved the lower limbs and was more commonly associated with UC. The mean number of small joints involved was significantly higher in CD than in UC pts (9.9+/-8.2 vs. 5.6+/-4.3; p<0.01). Bone scintigraphy was abnormal in 70% of pts.

CONCLUSIONS

Prevalence of self-reported articular symptoms in IBD patients exceeds 40% with 9.5% incidence during 1-year follow up. Symptoms predict entheropatic involvement of the locomotor system.

The early disease stage in axial spondylarthritis: results from the German Spondyloarthritis Inception Cohort

OBJECTIVE

Ankylosing spondylitis (AS) is diagnosed late, because radiographs of the sacroiliac joints often do not show definite sacroiliitis at the time of disease onset. The aim of this study was to investigate whether patients without definite radiographically defined sacroiliitis, referred to as nonradiographic axial spondylarthritis (SpA), are different from patients with AS with regard to clinical manifestations and disease activity measures. Moreover, we sought to identify determinants of the development of radiographic sacroiliitis.

METHODS

In a cross-sectional analysis of 462 patients, we compared 226 patients with nonradiographic axial SpA (symptom duration < or =5 years) and 236 patients with AS (symptom duration < or =10 years) who are participants in the German Spondyloarthritis Inception Cohort. Radiographs of the sacroiliac joints and the spine were assessed by 2 readers in a blinded manner. Logistic regression analysis was applied to identify parameters associated with structural damage.

RESULTS

The 2 groups did not differ in the frequency of HLA-B27 positivity, inflammatory back pain, arthritis, enthesitis, and uveitis and had similar levels of disease activity, using measures such as the Bath Ankylosing Spondylitis Disease Activity Index. In both groups, HLA-B27 positivity determined the age at disease onset. Male sex (adjusted odds ratio [OR] 2.38, 95% confidence interval [95% CI] 1.19-4.73 [P = 0.014]) and an elevated C-reactive protein (CRP) level (adjusted OR 1.85, 95% CI 0.96-3.56 [P = 0.066]) were associated with radiographic sacroiliitis. In patients with AS, male sex and an elevated CRP level were also associated with the presence of syndesmophytes.

CONCLUSION

Clinical manifestations and disease activity measures are highly comparable between patients with early nonradiographic axial SpA and those with early AS, suggesting that these 2 entities are part of the same disease. Male sex and an elevated CRP level are associated with structural damage on radiographs, whereas HLA-B27 positivity determines the age at disease onset.

Intraocular inflammation: its causes and investigations

Intraocular inflammation, or uveitis, incorporates a diverse group of infectious and immune-mediated disorders. In addition, some conditions masquerade as uveitis. However, classifying uveitis according to anatomic location in adult and pediatric populations, and appreciating the effect of immune status and regional differences, refines the list of potential causes. In this way, a select few investigations can be performed, rather than a nondirected battery of tests.