Sacroiliac joint beyond sacroiliitis-further insights and old concepts on magnetic resonance imaging.

The sacroiliac joint (SIJ) is an amphiarthrosis composed of a posterior syndesmosis and an anterior cartilaginous portion, with limited yet present mobility. Its main function is to transmit the load from the axial skeleton to the lower limbs and vice-versa; it is susceptible to early mechanical and degenerative changes which are much more common than inflammatory sacroiliitis. Magnetic resonance imaging (MRI) has increasingly been used to evaluate these changes, and while subchondral bone marrow edema (BME) is a common finding related to both, care must be taken when applying the ASAS research MRI definition for sacroiliitis without considering lesion BME topography, size and depth, concomitant structural damage and, of course, the clinical picture. In this review, we will discuss the anatomy and biomechanics of the SIJ, the noninflammatory causes of SIJ subchondral BME, and how these concepts combined can be used to increase our diagnostic confidence.

A study of MRI-based radiomics biomarkers for sacroiliitis and spondyloarthritis.

PURPOSE: To evaluate the performance of texture-based biomarkers by radiomic analysis using magnetic resonance imaging (MRI) of patients with sacroiliitis secondary to spondyloarthritis (SpA). RELEVANCE: The determination of sacroiliac joints inflammatory activity supports the drug management in these diseases. METHODS: Sacroiliac joints (SIJ) MRI examinations of 47 patients were evaluated. Thirty-seven patients had SpA diagnoses (27 axial SpA and ten peripheral SpA) which was established previously after clinical and laboratory follow-up. To perform the analysis, the SIJ MRI was first segmented and warped. Second, radiomics biomarkers were extracted from the warped MRI images for associative analysis with sacroiliitis and the SpA subtypes. Finally, statistical and machine learning methods were applied to assess the associations of the radiomics texture-based biomarkers with clinical outcomes. RESULTS: All diagnostic performances obtained with individual or combined biomarkers reached areas under the receiver operating characteristic curves ≥ 0.80 regarding SpA related sacroiliitis and and SpA subtypes classification. Radiomics texture-based analysis showed significant differences between the positive and negative SpA groups and differentiated the axial and peripheral subtypes (P < 0.001). In addition, the radiomics analysis was also able to correctly identify the disease even in the absence of active inflammation. CONCLUSION: We concluded that the application of the radiomic approach constitutes a potential noninvasive tool to aid the diagnosis of sacroiliitis and for SpA subclassifications based on MRI of sacroiliac joints.

IL-7 is a Key Driver Cytokine in Spondyloarthritis?

The rationale for a type 17 signature in the pathogenesis of spondyloarthritis (SpA) has been increasing and being ratified in studies recently. IL-7 is a cytokine whose ability to stimulate IL-17 production in both innate and adaptive immunity cells has made it a promising target not only for a better understanding of the disease as well as an important potential therapeutic target in patients with SpA.

Topographic MRI evaluation of the sacroiliac joints in patients with axial spondyloarthritis.

OBJECTIVE: To evaluate the imaging features of spondyloarthritis in magnetic resonance imaging (MRI) of the sacroiliac (SI) joint and topography (in thirds) and affected margin, considering that this issue is rarely addressed in the literature. METHODS: A cross-sectional study evaluating MRI (1.5T) of SI in 16 patients with axial spondyloarthritis, for the presence of acute (subchondral bone edema, enthesitis, synovitis and capsulitis) and chronic (erosions, subchondral bone sclerosis, bony bridges, and fatty infiltration) changes, performed by two blinded radiologists. MRI findings were correlated with clinical data, including age, duration of disease, medications, HLA-B27, BASDAI, ASDAS-ESR and ASDAS-CRP, BASMI, BASFI, and mSASSS. RESULTS: Bone edema pattern and erosions were predominant in the upper third of SI (p=0.050 and p=0.0014, respectively). There was a correlation between disease duration and structural changes by affected third (p=0.028-0.037), as well as between the presence of bone bridges with BASMI (p=0.028) and mSASSS (p=0.014). Patients with osteitis in the lower third showed higher values for ASDAS (ESR: p=0.011 and PCR: p=0.017). CONCLUSION: Chronic inflammatory changes and the pattern of bone edema predominated in the upper third of SI, but a simultaneous involvement of middle or lower thirds of the joint was also noted. The location of involvement in the upper third of SI is insufficient to differentiate between degeneration and inflammation.

Topographic MRI evaluation of the sacroiliac joints in patients with axial spondyloarthritis / Avaliação topográfica das articulações sacroilíacas por ressonância magnética em pacientes com espondiloartrite axial

Abstract Objective: To evaluate the imaging features of spondyloarthritis in magnetic resonance imaging (MRI) of the sacroiliac (SI) joint and topography (in thirds) and affected margin, considering that this issue is rarely addressed in the literature. Methods: A cross-sectional study evaluating MRI (1.5 T) of SI in 16 patients with axial spondyloarthritis, for the presence of acute (subchondral bone edema, enthesitis, synovitis and capsulitis) and chronic (erosions, subchondral bone sclerosis, bony bridges, and fatty infiltration) changes, performed by two blinded radiologists. MRI findings were correlated with clinical data, including age, duration of disease, medications, HLA-B27, BASDAI, ASDAS-ESR and ASDAS-CRP, BASMI, BASFI, and mSASSS. Results: Bone edema pattern and erosions were predominant in the upper third of SI (p = 0.050 and p = 0.0014, respectively). There was a correlation between disease duration and structural changes by affected third (p = 0.028-0.037), as well as between the presence of bone bridges with BASMI (p = 0.028) and mSASSS (p = 0.014). Patients with osteitis in the lower third showed higher values for ASDAS (ESR: p = 0.011 and PCR: p = 0.017). Conclusion: Chronic inflammatory changes and the pattern of bone edema predominated in the upper third of SI, but a simultaneous involvement of middle or lower thirds of the joint was also noted. The location of involvement in the upper third of SI is insufficient to differentiate between degeneration and inflammation.

Resumo Objetivo: Avaliar as características de imagem das espondiloartrites na ressonância magnética (RM) das articulações sacroilíacas (SI) quanto à topografia (em terços) e margem acometida, uma vez que esse aspecto é pouco abordado na literatura. Métodos: Estudo transversal com avaliação por RM (1,5 T) das SI em 16 pacientes com diagnóstico de espondiloartrite axial quanto à presença de alterações agudas (edema ósseo subcondral, entesite, sinovite e capsulite) e crônicas (erosões, esclerose óssea subcondral, ponte óssea e substituição gordurosa), feita por dois radiologistas, cegos para os dados clínicos. Os achados da RM foram correlacionados com dados clínicos, incluindo idade, tempo de doença, medicações, HLA-B27, BASDAI, ASDAS-VHS e ASDAS-PCR, BASMI, BASFI e mSASSS. Resultados: Padrão de edema ósseo e erosões apresentaram predomínio no terço superior das SI (p = 0,050 e p = 0,0014, respectivamente). Houve correlação entre o tempo de doença e alterações estruturais por terço acometido (p = 0,028-0,037), bem como a presença de pontes ósseas com o BASMI (p = 0,028) e o mSASSS (p = 0,014). Pacientes com osteíte no terço inferior apresentaram maiores valores de ASDAS (VHS: p = 0,011 e PCR: p = 0,017). Conclusão: As alterações inflamatórias crônicas e o padrão de edema ósseo predominaram no terço superior das SI, mas também havia acometimento concomitante dos terços médio ou inferior da articulação. A localização do acometimento no terço superior das SI se mostra insuficiente para a diferenciação entre degeneração e inflamação.

MRI assessment of bone marrow oedema in the sacroiliac joints of patients with spondyloarthritis: is the SPAIR T2w technique comparable to STIR?

OBJECTIVE: To compare short tau inversion-recovery (STIR) with another fat saturation method in the assessment of sacroiliac joint inflammation. METHODS: This prospective cross-sectional study comprised 76 spondyloarthritis (SpA) patients who underwent magnetic resonance imaging of the sacroiliac joints in a 1.5-T scanner, using STIR, spectral attenuated inversion recovery (SPAIR) T2w and spectral presaturation with inversion recovery (SPIR) T1w post-contrast sequences. Two independent readers (R1 and R2) assessed the images using the Spondyloarthritis Research Consortium of Canada (SPARCC) score. We assessed agreement of the SPARCC scores for SPAIR T2w and STIR with that for T1 SPIR post-contrast (reference standard) using the St. Laurent coefficient. We evaluated each sequence using the concordance correlation coefficient (CCC). RESULTS: We observed a strong agreement between STIR and SPAIR T2w sequences. Lin's CCC was 0.94 for R1 and 0.84 for R2 for STIR and 0.94 for R1 and 0.84 for R2 for SPAIR. The interobserver evaluation revealed a good CCC of 0.79 for SPAIR and 0.78 for STIR. CONCLUSION: STIR technique and SPAIR T2w sequence showed high agreement in the evaluation of sacroiliac joint subchondral bone marrow oedema in patients with SpA. SPAIR T2w may be an alternative to the STIR sequence for this purpose. KEY POINTS: • There are no studies evaluating which fat saturation technique should be used. • SPAIR T2w may be an alternative to STIR for sacroiliac joint evaluation. • The study will lead to changes in guidelines for spondyloarthritis.

An analysis of 372 patients with anterior uveitis in a large Ibero-American cohort of spondyloarthritis: the RESPONDIA Group.

OBJECTIVES: This study analysed the frequency of anterior uveitis (AU) and its correlations in a large cohort of patients with spondyloarthritis (SpA). METHODS: A common protocol of investigation was prospectively applied to 2012 SpA patients in 85 centres from 10 Ibero-American countries. Clinical and demographic variables and disease indexes were investigated. Categorical variables were compared by χ2 and Fisher's exact test, and continuous variables were compared by ANOVA or Kruskal-Wallis test. A value of p<0.05 was considered significant. RESULTS: AU was referred by 372 SpA patients (18.5%). AU was statistically associated with inflammatory low back pain (p<0.001), radiographic sacroiliitis (p<0.001), enthesopathies (p=0.004), urethritis/acute diarrhoea (p<0.001), balanitis (p=0.002), hip involvement (p=0.002), HLA-B27 (p=0.003), and higher C-reactive protein (p=0.001), whilst it was negatively associated with the number of painful (p=0.03) and swollen (p=0.005) peripheral joints, psoriatic arthritis (p<0.001), psoriasis (p<0.001), nail involvement (p<0.001), and dactilitis (p=0.062; trend). No association with gender, race, and indices (disease activity, functionality and quality of life) was observed. Logistic regression showed that ankylosing spondylitis (p=0.001) and HLA-B27 (p=0.083; trend) was significantly associated with AU, while extra-articular manifestations (predominantly psoriasis) were negatively associated (p=0.016). CONCLUSIONS: Anterior uveitis is a frequent extra-articular manifestation in SpA patients, positively associated with axial involvement and HLA-B27 and negatively associated with peripheral involvement and psoriatic arthritis.

Demographic, clinical, laboratory and treatment characteristics of spondyloarthritis patients with and without acute anterior uveitis.

CONTEXT AND OBJECTIVE: Acute anterior uveitis is a common extra-articular manifestation in spondyloarthritis patients. The aim of this study was to compare demographic, clinical, laboratory and treatment data among spondyloarthritis patients with and without acute anterior uveitis. DESIGN AND SETTING: This was a cross-sectional analytical study at the Rheumatology Outpatient Clinic of the Evangelical University Hospital, Curitiba, Brazil. METHODS: Spondyloarthritis patients with without acute anterior uveitis were compared regarding demographic data, spondyloarthritis subtype, peripheral arthritis, enthesitis, disease activity, functional index, physical examination, radiological involvement, HLA-B27 and treatment. RESULTS: Presence of acute anterior uveitis was not found to have any relationship with functional index, degree of radiological involvement, peripheral arthritis or enthesitis. Acute anterior uveitis showed a negative association with skin manifestations (P = 0.04) and a trend towards higher disease activity (P = 0.06). CONCLUSION: In the study sample, it could not be shown that AAU had any association with the functional and radiological prognoses. The patients with spondyloarthritis with and without acute anterior uveitis did not differ clinically except for a higher proportion of ankylosing spondylitis and smaller presence of skin involvement in those with uveitis.

Ethnic influence in clinical and functional measures of Brazilian patients with spondyloarthritis.

OBJECTIVE: Spondyloarthritides (SpA) can present different disease spectra according to ethnic background. The Brazilian Registry of Spondyloarthritis (RBE) is a nationwide registry that comprises a large databank on clinical, functional, and treatment data on Brazilian patients with SpA. The aim of our study was to analyze the influence of ethnic background in SpA disease patterns in a large series of Brazilian patients. METHODS: A common protocol of investigation was prospectively applied to 1318 SpA patients in 29 centers distributed through the main geographical regions in Brazil. The group comprised whites (65%), African Brazilians (31.3%), and people of mixed origins (3.7%). Clinical and demographic variables and various disease index scores were compiled. Ankylosing spondylitis (AS) was the most frequent disease in the group (65.1%); others were psoriatic arthritis (18.3%), undifferentiated SpA (6.8%), enteropathic arthritis (3.7%), and reactive arthritis (3.4%). RESULTS: White patients were significantly associated with psoriasis (p = 0.002), positive HLA-B27 (p = 0.014), and use of corticosteroids (p < 0.0001). Hip involvement (p = 0.02), axial inflammatory pain (p = 0.04), and radiographic sacroiliitis (p = 0.025) were associated with African Brazilian descent. Sex distribution, family history, and presence of peripheral arthritis, uveitis, dactylitis, urethritis, and inflammatory bowel disease were similar in the 3 groups, as well as age at disease onset, time from first symptom until diagnosis, and use of anti-tumor necrosis factor-α agents (p > 0.05). Schober test and thoracic expansion were similar in the 3 groups, whereas African Brazilians had higher Maastricht Ankylosing Spondylitis Enthesitis Scores (p = 0.005) and decreased lateral lumbar flexion (p = 0.003), while whites had a higher occiput-to-wall distance (p = 0.02). African Brazilians reported a worse patient global assessment of disease (p = 0.011). Other index scores and prevalence of work incapacity were similar in the 3 groups, although African Brazilians had worse performance in the Ankylosing Spondylitis Quality of Life questionnaire (p < 0.001). CONCLUSION: Ethnic background is associated with distinct clinical aspects of SpA in Brazilian patients. African Brazilian patients with SpA have a poorer quality of life and report worse disease compared to whites.

Demographic, clinical, laboratory and treatment characteristics of spondyloarthritis patients with and without acute anterior uveitis / Características demográficas, clínicas, laboratoriais e de tratamento entre pacientes com espondiloartrite com e sem uveíte anterior aguda

CONTEXT AND OBJECTIVE: Acute anterior uveitis is a common extra-articular manifestation in spondyloarthritis patients. The aim of this study was to compare demographic, clinical, laboratory and treatment data among spondyloarthritis patients with and without acute anterior uveitis. DESIGN AND SETTING: This was a cross-sectional analytical study at the Rheumatology Outpatient Clinic of the Evangelical University Hospital, Curitiba, Brazil. METHODS: Spondyloarthritis patients with without acute anterior uveitis were compared regarding demographic data, spondyloarthritis subtype, peripheral arthritis, enthesitis, disease activity, functional index, physical examination, radiological involvement, HLA-B27 and treatment. RESULTS: Presence of acute anterior uveitis was not found to have any relationship with functional index, degree of radiological involvement, peripheral arthritis or enthesitis. Acute anterior uveitis showed a negative association with skin manifestations (P = 0.04) and a trend towards higher disease activity (P = 0.06). CONCLUSION: In the study sample, it could not be shown that AAU had any association with the functional and radiological prognoses. The patients with spondyloarthritis with and without acute anterior uveitis did not differ clinically except for a higher proportion of ankylosing spondylitis and smaller presence of skin involvement in those with uveitis.

CONTEXTO E OBJETIVO: Uveíte anterior aguda é uma manifestação extra-articular comum em pacientes com espondiloartrite. O objetivo deste estudo foi comparar achados demográficos, clínicos, laboratoriais e de tratamento em pacientes com espondiloartrite com e sem uveíte anterior aguda. TIPO DE ESTUDO E LOCAL: Este é um estudo transversal analítico realizado no Ambulatório de Reumatologia do Hospital Universitário Evangélico de Curitiba, Brasil. MÉTODOS: Pacientes com espondiloartrite com e sem uveíte anterior aguda foram comparados quanto a dados demográficos, subtipo de espondiloartrite, artrite periférica, entesite, atividade da doença, índice funcional, exame físico, envolvimento radiológico, HLA-B27 e tratamento. RESULTADOS: Não se encontrou associação entre presença de uveíte anterior aguda e índice funcional, grau de envolvimento radiológico, artrite periférica e entesite. Encontrou-se uma associação negativa de uveíte anterior aguda com manifestações de pele (P = 0,04) e uma tendência para maior atividade de doença (P = 0,06). CONCLUSÃO: Na amostra estudada, não foi possível demonstrar associação entre uveíte anterior aguda no prognóstico funcional e radiológico. Pacientes com espondiloartrite com e sem uveíte anterior aguda não diferem clinicamente exceto por uma maior proporção de espondilite anquilosante e uma presença menor de envolvimento cutâneo naqueles com uveíte.

Differential features between primary ankylosing spondylitis and spondylitis associated with psoriasis and inflammatory bowel disease.

OBJECTIVE: To describe differential characteristics of axial involvement in ankylosing spondylitis (AS) as compared with that seen in psoriatic arthritis (PsA) and inflammatory bowel disease (IBD) in a cohort of Ibero-American patients. METHODS: This study included 2044 consecutive patients with spondyloarthritis (SpA; ESSG criteria). Demographic, clinical, disease activity, functional ability, quality of life, work status, radiologic, and therapeutic data were evaluated and collected by RESPONDIA members from different Ibero-American countries between June and December 2006. Patients selected for analysis met modified New York criteria (mNY) for AS. RESULTS: A total of 1264 patients met the New York criteria for AS: 1072 had primary AS, 147 had psoriatic, and 45 had IBD-associated spondylitis. Median disease duration was comparable among the 3 patient groups. Patients with primary AS were significantly younger (p = 0.01) and presented a higher frequency of males (p = 0.01) than the other 2 groups. Axial manifestations such as inflammatory back pain and sacroiliac pain were significantly more frequent in patients with primary AS (p = 0.05) versus other groups, whereas frequency of dactylitis, enthesitis, and peripheral arthritis was more common in patients with psoriatic spondylitis (p = 0.05). Spinal mobility was significantly more limited in patients with primary AS versus the other 2 groups (p = 0.0001). Radiologic changes according to BASRI total score were equally significant in primary AS. Disease activity (BASDAI), functional ability (BASFI), and quality of life (ASQoL) scores were comparable in the 3 groups. CONCLUSION: Patients with primary AS had more severe axial involvement than those with spondylitis associated with psoriasis or IBD. Functional capacity, disease activity, and quality of life were comparable among the groups studied.

Current controversies in spondyloarthritis: SPARTAN.

The Spondyloarthritis Research and Therapy Network (SPARTAN), founded in 2003 to promote research, education, and treatment of ankylosing spondylitis (AS) and related forms of spondyloarthritis (SpA), held its 7th Annual Research and Education Meeting in July 2009 in Houston, Texas. Current controversies in SpA discussed during the meeting included an update on the epidemiology of AS, axial SpA, and inflammatory back pain; the adequacy of the mSASS to assess radiographic involvement; the helpfulness of magnetic resonance imaging in assessing disease progression; the reliability of metrology in assessing damage; and whether biologic agents alter the course of AS. Presentations also were made on psoriasis in the SCID mouse model; the challenges and opportunities of SpA in China; a discussion of the special needs in managing SpA in Ibero-America, and the SPARK Survey in Europe and North America.

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.

Spondylitis in a humpback whale (Megaptera novaeangliae) from the southeast Pacific.

A 7.25 m long male humpback whale (Megaptera novaeangliae) with spondylitis was found beached on August 13, 1994 at Ancon, Ecuador (2 degrees 23' S, 80 degrees 47' W). The condition involved at least 11 vertebrae, 7 lumbar (L4 to L11) and 4 caudal (Ca1 to Ca4). Partial fusion of vertebrae was observed as a result of intervertebral bony proliferation, likely impeding full motion. The relatively young age of this specimen and the severity of the deformities suggest an infectious, rather than degenerative, process. The gross findings are most consistent with some type of spondyloarthritis. Although this condition has previously been identified in a number of cetacean species, the pathogenesis, population impact and ecologic implications have not been fully assessed. This is the third case described for humpback whales and the first for a humpback whale from the SE Pacific.