Colchicine-resistant sacroiliitis in a Japanese patient with familial Mediterranean fever.

The articular involvement in patients with familial Mediterranean fever (FMF) represents a clinical characteristic of acute monoarthritis with pain and hydrarthrosis, which always resolves spontaneously. Colchicine prevents painful arthritis attacks in most FMF cases. Spondyloarthritis is rarely associated with Japanese patients with FMF. Here, we report a Japanese male patient with FMF-related axial joint involvement. A 43-year-old male Japanese patient who presented with recurrent febrile episodes with hip joint and back pain was referred to our hospital. He carried heterozygous variants in exon 2 (L110P/E148Q) of the MEFV gene. FMF was suspected, and oral administration of colchicine (1 mg/day) was initiated. Colchicine treatment improved his febrile attack with hip joint pain. He was diagnosed as having FMF based on the Tel-Hashomer diagnostic criteria for FMF since he fulfilled one major criterion (repeated febrile attack accompanied by hip joint pain) and one minor criterion (improvement with colchicine treatment). Although the human leucocyte antigen-B27 allele was not detected, sacroiliitis-related symptoms progressed despite the ongoing colchicine treatment. Salazosulphapyridine and methotrexate were administered in addition to colchicine; however, these treatments were not effective. Canakinumab treatment successfully resolved this unique aspect of sacroiliitis, and the patient was finally diagnosed with FMF-associated axial joint involvement.

C1-C2 subluxation in enthesitis-related arthritis: two case reports and literature review of ten cases.

BACKGROUND: C1-C2 subluxation is a rare complication of enthesitis-related arthritis (ERA). If left untreated, it may lead to functional impairment or cervical spinal cord compression. This study aims to highlight key points regarding the management of C1-C2 subluxation in ERA. CASE PRESENTATION: We present two cases of C1-C2 subluxation: an 8-year-old boy with ERA and 16-year-old boy with ERA with bilateral sacroiliitis. Ten cases of ERA in the literature were reviewed. The diagnosis of C1-C2 subluxation is mostly based on radiographs and cervical spine computed tomography. All patients were treated with non-steroidal anti-inflammatory drugs. Six ERA patients were treated surgically for cervical fusion. Most ERA patients with sacroiliitis had cervical collar protection. Neurologic abnormalities after treatment were not reported. Despite the use of cervical collar, cervical fusion and persisting ankylosis were found in two ERA patients with sacroiliitis without surgical treatment. CONCLUSIONS: Cervical spine protection and ruling out spinal cord compression should be prioritized, in addition to controlling the underlying inflammation in ERA. Cervical halter traction may be applied after severe cervical inflammation is excluded. To reduce the risk of complications, early recognition and appropriate treatments of C1-C2 subluxation in ERA are essential.

Role of Patrick-FABER test in detecting sacroiliitis and diagnosing spondyloarthritis in subjects with low back pain.

OBJECTIVES: To evaluate sensitivity, specificity, and predictive value of Patrick-FABER test in assessing magnetic resonance imaging (MRI) sacroiliitis and addressing the diagnosis of spondyloarthritis (SpA) in subjects with low back pain (LBP). METHODS: Subjects with LBP were consecutively enrolled. The assessors were blinded to patients' clinical, laboratory, or imaging data. All subjects underwent sacroiliac joint MRI to detect presence of sacroiliac oedema or structural changes. RESULTS: One hundred and ten subjects were included in the study [males (61.8%); median age of 45 (21-69) years; LBP duration of 78 (3-240) months]. Patrick-FABER test sign's sensitivity was 76.2% (95% CI: 60.5-87.9%), specificity was 66.2% (95% CI: 53.6-77.2%), positive predictive value (PPV) was 58.1% (95% CI: 44.1-71.3%) and negative predictive value (NPV) was 81.8% (95% CI: 69.1-90.9%) for the diagnosis of sacroiliitis, with an overall diagnostic accuracy of 70%. At the univariate and multivariate analysis, Patrick-FABER test sign was associated with inflammatory lesions of sacroiliitis at MRI and SpA diagnosis. Univariate and multivariate analysis showed an association between smoking status (p=0.01), sacroiliitis, and SpA diagnosis. The odds of having sacroiliitis was 2.7 higher in smokers (OR: 2.7; 95% CI: 1.1-7) as compared to non-smokers and 6.3 higher in those with a positive Patrick-FABER test sign (OR: 6.3; 95%CI: 2.5-15.6) as compared to those with a negative sign. CONCLUSIONS: Our study shows that Patrick-FABER test positivity could represent a useful clinical test for addressing the use of sacroiliac joints MRI and SpA diagnosis in subjects with LBP. Further, smoking habit could represent an associate anamnestic element for addressing the use of sacroiliac MRI.

The Juvenile Spondyloarthritis Disease Activity Index Is a Useful Tool in Enthesitis-Related Arthritis: Real-Life Data.

OBJECTIVE: To compare enthesitis-related arthritis (ERA) patients with active and inactive disease at 6 months and define baseline predictors for disease inactivity. In addition, to evaluate the demographic, clinical, and laboratory characteristics of ERA patients and to identify the real-life impact of the Juvenile Spondyloarthritis Disease Activity Index (JSpADA) in predicting active disease in ERA. METHODS: This medical record review study was conducted with 56 patients who were diagnosed with ERA at our clinic between June 2009 and June 2022. Demographic and clinical characteristics, laboratory parameters, treatment, and JSpADA were recorded. RESULTS: The patients were divided into 2 groups as active (n = 34) and inactive (n = 22) according to their disease activity at month six. Sex, age at diagnosis, number and type of affected joints, and presence of sacroiliitis were similar in both groups. There was no difference in baseline erythrocyte sedimentation rate, but there was a significant difference in erythrocyte sedimentation rate at the third month ( p = 0.52 and p = 0.018, respectively). The median JSpADA values at disease onset were 3.5 (interquartile range [IQR], 3.0-4.5) and 3.3 (IQR, 2.5-4.0) in the active and inactive groups, respectively ( p = 0.27). At the third month, the median JSpADA values were 1.5 (IQR, 0.5-2.1) in the active group and 0.5 (IQR, 0.5-1.5) in the inactive group ( p = 0.037). The cutoff value for JSpADA at the third month for active disease persisting at the month six was determined as 1 point (area under the curve, 0.662 ± 0.06; p = 0.042; 95% confidence interval, 0.51-0.80) by receiver operating characteristic curve analysis. CONCLUSION: In ERA patients, a persistently high JSpADA value at follow-up is a predictive factor for active disease at the sixth month.

Data-Driven Magnetic Resonance Imaging Definitions for Active and Structural Sacroiliac Joint Lesions in Juvenile Spondyloarthritis Typical of Axial Disease: A Cross-Sectional International Study.

OBJECTIVE: We aimed to determine quantitative sacroiliac (SI) joint magnetic resonance imaging (MRI) cutoffs for active and structural lesions that will be incorporated as imaging domains in classification criteria of axial disease in juvenile spondyloarthritis (SpA). METHODS: MRI scans from an international cross-section of juvenile SpA patients were reviewed by 6 musculoskeletal imaging experts blinded to clinical details. Raters globally assessed the presence/absence of lesions typical of axial SpA and performed SI joint quadrant- or joint-based scoring. Sensitivity and specificity of lesion cutoffs were calculated using a rater majority (≥4 of 6 raters) on a global assessment of the presence/absence of active or structural lesions typical of axial SpA with high confidence as the reference standard. Cutoffs were validated in an independent cohort. RESULTS: Imaging from 243 subjects, 61% male, median age 14.9 years, had sequences available for detailed MRI scoring. Optimal cutoffs for defining lesions typical of axial disease in juvenile SpA were: 1) inflammatory lesion: bone marrow edema in ≥3 SI joint quadrants across all SI joint MRI slices (sensitivity 98.6%, specificity 96.5%); 2) structural lesions: erosion in ≥3 quadrants or sclerosis or fat lesion in ≥2 SI joint quadrants or backfill or ankylosis in ≥2 joint halves across all SI joint MRI slices (sensitivity 98.6%, specificity 95.5%). Sensitivity and specificity of the optimal cutoffs in the validation cohort were excellent. CONCLUSION: We propose data-driven cutoffs for active inflammatory and structural lesions on MRI typical of axial disease in juvenile SpA that have high specificity and sensitivity using central imaging global assessment as the reference standard and excellent reliability.

Case of reactive sacroiliitis possibly induced by an mRNA coronavirus disease vaccine.

A woman in her 30s received a second dose, first booster, Corminaty vaccine against the SARS-CoV-2. Three days later, the patient developed unilateral sacroiliitis. A pelvic scan revealed inflammatory joint edges, bone erosion and a heterogeneous mass of 2.5 cm in the psoas muscle. Joint puncture revealed no microcrystalline deposits, but bone marrow cells, erythroblast were identified. The standard bacterial cultures and culture for mycobacteria were negative. HLA B27 was negative, and no seroconversion was identified for HIV, Epstein-Barr virus, cytomegalovirus, chlamydia or Quantiferon. Two months later, the sacroiliitis resolved.The aetiologic approach of this erosive unilateral acute sacroiliitis in a person naïve to rheumatologic pathology was negative for inflammatory or infectious sacroiliitis. Arthralgias after vaccination are expected. Arthritis is less common, and acute sacroiliitis has not yet been described. Acute sacroiliitis may be considered a reactive sacroiliitis to the anti-COVID-19 mRNA vaccine.

Update on Juvenile Spondyloarthritis.

Spondyloarthritis (SpA) is a blanket term encompassing entities such as enthesitis-related arthritis, nonradiographic axial SpA, and ankylosing spondylitis. These diseases share many clinical features, including a predilection for inflammation of the entheses and the sacroiliac joints. The nomenclature is based on the evolution of the classification of the disease and the age of the patient. SpA has a prevalence of approximately 1% of the population of the United States, with 10% to 20% of patients experiencing the onset during childhood. Children with onset of arthritis before age 16 years are classified as having juvenile idiopathic arthritis. Children with enthesitis and/or sacroiliitis are further classified as belonging to the enthesitis-related arthritis subtype of juvenile idiopathic arthritis. The initial manifestations can be subtle and will usually include a peripheral pattern of arthritis and enthesitis. It may take several years for axial disease to develop in children. Except for an association with the human leukocyte antigen (HLA-B27) serotype, there are no laboratory markers for the disease, and the radiographic findings are often negative. A careful clinical evaluation for evidence of inflammation in the entheses and the joints and a search for comorbidities are required. Magnetic resonance imaging facilitates the early detection of sacroiliitis, an important feature that may be clinically silent. Because recent studies indicate that earlier introduction of therapy can help achieve better outcomes, rapid identification and treatment of children with SpA is essential.

Post-COVID-19 Arthritis and Sacroiliitis: Natural History with Longitudinal Magnetic Resonance Imaging Study in Two Cases and Review of the Literature.

Severe acute respiratory coronavirus-2 syndrome (SARS-CoV-2) is a well-known pandemic infectious disease caused by an RNA virus belonging to the coronaviridae family. The most important involvement during the acute phase of infection concerns the respiratory tract and may be fatal. However, COVID-19 may become a systemic disease with a wide spectrum of manifestations. Herein, we report the natural history of sacroiliac inflammatory involvement in two females who developed COVID-19 infection with mild flu-like symptoms. After the infection they reported inflammatory back pain, with magnetic resonance imaging (MRI) studies showing typical aspects of sacroiliitis. Symptoms improved with NSAIDs therapy over the following months while MRI remained positive. A literature review was performed on this emerging topic. To our knowledge, this is the first MRI longitudinal study of post-COVID-19 sacroiliitis with almost one year of follow-up. Predisposing factors for the development of articular involvement are unclear but a long-lasting persistence of the virus, demonstrated by nasopharyngeal swab, may enhance the probability of altering the immune system in a favourable background.

Sacroiliitis in children and adolescents with familial Mediterranean fever.

BACKGROUND: Familial Mediterranean fever (FMF) is an autoinflammatory disease characterized by recurrent episodes of fever and serositis. Sacroiliitis can be observed in some FMF patients. This study aimed to compare the demographic, clinical, and laboratory findings, and treatment in children with FMF and sacroiliitis, and children with juvenile spondyloarthropathy (JSpA). METHODS: In total, 1687 pediatric FMF patients that were followed-up between May 2010 and June 2020 were evaluated retrospectively. Among them, those with sacroiliitis (n = 63) were included in the study and compared to patients with JSpA (n = 102). RESULTS: The study included 63 FMF patients with sacroiliitis (38 males [60.3%] and 25 females [39.7%]) with a mean age of 15.2 ± 4.1 years. Mean age at symptom onset was 7.2 ± 5.05 years and mean age at diagnosis was 9.74 ± 4.67 years. The most common mutation in the FMF patients was M694V/M694V (n = 22). Patients were diagnosed with sacroiliitis with a mean of 12 months (range: 6-36 months) after the diagnosis of FMF. Among the FMF patients, 28 (44.4%) had enthesitis, 23 (36.5%) had heel pain, and 11 (17.4%) had low back pain. The study also included 102 JSpA patients (90 males [88.2%] and 12 females [11.8%]). Mean age of patients with JSpA was 16.1 ± 2.8 years. As compared to 102 JSpA patients, patients with FMF and sacroiliitis had higher acute phase reactants, whereas HLA-B27 positivity rate was lower. In addition, axial involvement rate was higher in the JSpA patients. CONCLUSION: Sacroiliitis is a common co-morbidity in FMF patients. The phenotypic features of these patients are different from patients with JSpA.

Atypical Unilateral Sacroiliitis Secondary to Mechanical Stress Injury.

We report for the first time a case of atypical unilateral sacroiliitis secondary to mechanical stress injury. Unilateral sacroiliitis can be caused by a variety of etiologies. The first diagnosis to rule out is infection since it requires urgent treatment to avoid its serious consequences. Spondyloarthritis can be manifested by unilateral sacroiliitis in its early stage. Sacral fractures should always be looked for on the imaging modalities performed. In our case, no signs of infection or systemic disease were found. No fracture was seen on the imaging examinations and we had negative cultures on the computed tomography-guided biopsy realized. A history of mechanical stress was the only clue found suggesting the diagnosis of a probable stress related sacroiliitis. A thorough review of the literature will be provided stating the different causes of sacroiliitis described till now, with discussion of this new reported entity.

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.

MRI of sacroiliac joints for the diagnosis of axial SpA: prevalence of inflammatory and structural lesions in nulliparous, early postpartum and late postpartum women.

OBJECTIVES: To determine the prevalence of bone marrow oedema (BME) at the sacroiliac joint (SIJ) in early postpartum (EPP), nulliparous (NP) and late postpartum (LPP) women, and to identify factors associated with BME presence at the SIJ. METHODS: Three groups were obtained: NP (never given birth), EPP (given birth within 12 months) and LPP (given birth more than 24 months). The primary outcome was the presence of BME and/or structural lesions (erosions, osteophytes, ankylosis and sclerosis) at the SIJ MRI. RESULTS: BME prevalence was greater among EPP (33%) than NP (14%, p=0.001), but was not different to LPP (21%, p=0.071). The Assessment of SpondyloArthritis international Society (ASAS) MRI criteria for sacroiliitis were positive in 75%, 71% and 80%, respectively, of EPP, NP and LPP women with BME. EPP (38%) had similar prevalence of sclerosis than LPP (28%, p=0.135), but greater than NP (18%, p=0.001). Lastly, EPP (28%) had similar prevalence of osteophytes than LPP (42%) and NP (27%), although there was a difference between LPP and NP (p=0.006). CONCLUSIONS: EPP have higher BME prevalence at the SIJ than NP, EPP tend to have higher BME prevalence compared with LPP and BME presence decreases with time from delivery. Three-quarters of women with BME at the SIJ had a positive ASAS MRI criteria for sacroiliitis, indicating that BME presence as the main criterion for a positive diagnosis can lead to false-positive results. SIJ MRIs should not be interpreted in isolation, since age, time from delivery and other factors may outweigh the pertinence of MRI findings. Trial registration number NCT02956824.

Sacroiliitis associated with familial Mediterranean fever in childhood: a case series and review of literature.

BACKGROUND AND OBJECTIVES: Familial Mediterranean fever (FMF) is an autosomal-recessive auto-inflammatory disorder characterized by recurrent episodes of fever with serositis. Sacroiliitis associated with FMF is very rare, especially in children. We aimed to describe the demographic, clinical, laboratory features, and treatment responses of pediatric patients with FMF -related sacroiliitis. METHODS: The study consisted of seven pediatric patients younger than 16 years, diagnosed with sacroiliitis associated with FMF between 2010 and 2017. Medical records of patients were retrospectively evaluated. Sacroiliitis was diagnosed based on magnetic resonance imaging. We also reviewed previous studies of FMF related sacroiliitis. RESULTS: Five of the seven patients (male:female ratio of 5:2) had a M694V (homozygous) mutation, one patient had a M694V (heterozygous) mutation, and one patient had a V726A (heterozygous) mutation. All patients were HLA-B27 negative. One of the cases achieved remission with colchicine plus non-steroidal anti-inflammatory drug treatment, and one patient`s symptoms were managed by the addition of sulfasalazine. Four patients responded to etanercept treatment, and one patient`s symptoms were suppressed with canakinumab. CONCLUSION: Sacroiliitis can be seen in pediatric FMF patients suffering with inflammatory back pain. This manifestation generally occurs in FMF patients who have M694V mutation. Etanercept could likely show a beneficial effect in patients who are resistant to disease modifying anti-rheumatic drugs and non-steroidal anti-inflammatory drugs. In addition, canakinumab treatment should be considered as a successful alternative therapy in this rare group of patients.

High prevalence of spondyloarthritis-like MRI lesions in postpartum women: a prospective analysis in relation to maternal, child and birth characteristics.

OBJECTIVES: Bone marrow oedema (BMO) on MRI of sacroiliac joints (SIJs) represents a hallmark of axial spondyloarthritis (SpA), yet such lesions may also occur under augmented mechanical stress in healthy subjects. We therefore sought to delineate the relationship between pregnancy/delivery and pelvic stress through a prospective study with repeated MRI. Results were matched with maternal, child and birth characteristics. METHODS: Thirty-five women underwent a baseline MRI-SIJ within the first 10 days after giving birth. MRI was repeated after 6 months and, if positive for sacroiliitis according to the Assessment of SpondyloArthritis International Society (ASAS) definition, after 12 months. BMO and structural lesions were scored by three trained readers using the Spondyloarthritis Research Consortium of Canada (SPARCC) method. RESULTS: Seventy-seven per cent of the subjects (27/35) displayed sacroiliac BMO immediately postpartum, 60% fulfilled the ASAS definition of a positive MRI. After 6 months, 46% of the subjects (15/33) still showed BMO, representing 15% (5/33) with a positive MRI. After 12 months, MRI was still positive in 12% of the subjects (4/33). Few structural lesions were detected. Intriguingly, in this study, the presence of BMO was related to a shorter duration of labour and lack of epidural anaesthesia. CONCLUSION: A surprisingly high prevalence of sacroiliac BMO occurs in women immediately postpartum. Our data reveal a need for a waiting period of at least 6 months to perform an MRI-SIJ in postpartum women with back pain. This study also underscores the importance of interpreting MRI-SIJ findings in the appropriate clinical context.

Sacroiliitis in cancer patients: a review of current literature.

The sacroiliac (SI) joint can be directly jeopardized by malignancy and indirectly by ergonomic changes of pelvic obliquity that introduces uneven weight distribution. Cancer treatment can exacerbate preexisting arthritis and cause diffuse arthropathies, but these are unlikely to be isolated to the SI joint. The cancer population is exposed to unique stressors that might facilitate development of SI joint pain that includes cancer itself and therapy-related complications. Like the general population, cancer patients are subject to aging and BMI and musculoskeletal structural changes that affect symmetric body functioning and posturing. No frank association between sacroiliitis and cancer has been identified. Therefore, we believe there is a need to characterize any relationship between cancer and SI joint dysfunction and pain.

MRI of the sacroiliac joints in athletes: recognition of non-specific bone marrow oedema by semi-axial added to standard semi-coronal scans.

OBJECTIVE: Assessment of combined semi-axial and semi-coronal SI joint MRI in two cohorts of young athletes to explore frequency and topography of non-specific bone marrow oedema (BMO), its association with four constitutional SI joint features, and potential restriction of false-positive assignments of Assessment of SpondyloArthritis International Society-defined sacroiliitis on standard semi-coronal scans alone. METHODS: Combined semi-axial and semi-coronal SI joint MRI scans of 20 recreational runners before/after running and 22 elite ice-hockey players were evaluated by three blinded readers for BMO and its association with four constitutional SI joint features: vascular partial volume effect, deep iliac ligament insertion, fluid-filled bone cyst and lumbosacral transitional anomaly. Scans of TNF-treated spondyloarthritis patients served to mask readers. We analysed distribution and topography of BMO and SI joint features across eight anatomical SI joint regions (upper/lower ilium/sacrum, subdivided in anterior/posterior slices) descriptively, as concordantly recorded by ⩾2/3 readers on both MRI planes. BMO confirmed on both scans was compared with previous evaluation of semi-coronal MRI alone, which met the Assessment of SpondyloArthritis International Society definition for active sacroiliitis. RESULTS: Perpendicular semi-axial and semi-coronal MRI scans confirmed BMO in the SI joint of every fourth young athlete, preferentially in the anterior upper sacrum. BMO associated with four constitutional SI joint features was observed in 20-36% of athletes, clustering in the posterior lower ilium. The proportion of Assessment of SpondyloArthritis International Society-positive sacroiliitis recorded on the semi-coronal plane alone decreased by 33-56% upon amending semi-axial scans. CONCLUSION: Semi-axial combined with standard semi-coronal scans in MRI protocols for sacroiliitis facilitated recognition of non-specific BMO, which clustered in posterior lower ilium/anterior upper sacrum.