Mucosal Immune Defence Gene Polymorphisms as Relevant Players in the Pathogenesis of IgA Vasculitis?

ITGAM-ITGAX (rs11150612, rs11574637), VAV3 rs17019602, CARD9 rs4077515, DEFA (rs2738048, rs10086568), and HORMAD2 rs2412971 are mucosal immune defence polymorphisms, that have an impact on IgA production, described as risk loci for IgA nephropathy (IgAN). Since IgAN and Immunoglobulin-A vasculitis (IgAV) share molecular mechanisms, with the aberrant deposit of IgA1 being the main pathophysiologic feature of both entities, we assessed the potential influence of the seven abovementioned polymorphisms on IgAV pathogenesis. These seven variants were genotyped in 381 Caucasian IgAV patients and 997 matched healthy controls. No statistically significant differences were observed in the genotype and allele frequencies of these seven polymorphisms when the whole cohort of IgAV patients and those with nephritis were compared to controls. Similar genotype and allele frequencies of all polymorphisms were disclosed when IgAV patients were stratified according to the age at disease onset or the presence/absence of gastrointestinal or renal manifestations. Likewise, no ITGAM-ITGAX and DEFA haplotype differences were observed when the whole cohort of IgAV patients, along with those with nephritis and controls, as well as IgAV patients, stratified according to the abovementioned clinical characteristics, were compared. Our results suggest that mucosal immune defence polymorphisms do not represent novel genetic risk factors for IgAV pathogenesis.

Development of a new ultrasound scoring system to evaluate glandular inflammation in Sjögren's syndrome: an OMERACT reliability exercise.

OBJECTIVE: The aim of this exercise from the OMERACT Ultrasound subgroup on Sjögren's syndrome was to develop and assess the reliability of a consensus-based semiquantitative colour Doppler US scoring system for pathologic salivary gland vascularization in patients with primary Sjögren's syndrome (pSS). METHODS: Using the Delphi method, a colour Doppler semiquantitative scoring system for vascularization of bilateral parotid and submandibular glands was developed and tested in static images and on patients (9 pSS patients and 9 sonographers). Intra-reader and inter-reader reliability of grading the salivary glands were computed by weighted Cohen and Light's kappa analysis, respectively. RESULTS: The consensus-based semiquantitative score was: grade 0, no visible vascular signals; grade 1, focal, dispersed vascular signals; grade 2, diffuse vascular signals detected in <50% of the gland; grade 3, diffuse vascular signals in >50% of the gland. In static images, the intra- and inter-reader reliability showed excellent kappa values (95% CI) of 0.90 (0.87, 0.93) and 0.80 (0.74, 0.84), respectively, for all four salivary glands together. In patients, the intra- and inter-reader reliability for all four salivary glands together was kappa = 0.84 (0.73, 0.92) and 0.70 (0.64, 0.76), respectively. CONCLUSION: The consensus-based colour Doppler US scoring for the evaluation of salivary gland vascularization in pSS showed a good inter-reader reliability and excellent intra-reader reliability in static images and in patients. The clinical application of the developed scoring system should be tested in clinical settings.

The paediatric foot: prevalence and differentiation of sonographic and podiatric findings in juvenile arthritis and healthy children.

OBJECTIVES: We aimed to, first, determine the prevalence of ultrasound (US) findings and podiatric anomalies in the paediatric foot, and to compare these findings between healthy and asymptomatic juvenile idiopathic arthritis (JIA) subjects, and then to analyse the associations between US and podiatric findings. METHODS: Healthy children and asymptomatic JIA patients underwent US and podiatric assessments. Grey-scale (GS) findings and Doppler signal in the joint recess, the tendon sheath and the enthesis of paediatric feet were assessed as present or absent. The podiatry assessment included: Foot Posture Index (FPI), footprint, standing heel-rise test, mobility of first toe and the Jack test. RESULTS: Forty-six children had at least one US finding (25 of 54 healthy children and 20 of 28 asymptomatic JIA patients). GSUS findings at the first metatarsophalangeal joint recess and physiological vascularisation at several locations were the most frequently detected findings in both groups. GSUS findings at the tibiotalar and subtalar joints were only detected in the JIA group. In comparison to the healthy group, the JIA group showed a trend towards pronated foot with abnormal footprint. However, the tibiotalar synovitis was significantly associated with supinated FPI. CONCLUSIONS: Improving the knowledge of US findings in the paediatric foot is crucial to evaluate properly children with suspected inflammatory diseases. US, in addition to podiatric assessment, would enable paediatric rheumatologists to discriminate between normal physiological findings and pathological abnormalities in asymptomatic children having JIA. Further studies are needed to confirm it.

The EFSUMB Guidelines and Recommendations for Musculoskeletal Ultrasound - Part I: Extraarticular Pathologies.

The first part of the guidelines and recommendations for musculoskeletal ultrasound, produced under the auspices of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB), provides information about the use of musculoskeletal ultrasound for assessing extraarticular structures (muscles, tendons, entheses, ligaments, bones, bursae, fasciae, nerves, skin, subcutaneous tissues, and nails) and their pathologies. Clinical applications, practical points, limitations, and artifacts are described and discussed for every structure. After an extensive literature review, the recommendations have been developed according to the Oxford Centre for Evidence-based Medicine and GRADE criteria and the consensus level was established through a Delphi process. The document is intended to guide clinical users in their daily practice.

The EFSUMB Guidelines and Recommendations for Musculoskeletal Ultrasound - Part II: Joint Pathologies, Pediatric Applications, and Guided Procedures.

The second part of the Guidelines and Recommendations for Musculoskeletal Ultrasound (MSUS), produced under the auspices of EFSUMB, following the same methodology as for Part 1, provides information and recommendations on the use of this imaging modality for joint pathology, pediatric applications, and musculoskeletal ultrasound-guided procedures. Clinical application, practical points, limitations, and artifacts are described and discussed for every joint or procedure. The document is intended to guide clinical users in their daily practice.

Upper-Limb Entheses in Healthy Children: A Comprehensive Ultrasound Study.

BACKGROUND: Interest in ultrasound (US) as a diagnostic tool in spondyloarthritis is growing. Although the literature has provided detailed description of normal lower-limb entheses for adults and children, validated normal US findings of the pediatric upper-limb (UL) entheses are lacking. OBJECTIVES: The aim of this study was to describe the sonographic characteristics of the UL entheses in healthy children to provide a basis for assessing pathologic findings in children with rheumatic diseases. METHODS: This is an observational, cross-sectional study. The recruited healthy children were grouped according to age: group 1, 3-9 years (n = 22); group 2, 10 to 13 years (n = 12); and group 3, 14 to 18 years (n = 9). The following UL entheses were examined: (1) supraspinatus, (2) common flexor, (3) common extensor, and (4) triceps. Ultrasound examination was performed in B mode for morphology and structural abnormalities, and power Doppler was applied to detect vascularization within the enthesis and cartilage sites. RESULTS: Forty-three children with a median age of 9 years (6-13 years) were included; 55% were boys. A total of 344 entheses were evaluated; all of them presented a homogeneous hyperechoic fibrillar pattern. Tendon insertion thickness at the bone attachment site increased with age and was greater in males. No signs of chronic enthesopathy were detected. Doppler signal was observed in children from groups 1 and 2, but not in any of the patients in group 3. In group 1, intraentheses signal was detected in the common extensor tendon insertion as an isolated signal (n = 2 patients), whereas intracartilage signal was detected in the supraspinatus (n = 1 patient) and the triceps (n = 1 patient). In group 2, intracartilage signal was detected in the common extensor (n = 2 patients) and the common flexor (n = 2 patients). Interobserver agreement for the entheses' thickness was as follows: intracorrelation coefficient class (ICC) of 0.86 (95% confidence interval [CI], 0.84-0.92) for the supraspinatus enthesis, ICC of 0.83 (95% CI, 0.83-0.90) for the common extensor enthesis, ICC of 0.96 (95% CI, 0.91-0.97) for the common flexor enthesis, and ICC of 0.94 (95% CI, 0.89-0.95) for the triceps enthesis. The κ index was 0.93 for the detection of the power Doppler signal. Intraobserver agreement was good for all evaluated entheses: ICC of 0.85 (95% CI, 0.83-0.91) for supraspinatus, ICC of 0.86 (95% CI, 0.84-0.91) for common extensor entheses, ICC of 0.89 (95% CI, 0.86-0.93) for common flexor entheses, and ICC of 0.96 (95% CI, 0.90-0.97) for evaluation of triceps entheses. The κ index was 0.91 for the detection of Doppler signal. CONCLUSIONS: The current study provides a comprehensive description of the structural appearance and vascularization of UL entheses on healthy children. This information can be useful as reference for interpretation of pathological findings in children with musculoskeletal diseases in clinical practice.

Video clip assessment of a salivary gland ultrasound scoring system in Sjögren's syndrome using consensual definitions: an OMERACT ultrasound working group reliability exercise.

OBJECTIVE: To develop ultrasound (US) definitions and a US novel scoring system for major salivary gland (SG) lesions in patients with primary Sjögren's syndrome (pSS) and to test their intrareader and inter-reader reliability using US video clips. METHODS: Twenty-five rheumatologists were subjected to a three-round, web-based Delphi process in order to agree on (1) definitions and scanning procedure of salivary gland ultrasonography (SGUS): parotid, submandibular and sublingual glands (PG, SMG and SLG); (2) definitions for the elementary SGUS lesions in patients with Sjögren's syndrome; (3) scoring system for grading changes. The experts rated the statements on a 1-5 Likert scale. In the second step, SGUS video clips of patients with pSS and non-pSS sicca cases were collected containing various spectrums of disease severity followed by an intrareader and inter-reader reliability exercise. Each video clip was evaluated according to the agreed definitions. RESULTS: Consensual definitions were developed after three Delphi rounds. Among the three selected SGs, US assessment of PGs and SMGs was agreed on. Agreement was reached to score only greyscale lesions and to focus on anechoic/hypoechoic foci in a semiquantitative matter or, if not possible on a qualitatively (present/absent) evaluation of fatty or fibrous lesions. Intrareader reliability for detecting and scoring these lesions was excellent (Cohen's kappa 0.81) and inter-reader reliability was good (Light's kappa 0.66). CONCLUSION: New definitions for developing a novel semiquantitative US score in patients with pSS were developed and tested on video clips. Inter-reader and intrareader reliabilities were good and excellent, respectively.

Development of semiquantitative ultrasound scoring system to assess cartilage in rheumatoid arthritis.

OBJECTIVES: To develop and test the reliability of a new semiquantitative scoring system for the assessment of cartilage changes by ultrasound in a web-based exercise as well as a patient exercise of patients with RA. METHODS: A taskforce of the Outcome Measures in Rheumatology Ultrasound Working Group performed a systematic literature review on the US assessment of cartilage in RA, followed by a Delphi survey on cartilage changes and a new semiquantitative US scoring system, and finally a web-based exercise as well as a patient exercise. For the web-based exercise, taskforce members scored a dataset of anonymized static images of MCP joints in RA patients and healthy controls, which also contained duplicate images. Subsequently, 12 taskforce members used the same US to score cartilage in MCP and proximal interphalangeal joints of six patients with RA in in a patient reliability exercise. Percentage agreement and prevalence of lesions were calculated, as intrareader reliability was assessed by weighted kappa and interreader reliability by Light's kappa. RESULTS: The three-grade semiquantitative scoring system demonstrated excellent intrareader reliability (kappa: 0.87 and 0.83) in the web-based exercise and the patient exercise, respectively. Interreader reliability was good in the web-based exercise (kappa: 0.64) and moderate (kappa: 0.48) in the patient exercise. CONCLUSION: Our study demonstrates that ultrasound is a reliable tool for evaluating cartilage changes in the MCP joints of patients with RA and supports further development of a new reliable semiquantitative ultrasound scoring system for evaluating cartilage involvement in RA.

Can ultrasound-detected subclinical synovitis be an indicator of flare recurrence in juvenile idiopathic arthritis remission patients on tapered TNFi?

OBJECTIVES: Subclinical synovitis is often detected by musculoskeletal ultrasound (MSUS) in juvenile idiopathic arthritis (JIA) patients in clinical remission. The main objective of this prospective, observational, longitudinal, multicentre study was to evaluate the predictive value of MSUS-detected subclinical synovitis in relation to flares at 12 months following TNFi tapering in a JIA population in stable clinical remission. METHODS: We included 56 JIA patients in stable remission undergoing TNFi therapy tapered at baseline and in some cases at 6 months. We performed baseline and 6-month MSUS assessment on B-mode (BM) and power Doppler (PD) mode of 22 joints and 8 tendons. RESULTS: Eighteen patients (32.1%) experienced a flare during the 12-month study period. BM synovitis was frequent (83.9%) but PD synovitis was scarcely found (8.9%). There were no significant differences in MSUS findings between patients who experienced a flare and those who remained in remission. Only 5 patients had positive for PD synovitis, in joints with BM synovitis grades 2 or 3, and none experienced a flare. Concomitant methotrexate (MTX) was more frequent in patients who were successfully tapered (71.1% vs. 27.8%; p=0.002) and patients older than 12 experienced a greater number of flares and earlier onset. CONCLUSIONS: Subclinical synovitis, as detected by MSUS, proved not to be a predictor of flares. Those patients on a TNFi-tapered concomitant methotrexate regimen experienced the fewest flares although flare risk increased with age.

Current state of musculoskeletal ultrasound in paediatric rheumatology: results of an international survey.

OBJECTIVE: The aim of this study was to investigate the current use of musculoskeletal US (MSUS) and the most relevant areas of interest for this imaging modality in paediatric rheumatology. METHODS: A questionnaire was developed by the paediatric subgroup of the OMERACT US task force and e-mailed to the members of the main international paediatric rheumatology networks and societies. Responses were entered in an electronic database. Results were analysed quantitatively or summarized qualitatively in the case of open questions. RESULTS: The overall response rate was 36% (262/719). The use of MSUS varied among members of the various networks/societies. MSUS was considered of high relevance for improvement of diagnostic skills, for the guidance of joint injections and for the assessment of specific joints, namely the hip, ankle, midfoot and wrist. It was considered useful for early detection of synovitis and in determining disease activity and disease remission. CONCLUSION: Although at present MSUS is not widely used by paediatric rheumatologists, there is considerable interest in this imaging technology among members of the international networks. The results of this survey suggest that the next objective in the research agenda should be the standardization of the assessment of joints in healthy children. This will then help differentiate pathological (i.e. synovitic) joints from normal joints. The initial target joints should be the hip, ankle, midfoot and wrist. MSUS training focused on the assessment of paediatric patients might be very important in implementing the use of this technique in clinical practice and research.

Detection of synovitis by ultrasonography in clinically inactive juvenile idiopathic arthritis on and off medication.

OBJECTIVES: To determine the prevalence of abnormalities detected by ultrasonography (US) in children with juvenile idiopathic arthritis (JIA) showing clinically inactive disease (ID) on medication and off medication. INCLUSION CRITERIA: 1) JIA patients, 2) clinician-determined ID, 3) JIA drugs withdrawal or stably dosed modified anti-rheumatic drugs (DMARDs) therapy for at least 6 months prior to inclusion, 4) biologics naïve patients. Clinical and US assessments were performed on 44 joints, which were scored for grey-scale (GS) synovitis and Power Doppler (PD) signal. PD signal inside intra-articular synovium or tendon sheath was considered as inflammatory activity. RESULTS: Thirty-four patients were included, of whom 23 patients were labelled as ID on medication and 11 patients without medication. The duration of the current episode of ID at the inclusion time was 9.5 months. Although it was longer for the group off medication there was no significant difference between the two groups (p=0.06). Thirteen patients presented US findings. Number of US-detected synovial abnormalities was higher in patients on medication, but there were no significant differences between both groups in the detection of GS synovitis (p=0.86), GS tenosynovitis (p=0.78) and PD signal (p=0.38). Out of 37 joints presenting US-determined GS-synovitis, 18 joints showed PD signal. CONCLUSIONS: Our study provides evidence of synovitis and tenosynovitis on B-mode US in JIA patients with clinical inactivity. In addition, inflammatory activity upheld by power-Doppler has been shown in a few joints from patients on medication.

Reduced joint assessment vs comprehensive assessment for ultrasound detection of synovitis in juvenile idiopathic arthritis.

OBJECTIVE: To propose a reduced joint power Doppler US (PDUS) assessment and provide preliminary evidence of its validity, feasibility, reliability and sensitivity to change compared with a comprehensive (i.e. 44 joints) PDUS assessment in evaluating synovitis in JIA. METHODS: This multicentre study included 42 children with active JIA with ≥4 clinically involved joints requiring modified therapy. At each visit, clinical and PDUS assessments were performed blinded. Each joint was scored for greyscale (GS) synovitis and power Doppler signal according to a 4-point semiquantitative scale with calculation of US composite indices and US composite joint counts. A process of data reduction based on the frequency of US joint involvement was performed to obtain a reduced PDUS assessment. The relationship between the comprehensive and the reduced PDUS assessments was investigated by Spearman's coefficient at all visits, as well as the relationship between changes in the two PDUS assessments during follow-up. In addition, the metric properties of the comprehensive and the reduced PDUS assessments were tested. RESULTS: The 10-joint PDUS assessment, including bilateral knee, ankle, wrist, elbow and the second MCP joints, detected 100% of children with GS synovitis and power Doppler signal. The two PDUS assessments were highly correlated at all visits. The reduced model had a higher responsiveness than the comprehensive model. Intraobserver and interobserver agreement was good for both US findings. CONCLUSION: The 10-joint PDUS assessment is valid and feasible for assessment of synovitis in JIA in clinical practice.

Validity of ultrasonography in detecting enthesitis in children: A systematic literature review.

OBJECTIVE: A systematic review to assess the value of ultrasonography (US) for detecting enthesitis in juvenile idiopathic arthritis (JIA). METHODS: PubMed and Embase databases were searched for articles published from January 1966 to May 2021; we selected those meeting the inclusion criteria according to the US definition of enthesitis and metric properties studied. We assessed the clinical features of the population, study design, the type and number of entheses examined, the definition and scoring system of US enthesitis and metric properties according to the OMERACT filter (truth, discrimination and feasibility). The quality of the studies was evaluated with the Quality Assessment of Diagnostic Accuracy Studies 2. RESULTS: Five publications met the inclusion criteria (26 to 146 patients and 1 to 10 bilaterally examined entheses). All studies focused on lower-limb entheses. The elementary lesions included in the definition of adult enthesitis were generally assessed. Few studies reported US reliability and none evaluated sensitivity to change of US. US revealed entheseal abnormalities in 9.4 to 53% of JIA patients and 20 to 83% of enthesitis-related arthritis cases. No significant abnormalities were found in healthy children. US findings were poorly correlated with clinical examination. The overall quality of the studies was low, mainly because of the lack of a reference standard. CONCLUSION: US is a sensitive tool to detect entheseal abnormalities in JIA. The current evidence highlights that a standardized US definition of enthesitis in children is lacking and US criteria and discriminant validity have not been established.

OMERACT International Consensus for Ultrasound Definitions of Tenosynovitis in Juvenile Idiopathic Arthritis: Systematic Literature Review and Delphi Process.

OBJECTIVE: Synovitis and tenosynovitis are present in juvenile idiopathic arthritis (JIA), both as joint pain and/or inflammation, making them difficult to detect on physical examination. Although ultrasonography (US) allows for discrimination of the 2 entities, only definitions and scoring of synovitis in children have been established. This study was undertaken to produce consensus-based US definitions of tenosynovitis in JIA. METHODS: A systematic literature search was performed. Selection criteria included studies focused on US definition and scoring systems for tenosynovitis in children, as well as US metric properties. Through a 2-step Delphi process, a panel of international US experts developed definitions for tenosynovitis components (step 1) and validated them by testing their applicability on US images of tenosynovitis in several age groups (step 2). A 5-point Likert scale was used to rate the level of agreement. RESULTS: A total of 14 studies were identified. Most used the US definitions developed for adults to define tenosynovitis in children. Construct validity was reported in 86% of articles using physical examination as a comparator. Few studies reported US reliability and responsiveness in JIA. In step 1, experts reached a strong group agreement (>86%) by applying adult definitions in children after one round. After 4 rounds of step 2, the final definitions were validated on all tendons and at all locations, except for biceps tenosynovitis in children <4 years old. CONCLUSION: The study shows that the definition of tenosynovitis used in adults is applicable to children with minimal modifications agreed upon through a Delphi process. Further studies are required to confirm our results.

IgA Vasculitis: Influence of CD40, BLK and BANK1 Gene Polymorphisms.

CD40, BLK and BANK1 genes involved in the development and signaling of B-cells are identified as susceptibility loci for numerous inflammatory diseases. Accordingly, we assessed the potential influence of CD40, BLK and BANK1 on the pathogenesis of immunoglobulin-A vasculitis (IgAV), predominantly a B-lymphocyte inflammatory condition. Three genetic variants within CD40 (rs1883832, rs1535045, rs4813003) and BLK (rs2254546, rs2736340, rs2618476) as well as two BANK1 polymorphisms (rs10516487, rs3733197), previously associated with inflammatory diseases, were genotyped in 382 Caucasian patients with IgAV and 955 sex- and ethnically matched healthy controls. No statistically significant differences were observed in the genotype and allele frequencies of CD40, BLK and BANK1 when IgAV patients and healthy controls were compared. Similar results were found when CD40, BLK and BANK1 genotypes or alleles frequencies were compared between patients with IgAV stratified according to the age at disease onset or to the presence/absence of gastrointestinal or renal manifestations. Moreover, no CD40, BLK and BANK1 haplotype differences were disclosed between patients with IgAV and healthy controls and between patients with IgAV stratified according to the clinical characteristics mentioned above. Our findings indicate that CD40, BLK and BANK1 do not contribute to the genetic background of IgAV.

Diagnostic concordance between primary care physicians and rheumatologists in patients with work disability related to musculoskeletal disorders.

To assess the diagnostic correlation between primary care physicians and rheumatologists in patients with temporary work disability (TWD) related to musculoskeletal diseases (MSD). All patients with TWD related to MSDs in three health districts of Madrid, Spain, were randomized into standard care by primary care physicians (PCP) or the intervention group by rheumatologists. According to the cause, every TWD episode was classified into 11 syndrome categories. To examine the concordance between the rheumatologist and the referring PCP for each diagnosis, we used Kappa statistic (k) and 95% confidence interval (CI). A total of 3,311 (62.8%) were analyzed, 49.8% women, with a mean age of 41 years ± 12 years, 93.3% were general workers. The agreement between PCP and rheumatologists in all the diagnoses was moderated (k = 0.62). The highest agreement was found in tendonitis (k = 0.81, 95% CI 0.78-0.84), and microcrystalline and undifferentiated arthritis (k = 0.72, 95% CI 0.68-0.77). Lowest agreements were found for peripheral osteoarthritis (k = 0. 48 95% CI 0.38-0.57), knee pain (k = 0.40, 95% CI 0.29-0.52), and muscular pain (k = 0.15, 95% CI 0.10-0.20) Although the global agreement on the musculoskeletal diagnosis between PCPs and rheumatologist in patients with TWD related to MSDs was reasonable, the correlation for peripheral osteoarthritis, knee pain, and muscular pain was low.

BAFF, APRIL and BAFFR on the pathogenesis of Immunoglobulin-A vasculitis.

BAFF, APRIL and BAFF-R are key proteins involved in the development of B-lymphocytes and autoimmunity. Additionally, BAFF, APRIL and BAFFR polymorphisms were associated with immune-mediated conditions, being BAFF GCTGT>A a shared insertion-deletion genetic variant for several autoimmune diseases. Accordingly, we assessed whether BAFF, APRIL and BAFFR represent novel genetic risk factors for Immunoglobulin-A vasculitis (IgAV), a predominantly B-lymphocyte inflammatory condition. BAFF rs374039502, which colocalizes with BAFF GCTGT>A, and two tag variants within APRIL (rs11552708 and rs6608) and BAFFR (rs7290134 and rs77874543) were genotyped in 386 Caucasian IgAV patients and 806 matched healthy controls. No genotypes or alleles differences were observed between IgAV patients and controls when BAFF, APRIL and BAFFR variants were analysed independently. Likewise, no statistically significant differences were found in the genotype and allele frequencies of BAFF, APRIL or BAFFR when IgAV patients were stratified according to the age at disease onset or to the presence/absence of gastrointestinal (GI) or renal manifestations. Similar results were disclosed when APRIL and BAFFR haplotypes were compared between IgAV patients and controls and between IgAV patients stratified according to the clinical characteristics mentioned above. Our results suggest that BAFF, APRIL and BAFFR do not contribute to the genetic network underlying IgAV.

Role of the IL33 and IL1RL1 pathway in the pathogenesis of Immunoglobulin A vasculitis.

Cytokines signalling pathway genes are crucial factors of the genetic network underlying the pathogenesis of Immunoglobulin-A vasculitis (IgAV), an inflammatory vascular condition. An influence of the interleukin (IL)33- IL1 receptor like (IL1RL)1 signalling pathway on the increased risk of several immune-mediated diseases has been described. Accordingly, we assessed whether the IL33-IL1RL1 pathway represents a novel genetic risk factor for IgAV. Three tag polymorphisms within IL33 (rs3939286, rs7025417 and rs7044343) and three within IL1RL1 (rs2310173, rs13015714 and rs2058660), that also were previously associated with several inflammatory diseases, were genotyped in 380 Caucasian IgAV patients and 845 matched healthy controls. No genotypes or alleles differences were observed between IgAV patients and controls when IL33 and IL1RL1 variants were analysed independently. Likewise, no statistically significant differences were found in IL33 or IL1RL1 genotype and allele frequencies when IgAV patients were stratified according to the age at disease onset or to the presence/absence of gastrointestinal (GI) or renal manifestations. Similar results were disclosed when IL33 and IL1RL1 haplotypes were compared between IgAV patients and controls and between IgAV patients stratified according to the clinical characteristics mentioned above. Our results suggest that the IL33-IL1RL1 signalling pathway does not contribute to the genetic network underlying IgAV.

Pan-American League of Associations for Rheumatology (PANLAR) recommendations and guidelines for musculoskeletal ultrasound training in the Americas for rheumatologists.

OBJECTIVE: To develop guidelines for Musculoskeletal Ultrasound (MSKUS) training for rheumatologists in the Americas. METHODS: A total of 25 Rheumatologists from 19 countries of the American Continent participated in a consensus-based interactive process (Delphi method) using 2 consecutive electronic questionnaires. The first questionnaire included the following: the relevance of organizing courses to teach MSKUS to Rheumatologists, the determination of the most effective educational course models, the trainee levels, the educational objectives, the requirements for passing the course(s), the course venues, the number of course participants per instructor, and the percentage of time spent in hands-on sessions. The second questionnaire consisted of questions that did not achieve consensus (>65%) in the first questionnaire, topics, and pathologies to be covered at each course MSKUS level. RESULTS: General consensus was obtained for MSKUS courses to be divided into 3 educational levels: basic, intermediate, and advanced. These courses should be taught using a theoretical-didactic and hands-on model. In addition, the group established the minimum requirements for attending and passing each MSKUS course level, the ideal number of course participants per instructor (4 participants/instructor), and the specific topics and musculoskeletal pathologies to be covered. In the same manner, the group concluded that 60% to 70% of course time should be focused on hands-on sessions. CONCLUSION: A multinational group of MSKUS sonographers using a consensus-based questionnaire (Delphi method) established the first recommendations and guidelines for MSKUS course training in the Americas. Pan-American League of Associations for Rheumatology urges that these guidelines and recommendations be adopted in the future by both national and regional institutions in the American continent involved in the training of Rheumatologists for the performance of MSKUS.

Age-Related Vascularization and Ossification of Joints in Children: An International Pilot Study to Test Multiobserver Ultrasound Reliability.

OBJECTIVE: To determine the intra- and interobserver reliability of ultrasound (US)-detected age-related joint vascularization and ossification grading in healthy children. METHODS: Following standardized image acquisition and machine setting protocols, 10 international US experts examined 4 joints (wrist, second metacarpophalangeal joint, knee, and ankle) in 12 healthy children (divided into 4 age groups: 2-4, 5-8, 9-12, and 13-16 years). Gray-scale was used to detect the ossification grade, and power Doppler ultrasound (PDUS) was used to detect physiologic vascularization. Ossification was graded from 0 (no ossification) to 3 (complete ossification). A positive PDUS signal was defined as any PDUS signal inside the joint. Kappa statistics were applied for intra- and interobserver reliability. RESULTS: According to the specific joint and age, up to 4 solitary PDUS signals (mean 1.5) were detected within each joint area with predominant localization of the physiologic vascularization in specific anatomic positions: fat pad, epiphysis, physis, and short bone cartilage. The kappa values for ossification grading were 0.87 (range 0.85-0.91) and 0.58 for intra- and interobserver reliability, respectively. The bias-adjusted kappa values for intra- and interobserver reliability were 0.71 (range 0.44-1.00) and 0.69, respectively. CONCLUSION: Detection of normal findings (i.e., grading of physiologic ossification during skeletal maturation and identification of physiologic vessels) can be highly reliable by using clear definitions and a standardized acquisition protocol. These data will permit development of a reliable and standardized US approach for evaluating pediatric joint pathologies.