Early detection of sacroiliitis on magnetic resonance imaging and subsequent development of sacroiliitis on plain radiography. A prospective, longitudinal study.

OBJECTIVE: To investigate the diagnostic value of magnetic resonance imaging (MRI) in the detection of early sacroiliitis. METHODS: Twenty-five consecutive HLA-B27 positive patients with inflammatory low back pain and < or = grade 2 unilateral sacroiliitis on conventional radiography (modified New York criteria) were studied. Erythrocyte sedimentation rate, C-reactive protein, plain radiography (PR), and MRI of the sacroiliac (SI) joints were obtained at study entry and PR of the SI joints after 3 years. Each radiograph and MR image set was interpreted independently. SI joints were scored according to the modified New York Criteria for radiological sacroiliitis. MRI scans were also scored for the presence of subchondral marrow edema. The relationship between > or = grade 2 sacroiliitis (by modified New York criteria for radiological sacroiliitis) shown on MRI and the subsequent development of > or = grade 2 sacroiliitis on PR after 3 years was investigated. RESULTS: At study entry > or = grade 2 sacroiliitis was found on MRI in 36 of 50 SI joints. Edema was found in 20 of 50 SI joints. After 3 years > or = grade 2 sacroiliitis was found on PR in 21 of 44 SI joints. The positive predictive value of > or = grade 2 sacroiliitis on MRI for the development of > or = grade 2 sacroiliitis on PR after 3 years was 60%; sensitivity was 85% and specificity 47%. CONCLUSION: Our data suggest that MRI of the SI joints can be used to identify sacroiliitis earlier than PR.     

Studying patients with inflammatory back pain and arthritis of the lower limbs clinically and by magnetic resonance imaging: many, but not all patients with sacroiliitis have spondyloarthropathy.

OBJECTIVE: Clinical and magnetic resonance imaging (MRI) data of 170 consecutive patients with inflammatory back pain (IBP) and/or oligoarthritis of the lower limbs were evaluated in a retrospective study. The aim was to determine the frequency of sacroiliitis and spondyloarthropathy (SpA) in this population, and to assess the significance of HLA B27 measurements for diagnosis in early disease. METHODS: Pelvic X-rays were performed in all IBP patients and dynamic MRI of the sacroiliac joints in patients with IBP who had indefinite results on sacroiliac X-rays (n = 32). RESULTS: European Spondyloarthropathy Study Group criteria for SpA were fulfilled by 106/170 patients (62.4%); eight additional patients had symptoms suggestive of SpA (4.7%). The most frequent SpA subset was undifferentiated SpA (uSpA), diagnosed in 46/106 patients (43.4%). Sacroiliitis was detected by MRI in 21/32 patients with IBP and unclear X-rays (65.6%). Of those, 14 were diagnosed as SpA and seven females with moderate unilateral sacroiliitis, but no features of SpA, also not on follow-up (at least 1 yr), were classified as undifferentiated sacroiliitis (US). Ten of the 14 SpA (71.4%) and none of the seven US patients were HLA B27 positive. CONCLUSION: HLA B27 positivity in IBP patients with MRI-proven sacroiliitis positively predicts SpA. uSpA is a frequent SpA subset. There are HLA B27-negative non-SpA patients with moderate unilateral sacroiliitis whom we propose to be classified as US.     

Anatomic structures involved in early- and late-stage sacroiliitis in spondylarthritis: a detailed analysis by contrast-enhanced magnetic resonance imaging

OBJECTIVE: To localize inflammatory and chronic changes to defined areas in the sacroiliac joints in patients with early-stage compared with late-stage spondylarthritis (SpA), using magnetic resonance imaging (MRI). METHODS: Using MRI, 93 patients with SpA and inflammatory back pain who had radiographs of the sacroiliac joints were examined, comprising 31 patients with ankylosing spondylitis (AS) and 62 with other SpA subsets, including 48 with undifferentiated SpA (uSpA). MRI was performed using T1-weighted, T2*-weighted, STIR, and dynamic contrast-enhanced (gadolinium diethylenetriaminepentaacetic acid) sequences. Two readers retrospectively analyzed the images by differentiating 9 areas of the sacroiliac joints: the ventral and caudal joint capsule, cavum, subchondral bone, bone marrow, ligament entheses, and ligaments; the sacral and iliac sides were tabulated separately. RESULTS: By MRI, sacroiliitis was more often bilateral in AS (84%) than in uSpA (48%) (P = 0.01). Inflammatory changes were found in a mean +/- SD 4.7 +/- 2.9 regions/joint, with involvement of 4.5 +/- 3.2 regions in early disease versus 5.2 +/- 2.3 regions in late disease (P not significant [NS]). Involvement of the iliac side of the sacroiliac joints was found to be more frequent than the sacral side in early disease (58% versus 48%; P < 0.01) as compared with that in late disease (58% versus 63%; P NS). The dorsocaudal parts of the synovial joint and the bone marrow were the most frequently inflamed structures in early disease (P < 0.001 for ventral versus dorsal joint capsule). In contrast, involvement of the entheses was more common in advanced disease (early 43% versus late 86%; P < 0.001). Similarly, the ligaments were more frequently involved in the late stages (early 26% versus late 40%; P = 0.06). Both patterns of bone marrow inflammation (focal and diffuse) were observed in equal frequencies in early and late disease (17% and 42% versus 26% and 43%, respectively; P NS). HLA-B27-positive patients (n = 80) had more entheseal involvement than did HLA-B27-negative patients (n = 13) (60% versus 39%; P = 0.05). HLA-B27-negative patients had a shorter disease duration (2.2 years versus 4.4 years; P = 0.05) and were more often female (62%; P = 0.02). When all pathologic changes were assessed, the STIR sequence (performed in 62 patients) was less sensitive than the contrast-enhanced sequences in that it was not able to show all relevant changes in 27% of these patients (n = 17), failing to reveal inflammation of the cavum in 15 patients and of the bone marrow and joint capsule in 1 patient each. CONCLUSION: As visualized by MRI, sacroiliitis in SpA is characterized by involvement of different joint structures. Whereas the iliac and the sacral side of the sacroiliac joints are almost equally affected, the dorsocaudal synovial part of the joint is involved significantly more often than the ventral part, especially in early disease. Sacroiliac enthesitis is not a special feature of early sacroiliac inflammation.     

The frequency of sacroiliitis in familial Mediterranean fever and the role of HLA-B27 and MEFV mutations in the development of sacroiliitis

The objective of this study was to investigate the frequency of sacroiliitis in familial Mediterranean fever (FMF) patients and the role of HLA-B27 and MEFV mutations in the development of sacroiliitis. The study group consisted of 256 FMF patients (male 128, female 128, mean age 27.2 ± 6.3 years). After evaluation of the medical records, 70 patients (27.4%) were determined to have one or more of musculoskeletal manifestations. Sacroiliitis was determined in 18 (32.7%) FMF patients. The frequency of sacroiliitis among all FMF patients was found to be 7%. HLA-B27 was 47% and 6.3% in FMF patients with and without sacroiliitis, respectively. The frequency of M694V mutations in FMF patients with sacroiliitis was 93.7%. Sacroiliitis may be seen more frequently in FMF patients than expected. HLA-B27 positivity and/or M694V mutation may play a role in the development of sacroiliitis and the severity of seronegative spondyloarthropathy.     

Low back pain,sacroiliitis, and the relationship with HLA-B27 in Crohn's disease

OBJECTIVE: To determine the prevalence of sacroiliitis in patients who have back pain in Crohn's disease (CD) using computed tomography (CT); and to reassess the association of sacroiliitis in CD with HLA-B27. METHODS: A total of 134 consecutive patients with CD completed a questionnaire about musculoskeletal symptoms. Those reporting low back pain were assessed, including plain radiographs and CT of the sacroiliac joints. HLA-B27 status was determined in patients with and without back pain. RESULTS: There were 70 (52%) patients with low back pain, of whom 31 (45%) had CT evidence of sacroiliitis. These were characterized by more frequent morning spinal stiffness and positive sacroiliac compression tests even when sacroiliitis was not suspected. Nine had previously recognized radiological and clinical ankylosing spondylitis (AS), and of these 78% were HLA-B27 positive. Of those with newly identified sacroiliitis, 14% were HLA-B27 positive. This frequency was not statistically dissimilar to the 9% HLA-B27 positivity of those without back pain. CONCLUSION: Sacroiliitis defined by CT is a common cause of low back pain in CD. A relationship of sacroiliitis and HLA-B27 could be confirmed only for those with classical AS. Our results accord with the possibility that sacroiliitis in CD is an isolated phenomenon, which is unrelated to HLA-B27 and which may evolve into classical spinal ankylosis in genetically susceptible subjects.     

磁共振成像对早期骶髂关节炎的诊断价值研究

目的了解磁共振成像(MRI)在早期骶髂关节炎诊断中的意义。方法对82例炎症性腰背痛或不对称性下肢滑膜炎患者的骶髂关节CT扫描、MRI平扫以及病理检查结果进行分析比较。结果45例病理证实的早期骶髂关节炎中,69%(31/45)MRI显示骶髂关节存在炎症性改变。但17例病理检查骶髂关节无炎症性改变者,也有59%(10/17)MRI表现不同程度骶髂关节炎症性改变。以病理检查结果为依据,MRI对早期骶髂关节炎诊断的敏感性、特异性分别为69%和41%。结论MRI对早期骶髂关节炎的诊断有一定的敏感性,但特异性不高,临床应用要慎重考虑。     

Acute brucella sacroiliitis: Clinical features

Although back pain is very common, the differential diagnosis may sometimes be very difficult. Both inflammation and infections of spinal or sacroiliac joints are examples of such causes. We report three cases of brucella sacroiliitis resembling acute low back pain or lumbar disc herniation. All patients had had a recent infection and were referred complaining of acute back pain with a suspicion of lumbar disc herniation. The complaints of all patients reduced dramatically after proper medication. Radiographs of all patients and bone scans of two patients revealed sacroiliitis. One of the patients was positive for HLA-B27; in the other two patients HLA-B27 could not be determined.     

The sternoclavicular syndrome: experience from a district general hospital and results of a national postal survey

OBJECTIVE: To report our local experience of the sternoclavicular syndrome and sample the experience of other rheumatologists in the UK. METHODS: We studied case records of 23 patients referred to the Southend rheumatology clinic and data obtained from a postal questionnaire survey of British rheumatologists. RESULTS: We describe 58 cases (20 males and 38 females, mean age 47.2 yr). The disease was unilateral in 40 patients. Shoulder and/or arm pain (38 cases) with limitation of shoulder movements was an important presenting feature; other presenting features were anterior chest wall pain (14 cases) and neck pain (15 cases). Peripheral joint involvement was seen in 12 cases. Skin rash was reported in 12 cases (psoriasis, 6; acne, 2; none had pustulosis). No patients had symptoms or signs of sacroiliitis, and HLA-B27 was negative in 22 out of 23 patients. 99Technetium scintiscanning showed increased uptake in the sternoclavicular region in 31/34 patients (91.1%), but not in the sacroiliac areas. Plain radiographs were abnormal in 18 cases (sclerosis, 9; erosions, 2; soft tissue swelling, 2; bony expansion, 5). CT and/or MRI scans (available in 27 cases) showed erosions in 12 and osteitis in 18. Available histology showed a variable picture, including inflammation, bone erosion, sterile osteomyelitis and fibrosis. The majority of patients (45) were treated with non-steroidal anti-inflammatory drugs: 12 received steroids and 10 received disease-modifying anti-rheumatic drugs (methotrexate, 4; sulphasalazine, 6). Follow-up information was available for 38 patients, of whom 14 became asymptomatic and 24 had chronic disease with intermittent flares. CONCLUSION: Sternoclavicular disease is not uncommon in the UK. It can present with pain in the shoulder, neck or anterior chest wall, and may be underdiagnosed. Our results do not show a link with acne or pustulosis. Features of spondyloarthropathies, such as sacroiliitis and HLA-B27 positivity, were rare in this survey.     

Psoriatic spondyloarthropathy: a comparative study between HLA-B27 positive and HLA-B27 negative disease

OBJECTIVES: To evaluate the relative contribution of the human leukocyte antigen (HLA)-B27 to psoriatic spondyloarthropathy (PsSpA) susceptibility and to analyze whether this antigen contributes to disease expression. METHODS: This cross-sectional study included 70 patients (mean age 48 +/- 14.5 years; 44 men and 26 women). PsSpA was defined according to radiological findings (grade 2 or more sacroiliitis), and patients were classified into 3 main subtypes: isolated axial disease (n = 16), axial plus oligoarthritis (n = 29) and axial plus polyarthritis (n = 25). All patients were studied following a standard protocol that included the collection of demographic and epidemiological data, clinical history, radiographs, complementary tests, physical examination, and HLA-B27 testing (serological method). For functional evaluation, the Health Assessment Questionnaire-Specific for spondyloarthropathy (HAQ-S) was used. Patients with and without HLA-B27 antigen were compared on the basis of the data. RESULTS: Twenty-four patients (34%) carried the HLA-B27 antigen (RR 6.4, P <.0004). Fifty-six percent of those patients with the isolated axial pattern had this antigen, compared with 24% in the poly-arthritis axial pattern and 31% of those in the oligo-arthritis axial group (P =.016). Univariate analysis demonstrated correlations between HLA-B27 and an earlier age of onset for both psoriasis (P =.028) and arthritis (P =.006), male gender (P =.002), bilateral sacroiliitis (P =.002), and uveitis (P =.026). HLA-B27 negative patients developed more peripheral erosions than HLA-B27 positive patients (P =.05). No correlation was found between B27 and clinical symptoms of back involvement, syndesmophytes, or functional impairment. CONCLUSIONS: The HLA-B27 antigen is not only important for PsSpA susceptibility, but also determines some clinical features. This antigen was associated with earlier age of psoriasis and arthritis onset, bilateral sacroiliitis, and male gender. However, it was not associated with either the severity or extension of the spondylitic process or with functional impairment.     

Radiological sacroiliitis, a hallmark of spondylitis, is linked with CARD15 gene polymorphisms in patients with Crohn's disease

BACKGROUND: Sacroiliitis is a common extraintestinal manifestation of Crohn's disease but its association with the HLA-B27 phenotype is less evident. Polymorphisms in the CARD15 gene have been linked to higher susceptibility for Crohn's disease. In particular, associations have been found with ileal and fibrostenosing disease, young age at onset of disease, and familial cases. OBJECTIVES: To investigate whether the presence of sacroiliitis in patients with Crohn's disease is linked to the carriage of CARD15 polymorphisms. METHODS: 102 consecutive patients with Crohn's disease were clinically evaluated by a rheumatologist. Radiographs of the sacroiliac joints were taken and assessed blindly by two investigators. The RFLP-PCR technique was used to genotype all patients for three single nucleotide polymorphisms (SNP) in the CARD15 gene. Every SNP was verified by direct sequencing. The HLA-B27 phenotype was determined. RESULTS: Radiological evidence of sacroiliitis with or without ankylosing spondylitis was found in 23 patients (23%), of whom only three were HLA-B27 positive. In contrast, 78% of patients with sacroiliitis carried a CARD15 variant v 48% of those without sacroiliitis (p = 0.01; odds ratio 3.8 (95% confidence interval, 1.3 to 11.5)). Multivariate analysis (logistic regression) showed that the association between sacroiliitis and CARD15 polymorphisms was independent of other CARD15 related phenotypes (ileal and fibrostenosing disease, young age at onset of disease, familial Crohn's disease) (p = 0.039). CONCLUSIONS: CARD15 variants were identified as genetic predictors of Crohn's disease related sacroiliitis. An association was demonstrated between these polymorphisms and an extraintestinal manifestation of Crohn's disease.     

Clinical features of late onset psoriatic arthritis.

The aim of this work is to compare the clinical and radiological manifestations of patients presenting late onset psoriatic arthritis (PsA) with early onset PsA. An overall of 96 consecutive PsA patients were studied over an 8-month-period. Clinical, laboratory and radiographic signs were assessed. Of the 96 patients studied, 84 had their earliest symptoms before the age of 60 (Group I) and 12 after it (Group II). In Group II the mean age was 65.7 years (range 60-73), the sex ratio (male/female) was 9/3. All patients were HLA-B27 negative; the clinical forms observed were: polyarticular (6 patients; 50%), oligoarticular (4 patients; 33%) and spondyloarthropathy (SpA) (2 patients; 17%). Only two patients had asymmetric sacroiliitis and three had history of dactylitis episodes. In conclusion, we found distinct clinical manifestations in late onset PsA. Peripheral affection was found predominant. The male/female ratio was higher than other age groups.     

The functional significance of sacroiliitis and ankylosing spondylitis in Reiter's syndrome

The frequent development of sacroiliitis and ankylosing spondylitis (AS) in patients suffering from Reiter's Syndrome (RS) has been stressed by a number of authors. This study was designed to ascertain the frequency of these problems in our RS patients, whether they were related to other clinical features of RS and what was the extent of the resulting disability. Fifty-five patients (50 men and 5 women) with RS with a mean duration of 9.3 years were assessed radiologically to determine the prevalence of sacroiliitis and thoracolumbar syndesmophyte formation. These radiological findings were correlated with HLA-B27, clinical features and functional status. Sacroiliitis was found in 22 patients (40%) but was mild in severity, frequently asymmetrical and very rarely associated with syndesmophyte formation. Sacroiliitis occurred significantly more commonly in patients with iritis and/or a prolonged disease duration (p less than 0.05) but although it was also found more frequently in HLA-B27 positive patients this was not significant (0.1 greater than p greater than 0.05). Some restriction in back movement was observed in 31 patients (56.3%) but only two patients satisfied New York criteria for AS and just one was functionally impaired by his back disease. Although the frequent finding of sacroiliitis in RS may provide an interesting insight into the interrelationship between RS and AS, our study shows that this sacroiliitis is commonly asymptomatic and does not provide a problem in management.     

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

OBJECTIVE: To determine the rate and factors associated with ankylosing spondylitis in a cohort of patients with undifferentiated spondyloarthritides (SpA). METHODS: 62 consecutive patients with undifferentiated SpA seen between 1998 and 1999 underwent clinical and imaging evaluations throughout follow up. The main outcome measure was a diagnosis of ankylosing spondylitis. RESULTS: 50 patients with peripheral arthritis (n = 35) and inflammatory back pain (n = 24) (26 male; mean (SD) age at onset, 20.4 (8.8) years; disease duration 5.4 (5.7) years) were followed up for 3-5 years. At baseline, >90% of patients had axial and peripheral disease, while 38% had radiographic sacroiliitis below the cut off level for a diagnosis of ankylosing spondylitis (BASDAI 3.9, BASFI 2.9). At the most recent evaluation, 21 patients (42%) had ankylosing spondylitis. Two factors were associated with a diagnosis of ankylosing spondylitis in multivariate analysis: radiographic sacroiliitis grade <2 bilateral, or grade <3 unilateral (odds ratio (OR) = 11.18 (95% confidence interval, 2.59 to 48.16), p = 0.001), particularly grade 1 bilateral (OR = 12.58 (1.33 to 119.09), p = 0.027), and previous uveitis (OR = 19.25 (1.72 to 214.39), p = 0.001). Acute phase reactant levels, juvenile onset, and HLA-B27 showed a trend to linkage with ankylosing spondylitis (NS). CONCLUSIONS: Low grade radiographic sacroiliitis is a prognostic factor for ankylosing spondylitis in patients originally classified as having undifferentiated SpA. Low grade radiographic sacroiliitis should be regarded as indicative of early ankylosing spondylitis in patients with undifferentiated SpA.     

Magnetic resonance imaging of sacroiliitis in early seronegative spondylarthropathy. Abnormalities correlated to clinical and laboratory findings

OBJECTIVE: To compare a new MRI scoring system of the sacroiliac joints (SIJs) in early spondylarthropathy (SpA) with clinical and laboratory parameters. METHODS: Forty-one patients (24 males, 17 females) with a median age of 26 yr and a median duration of inflammatory low back pain of 19 months were included. They all fulfilled the ESSG-criteria for SpA. The patients were examined by MRI of the SIJs using a new scoring system. Clinical examinations, biochemical tests, functional score (BASFI), and pain score (BASDAI) were also performed. RESULTS: 95% of the patients had inflammation and/or destructive bone changes of the SIJs at MRI. No correlation was found between MRI pathology and clinical findings. MRI demonstrated significantly greater severity of both inflammation and destruction of the SIJs in HLA B27 positive patients than in the HLA B27 negative patients. CONCLUSIONS: In patients with early SpA, MRI was able to detect inflammatory and destructive changes of the SIJs, but the changes were not associated to clinical findings. Our results suggest a role of MRI in the detection of early-stage sacroiliitis.     

Evaluation of acute and chronic MRI features of sacroiliitis in asymptomatic primary hyperparathyroid patients

Asymptomatic primary hyperparathyroidism (PHPT) is characterized with autonomous overproduction of parathyroid hormone without signs or symptoms associated with hyperparathyroidism. Before symptoms become obvious, PHPT may affect structures like sacroiliac joints, which consist of bone. So, in the asymptomatic PHPT patients, structural and inflammatory changes in sacroiliac joints may lead to confusion during diagnosis workup of axial spondyloarthropathy. In this study, we evaluated active and chronic sacroiliac magnetic resonance imaging (MRI) changes relevant to sacroiliitis in the patients with asymptomatic PHPT and interpreted bone marrow edema within the scope of Assessment of SpondyloArthritis International Society–Outcome Measures in Rheumatology Clinical Trials (ASAS-OMERACT) criteria. Forty-nine patients with asymptomatic PHPT, 26 patients with newly diagnosed axial spondyloarthropathy (SpA), and 37 healthy controls were enrolled. All subjects were evaluated by sacroiliac MRI for four active (bone marrow edema, enthesitis, capsulitis, and synovitis) and four chronic (subchondral sclerosis, subchondral/periarticular erosions, periarticular fat deposition, and bony bridges/ankylosis) lesions relevant to sacroiliitis. Bone marrow edema compatible with ASAS-OMERACT active sacroiliitis criteria in sacroiliac MRI was fulfilled by 16.3 % (8/49) of the asymptomatic PHPT patients which was similar with controls but statistically lower than axial SpA. Moreover, asymptomatic PHPT patients and controls were similar for other chronic or active MRI findings. Also, we detected lower frequency of all other MRI findings, except enthesis, in asymptomatic PHPT patients according to axial SpA. Acute inflammatory including bone marrow edema fulfilling ASAS-OMERACT active sacroiliitis criteria and chronic structural sacroiliac lesions relevant to sacroiliitis in MRI were detected in asymptomatic PHPT similar frequency with controls but as expected, lower than axial SpA. But, these findings could not be attributed to excessive secretion of parathyroid hormone.     

The occurrence of sacroiliitis in HLA-B*35-positive patients with undifferentiated spondyloarthritis. A cross sectional MRI study

Clinical Rheumatology - To investigate possible association between sacroiliitis and HLA-B*35 positivity. After excluding patients with axial spondyloarthritis and HLA-B*27 positivity, psoriasis...     

Clinical and genetic factors associated with sacroiliitis in Crohn's disease

Background and Aim: Radiographic sacroiliitis (SI), often asymptomatic, is considered the most frequent extra‐intestinal manifestation (EIM) of Crohn's disease (CD). Data on the association of SI with other clinical features of CD are limited. Association of SI with CARD15 polymorphisms has recently been suggested. In a multicenter study, we investigated the association of SI in CD patients with clinical phenotypes, other EIM and CARD15 polymorphisms. Methods: Radiographs of the sacroiliac joints were taken in 251 CD patients from three Belgian university hospitals and scored by two blinded rheumatologists. Clinical features were obtained from medical records. Forty‐three percent of patients carried at least one CARD15 polymorphism. Results: Sacroiliitis, defined as the presence of at least grade 2 unilateral changes, was diagnosed in 65 of the 244 scorable radiographs (27%). Only 16 of these patients were previously diagnosed with ankylosing spondylitis (AS). HLA‐B27 positivity was observed in 53% of patients with AS and 7% of patients with radiographic SI. In univariate and multivariate analysis, associations between the presence of SI and peripheral arthritis (P = 0.005) and between AS and uveitis (P = 0.005) were found. No associations with other recorded clinical features or with CARD15 polymorphisms were observed. Conclusion: We confirm the high prevalence of radiographic sacroiliitis in a multicenter CD cohort. Uveitis is only associated with AS whereas all patients with SI are more prone to develop peripheral arthritis during their disease course, suggesting similar pathogenetic mechanisms in the development of these EIM. The previously reported association between SI and CARD15 polymorphisms was not confirmed.     

The influence of patient characteristics, disease variables, and HLA alleles on the development of radiographically evident sacroiliitis in juvenile idiopathic arthritis

OBJECTIVE: To assess the frequency of sacroiliitis and the radiographic and clinical outcome in juvenile idiopathic arthritis (JIA) and determine patient characteristics, early disease variables, and genetic markers that predict development of sacroiliitis. METHODS: We performed a retrospective cohort study of 314 (79%) of the 400 JIA patients first admitted to the hospital between 1980 and 1985. The participants were examined after a median disease duration of 14.9 years (range 11.7-25.1). Radiographs of the sacroiliac joints, hips, ankles, and tarsi were obtained and studied in a blinded manner by 2 radiologists. The presence of HLA-DRB1 and DPB1 alleles was determined by genotyping and that of HLA-B27 by serologic testing. Variables relating to the onset and course of the disease were obtained by chart reviews. RESULTS: Twenty (6%) of the JIA patients developed radiographic sacroiliitis according to the New York criteria. In 9 patients (45%), sacroiliitis had not been demonstrated before the followup examination. At followup, spinal flexion (lateral and anterior) was reduced in 70-75% of patients with sacroiliitis and in 30-35% of those without sacroiliitis. Compared with the JIA patients without sacroiliitis, those with sacroiliitis more frequently had inflammatory back pain, enthesitis, radiographic changes in the hips and calcanei, erosions of any peripheral joint, and uveitis. Predictors of sacroiliitis were HLA-B27, absence of DPB1*02, hip joint involvement within the first 6 months, and disease onset after age 8 years. The following factors were more common among patients in whom sacroiliitis developed than in other JIA patients: DRB1*04, male sex, family history of ankylosing spondylitis, psoriasis, inflammatory back pain, and enthesitis within the first 6 months. CONCLUSION: In the current study, radiographically evident sacroiliitis had developed in 6% of JIA patients after a median disease duration of 14.9 years. HLA-B27, absence of DPB1*02, late onset of disease, and early hip involvement were predictors of sacroiliitis.     

Radiographic assessment of sacroiliitis by radiologists and rheumatologists: does training improve quality?

OBJECTIVE: To assess performance of radiologists and rheumatologists in detecting sacroiliitis METHODS: 100 rheumatologists and 23 radiologists participated. One set of films was used for each assessment, another for training, and the third for confidence judgment. Films of HLA-B27+ patients with AS were used to assess sensitivity. For specificity films of healthy HLA-B27- relatives were included. Plain sacroiliac (SI) films with simultaneously taken computed tomographic scans (CTs) were used for confidence judgment. Three months after reading the training set, sensitivity and specificity assessments were repeated. Next, participants attended a workshop. They also rated 26 SI radiographs and 26 CTs for their trust in each judgment. Three months later final assessments were done. RESULTS: Sensitivity (84.3%/79.8%) and specificity (70.6%/74.7%) for radiologists and rheumatologists were comparable. Rheumatologists showed 6.3% decrease in sensitivity after self education (p=0.001), but 3.0% better specificity (p=0.008). The decrease in sensitivity reversed after the workshop. Difference in sensitivity three months after the workshop and baseline was only 0.5%. Sensitivity <50% occurred in 13% of participants. Only a few participants showed changes of >5% in both sensitivity and specificity. Intraobserver agreement for sacroiliitis grade 1 or 2 ranged from 65% to 100%. Sensitivity for CT (86%) was higher than for plain films (72%) (p<0.001) with the same specificity (84%). Confidence ratings for correctly diagnosing presence (7.7) or absence (8.3) of sacroiliitis were somewhat higher than incorrectly diagnosing the presence (6.6) or absence (7.4) of sacroiliitis (p<0.001). CONCLUSION: Radiologists and rheumatologists show modest sensitivity and specificity for sacroiliitis and sizeable intraobserver variation. Overall, neither individual training nor workshops improved performance.     

How to diagnose axial spondyloarthritis early

BACKGROUND: Chronic low back pain (LBP), the leading symptom of ankylosing spondylitis (AS) and undifferentiated axial spondyloarthritis (SpA), precedes the development of radiographic sacroiliitis, sometimes by many years. OBJECTIVE: To assign disease probabilities and to develop an algorithm to help in the early diagnosis of axial SpA. METHODS: Axial SpA comprises AS and undifferentiated SpA with predominant axial involvement. Clinical features include inflammatory back pain (IBP), alternating buttock pain, enthesitis, arthritis, dactylitis, acute anterior uveitis, a positive family history, psoriasis, inflammatory bowel disease, and good response to NSAIDs. Associated laboratory findings include raised acute phase reactions, HLA-B27 association, and abnormalities on skeletal imaging. Sensitivities, specificities, and likelihood ratios (LRs) of these parameters were determined from published studies. A 5% prevalence of axial SpA among patients with chronic LBP was used. The probability of the presence of axial SpA, depending on the presence or absence of the above clinical features of SpA, was determined. A probability of > or = 90% was used to make a diagnosis of axial SpA. RESULTS: The presence of inflammatory back pain features increased the probability of axial SpA from the background 5% prevalence to 14%. The presence of 2-3 SpA features was necessary to increase the probability of axial SpA to 90%. The highest LRs were obtained for HLA-B27 and MRI. Diagnostic algorithms to be used in daily practice were suggested. CONCLUSIONS: This approach can help clinicians to diagnose with a high degree of confidence axial SpA at an early stage in patients with IBP who lack radiographic sacroiliitis.