Male spondyloarthritis patients and those with longer disease duration have less severe disc degeneration: propensity score-matched comparison

Objective

Using whole spine sagittal T2 MRI, we aimed to compare the severity and prevalence of disc degeneration (DD) in axial SpA patients vs the general population and to determine any association between spinal inflammation, structural changes, mobility and DD among SpA patients.

Methods

Two prospectively collected cohorts of SpA patients (n = 411) and the general population (n = 2007) were recruited. Eventually, 967 participants from the populational cohort and 304 participants from the SpA cohort were analysed. Two hundred and nineteen matched pairs were generated by propensity score matching. Imaging parameters, including Pfirrmann grading, disc herniation, high-intensity zone, Schmorl's node, Modic change and anterior marrow change were studied and compared from C2/3 to L5/S1. DD was defined as Pfirrmann grade 4 or 5. Demographic factors, including age, sex and BMI, were collected. Multivariable linear regression was used to determine the association between spinal inflammation [Spondyloarthritis Research Consortium of Canada (SPARCC) spine MRI index], structural changes [modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS)] and mobility (BASMI) with lumbar Pfirrmann score.

Results

SpA patients had lower prevalence of DD (P < 0.001). The disease stage-stratified regression model showed that SPARCC spinal MRI index was associated with higher lumbar Pfirrmann scores in early disease (β = 0.196, P = 0.044), whereas mSASSS was associated with lower lumbar Pfirrmann scores in later disease (β = -0.138, P = 0.038). Males had higher mSASSS (P < 0.001) and lower odds of whole spine DD (odds ratio = 0.622, P = 0.028).

Conclusion

SpA patients had lower DD severity than the general population. Males had higher mSASSSs, and increased mSASSS at later disease was associated with less severe DD.

Propensity-matched Comparison Between Chronic Nonspecific Low Back Pain and Axial Spondyloarthritis: Impact on patient-perceived Quality of Life

STUDY DESIGN

Prospective study.

OBJECTIVE

To compare the burden between chronic nonspecific low back pain (LBP) and axial spondyloarthropathy (SpA).

SUMMARY OF BACKGROUND DATA

Chronic nonspecific LBP and SpA are two debilitating yet different chronic musculoskeletal disorders. To compare their burden, propensity score matching is used to control for potential confounders and match the study subjects.

MATERIALS AND METHODS

Two prospectively collected cohorts of LBP (n=269) and SpA (n=218) patients were studied. Outcomes included current LBP, 36-item Short Form Questionnaire, Oswestry Disability Index, EuroQol 5-dimension 5-level Questionnaire, and EuroQol Visual Analog Scale. With the inherent differences between the two types of patients, propensity score matching was performed for comparing the two groups. Baseline covariates of age, sex, education level, occupation, smoking, and drinking history were selected for the estimation of propensity scores for each subject with the logistic regression model. Significant independent variables for the outcome of current back pain were included in the multivariate logistic regressions.

RESULTS

A total of 127 matched pairs were identified, with 254 patients. In the matched cohort, more patients with chronic LBP had current back pain (95.3%) as compared with SpA (71.7%). Patients with SpA were younger ( P <0.001), with more males ( P <0.001), and better educated ( P =0.001). There was less current back pain and higher nonsteroidal anti-inflammatory drug use ( P <0.001). Most SpA patients had lower Oswestry Disability Index than LBP patients and with low disease activity. Patients with LBP had worse outcome scores as compared with SpA patients given the same Visual Analog Scale. LBP patients had 8.6 times the odds (95% CI: 3.341-20.671; P <0.001) of experiencing current back pain compared with SpA patients.

CONCLUSIONS

The disease activity of SpA patients is well controlled. However, patients with chronic LBP have worse pain severity, disability, and health-related quality of life. This has implications on resource utilization and the necessity of advancing LBP understanding and management.

LEVEL OF EVIDENCE

Type I prognostic study.

MRI lesions in SpA: a comparison with noninflammatory back pain using propensity score adjustment method

Background:

Magnetic resonance imaging (MRI) is important in the management of axial spondyloarthritis (SpA). However, many MRI lesions are not exclusive to axial SpA. Further characterization of these lesions may lead to better clinical decisions.

Objective:

The objective of this study was to compare the frequency of individual spinal MRI lesions between axial SpA and noninflammatory back pain. The factors associated with individual lesions in participants with axial SpA were also determined.

Design:

This was a cross-sectional observational study.

Methods:

MRI lesions in 447 participants with axial SpA and 122 participants with noninflammatory back pain were compared using the propensity score adjustment method. Individual lesions included discovertebral lesions (DVL), Modic type 1 lesions, DVL without Modic type 1 lesions, facet joint lesions, costovertebral joint lesions, corner inflammatory lesions (CIL), and fatty corner lesions (FCL). The factors associated with the lesions were determined using regression analyses.

Results:

Among participants with axial SpA, 81.9% were HLA-B27-positive, 55.0% had radiographic axial SpA, and 60.5% had radiographic features of spinal damage (mSASSS >2). Almost half (48.6% in axial SpA versus 31.1% in noninflammatory back pain) had inflammatory lesions on spinal MRI. In propensity score matching with noninflammatory back pain, axial SpA had an increased occurrence of DVL without Modic type 1 lesion (OR = 3.43, p = 0.01), costovertebral lesion (OR = 11.89, p = 0.02), number of CIL (B = 1.19, p < 0.001), and number of FCL (B = 3.33, p < 0.001). Similar associations were found in the regression models in the radiographic axial SpA subgroup: DVL without Modic type 1 lesion (OR = 2.46, p = 0.001), costovertebral lesion (OR = 3.86, p < 0.001), number of CIL (B = 1.13, p < 0.001), and FCL (B = 2.29, p < 0.01).

Conclusion:

MRI lesions including DVL without Modic type 1, costovertebral joint lesions, CIL, and FCL were more specific in axial SpA.

Clinical, radiological, and magnetic resonance imaging characteristics of axial spondyloarthritis with late onset

We aimed to investigate the clinical, diagnostic, and imaging features of patients with late onset axial spondyloarthritis (SpA) with initial symptom manifestation aged over 45 years. Participants with axial SpA were consecutively recruited. Clinical, demographic, blood, and imaging parameters were compared between the groups with early (≤45 years) and late onset (>45 years) at a cross-sectional level. Logistic regressions were used to determine the independent associations with axial SpA with late onset. A total of 455 participants were recruited. Among them, 70 (15.4%) had late onset disease. Multivariate analyses showed that axial SpA with late onset was associated with higher C-reactive protein based ankylosing spondylitis disease activity index (ASDAS-CRP) (B = 0.10; P = .04), higher intensity of spinal inflammation as measured by maximum apparent diffusion coefficient (spinal ADC max) (B = 0.27; P = .03) and mean ADC (spinal ADC mean) (B = 0.30; P = .004), lower modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) (B = -0.12; P = .02), more tender joint count (B = 0.12; P = .02), and fewer inflammatory back pain (IBP) (OR = 0.26; P < .001). Axial SpA with late onset had higher clinical disease activity, higher intensity of spinal MRI inflammation, less radiographic damage, and more tender joint count. There was also less inflammatory back pain, which could make the diagnosis more difficult.

Both ASDAS and ADC are associated with spinal mobility in active axial spondyloarthritis: A comparison between early and later disease

OBJECTIVE

Using diffusion-weighted imaging (DWI)-derived apparent diffusion coefficient (ADC), we aimed to determine the relationship between intensity of spinal inflammation and mobility in patients with axial spondyloarthritis (SpA) in early and later stages of active disease. The Ankylosing Spondylitis Disease Activity Score (ASDAS) was also used for a more comprehensive evaluation.

METHODS

Participants with axial SpA and back pain were recruited from 10 rheumatology centers. Clinical, biochemical and radiological parameters were collected. Short tau inversion recovery (STIR) sequence magnetic resonance imaging (MRI) and DWI of the spine and sacroiliac (SI) joints were performed. ADC maps were generated. Participants were examined for Bath Ankylosing Spondylitis Metrology Index (BASMI). Linear regression models were used to determine associations between BASMI and various clinical, radiological, and MRI parameters in participants with active inflammation on spinal ADC maps.

RESULTS

One-hundred and twenty-seven participants were included in the analyses. Multivariate linear regression showed that mean ADC spine (ß = .16; P = .03), ASDAS-C-reactive protein (CRP) (ß = .29, P < .001), and ASDAS-erythrocyte sedimentation rate (ESR) (ß = .25, P < .01) were associated with BASMI. In participants with duration of back pain ≤3 years, mean spine ADC (ß = .37; P = .03), ASDAS-CRP (ß = .44; P = .01), and ASDAS-ESR (ß = .42; P = .01) were associated with BASMI after adjustment for confounding factors. In participants with duration of back pain >3 years, only ASDAS-CRP (ß = .25; P < .01) and ASDAS-ESR (ß = .20; P = .20) were associated with BASMI.

CONCLUSION

Intensity of inflammation and clinical disease activity were independently associated with impairment of spinal mobility. The associations were stronger in early (≤3 years) than later disease.

Responsiveness of the EuroQoL 5-Dimension (EQ-5D) questionnaire in patients with spondyloarthritis

Background

Spondyloarthritis (SpA) has a significant impact on patients’ quality of life due to functional impairments. Generic health instruments like the EuroQoL 5-dimension (EQ-5D) is important for cost-utility analysis of health care interventions and calculation of quality-adjusted life-years. It has been validated in patients with SpA. However, its responsiveness property is unclear. Hence, the aim of study is to test the responsiveness properties of the EQ-5D health measure for Chinese patients with SpA.

Methods

Prospective and consecutive recruitment of 151 Chinese patients with SpA was conducted with follow-up assessments 6 months later. Demographic data including smoking and drinking habits, education level, income and occupation was collected. Disease-associated data including disease duration, presence of back pain, peripheral arthritis, dactylitis, enthesitis, uveitis, psoriasis, and inflammatory bowel disease was also recorded. Questionnaires regarding disease activity and functional disability (BASDAI, BASFI, BASGI, BASMI, ASDAS), mental health (HADS) and the EQ-5D scores were recorded. Responsiveness was tested against the global rating of change scale (GRC) and changes in disease activity using BASDAI and ASDAS-CRP.

Results

A total of 113 (74.8%) patients completed the follow-up assessments. Most patients (61.6%) had low disease activity level with BASDAI <4 and 39.7% of patients had inactive disease by ASDAS-CRP. EQ-5D scores was well discriminated along with BASDAI and BASFI scores. EQ-5D scores also correlated well with HADS. The GRC was not able to discriminate adequately. No significant ceiling or floor effect was observed.

Conclusions

EQ-5D demonstrates satisfactory responsiveness property for assessment of changes in SpA disease activity.

Level of evidence

II

MRI inflammation of facet and costovertebral joints is associated with restricted spinal mobility and worsened functional status

OBJECTIVE

To investigate the association of spinal inflammation on MRI in patients with various clinical, functional and radiological outcomes in patients with axial spondyloarthritis (SpA).

METHODS

Three hundred and ninety-seven participants with axial SpA and back pain were recruited from 10 rheumatology centres. Clinical, biochemical and radiological parameters were collected and participants underwent MRI of the spine. MRI features including inflammatory lesions of facet joints and costovertebral joints, corner inflammatory lesions, and spondylitis were assessed. BASFI, Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis Global Index, BASMI and modified Stoke Ankylosing Spondylitis Spinal Score were measured. Multivariate linear regression models were used to determine the associations between MRI parameters and various clinical, functional and radiological outcomes.

RESULTS

BASMI and BASFI correlated well with inflammatory features in spinal MRI. Multivariate analysis showed that lumbar facet joint inflammation was independently associated with BASMI (regression coefficient (β) = 0.12, P < 0.001), lumbar spinal flexion (β = 0.13, P = 0.00), lateral spinal flexion (β = 0.09, P = 0.04), tragus-to-wall distance (β = 0.16, P < 0.001) and BASFI (β = 0.14, P = 0.01). Costovertebral joint inflammation was also associated with BASMI (β = 0.08, P = 0.05).

CONCLUSION

Inflammatory lesions of facet and costovertebral joints in MRI are associated with restriction in spinal mobility and functional impairment. These important yet commonly overlooked lesions should be reviewed in clinical practice in patients with SpA.

Diagnostic utility of whole spine and thoracic spine MRI corner inflammatory lesions in axial spondyloarthritis

Background:

The presence of ⩾3 corner inflammatory lesions has been proposed as the definition of a positive spinal magnetic resonance imaging (MRI) for axial spondyloarthritis (axSpA), but subsequent studies showed inconclusive findings. Our objective was to evaluate whether locations of corner inflammatory lesions (CILs) would affect the diagnostic utility of MRI in axSpA.

Method:

Two groups were consecutively recruited from eight rheumatology centers in Hong Kong. The ‘axSpA’ group included 369 participants with a known diagnosis of axSpA. The ‘non-specific back pain’ (NSBP) control group consisted of 117 participants. Clinical, biochemical, and radiological parameters were collected and all patients underwent MRI of the spine and sacroiliac joints. CILs were assessed based on their locations (cervical, thoracic or lumbar) to determine the optimal cutoff for diagnosis.

Results:

The cutoff of ⩾5 whole spine CILs (W-CILs) and ⩾3 thoracic spine CILs (T-CILs) had comparable specificity to MRI sacroiliitis. Of 85/369 axSpA patients without sacroiliitis on conventional radiograph or MRI, 7 had ⩾5 W-CILs and 11 had ⩾3 T-CILs. Incorporating the proposed cutoffs into Assessment of SpondyloArthritis international Society axSpA criteria, ⩾5 W-CILs and ⩾3 T-CILs had similar performance when added to the imaging criteria for sacroiliitis (sensitivity 0.79 versus 0.80, specificity 0.92 versus 0.91).

Conclusion:

Spinal MRI provided little incremental diagnostic value in unselected axSpA patients. However, in patients without sacroiliitis on MRI or radiographs, 8–13% might be diagnosed by spinal MRI. Thoracic and whole spine MRI had similar diagnostic performance using the proposed cutoff of ⩾5 W-CILs and ⩾3 T-CILs.

Intensity of spinal inflammation is associated with radiological structural damage in patients with active axial spondyloarthritis

Objective

The aim was to investigate the relationship between the intensity of spinal inflammation using the apparent diffusion coefficient (ADC) and radiographic progression in axial SpA.

Methods

This is a cross-sectional study of participants with axial SpA and back pain. Clinical, biochemical and radiological parameters were collected. The ankylosing spondylitis disease activity score (ASDAS)-CRP was determined. Radiographic progression was represented by the modified Stoke ankylosing spondylitis spine score (mSASSS). MRI with short tau inversion recovery (STIR) and diffusion-weighted imaging sequences were performed simultaneously. Inflammatory lesions on STIR were used for the Spondyloarthritis Research Consortium of Canada (SPARCC) MRI indexes and as references in outlining regions of interest in ADC maps to produce mean (ADC_mean) and maximal (ADC_max) ADC values. Univariate and multivariate linear regression analyses were used to determine independent associations between ADC and radiographic progression.

Results

The 84 participants with identifiable lesions on spinal ADC maps recruited were characterized by a mean (s.d.) age of 45.01 (13.68) years, long disease duration [13.40 (11.01) years] and moderate clinical disease activity [ASDAS-CRP 2.07 (0.83)]. Multivariate regression analysis using ADC_mean as the independent variable showed that age (regression coefficient [B] = 0.34; P = 0.01), male sex (B = 0.25; P = 0.04) and ADC_mean (B = 0.30; P = 0.01) were positively associated with mSASSS. Multivariate regression analysis using ADC_max as the independent variable showed a tendency for ADC_max to be associated with mSASSS (B = 0.21; P = 0.07).

Conclusion

The intensity of spinal inflammation as determined by ADC is associated with radiographic progression in participants with active axial SpA.

Pack-year Smoking Associated with Poorer Functional Status, Worsened Spinal Mobility and More Radiological Damages

Introduction: To study the dose-response relationship between smoking and axial Spondyloarthritis (axSpA) disease outcome.

Method: One hundred and sixty participants with axSpA were recruited from a single rheumatology center. All of them fulfilled the classification criteria for axSpA by the Assessment of SpondyloArthritis International Society (ASAS). Clinical, demographic and biochemical data was collected. Participants were asked for detailed smoking histories including past and current smoking, smoking duration and quantity. Radiographs of cervical and lumbar spine were performed for modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) and modified New York (MNY) criteria for radiological sacroiliitis. Ankylosing Spondylitis Disease Activity Score (ASDAS) was calculated based on C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Univariate and multivariate regression models were performed to determine the associations between pack-year smoking and different disease outcomes.

Results: Among the participants, 62 (38.7%) were either current (N [Formula: see text] 39) or former smokers (N [Formula: see text] 23). Ex-smokers quit smoking by 18.8 ± 12.4 years. The mean pack-year for patients who had ever smoked was 19.4 ± 23.1. In univariate analyses, pack-year smoking was associated with BASFI (p <0.001), modified Schober test (p [Formula: see text] 0.01) and mSASSS (p <0.001). Multivariate regression models showed independent dose-response associations between pack-year of smoking and BASFI (SC 0.23; 95% CI 0.01 to 0.06; p [Formula: see text] 0.004), modified Schober test (SC −0.16; 95% CI −0.03 to 0.00; p [Formula: see text] 0.049) and mSASSS (SC 0.22; 95% CI 0.09 to 0.47; p [Formula: see text] 0.01).

Conclusion: In Chinese axSpA patients, pack-year smoking was independently associated with poorer functional status, worsened spinal mobility and more radiological damages. Smoking cessation should be encouraged in patients with axSpA.

ASDAS is associated with both the extent and intensity of DW-MRI spinal inflammation in active axial spondyloarthritis

Objective

To investigate the relationship between Ankylosing Spondylitis Disease Activity Score (ASDAS) and intensity of spinal inflammation measured by apparent diffusion coefficient (ADC) in MRI in participants with active axial spondyloarthritis (SpA).

Methods

Participants with axial SpA and back pain were recruited. Clinical, demographic, biochemical and imaging data were collected. ASDAS was calculated based on C reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Inflammatory lesions were identified in short tau inversion recovery images and the corresponding ADC maps to determine the maximum apparent diffusion coefficient (ADCmax), normalised maximum ADC, mean apparent diffusion coefficient (ADCmean) and normalised mean ADC by two independent readers. Spondyloarthritis Research Consortium of Canada (SPARCC) spine and sacroiliac (SI) joint MRI indexes were determined. Univariate and multivariate linear regression models were used to determine the associations between of ASDAS with ADC values, SPARCC spine and SI MRI scores.

Results

Eighty-two participants had identifiable ADC lesions. Multivariate analyses using ADCmax and SPARCC spine MRI as independent variables showed associations with ASDAS-CRP (ADCmax: B=0.27, p=0.02; SPARCC: B=0.32, p=0.01) and ASDAS-ESR (ADCmax: B=0.24, p=0.03; SPARCC: B=0.36, p<0.01); using ADCmean and SPARCC spine MRI as independent variables also showed an association with ASDAS-ESR (ADCmean: B=0.22, p=0.05; SPARCC: B=0.36, p<0.01) and a tendency to associate with ASDAS-CRP (ADCmean: B=0.21, p=0.07; SPARCC: B=0.34, p<0.01).

Conclusion

ASDAS is associated with both the extent and the intensity of spinal inflammation in patients with detectable inflammatory lesions. Our results showed that ASDAS is an objective disease assessment tool.

Trial registration number

HKUCTR-2087.

Psychometric validation of the EuroQoL 5-dimension (EQ-5D) questionnaire in patients with spondyloarthritis

BACKGROUND

Spondyloarthritis (SpA) has a significant impact on patients' quality of life due to functional impairments. Generic health instruments like the EuroQoL 5-dimension (EQ-5D) is important for the cost-utility analysis of health care interventions and calculation of quality-adjusted life years. However, the applicability of the EQ-5D health measure in Chinese patients with SpA is currently unknown. Hence, the aim of the study is to test the psychometric properties and to validate the use of the EQ-5D health measure for utility analyses in Chinese patients with SpA.

METHODS

Prospective and consecutive recruitment of 220 Chinese patients with SpA was conducted. Demographic data including smoking and drinking habits, education level, income, and occupation was collected. Disease-associated data including disease duration, the presence of back pain, peripheral arthritis, dactylitis, enthesitis, uveitis, psoriasis, and inflammatory bowel disease was also recorded. Questionnaires regarding disease activity and functional disability (BASDAI, BASFI, BASGI, BASMI, ASDAS, ODI), mental health (HADS depression and anxiety), and the EQ-5D scores were recorded. SF-36 scores were used to verify the findings. Baseline correlations were performed along with test-retest reliability, validity, and internal consistency tests. Specifically, the relationship between EQ-5D and disease activity and functional scores was studied.

RESULTS

EQ-5D scores achieved acceptable internal consistency and reliability. A ceiling effect was observed for all domains of the EQ-5D except for pain/discomfort. No floor effect was observed. Significant negative correlations were observed between ODI, HADS, BASFI, BASMI, BASDAI, and ASDAS-CRP and with EQ-5D. A higher disease activity was well-differentiated by EQ-5D, as with the disability and mental health scores.

CONCLUSIONS

The EQ-5D demonstrates satisfactory psychometric properties for assessment of SpA patients. It has high utility for demonstrating changes in disease activity and disability.

Diffusion-weighted imaging versus short tau inversion recovery sequence: Usefulness in detection of active sacroiliitis and early diagnosis of axial spondyloarthritis

Objective

To compare the utility of Diffusion weighted imaging (DWI) with short tau inversion recovery (STIR) sequence in the diagnosis of early axial spondyloarthritis (SpA).

Methods

Three hundred and five patients with chronic back pain were recruited consecutively from 3 rheumatology centers. Clinical, radiological and blood parameters were recorded. Patients with back pain duration no more than 3 years were classified as having early disease. STIR sequence and DWI of the sacroiliac joints were obtained and assessed using the Spondyloarthritis Research Consortium of Canada (SPARCC) method. The Assessment in Spondyloarthritis international Society definition was used to define positive STIR and DWI. Results were compared to expert diagnosed axial SpA.

Results

When compared to STIR sequence, DWI had similar sensitivity (STIR 0.29, DWI 0.30) and specificity (STIR 0.97, DWI 0.92) in diagnosing sacroiliitis. However, STIR sequence had better reliability (STIR 0.78, DWI 0.61). In early disease group, DWI was not better than STIR sequence in detecting active sacroiliitis (sensitivity DWI vs STIR: 0.34 vs 0.36; specificity DWI vs STIR: 0.93 vs 0.93; positive predictive value DWI vs STIR: 0.92 vs 0.92; negative predictive value DWI vs STIR: 0.36 vs 0.37). Using the Assessment in SpondyloArthritis international Society (ASAS) classification criteria, 67/98 patients with early disease (sensitivity 0.91 specificity 0.90) and 221/305 overall (sensitivity 0.90; specificity 0.92) were classified as axial SpA. Among the expert diagnosed axial SpA patients who did not meet the ASAS criteria, only 2 had positive DWI.

Conclusion

DWI and STIR have similar sensitivity in diagnosing axSpA in early disease. However, the use of DWI is limited by poorer reliability when compared with STIR.

Comparing diffusion weighted imaging with clinical and blood parameters, and with short tau inversion recovery sequence in detecting spinal and sacroiliac joint inflammation in axial spondyloarthritis

OBJECTIVES

To investigate the usefulness of diffusion weighted imaging (DWI) by comparing with clinical features, blood parameters and traditional short tau inversion recovery (STIR) sequence in detecting spinal and sacroiliac (SI) joint inflammation in axial spondyloarthritis (axSpA) patients.

METHODS

One hundred and ten axSpA patients were recruited. Clinical, radiological and blood parameters were recorded. DWI and STIR MRI were performed simultaneously and results were scored according to the Spondyloarthritis Research Consortium of Canada (SPARCC) for comparison. Apparent diffusion coef cient (ADC) values were also calculated.

RESULTS

DWI did not correlate with clinical parameters or blood parameters. It also had lowered sensitivity. When compared with STIR sequence, it correlated well with STIR sequence at the SI joint level (CC 0.76, p<0.001), but weakly at the spinal level (CC 0.23, p=0.02). At the SI joint level, the presence of inflammation on both STIR sequence and DWI was associated with an increase in maximum (B=0.24, p=0.02 in STIR; B=0.37, p<0.001 in DWI) and mean ADC values (B=0.17, p=0.003 in STIR; B=0.15, p=0.01 in DWI). Maximum (B=0.19, p=0.04) and mean spinal ADC values (B=0.18, p=0.01) were also positively associated with DWI detected spinal inflammation. Presence of Modic lesions showed positive correlation with STIR sequence (B=7.12, p=0.01) but not spinal ADC values.

CONCLUSIONS

Despite DWI correlates with STIR sequence, it has lower sensitivity. However, ADC values appear to be independent of Modic lesions and may supplement STIR sequence to differentiate degeneration.

Male smokers with HLA-B27 positivity, SI joints inflammation have more radiological damages and higher prevalence of AS while females have higher BASDAI scores: observations from cluster analyses of a group of SpA patients

Objectives

To describe the clinical characteristics and the relations with disease activity, functional status, and syndesmophytes formation in patients with axial spondyloarthritis (AxSpA) by categorizing them into different groups.

Methods

One hundred and sixty three patients with AxSpA were recruited. Clinical and blood parameters were collected. Patients were asked to complete the self-assessment questionnaires, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and Bath Ankylosing Spondylitis Functional Index (BASFI). Spinal mobility was measured according to Bath Ankylosing Spondylitis Metrology Index (BASMI). Radiographs of cervical and lumbosacral spine were performed for modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). Radiological sacroiliitis was scored for ankylosing spondylitis (AS). Magnetic resonance imaging (MRI) of the sacroiliac (SI) joints was performed for spondyloarthritis research consortium of Canada (SPARCC) MRI inflammation score. Two-way cluster analyses were performed to determine the relationships between the parameters.

Results

Two cluster models were built using SPARCC scores of different scorers. Results were similar. The group of patients with highest mSASSS (20.33 vs 20.33) and prevalence radiological AS (85% vs 86%) were male patients (75% vs 75%), positive for HLA-B27 (70.0% vs 66.7%), smokers (87.5% vs 97.2%), and higher SPARCC SI joints score (5.32 vs 3.17). Higher BASDAI was observed among female sex. BASMI varies little but the group with highest BASMI (3.60 vs 3.62) also had highest mSASSS (20.33 vs 20.33).

Conclusion

Our data showed that male smokers with HLA-B27 positivity and SI joints inflammation have more radiological damage and higher prevalence of AS, consistent with known poor prognosis factors.

Diffuse large B-cell lymphoma of the central nervous system in mycophenolate mofetil-treated patients with systemic lupus erythematosus

Patients with systemic lupus erythematosus (SLE) are susceptible to the development of lymphoproliferative disorders and postulated causes include intrinsic defects in immune surveillance and iatrogenic administration of immunosuppressants. Since the introduction of mycophenolate mofetil (MMF) to the immunosuppressive regimen for the management of post-organ transplantation, there have been reports of primary lymphoma of the central nervous system (PCNSL). MMF has been widely used to treat active SLE patients with Class IV lupus nephritis. In addition to two previously reported cases of PCNSL among SLE patients on long-term MMF, we report a third patient who has been on treatment with MMF for 8 years. The histology showed features compatible with diffuse large B-cell lymphoma with strong immunohistochemical staining for CD20 and positive signal for Epstein-Barr virus (EBV)-encoded RNA by in-situ hybridization that is similar to other case reports, suggesting EBV driven B-cell lymphoproliferative disease. The patient responded to withdrawal of MMF, intravenous methotrexate, rituximab and whole brain radiotherapy. With the increasing use of MMF in active renal as well as non-renal exacerbations of SLE, PCNSL should be included in the differential diagnosis in patients who present with gradual onset of focal neurological deficit.