Stroke frequency, associated factors, and clinical features in primary systemic vasculitis: a multicentric observational study

OBJECTIVES

The cerebral vessels may be affected in primary systemic vasculitis (PSV), but little is known about cerebrovascular events (CVEs) in this population. This study aimed to determine the frequency of CVEs at the time of diagnosis of PSV, to identify factors associated with CVEs in PSV, and to explore features and outcomes of stroke in patients with PSV.

METHODS

Data from adults newly diagnosed with PSV within the Diagnostic and Classification Criteria in VASculitis (DCVAS) study were analysed. Demographics, risk factors for vascular disease, and clinical features were compared between patients with PSV with and without CVE. Stroke subtypes and cumulative incidence of recurrent CVE during a prospective 6-month follow-up were also assessed.

RESULTS

The analysis included 4828 PSV patients, and a CVE was reported in 169 (3.50%, 95% CI 3.00-4.06): 102 (2.13% 95% CI 1.73-2.56) with stroke and 81 (1.68% 95% CI 1.33-2.08) with transient ischemic attack (TIA). The frequency of CVE was highest in Behçet's disease (9.5%, 95% CI 5.79-14.37), polyarteritis nodosa (6.2%, 95% CI 3.25-10.61), and Takayasu's arteritis (6.0%, 95% CI 4.30-8.19), and lowest in microscopic polyangiitis (2.2%, 95% CI 1.09-3.86), granulomatosis with polyangiitis (2.0%, 95% CI 1.20-3.01), cryoglobulinaemic vasculitis (1.9%, 95% CI 0.05-9.89), and IgA-vasculitis (Henoch-Schönlein) (0.4%, 95% CI 0.01-2.05). PSV patients had a 11.9% cumulative incidence of recurrent CVE during a 6-month follow-up period.

CONCLUSION

CVEs affect a significant proportion of patients at time of PSV diagnosis, and the frequency varies widely among different vasculitis, being higher in Behçet's. Overall, CVE in PSV is not explained by traditional vascular risk factors and has a high risk of CVE recurrence.

2022 American College of Rheumatology/EULAR Classification Criteria for Giant Cell Arteritis

OBJECTIVE

To develop and validate updated classification criteria for giant cell arteritis (GCA).

METHODS

Patients with vasculitis or comparator diseases were recruited into an international cohort. The study proceeded in 6 phases: 1) identification of candidate items, 2) prospective collection of candidate items present at the time of diagnosis, 3) expert panel review of cases, 4) data-driven reduction of candidate items, 5) derivation of a points-based risk classification score in a development data set, and 6) validation in an independent data set.

RESULTS

The development data set consisted of 518 cases of GCA and 536 comparators. The validation data set consisted of 238 cases of GCA and 213 comparators. Age ≥50 years at diagnosis was an absolute requirement for classification. The final criteria items and weights were as follows: positive temporal artery biopsy or temporal artery halo sign on ultrasound (+5); erythrocyte sedimentation rate ≥50 mm/hour or C-reactive protein ≥10 mg/liter (+3); sudden visual loss (+3); morning stiffness in shoulders or neck, jaw or tongue claudication, new temporal headache, scalp tenderness, temporal artery abnormality on vascular examination, bilateral axillary involvement on imaging, and fluorodeoxyglucose-positron emission tomography activity throughout the aorta (+2 each). A patient could be classified as having GCA with a cumulative score of ≥6 points. When these criteria were tested in the validation data set, the model area under the curve was 0.91 (95% confidence interval [95% CI] 0.88-0.94) with a sensitivity of 87.0% (95% CI 82.0-91.0%) and specificity of 94.8% (95% CI 91.0-97.4%).

CONCLUSION

The 2022 American College of Rheumatology/EULAR GCA classification criteria are now validated for use in clinical research.

2022 American College of Rheumatology/EULAR classification criteria for giant cell arteritis

OBJECTIVE

To develop and validate updated classification criteria for giant cell arteritis (GCA).

METHODS

Patients with vasculitis or comparator diseases were recruited into an international cohort. The study proceeded in six phases: (1) identification of candidate items, (2) prospective collection of candidate items present at the time of diagnosis, (3) expert panel review of cases, (4) data-driven reduction of candidate items, (5) derivation of a points-based risk classification score in a development data set and (6) validation in an independent data set.

RESULTS

The development data set consisted of 518 cases of GCA and 536 comparators. The validation data set consisted of 238 cases of GCA and 213 comparators. Age ≥50 years at diagnosis was an absolute requirement for classification. The final criteria items and weights were as follows: positive temporal artery biopsy or temporal artery halo sign on ultrasound (+5); erythrocyte sedimentation rate ≥50 mm/hour or C reactive protein ≥10 mg/L (+3); sudden visual loss (+3); morning stiffness in shoulders or neck, jaw or tongue claudication, new temporal headache, scalp tenderness, temporal artery abnormality on vascular examination, bilateral axillary involvement on imaging and fluorodeoxyglucose-positron emission tomography activity throughout the aorta (+2 each). A patient could be classified as having GCA with a cumulative score of ≥6 points. When these criteria were tested in the validation data set, the model area under the curve was 0.91 (95% CI 0.88 to 0.94) with a sensitivity of 87.0% (95% CI 82.0% to 91.0%) and specificity of 94.8% (95% CI 91.0% to 97.4%).

CONCLUSION

The 2022 American College of Rheumatology/EULAR GCA classification criteria are now validated for use in clinical research.

2022 American College of Rheumatology/EULAR Classification Criteria for Takayasu Arteritis

OBJECTIVE

To develop and validate new classification criteria for Takayasu arteritis (TAK).

METHODS

Patients with vasculitis or comparator diseases were recruited into an international cohort. The study proceeded in 6 phases: 1) identification of candidate criteria items, 2) collection of candidate items present at diagnosis, 3) expert panel review of cases, 4) data-driven reduction of candidate items, 5) derivation of a points-based classification score in a development data set, and 6) validation in an independent data set.

RESULTS

The development data set consisted of 316 cases of TAK and 323 comparators. The validation data set consisted of an additional 146 cases of TAK and 127 comparators. Age ≤60 years at diagnosis and imaging evidence of large-vessel vasculitis were absolute requirements to classify a patient as having TAK. The final criteria items and weights were as follows: female sex (+1), angina (+2), limb claudication (+2), arterial bruit (+2), reduced upper extremity pulse (+2), reduced pulse or tenderness of a carotid artery (+2), blood pressure difference between arms of ≥20 mm Hg (+1), number of affected arterial territories (+1 to +3), paired artery involvement (+1), and abdominal aorta plus renal or mesenteric involvement (+3). A patient could be classified as having TAK with a cumulative score of ≥5 points. When these criteria were tested in the validation data set, the model area under the curve was 0.97 (95% confidence interval [95% CI] 0.94-0.99) with a sensitivity of 93.8% (95% CI 88.6-97.1%) and specificity of 99.2% (95% CI 96.7-100.0%).

CONCLUSION

The 2022 American College of Rheumatology/EULAR classification criteria for TAK are now validated for use in research.

2022 American College of Rheumatology/EULAR classification criteria for Takayasu arteritis

Objective

To develop and validate new classification criteria for Takayasu arteritis (TAK).

Methods

Patients with vasculitis or comparator diseases were recruited into an international cohort. The study proceeded in six phases: (1) identification of candidate criteria items, (2) collection of candidate items present at diagnosis, (3) expert panel review of cases, (4) data‐driven reduction of candidate items, (5) derivation of a points‐based classification score in a development data set and (6) validation in an independent data set.

Results

The development data set consisted of 316 cases of TAK and 323 comparators. The validation data set consisted of an additional 146 cases of TAK and 127 comparators. Age ≤60 years at diagnosis and imaging evidence of large‐vessel vasculitis were absolute requirements to classify a patient as having TAK. The final criteria items and weights were as follows: female sex (+1), angina (+2), limb claudication (+2), arterial bruit (+2), reduced upper extremity pulse (+2), reduced pulse or tenderness of a carotid artery (+2), blood pressure difference between arms of ≥20 mm Hg (+1), number of affected arterial territories (+1 to +3), paired artery involvement (+1) and abdominal aorta plus renal or mesenteric involvement (+3). A patient could be classified as having TAK with a cumulative score of ≥5 points. When these criteria were tested in the validation data set, the model area under the curve was 0.97 (95% CI 0.94 to 0.99) with a sensitivity of 93.8% (95% CI 88.6% to 97.1%) and specificity of 99.2% (95% CI 96.7% to 100.0%).

Conclusion

The 2022 American College of Rheumatology/EULAR classification criteria for TAK are now validated for use in research.

Fuzzy Inference System (FIS) - Long Short-Term Memory (LSTM) Network for Electromyography (EMG) signal analysis

A wide range of application domains such as remote robotic control, rehabilitation, and remote surgery require capturing neuromuscular activities. The reliability of the application is highly dependent on an ability to decode intentions accurately based on captured neuromuscular signals. Physiological signals such as Electromyography (EMG) and Electroencephalography (EEG) generated by neuromuscular activities contain intrinsic patterns for users' particular actions. Such actions can generally be classified as motor states, such as Forward, Reverse, Hand-Grip, and Hand Release. In order to classify these motor states truthfully, the signals must be captured and decoded correctly. This paper proposes a novel classification technique using a Fuzzy Inference System (FIS) and Long Short Term Memory (LSTM) networks to classify the motor states based on EMG signals. Existing EMG signal classification techniques generally rely on features derived from data captured at a specific time instance. This typical approach does not consider the temporal correlation of the signal in the entire window. In this paper, the authors propose Long Short Term Memory with Fuzzy Logic method to classify four major hand movements, forward, reverse, raise, and lower. We extract the features associated with the motor state movement by exploring published with the pattern generated data within a given time window. The classification results are promising to achieve 91.3% accuracy for the 4-way action (Forward/Reverse/GripUp/RelDown) and 95.1% (Forward/Reverse Action) and 96.7% (GripUp/RelDown action) for 2-way actions. The proposed mechanism demonstrates high-level, human interpretable results that can be employed in rehabilitation or medical-device industries.

2022 American College of Rheumatology/European Alliance of Associations for Rheumatology Classification Criteria for Eosinophilic Granulomatosis With Polyangiitis

OBJECTIVE

To develop and validate revised classification criteria for eosinophilic granulomatosis with polyangiitis (EGPA).

METHODS

Patients with vasculitis or comparator diseases were recruited into an international cohort. The study proceeded in 5 phases: 1) identification of candidate criteria items using consensus methodology, 2) prospective collection of candidate items present at the time of diagnosis, 3) data-driven reduction of the number of candidate items, 4) expert panel review of cases to define the reference diagnosis, and 5) derivation of a points-based risk score for disease classification in a development set using least absolute shrinkage and selection operator logistic regression, with subsequent validation of performance characteristics in an independent set of cases and comparators.

RESULTS

The development set for EGPA consisted of 107 cases of EGPA and 450 comparators. The validation set consisted of an additional 119 cases of EGPA and 437 comparators. From 91 candidate items, regression analysis identified 11 items for EPGA, 7 of which were retained. The final criteria and their weights were as follows: maximum eosinophil count ≥1 × 10⁹ /liter (+5), obstructive airway disease (+3), nasal polyps (+3), cytoplasmic antineutrophil cytoplasmic antibody (ANCA) or anti-proteinase 3 ANCA positivity (-3), extravascular eosinophilic predominant inflammation (+2), mononeuritis multiplex/motor neuropathy not due to radiculopathy (+1), and hematuria (-1). After excluding mimics of vasculitis, a patient with a diagnosis of small- or medium-vessel vasculitis could be classified as having EGPA if the cumulative score was ≥6 points. When these criteria were tested in the validation data set, the sensitivity was 85% (95% confidence interval [95% CI] 77-91%) and the specificity was 99% (95% CI 98-100%).

CONCLUSION

The 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology classification criteria for EGPA demonstrate strong performance characteristics and are validated for use in research.

2022 American College of Rheumatology/European Alliance of Associations for Rheumatology Classification Criteria for Microscopic Polyangiitis

OBJECTIVE

To develop and validate classification criteria for microscopic polyangiitis (MPA).

METHODS

Patients with vasculitis or comparator diseases were recruited into an international cohort. The study proceeded in 5 phases: 1) identification of candidate items using consensus methodology, 2) prospective collection of candidate items present at the time of diagnosis, 3) data-driven reduction of the number of candidate items, 4) expert panel review of cases to define the reference diagnosis, and 5) derivation of a points-based risk score for disease classification in a development set using least absolute shrinkage and selection operator logistic regression, with subsequent validation of performance characteristics in an independent set of cases and comparators.

RESULTS

The development set for MPA consisted of 149 cases of MPA and 408 comparators. The validation set consisted of an additional 142 cases of MPA and 414 comparators. From 91 candidate items, regression analysis identified 10 items for MPA, 6 of which were retained. The final criteria and their weights were as follows: perinuclear antineutrophil cytoplasmic antibody (ANCA) or anti-myeloperoxidase-ANCA positivity (+6), pauci-immune glomerulonephritis (+3), lung fibrosis or interstitial lung disease (+3), sino-nasal symptoms or signs (-3), cytoplasmic ANCA or anti-proteinase 3 ANCA positivity (-1), and eosinophil count ≥1 × 109 /liter (-4). After excluding mimics of vasculitis, a patient with a diagnosis of small- or medium-vessel vasculitis could be classified as having MPA with a cumulative score of ≥5 points. When these criteria were tested in the validation data set, the sensitivity was 91% (95% confidence interval [95% CI] 85-95%) and the specificity was 94% (95% CI 92-96%).

CONCLUSION

The 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology classification criteria for MPA are now validated for use in clinical research.

2022 American College of Rheumatology/European Alliance of Associations for Rheumatology Classification Criteria for Granulomatosis With Polyangiitis

OBJECTIVE

To develop and validate revised classification criteria for granulomatosis with polyangiitis (GPA).

METHODS

Patients with vasculitis or comparator diseases were recruited into an international cohort. The study proceeded in 5 phases: 1) identification of candidate criteria items using consensus methodology, 2) prospective collection of candidate items present at the time of diagnosis, 3) data-driven reduction of the number of candidate items, 4) expert panel review of cases to define the reference diagnosis, and 5) derivation of a points-based risk score for disease classification in a development set using least absolute shrinkage and selection operator logistic regression, with subsequent validation of performance characteristics in an independent set of cases and comparators.

RESULTS

The development set for GPA consisted of 578 cases of GPA and 652 comparators. The validation set consisted of an additional 146 cases of GPA and 161 comparators. From 91 candidate items, regression analysis identified 26 items for GPA, 10 of which were retained. The final criteria and their weights were as follows: bloody nasal discharge, nasal crusting, or sino-nasal congestion (+3); cartilaginous involvement (+2); conductive or sensorineural hearing loss (+1); cytoplasmic antineutrophil cytoplasmic antibody (ANCA) or anti-proteinase 3 ANCA positivity (+5); pulmonary nodules, mass, or cavitation on chest imaging (+2); granuloma or giant cells on biopsy (+2); inflammation or consolidation of the nasal/paranasal sinuses on imaging (+1); pauci-immune glomerulonephritis (+1); perinuclear ANCA or antimyeloperoxidase ANCA positivity (-1); and eosinophil count ≥1 × 109 /liter (-4). After excluding mimics of vasculitis, a patient with a diagnosis of small- or medium-vessel vasculitis could be classified as having GPA if the cumulative score was ≥5 points. When these criteria were tested in the validation data set, the sensitivity was 93% (95% confidence interval [95% CI] 87-96%) and the specificity was 94% (95% CI 89-97%).

CONCLUSION

The 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology classification criteria for GPA demonstrate strong performance characteristics and are validated for use in research.

2022 American College of Rheumatology/European Alliance of Associations for Rheumatology Classification Criteria for Eosinophilic Granulomatosis with Polyangiitis

OBJECTIVE

To develop and validate revised classification criteria for eosinophilic granulomatosis with polyangiitis (EGPA).

METHODS

Patients with vasculitis or comparator diseases were recruited into an international cohort. The study proceeded in five phases: (1) identification of candidate criteria items using consensus methodology, (2) prospective collection of candidate items present at the time of diagnosis, (3) data-driven reduction of the number of candidate items, (4) expert panel review of cases to define the reference diagnosis and (5) derivation of a points-based risk score for disease classification in a development set using least absolute shrinkage and selection operator logistic regression, with subsequent validation of performance characteristics in an independent set of cases and comparators.

RESULTS

The development set for EGPA consisted of 107 cases of EGPA and 450 comparators. The validation set consisted of an additional 119 cases of EGPA and 437 comparators. From 91 candidate items, regression analysis identified 11 items for EPGA, 7 of which were retained. The final criteria and their weights were as follows: maximum eosinophil count ≥1×10⁹/L (+5), obstructive airway disease (+3), nasal polyps (+3), cytoplasmic antineutrophil cytoplasmic antibody (ANCA) or anti-proteinase 3-ANCA positivity (-3), extravascular eosinophilic predominant inflammation (+2), mononeuritis multiplex/motor neuropathy not due to radiculopathy (+1) and haematuria (-1). After excluding mimics of vasculitis, a patient with a diagnosis of small- or medium-vessel vasculitis could be classified as having EGPA if the cumulative score was ≥6 points. When these criteria were tested in the validation data set, the sensitivity was 85% (95% CI 77% to 91%) and the specificity was 99% (95% CI 98% to 100%).

CONCLUSION

The 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology Classification Criteria for Eosinophilic Granulomatosis with Polyangiitis demonstrate strong performance characteristics and are validated for use in research.

2022 American College of Rheumatology/European Alliance of Associations for Rheumatology classification criteria for microscopic polyangiitis

OBJECTIVE

To develop and validate classification criteria for microscopic polyangiitis (MPA).

METHODS

Patients with vasculitis or comparator diseases were recruited into an international cohort. The study proceeded in five phases: (1) identification of candidate items using consensus methodology, (2) prospective collection of candidate items present at the time of diagnosis, (3) data-driven reduction of the number of candidate items, (4) expert panel review of cases to define the reference diagnosis and (5) derivation of a points-based risk score for disease classification in a development set using least absolute shrinkage and selection operator logistic regression, with subsequent validation of performance characteristics in an independent set of cases and comparators.

RESULTS

The development set for MPA consisted of 149 cases of MPA and 408 comparators. The validation set consisted of an additional 142 cases of MPA and 414 comparators. From 91 candidate items, regression analysis identified 10 items for MPA, 6 of which were retained. The final criteria and their weights were as follows: perinuclear antineutrophil cytoplasmic antibody (ANCA) or anti-myeloperoxidase-ANCA positivity (+6), pauci-immune glomerulonephritis (+3), lung fibrosis or interstitial lung disease (+3), sino-nasal symptoms or signs (-3), cytoplasmic ANCA or anti-proteinase 3 ANCA positivity (-1) and eosinophil count ≥1×10⁹/L (-4). After excluding mimics of vasculitis, a patient with a diagnosis of small- or medium-vessel vasculitis could be classified as having MPA with a cumulative score of ≥5 points. When these criteria were tested in the validation data set, the sensitivity was 91% (95% CI 85% to 95%) and the specificity was 94% (95% CI 92% to 96%).

CONCLUSION

The 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology classification criteria for MPA are now validated for use in clinical research.

2022 American College of Rheumatology/European Alliance of Associations for Rheumatology classification criteria for granulomatosis with polyangiitis

OBJECTIVE

To develop and validate revised classification criteria for granulomatosis with polyangiitis (GPA).

METHODS

Patients with vasculitis or comparator diseases were recruited into an international cohort. The study proceeded in five phases: (1) identification of candidate criteria items using consensus methodology, (2) prospective collection of candidate items present at the time of diagnosis, (3) data-driven reduction of the number of candidate items, (4) expert panel review of cases to define the reference diagnosis and (5) derivation of a points-based risk score for disease classification in a development set using least absolute shrinkage and selection operator logistic regression, with subsequent validation of performance characteristics in an independent set of cases and comparators.

RESULTS

The development set for GPA consisted of 578 cases of GPA and 652 comparators. The validation set consisted of an additional 146 cases of GPA and 161 comparators. From 91 candidate items, regression analysis identified 26 items for GPA, 10 of which were retained. The final criteria and their weights were as follows: bloody nasal discharge, nasal crusting or sino-nasal congestion (+3); cartilaginous involvement (+2); conductive or sensorineural hearing loss (+1); cytoplasmic antineutrophil cytoplasmic antibody (ANCA) or anti-proteinase 3 ANCA positivity (+5); pulmonary nodules, mass or cavitation on chest imaging (+2); granuloma or giant cells on biopsy (+2); inflammation or consolidation of the nasal/paranasal sinuses on imaging (+1); pauci-immune glomerulonephritis (+1); perinuclear ANCA or antimyeloperoxidase ANCA positivity (-1); and eosinophil count ≥1×10⁹ /L (-4). After excluding mimics of vasculitis, a patient with a diagnosis of small- or medium-vessel vasculitis could be classified as having GPA if the cumulative score was ≥5 points. When these criteria were tested in the validation data set, the sensitivity was 93% (95% CI 87% to 96%) and the specificity was 94% (95% CI 89% to 97%).

CONCLUSION

The 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology classification criteria for GPA demonstrate strong performance characteristics and are validated for use in research.

Pulmonary Involvement in Primary Systemic Vasculitides

OBJECTIVES

This study describes the spectrum and initial impact of pulmonary manifestations in the primary systemic vasculitides.

METHODS

Description and comparison of pulmonary manifestations in adults with Takayasu's arteritis (TAK), giant cell arteritis (GCA), granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), eosinophilic granulomatosis with polyangiitis (EGPA), polyarteritis nodosa (PAN), and IgA vasculitis (IgAV), using data collected within the Diagnostic and Classification Criteria in Vasculitis (DCVAS) study.

RESULTS

Data from 1952 patients with primary vasculitides were included: 170 TAK, 657 GCA, 555 GPA, 223 MPA, 146 EGPA, 153 IgAV, and 48 PAN. Pulmonary manifestations were observed in patients with TAK (21.8%), GCA (15.8%), GPA (64.5%), MPA (65.9%), EGPA (89.0%), PAN (27.1%) and IgAV (5.9%). Dyspnea occurred in patients with TAK (14.7%), GCA (7.8%), GPA (41.8%), MPA (43.5%), EGPA (65.8%), PAN (18.8%) and IgAV (2.6%). Cough was reported in TAK (7.6%), GCA (9.3%), GPA (34.8%), MPA (37.7%), EGPA (55.5%), PAN (16.7%) and IgAV (3.3%). Hemoptysis occurred mainly in patients with ANCA-associated vasculitis (AAV). Fibrosis on imaging at diagnosis was documented in GPA (1.9%), MPA (24.9%), and EGPA (6.3%). Only patients with AAV (GPA 2.7%, MPA 2.7% and EGPA 3.4%) required mechanical ventilation. At 6 months, the presence of at least one pulmonary item in the Vasculitis Damage Index (VDI) was observed in TAK (4.1%), GCA (3.3%), GPA (15.4%), MPA (28.7%), EGPA (52.7%), PAN (6.2%), and IgAV (1.3%).

CONCLUSIONS

Pulmonary manifestations can occur in all primary systemic vasculitides, but are more frequent and more often associated with permanent damage in AAV.

Clinicopathologic Associations in a Large International Cohort of Patients with Giant Cell Arteritis

OBJECTIVE

In addition to aiding in diagnosis, histopathologic findings from temporal artery biopsy (TAB) specimens in giant cell arteritis (GCA) may be valuable for their associations with clinical features of the disease. This study compared histopathologic findings on TAB with biopsy interpretation and demographic, clinical, and imaging features at time of diagnosis.

METHODS

Patients with a clinical diagnosis of GCA who had a TAB were selected from an international, multicenter observational cohort of vasculitis. Associations between demographic, clinical, radiographic, and histopathologic features were identified using bivariate testing and multivariate regression modeling.

RESULTS

Out of 705 patients with GCA who underwent TAB, 69% had histopathological evidence of definite vasculitis. Specific histopathological findings included the presence of giant cells (51%), fragmentation of the internal elastic lamina (41%), intimal thickening (33%), and predominantly mononuclear leukocyte infiltration (32%). Histopathologic interpretation of definite vasculitis was independently associated with giant cells (odds ratios (OR) 151.8, 95% confidence interval (CI): 60.2-551.6), predominantly mononuclear leukocyte infiltration (OR 11.8, CI 5.9-24.9), and fragmentation of the internal elastic lamina (OR 3.7, CI 1.9-7.4). A halo sign on temporal artery ultrasound and luminal damage of large arteries on angiography were significantly associated with presence of giant cells (OR 2.6, CI 1.1-6.5 and OR 2.4, CI 1.1-5.2, respectively). Specific histopathologic findings were associated with older age but no associations were identified with vision loss or other clinical features.

CONCLUSION

Histopathologic findings in GCA are strongly associated with the clinical diagnosis of GCA but have a limited role in identifying patterns of disease.

Patterns of Arterial Disease in Takayasu Arteritis and Giant Cell Arteritis

OBJECTIVE

To identify and validate, using computer-driven methods, patterns of arterial disease in Takayasu arteritis (TAK) and giant cell arteritis (GCA).

METHODS

Patients with TAK or GCA were studied from the Diagnostic and Classification Criteria for Vasculitis (DCVAS) cohort and a combined North American cohort. Case inclusion required evidence of large-vessel involvement, defined as stenosis, occlusion, or aneurysm by angiography/ultrasonography, or increased ¹⁸ F-fluorodeoxyglucose (FDG) uptake by positron emission tomography (PET) in at least 1 of 11 specified arterial territories. K-means cluster analysis identified groups of patients based on the pattern of arterial involvement. Cluster groups were identified in the DCVAS cohort and independently validated in the North American cohort.

RESULTS

A total of 1,068 patients were included (DCVAS cohort: TAK = 461, GCA = 217; North American cohort: TAK = 225, GCA = 165). Six distinct clusters of patients were identified in DCVAS and validated in the North American cohort. Patients with TAK were more likely to have disease in the abdominal vasculature, bilateral disease of the subclavian and carotid arteries, or focal disease limited to the left subclavian artery than GCA (P < 0.01). Patients with GCA were more likely to have diffuse disease, involvement of bilateral axillary/subclavian arteries, or minimal disease without a definable pattern than TAK (P < 0.01). Patients with TAK were more likely to have damage by angiography, and patients with GCA were more likely to have arterial FDG uptake by PET without associated vascular damage.

CONCLUSION

Arterial patterns of disease highlight both shared and divergent vascular patterns between TAK and GCA and should be incorporated into classification criteria for large-vessel vasculitis.

Diagnostic Assessment Strategies and Disease Subsets in Giant Cell Arteritis: Data From an International Observational Cohort

OBJECTIVE

Diagnostic assessment in giant cell arteritis (GCA) is rapidly changing as vascular imaging becomes more available. This study was undertaken to determine if clinical GCA subsets have distinct profiles or reflect differential diagnostic assessments.

METHODS

Patients were recruited from an international cohort and divided into 4 subsets based on a temporal artery (TA) abnormality (positive TA biopsy [TAB] or halo sign on TA ultrasound [TA-US]) and/or evidence of large vessel (LV) involvement on imaging: 1) both TA abnormality and LV involvement (TA+/LV+ GCA); 2) TA abnormality without LV involvement (TA+/LV- GCA); 3) LV involvement without TA abnormality (TA-/LV+ GCA); and 4) clinically diagnosed GCA without LV involvement or TA abnormality (TA-/LV- GCA).

RESULTS

Nine hundred forty-one patients with GCA were recruited from 72 international study sites. Most patients received multiple forms of diagnostic assessment, including TAB (n = 705 [75%]), TA-US (n = 328 [35%]), and LV imaging (n = 534 [57%]). Assessment using TAB, TA-US, and LV imaging confirmed the diagnosis of GCA in 66%, 79%, and 40% of cases, respectively. GCA subsets had distinct profiles independent of diagnostic assessment strategies. TA+/LV- were the most common subset (51%), with a high burden of cranial ischemia. Those in the TA-/LV- subset (26%) had a high prevalence of cranial ischemia and musculoskeletal symptoms. Patients in the TA-/LV+ subset (12%) had prevalent upper extremity vascular abnormalities and a low prevalence of vision loss, and those in the TA+/LV+ subset (11%) were older and had a high prevalence of cranial ischemia, constitutional symptoms, and elevated acute-phase reactant levels.

CONCLUSION

Vascular imaging is increasingly incorporated into the diagnostic assessment of GCA and identifies clinical subsets of patients based on involvement of temporal and extracranial arteries.

VITALITY: impact of adalimumab on health and disability outcomes in patients with Crohn's disease, rheumatoid arthritis, or psoriasis treated in clinical practice in New Zealand

Objective: VITALITY, a 6-month, multicenter, prospective, observational study, assessed the effects of originator adalimumab (HUMIRA) on health and disability outcomes in patients with Crohn's disease (CD), rheumatoid arthritis (RA), or psoriasis treated in routine clinical practice in New Zealand (NZ). Methods: Biologic-naïve adults initiating adalimumab in accordance with NZ funding requirements were recruited. The primary endpoint was 6-month change from baseline in World Health Organization Disability Assessment Schedule (WHODAS) 2.0 score in all participants completing the study (full analysis set). Secondary endpoints included 6-month change in other patient-reported outcomes (PROs) of work activity and wellbeing (Work Productivity and Activity Impairment Questionnaire: General Health, Kessler Psychological Distress Scale, Flourishing Scale, and Subject Vitality Scale) and in disease-specific PRO measures. Results: In total, 164 participants with severe disease initiating adalimumab completed the WHODAS 2.0 at baseline, of whom 114 (69.5%) completed the study at 6 months. Mean WHODAS 2.0 score halved from 15.2 points (SD = ±9.1) at baseline to 7.3 points (SD = ±7.2) after 6 months' adalimumab treatment (mean difference = 7.9 points; 95% CI = 6.4-9.4; p < .001), with statistically significant improvements seen as early as 2 months after adalimumab initiation (p < .001). The proportion of participants with a WHODAS 2.0 score ≥ 10 more than halved, from 68.3% to 28.9%, between baseline and 6 months. Other PROs also improved significantly at 6 months, as did disease-specific measures. No new adalimumab safety signals were observed. Conclusions: Health and disability outcomes improved significantly after 6 months of adalimumab use in NZ patients with severe CD, RA, or psoriasis. Clinicaltrials.gov: NCT02451839.

Peripheral neuropathy in antineutrophil cytoplasmic antibody-associated vasculitides: Insights from the DCVAS study

Objective

Reported prevalence of vasculitic neuropathy (VN) in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is highly variable, and associations with other organ manifestations have not been studied systematically while accounting for diagnostic certainty of VN.

Methods

Data of all patients with AAV within the Diagnostic and Classification criteria for primary systemic VASculitis study were analyzed cross-sectionally. VN was categorized as definite (histology proven), probable (multiple mononeuropathy or nerve biopsy consistent with vasculitis), or possible (all others). Associations with other organ manifestations were compared in patients with and without VN.

Results

Nine hundred fifty-five patients (mean age 57 years, range 18–91 years, 51% female) were identified. Of these, 572 had granulomatosis with polyangiitis (GPA), 218 microscopic polyangiitis (MPA), and 165 eosinophilic granulomatosis with polyangiitis (EGPA). The prevalence of VN was 65% in EGPA, 23% in MPA, and 19% in GPA. Nerve biopsy was performed in 32/269 (12%) patients, demonstrating definite vasculitis in 17/32 (53%) of patients. VN was associated with myeloperoxidase-ANCA positivity (p = 0.004) and skin (p < 0.001), musculoskeletal, (p < 0.001) and cardiovascular (p = 0.005) involvement. Patients with VN were less likely to have renal (p < 0.001), eye (p < 0.001), and gastrointestinal (p = 0.023) involvement.

Conclusions

Our study provides comprehensive insights into the prevalence and organ associations of VN in a large, systematically collected AAV cohort. VN is most commonly associated with skin, musculoskeletal, and cardiovascular manifestations. In routine clinical practice, diagnosis of VN is infrequently confirmed by the gold standard of nerve biopsy but rather supported by the clinical setting of active systemic AAV.

Quantification of Bone Marrow Edema by Magnetic Resonance Imaging Only Marginally Reflects Clinical Neck Pain Evaluation in Rheumatoid Arthritis and Ankylosing Spondylitis

OBJECTIVE

Neck pain is common in rheumatoid arthritis (RA) and ankylosing spondylitis (AS). We investigated the correlation of bone marrow edema (BME) on magnetic resonance imaging (MRI) in RA and AS and its association with clinical complaints of neck pain.

METHODS

Cervical spine short-tau inversion recovery-MRI and T1w-MRI of 34 patients with RA and 6 patients with AS complaining about neck pain were obtained. Clinical and laboratory data were available. BME was scored by 2 blinded readers using a modification of a published score, including various cervical sites. Degenerative changes were also quantified.

RESULTS

Patients were predominantly women (82.5%), and mean ± SD age was 57.5 ± 11.8 years, C-reactive protein (CRP) was 0.8 ± 1.3 mg/dl, and pain score was 46.0 ± 17.5. BME was detected in 24/40 patients (60%) involving the atlantoaxial region (21%), vertebral bodies (75%), facet joints (29%), and spinous processes (46%). Degenerative changes were identified in 21/40 patients (52.5%), 13 (62%) of whom also had BME in vertebral bodies. No differences were found between patients with versus without cervical BME for clinical assessments: numeric rating scale pain (median ± interquartile range) 5.5 ± 3.0 vs 6.0 ± 4.0 (p = 0.69), Funktionsfragebogen Hannover 68.2 ± 41.0 vs 42.0 ± 55.5 (p = 0.19), Northwick pain score 44.4 ± 21.8 vs 47.2 ± 27.0 (p = 0.83), or CRP 0.40 ± 0.80 vs 0.60 ± 0.66 (p = 0.94). For patients with degenerative changes, symptom duration was longer than for patients without (10 ± 12.5 vs 5.0 ± 18.0 yrs, p = 0.73).

CONCLUSION

In this small study of patients with RA and AS complaining about neck pain, BME was found in many different cervical sites, including the facet joints and the spinous processes. However, the occurrence and severity of BME did not correlate with the severity of neck pain.

Late-onset rheumatoid arthritis in the Counties Manukau District Health Board region of New Zealand: an observational study of treatment

AIM

The aim of this retrospective study was to investigate whether there are differences in the early treatment of Rheumatoid Arthritis (RA) depending on the age of the patient at diagnosis.

METHODS

The electronic records of 127 newly diagnosed RA patients presenting to the Counties Manukau District Health Board Rheumatology outpatient clinic between January 2008 and December 2010 were reviewed. Demographics, disease severity, relevant investigations, and medication use were analysed using Pearson's Chi squared test, Fisher's exact test and t-test.

RESULTS

The cohort included 32 aged greater than or equal to 60 years with Late Onset RA (LORA) and 95 aged <60 years with Young Onset RA (YORA). No significant differences in baseline disease severity, disease modifying anti-rheumatic drug or prednisone use rates were observed between the LORA and YORA groups, with methotrexate use rates of 26/32 (81.25%) and 74/95 (77.89%) respectively. Nonsteroidal anti-inflammatory (NSAID) rate was significantly lower (p=0.013) in the LORA group 14/32 (43.75%) compared to the YORA group 65/95 (68.42%), reflecting an awareness of the adverse effects of these drugs in an older population.

CONCLUSION

Patients with new onset rheumatoid arthritis at our institution received similar disease modifying anti-rheumatic drug treatment irrespective of their age.

Glucocorticoid treatment and damage in the anti-neutrophil cytoplasm antibody-associated vasculitides: long-term data from the European Vasculitis Study Group trials

OBJECTIVE

Granulomatosis with polyangiitis and microscopic polyangiitis are ANCA-associated vasculitides (AAVs). The Vasculitis Damage Index (VDI) quantifies damage. This study aims to determine the factors associated with long-term damage in the AAVs.

METHODS

Data from 535 patients from four European Vasculitis Study Group trials were studied. A long-term follow-up (LTFU) questionnaire at 7 years post-diagnosis was completed. The associations between baseline (age, creatinine and BVAS score) and cumulative (number of relapses and duration of glucocorticoid use) factors and damage accrued (total VDI scores and individual treatment-related damage items) during follow-up were explored. Multiple regressions identified independent associations between baseline measures, cumulative factors and VDI scores at LTFU.

RESULTS

Two hundred and ninety-six patients had glucocorticoid use and VDI data available at LTFU, with the mean length of glucocorticoid use being 40.4 months (S.D. 16.7). High levels of damage were independently associated with older age at baseline (P = 0.051), lower glomerular filtration rate (P = 0.041), higher BVAS scores (P = 0.046), increased cumulative glucocorticoid use (P = 0.016) and increasing number of relapses. Patients with longer duration of glucocorticoid treatment were more likely to have a total VDI score ≥5 [odds ratio 1.26 per 12 months of glucocorticoid use (95% CI 1.03, 1.53), P = 0.022]. The main limitation is that approximately half of the patients enrolled had no LTFU data available; these patients were older with more severe initial disease.

CONCLUSION

Long-term damage in the AAVs may be associated with severity of initial disease, age, number of relapses and duration of glucocorticoid use.

Damage in the anca-associated vasculitides: long-term data from the European vasculitis study group (EUVAS) therapeutic trials

OBJECTIVES

To describe short-term (up to 12 months) and long-term (up to 7 years) damage in patients with newly diagnosed antineutrophil-cytoplasm antibody-associated vasculitis (AAV).

METHODS

Data were combined from six European Vasculitis Study group trials (n=735). Long-term follow-up (LTFU) data available for patients from four trials (n=535). Damage accrued was quantified by the Vasculitis Damage Index (VDI). Sixteen damage items were defined a priori as being potentially treatment-related.

RESULTS

VDI data were available for 629 of 735 patients (85.6%) at baseline, at which time 217/629 (34.5%) had ≥1 item of damage and 32 (5.1%) ≥5 items, reflecting disease manifestations prior to diagnosis and trial enrolment. LTFU data were available for 467/535 (87.3%) at a mean of 7.3 years postdiagnosis. 302/535 patients (56.4%) had VDI data at LTFU, with 104/302 (34.4%) having ≥5 items and only 24 (7.9%) no items of damage. At 6 months and LTFU, the most frequent items were proteinuria, impaired glomerular filtration rate, hypertension, nasal crusting, hearing loss and peripheral neuropathy. The frequency of damage, including potentially treatment-related damage, rose over time (p<0.01). At LTFU, the most commonly reported items of treatment-related damage were hypertension (41.5%; 95% CI 35.6 to 47.4%), osteoporosis (14.1%; 9.9 to 18.2%), malignancy (12.6%; 8.6 to 16.6%), and diabetes (10.4%; 6.7 to 14.0%).

CONCLUSIONS

In AAV, renal, otolaryngological and treatment-related (cardiovascular, disease, diabetes, osteoporosis and malignancy) damage increases over time, with around one-third of patients having ≥5 items of damage at a mean of 7 years postdiagnosis.

ACR/EULAR-endorsed study to develop Diagnostic and Classification Criteria for Vasculitis (DCVAS)

The systemic vasculitides are a group of uncommon diseases characterized by blood vessel inflammation. There are currently no diagnostic criteria for the primary systemic vasculitides and physicians must rely on experience and disease definitions. The absence of validated criteria can result in delays in making the correct diagnosis and starting appropriate therapy. With the increased understanding of the pathophysiology of vasculitis and newer diagnostic tests in widespread clinical use, it is an appropriate time for classification criteria for primary vasculitis to be revised. The Diagnostic and Classification Criteria for Vasculitis (DCVAS) study is a multinational observational study designed to develop and validate diagnostic criteria and to improve and validate classification criteria for primary systemic vasculitis. The analytic approach will be based on the traditional approach of vessel size for classification of vasculitis but will also incorporate detailed clinical data, evaluation of anti-neutrophil cytoplasm antibody diagnostic testing, biopsy and imaging data. The study is following the guidelines for the development of classification criteria established by the American College of Rheumatology and the European League against Rheumatism. The study will incorporate the use of pre-defined cases of each condition to reduce the inherent circularity when developing new classification criteria and will explore alternative approaches to deriving reference standards by creating data-driven classification algorithms. We anticipate recruiting >2,000 patients with primary systemic vasculitis and 1,500 patients with autoimmune diseases and other conditions that mimic vasculitis. As of June 2013, >100 medical centers across 31 countries in Asia, Australasia, Europe, North America, and South America were contributing data to the study. The DCVAS study provides a unique opportunity to increase generalizability and collate a large dataset on the occurrence, presentation, and outcome of vasculitis in different populations.

High-risk childhood acute lymphoblastic leukemia in first remission treated with novel intensive chemotherapy and allogeneic transplantation

Children with acute lymphoblastic leukemia (ALL) and high minimal residual disease (MRD) levels after initial chemotherapy have a poor clinical outcome. In this prospective, single arm, Phase 2 trial, 111 Dutch and Australian children aged 1-18 years with newly diagnosed, t(9;22)-negative ALL, were identified among 1041 consecutively enrolled patients as high risk (HR) based on clinical features or high MRD. The HR cohort received the AIEOP-BFM (Associazione Italiana di Ematologia ed Oncologia Pediatrica (Italy)-Berlin-Frankfurt-Münster ALL Study Group) 2000 ALL Protocol I, then three novel HR chemotherapy blocks, followed by allogeneic transplant or chemotherapy. Of the 111 HR patients, 91 began HR treatment blocks, while 79 completed the protocol. There were 3 remission failures, 12 relapses, 7 toxic deaths in remission and 10 patients who changed protocol due to toxicity or clinician/parent preference. For the 111 HR patients, 5-year event-free survival (EFS) was 66.8% (±5.5) and overall survival (OS) was 75.6% (±4.3). The 30 patients treated as HR solely on the basis of high MRD levels had a 5-year EFS of 63% (±9.4%). All patients experienced grade 3 or 4 toxicities during HR block therapy. Although cure rates were improved compared with previous studies, high treatment toxicity suggested that novel agents are needed to achieve further improvement.

Gout in women: differences in risk factors in young and older women

AIM

To describe the clinical characteristics of female patients with gout, assess risk factors in this group and to identify any differences between pre- and postmenopausal women with this diagnosis.

METHODS

We retrospectively reviewed the case records of all women who were seen with gout in a secondary care setting (inpatient and outpatient) at Counties Manukau District Health Board between July 2007 and July 2008. Demographic data, risk factors for gout and information on urate-lowering therapy was collected. A cut-off of less than and equal to 50 years was used to estimate pre-menopausal status.

RESULTS

122/509 (24%) of patients seen with gout were female. Fourteen female patients were less than or equal to 50 years of age; all of these patients were either Maori (43%) or of Pacific Island ethnicity (57%). Comorbidities in those =50 years old were renal impairment (78.6%), hypertension (64.3%), congestive heart failure (43%) and diabetes mellitus (42.9%). Comorbidities in women >50 years old were similar: hypertension (77%), renal impairment (70%), dyslipidemia (53%) and diabetes mellitus (50%). Ischemic heart disease was more common in older women (43% vs 7%), P<0.01. Mean body mass index (BMI) was significantly higher in the younger women (43.5 vs 33.1), P<0.01. Half of all the female patients were on diuretics, and medication used to lower uric acid level was prescribed in 35.7% of women less than and equal to 50 years of age, and 42.59% of women >50 years of age.

CONCLUSION

Women who develop gout are more likely to be over the age of 50, have other comorbidities and be on diuretics. In comparison, younger women who develop gout have similar risk factors but tended to have a higher body mass index and are more likely to be of Maori or Pacific Island ethnicity.

The OMERACT core set of outcome measures for use in clinical trials of ANCA-associated vasculitis

There has been a marked increase in the past 15 years in the number and quality of clinical trials in the idiopathic inflammatory vasculitides, especially the small-vessel vasculitides known as antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis [AAV; granulomatosis, with polyangiitis (Wegener's)]. These trials have been conducted by multicenter, international groups in Europe and the United States with financial support provided by government agencies and biopharmaceutical companies. This increased clinical trial activity in vasculitis has been accompanied by the development and validation of new outcome measures--a challenging process for these complex, multiorgan system diseases. The international OMERACT Vasculitis Working Group has developed and implemented an iterative research agenda that has utilized accumulated experience and datasets from several multicenter clinical trials and large cohort studies. This work has led to the development, evaluation, validation, and endorsement, through the OMERACT consensus and validation processes, of a "core set" of outcome measurements for use in clinical trials of AAV. The core set includes domains of disease activity, damage assessment, patient-reported outcomes, and mortality; there is at least one validated outcome measurement instrument available for each domain. This report reviews the domains of illness in AAV included in the OMERACT core set, describes the instruments validated to measure these domains, and presents the approved core set.

Development of outcome measures for large-vessel vasculitis for use in clinical trials: opportunities, challenges, and research agenda

Giant cell (GCA) and Takayasu's arteritis (TAK) are 2 forms of large-vessel vasculitis (LVV) that involve the aorta and its major branches. GCA has a predilection for the cranial branches, while TAK tends to affect the extracranial branches. Both disorders may also cause nonspecific constitutional symptoms. Although some clinical features are more common in one or the other disorder and the ages of initial presentation differ substantially, there is enough clinical and histopathologic overlap between these disorders that some investigators suggest GCA and TAK may be 2 processes within the spectrum of a single disease. There have been few randomized therapeutic trials completed in GCA, and none in TAK. The lack of therapeutic trials in LVV is only partially explained by the rarity of these diseases. It is likely that the lack of well validated outcome measures for LVV and uncertainties regarding trial design contribute to the paucity of trials for these diseases. An initiative to develop a core set of outcome measures for use in clinical trials of LVV was launched by the international OMERACT Vasculitis Working Group in 2009 and subsequently endorsed by the OMERACT community at the OMERACT 10 meeting. Aims of this initiative include: (1) to review the literature and existing data related to outcome assessments in LVV; (2) to obtain the opinion of experts and patients on disease content; and (3) to formulate a research agenda to facilitate a more data-based approach to outcomes development.

Investigation of inflicted injury in a young girl reveals mild haemophilia A and Turner's syndrome

A 2-year-old girl presented to casualty with a right knee effusion after apparently minor trauma. Inflicted injury was suspected and full forensic coagulation studies were performed which revealed a mild deficiency of factor VIII. Screening of the exons and intron/exon boundaries of F8 gene indicated that the child appeared to be homozygous for the missense mutation c.5123G>A (p.Arg1708His) in exon 14 of the F8 gene. This mutation has been reported to be associated with mild haemophilia A. The possibility of hemizygosity had been masked by the test kit employed but referral to the genetics service and subsequent array CGH resulted in a diagnosis of Turner syndrome.

A model to predict cardiovascular events in patients with newly diagnosed Wegener's granulomatosis and microscopic polyangiitis

OBJECTIVE

To create a prognostic tool to quantify the 5-year cardiovascular (CV) risk in patients with newly diagnosed Wegener's granulomatosis (WG) and microscopic polyangiitis (MPA) without premorbid CV disease.

METHODS

We reviewed CV outcomes during the long-term followup of patients in the first 4 European Vasculitis Study Group (EUVAS) trials of WG and MPA. CV events were defined as CV death, stroke, myocardial infarction, coronary artery bypass graft, or percutaneous coronary intervention. Logistic regression was performed to create a model to predict the absolute risk of a CV event. The model was tested using the Wegener's Granulomatosis Etanercept Trial (WGET) cohort.

RESULTS

Seventy-four (13.8%) of 535 patients with 5 years of followup from the EUVAS trials had at least 1 CV event: 33 (11.7%) of 281 WG versus 41 (16.1%) of 254 MPA. The independent determinants of CV outcomes were older age (odds ratio [OR] 1.45, 95% confidence interval [95% CI] 1.11-1.90), diastolic hypertension (OR 1.97, 95% CI 0.98-3.95), and positive proteinase 3 (PR3) antineutrophil cytoplasmic antibody (ANCA) status (OR 0.39, 95% CI 0.20-0.74). The model was validated using the WGET cohort (area under the receiver operating characteristic curve of 0.80).

CONCLUSION

Within 5 years of diagnosis of WG or MPA, 14% of patients will have a CV event. We have constructed and validated a tool to quantify the risk of a CV event based on age, diastolic hypertension, and PR3 ANCA status in patients without prior CV disease. In patients with vasculitis, PR3 ANCA is associated with a reduced CV risk compared to myeloperoxidase ANCA or negative ANCA status.

Nomenclature and classification of vasculitis - update on the ACR/EULAR diagnosis and classification of vasculitis study (DCVAS)

Classification of vasculitis remains unsatisfactory. This is largely because the pathogenetic mechanisms of this family of related disorders have not been fully understood. Existing classification criteria are useful but limited. This has become more apparent with the advent of more effective and more specific therapies. A rational basis for classification could significantly improve our approach to treatment. The development of diagnostic criteria in vasculitis is an even greater challenge but may ultimately provide more useful for the non-specialist clinician. International efforts are underway to provide more effective classification and diagnostic criteria.