Development of a diagnostic prediction model for giant cell arteritis by sequential application of Southend Giant Cell Arteritis Probability Score and ultrasonography: a prospective multicentre study

BACKGROUND

Giant cell arteritis is a critically ischaemic disease with protean manifestations that require urgent diagnosis and treatment. European Alliance of Associations for Rheumatology (EULAR) recommendations advocate ultrasonography as the first investigation for suspected giant cell arteritis. We developed a prediction tool that sequentially combines clinical assessment, as determined by the Southend Giant Cell Arteritis Probability Score (SGCAPS), with results of quantitative ultrasonography.

METHODS

This prospective, multicentre, inception cohort study included consecutive patients with suspected new onset giant cell arteritis referred to fast-track clinics (seven centres in Italy, the Netherlands, Spain, and UK). Final clinical diagnosis was established at 6 months. SGCAPS and quantitative ultrasonography of temporal and axillary arteries with three scores (ie, halo count, halo score, and OMERACT GCA Score [OGUS]) were performed at diagnosis. We developed prediction models for diagnosis of giant cell arteritis by multivariable logistic regression analysis with SGCAPS and each of the three ultrasonographic scores as predicting variables. We obtained intraclass correlation coefficient for inter-rater and intra-rater reliability in a separate patient-based reliability exercise with five patients and five observers.

FINDINGS

Between Oct 1, 2019, and June 30, 2022, we recruited and followed up 229 patients (150 [66%] women and 79 [34%] men; mean age 71 years [SD 10]), of whom 84 were diagnosed with giant cell arteritis and 145 with giant cell arteritis mimics (controls) at 6 months. SGCAPS and all three ultrasonographic scores discriminated well between patients with and without giant cell arteritis. A reliability exercise showed that the inter-rater and intra-rater reliability was high for all three ultrasonographic scores. The prediction model combining SGCAPS with the halo count, which was termed HAS-GCA score, was the most accurate model, with an optimism-adjusted C statistic of 0·969 (95% CI 0·952 to 0·990). The HAS-GCA score could classify 169 (74%) of 229 patients into either the low or high probability groups, with misclassification observed in two (2%) of 105 patients in the low probability group and two (3%) of 64 of patients in the high probability group. A nomogram for easy application of the score in daily practice was created.

INTERPRETATION

A prediction tool for giant cell arteritis (the HAS-GCA score), combining SGCAPS and the halo count, reliably confirms and excludes giant cell arteritis from giant cell arteritis mimics in fast-track clinics. These findings require confirmation in an independent, multicentre study.

FUNDING

Royal College of Physicians of Ireland, FOREUM.

Examining the variation in consent in general surgery

INTRODUCTION

Consent is a fundamental aspect of surgery and expectations around the consent process have changed following the Montgomery vs Lanarkshire Health Board (2015) court ruling. This study aimed to identify trends in litigation pertaining to consent, explore variation in how consent is practised among general surgeons and identify potential causes of this variation.

METHODS

This mixed-methods study examined temporal variation in litigation rates relating to consent (between 2011 and 2020), using data obtained from National Health Service (NHS) Resolutions. Semi-structured clinician interviews were then conducted to gain qualitative data regarding how general surgeons take consent, their ideologies and their outlook on the recent legal changes. The quantitative component included a questionnaire survey aiming to explore these issues with a larger population to improve the generalisability of the findings.

RESULTS

NHS Resolutions litigation data showed a significant increase in litigation pertaining to consent following the 2015 health board ruling. The interviews demonstrated considerable variation in how surgeons approach consent. This was corroborated by the survey, which illustrated considerable variation in how consent is documented when different surgeons are presented with the same case vignette.

CONCLUSION

A clear increase in litigation relating to consent was seen in the post-Montgomery era, which may be due to legal precedent being established and increased awareness of these issues. Findings from this study demonstrate variability in the information patients receive. In some cases, consent practices did not adequately meet current regulations and therefore are susceptible to potential litigation. This study identifies areas for improvement in the practice of consent.

Disease stratification in GCA and PMR: state of the art and future perspectives

Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are closely related conditions characterized by systemic inflammation, a predominant IL-6 signature, an excellent response to glucocorticoids, a tendency to a chronic and relapsing course, and older age of the affected population. This Review highlights the emerging view that these diseases should be approached as linked conditions, unified under the term GCA-PMR spectrum disease (GPSD). In addition, GCA and PMR should be seen as non-monolithic conditions, with different risks of developing acute ischaemic complications and chronic vascular and tissue damage, different responses to available therapies and disparate relapse rates. A comprehensive stratification strategy for GPSD, guided by clinical findings, imaging and laboratory data, facilitates appropriate therapy and cost-effective use of health-economic resources. Patients presenting with predominant cranial symptoms and vascular involvement, who usually have a borderline elevation of inflammatory markers, are at an increased risk of sight loss in early disease but have fewer relapses in the long term, whereas the opposite is observed in patients with predominant large-vessel vasculitis. How the involvement of peripheral joint structures affects disease outcomes remains uncertain and understudied. In the future, all cases of new-onset GPSD should undergo early disease stratification, with their management adapted accordingly.

POS0818 SOUTHEND PRE-TEST PROBABILITY SCORE AND HALO SCORE AS MARKERS FOR DIAGNOSIS AND MONITORING OF GCA: EARLY RESULTS FROM THE PROSPECTIVE HAS-GCA STUDY

Background

Ultrasound (US) is recommended as the first line imaging test in patients with suspected Giant Cell Arteritis (GCA). Traditionally, the US halo sign has been used for diagnosis. We have recently described a composite Halo Score that allows to quantify vascular inflammation on US. Prospective studies on response and disease monitoring are lacking.

Objectives

To prospectively assess the role of US in diagnosing and monitoring GCA patients. We report early baseline and 12-month data on our current recruitment in a study that has suffered disruption from the pandemic.

Methods

HAS GCA (IRAS#264294) is an ongoing, prospective, multicentre study recruiting from referrals of suspected GCA to fast-track clinics. Based on the Southend GCA clinical pre-test probability score (SPTPS)1, patients were stratified in to low, intermediate and high risk categories2. Temporal and axillary US Halo Scores were calculated from the halo thickness and extent in bilateral temporal arteries, parietal and frontal branches (TAHS) and axillary arteries (AAHS). These scores were summed (TAHS x1 plus; AAHS x3) to generate a Total Halo Score (THS)3.

Mann Whitney U test was used to compare baseline features between GCA and controls. Wilcoxon signed rank test was used to evaluate disease features at baseline and at 12 months in GCA patients. Sensitivity (Sn), Specificity (Sp) and ROC curve were calculated, where applicable. P value <0.05 is statistically significant

Results

202 patients (71 GCA, 131 controls) have been recruited thus far: 23 completed 12-month follow up assessment; 6 were lost to follow up (4 died, 2 withdrew consent due to pandemic). Demographics, clinical features, and US results are shown (Table 1).

Table 1.

Baseline features of GCA patients and controls

GCA (n=71)Controls (n=131)P-valueAge, median (IQR)75 (70-81)68 (62-76)0.001Female, n (%)38 (54)89 (68)0.05SPTPS category, n (%) Low risk0 (0)59 (45)<0.001 Intermediate risk16 (23)49 (37)0.04 High risk55 (77)23 (18)<0.001Halo score (HS), median (range) Temporal artery HS12 (0-22)2 (0-17)<0.0001 Axillary artery HS12 (0-21)6 (0-18)<0.0001 Total HS21 (2-40)8 (0-29)<0.0001Clinical features, n (%) Temporal headache53 (75)93 (71)0.62 Scalp tenderness36 (51)40 (31)0.006 Jaw claudication38 (54)9 (7)<0.001 PMR symptoms29 (41)35 (27)0.06 Constitutional symptoms42 (59)29 (22)<0.001 Visual disturbance40 (56)58 (44)0.11 Vision loss21 (30)9 (7)<0.001

AA, axillary artery; GCA, Giant cell arteritis; TA, Temporal artery

Among GCA patients, 50 had cranial, 5 large-vessel and 16 mixed phenotypes. Diseases were diagnosed by US and additional tests such as PET CT.

Jaw claudication (54%) and constitutional symptoms (59%) were the dominant features in GCA patients. Median age was 75 years in GCA (54% females) and 68 years in controls (68% females). GCA and controls were stratified by SPTPS to Low risk (0% vs 45%; Sn-undefined, Sp-98), Intermediate risk (23% vs 37%; Sn-81, Sp-98) and High risk (77% vs 18%; Sn-98, Sp-91). Optimal SPTPS cut-off point was ≥12 (Sn-89, Sp-76).

Median THS was 21 in GCA and 8 in controls. Optimal cut-off Halo Score in diagnosis was TAHS ≥5 (Sn-89, Sp-86), AAHS ≥11 (Sn-55, Sp-75), THS ≥15 (Sn-79%, Sp-86%). Baseline Halo Score and CRP levels showed positive correlation (spearman rank correlation). Among the 23 patients who completed 12-months follow up, median TAHS, AAHS and THS reduced from 12 to 2, 12 to 6 and 21 to 10, respectively (Figure 1).

Conclusion

Along with SPTPS, Halo Score successfully discriminates GCA from non GCA mimics and. HS is effective in showing 12-month response. This score may be a useful marker to monitor GCA disease activity

References

[1]Laskou F et al. Clin Exp Rheumatol. 2019

[2]Sebastian A et al. RMD Open. 2020

[3]Sebastian A et al. BMC Rheumatol. 2020

Disclosure of Interests

Alwin Sebastian: None declared, Alessandro Tomelleri: None declared, Pierluigi Macchioni: None declared, Giulia Klinowski: None declared, Carlo Salvarani: None declared, Abdul Kayani: None declared, Mohammad Tariq: None declared, Diana Prieto-Peña: None declared, Edoardo Conticini: None declared, Muhammad Khurshid: None declared, Sue Inness: None declared, Jo Jackson: None declared, Kornelis van der Geest Speakers bureau: Roche, Grant/research support from: Mandema stipend, Bhaskar Dasgupta: None declared

Role of the halo sign in the assessment of giant cell arteritis: a systematic review and meta-analysis

Objectives

This systematic review and meta-analysis aimed to evaluate the diagnostic value of the halo sign in the assessment of GCA.

Methods

A systematic literature review was performed using MEDLINE, EMBASE and Cochrane central register databases up to August 2020. Studies informing on the sensitivity and specificity of the US halo sign for GCA (index test) were selected. Studies with a minimum of five participants were included. Study articles using clinical criteria, imaging such as PET-CT and/or temporal artery biopsy (TAB) as the reference standards were selected. Meta-analysis was conducted with a bivariate model.

Results

The initial search yielded 4023 studies. Twenty-three studies (patients n = 2711) met the inclusion criteria. Prospective (11 studies) and retrospective (12 studies) studies in academic and non-academic centres were included. Using clinical diagnosis as the standard (18 studies) yielded a pooled sensitivity of 67% (95% CI: 51, 80) and a specificity of 95% (95% CI: 89, 98%). This gave a positive and negative likelihood ratio for the diagnosis of GCA of 14.2 (95% CI: 5.7, 35.5) and 0.375 (95% CI: 0.22, 0.54), respectively. Using TAB as the standard (15 studies) yielded a pooled sensitivity of 63% (95% CI: 50, 75) and a specificity of 90% (95% CI: 81, 95).

Conclusion

The US halo sign is a sensitive and specific approach for GCA assessment and plays a pivotal role in diagnosis of GCA in routine clinical practice.

Registration

PROSPERO 2020 CRD42020202179.

Probability-based algorithm using ultrasound and additional tests for suspected GCA in a fast-track clinic

Objectives

Clinical presentations of giant cell arteritis (GCA) are protean, and it is vital to make a secure diagnosis and exclude mimics for urgent referrals with suspected GCA. The main objective was to develop a joined-up, end-to-end, fast-track confirmatory/exclusionary, algorithmic process based on a probability score triage to drive subsequent investigations with ultrasound (US) and any appropriate additional tests as required.

Methods

The algorithm was initiated by stratifying patients to low-risk category (LRC), intermediate-risk category (IRC) and high-risk category (HRC). Retrospective data was extracted from case records. The Southend pretest probability score (PTPS) overall showed a median score of 9 and a 75th percentile score of 12. We, therefore, classified LRC as PTPS <9, IRC 9–12 and HRC >12. GCA diagnosis was made by a combination of clinical, US, and laboratory findings. The algorithm was assessed in all referrals seen in 2018–2019 to test the diagnostic performance of US overall and in individual categories.

Results

Of 354 referrals, 89 had GCA with cases categorised as LRC (151), IRC (137) and HRC (66). 250 had US, whereas 104 did not (score <7, and/or high probability of alternative diagnoses). In HRC, US showed sensitivity 94%, specificity 85%, accuracy 92% and GCA prevalence 80%. In LRC, US showed sensitivity undefined (0/0), specificity 98%, accuracy 98% and GCA prevalence 0%. In IRC, US showed sensitivity 100%, specificity 97%, accuracy 98% and GCA prevalence 26%. In the total population, US showed sensitivity 97%, specificity 97% and accuracy 97%. Prevalence of GCA overall was 25%.

Conclusions

The Southend PTPS successfully stratifies fast-track clinic referrals and excludes mimics. The algorithm interprets US in context, clarifies a diagnostic approach and identifies uncertainty, need for re-evaluation and alternative tests. Test performance of US is significantly enhanced with PTPS.

POS0337 SOUTHEND PRE-TEST PROBABILITY SCORE AND HALO SCORE AS MARKERS FOR DIAGNOSIS AND MONITORING OF GCA: EARLY RESULTS FROM THE PROSPECTIVE HAS-GCA STUDY

Background:

EULAR recommends doppler ultrasound (US) as the first line imaging in patients with Giant Cell Arteritis (GCA) suspect. Traditionally, US non-compressive halo sign has been used for diagnosis but prospective studies on response and disease monitoring are lacking

Objectives:

The HAS GCA study has the objective of prospectively assessing role of US in diagnosis, prognosis and monitoring in newly diagnosed GCA. We report early baseline and up to month 3 data on our current recruitment in a study that has suffered disruption from the pandemic

Methods:

HAS GCA (IRAS#264294) is an ongoing, prospective, multicentre study recruiting from referrals of suspected GCA to fast track clinics. The objective is to recruit 270 patients, including 68 GCA patients. Based on the Southend GCA clinical pre-test probability score (SPTPS)1, patients were stratified in to low, intermediate and high risk categories2. Temporal and axillary US Halo Scores were calculated from the halo thickness and extent in bilateral temporal arteries, parietal and frontal branches and axillary arteries. These individual scores were summed (TA Halo Score x1 plus; AA Halo Score x3) to generate a Total Halo Score (THS)3.

Mann Whitney U test and Fisher’s exact test were used to compare baseline features between GCA and controls. Wilcoxon signed rank test was used to evaluate disease features at baseline and at 3 months in GCA patients. Sensitivity (Sn) and Specificity (Sp) were calculated, where applicable. P value <0.05 is statistically significant

Results:

Ninety-three patients (29 GCA, 64 controls) have been recruited thus far: 18 completed 3-month follow up assessment; 4 were lost to follow up (2 died, 2 withdrew consent due to pandemic). Demographics, clinical features, and US results are shown (Table 1).

Table 1.

Baseline features of GCA patients and controls.

GCA (n=29)Controls (n=64)P-valueAge, median (IQR)75 (71-80)67 (61.25 – 75.0)0.001Female, n (%)15 (42)50 (78)0.01SPTPS category, n (%) Low risk0 (0)31 (48)<0.001 Intermediate risk7 (24)25 (39)0.24 High risk22 (76)8 (13)<0.001Halo score (HS), median (range) Temporal artery HS10 (1-21)1 (0-9)<0.001 Axillary artery HS12 (0-18)6 (0-18)<0.001 Total HS21 (2-38)6 (0-19)<0.001Clinical features, n (%) Temporal headache21 (72)40 (63)0.48 Scalp tenderness17 (59)31 (48)0.38 Jaw claudication19 (66)4 (6)<0.001 PMR symptoms16 (55)6 (9)<0.001 Constitutional symptoms17 (59)18 (28)0.006 Visual disturbance18 (62)38 (59)1 Vision loss7 (24)4 (6)0.03

Among GCA patients, 23 had cranial, 2 large-vessel and 4 mixed phenotypes (cranial plus large vessel) disease.

Jaw claudication (66%) and polymyalgic symptoms (55%) were the dominant features in GCA patients. Median age 75 years in GCA (42% females) and 67 years in controls (78% females). GCA and controls were stratified by SPTPS to Low risk (0% vs 48%; Sn-undefined, Sp-97), Intermediate risk (24% vs 39%; Sn-100, Sp-100) and High risk (76% vs 13%; Sn-95, Sp-88). Optimal SPTPS cut-off point was ≥12 (Sn-93, Sp-86); ≥10 (Sn-100 & Sp-69).

Median THS was 21 in GCA and 6 in controls. Optimal cut-off Halo Score in diagnosis was TAHS ≥5 (Sn-90, Sp-98), AAHS ≥11 (Sn-55, Sp-80), THS ≥18 (Sn-72%, Sp-98%). Among the 18 patients who completed 3-months follow up, median TAHS, AAHS and THS reduced from 10 to 2.5, 12 to 6 and 21 to 10, respectively (Figure 1).

Conclusion:

Along with SPTPS, Halo Score successfully discriminates GCA from non GCA mimics. HS is effective in showing 3-month response and may be a useful marker to monitor GCA disease activity.

References:

[1]Laskou F et al. A probability score to aid the diagnosis of suspected giant cell arteritis. Clin Exp Rheumatol. 2019

[2]Sebastian A et al. Probability-based algorithm using ultrasound and additional tests for suspected GCA in a fast-track clinic. RMD Open. 2020

[3]Sebastian A et al. Halo score (temporal artery, its branches and axillary artery) as a diagnostic, prognostic and disease monitoring tool for Giant Cell Arteritis (GCA). BMC Rheumatol. 2020

Disclosure of Interests:

Alwin Sebastian: None declared, Alessandro Tomelleri: None declared, Abdul Kayani: None declared, Mohammad Tariq: None declared, Diana Prieto-Peña: None declared, Sue Inness: None declared, Jo Jackson: None declared, Kornelis van der Geest Speakers bureau: Roche, Bhaskar Dasgupta Speakers bureau: Roche, GSK, BMS, Sanofi, Abbie, Grant/research support from: Roche

Ultrasonographic Halo Score in giant cell arteritis: association with intimal hyperplasia and ischaemic sight loss

Objectives

We investigated the relationship between the ultrasonographic Halo Score and temporal artery biopsy (TAB) findings in GCA.

Methods

This is a prospective study including 90 patients suspected of having GCA. Ultrasonography of temporal/axillary arteries and a TAB were obtained in all patients at baseline. An experienced pathologist evaluated whether TAB findings were consistent with GCA, and whether transmural inflammation, giant cells and intimal hyperplasia were present. Ultrasonographic Halo Scores were determined. Receiver operating characteristic analysis was performed.

Results

Twenty-seven patients had a positive TAB, while 32 patients with a negative TAB received a clinical diagnosis of GCA after 6 months of follow-up. Patients with a positive TAB showed higher Halo Scores than patients with a negative TAB. The presence of intimal hyperplasia in the biopsy, rather than the presence of transmural inflammation or giant cells, was associated with elevated Halo Scores in patients with GCA. The Halo Score discriminated well between TAB-positive patients with and without intimal hyperplasia, as indicated by an area under the curve of 0.82 in the receiver operating characteristic analysis. Patients with a positive TAB and intimal hyperplasia more frequently presented with ocular ischaemia (40%) than the other patients with GCA (13–14%).

Conclusion

The ultrasonographic Halo Score may help to identify a subset of GCA patients with intimal hyperplasia, a TAB feature associated with ischaemic sight loss.

Efficacy and safety of tocilizumab in giant cell arteritis: a single centre NHS experience using imaging (ultrasound and PET-CT) as a diagnostic and monitoring tool

Tocilizumab (TCZ), an IL-6 receptor blocker, is approved for relapsing, refractory giant cell arteritis (GCA). We report real-life clinical experience with TCZ in GCA including assessment of responses on imaging (ultrasound (US) and 18F-Fluorodeoxyglucose Positron Emission Tomography-computed Tomography (¹⁸FDG-PET-CT)) during the first year of treatment. We included 22 consecutive patients with GCA treated with TCZ where EULAR core data set on disease activity, quality of life (QoL) and treatment-related complications were collected. Pre-TCZ US and ¹⁸FDG-PET/CT findings were available for 21 and 4 patients, respectively, where we determined the effect on US halo thickness, temporal and axillary artery Southend Halo Score and Total Vascular Score on ¹⁸FDG-PET-CT. The 22 patients with GCA (10 cranial, 10 large vessel, 2 both) had a median disease duration of 58.5 (range, 1-370) weeks prior to initiation of TCZ. Half had used prior conventional synthetic disease-modifying antirheumatic drug (csDMARDs). TCZ was initiated for refractory (50%), ischaemic (36%) or relapsing (14%) disease. Median follow-up was 43 (12-52) weeks. TCZ was discontinued due to serious adverse events (SAEs) in two patients. On treatment with TCZ, 4 discontinued prednisolone, 11 required doses ≤2.5 mg, 2 required daily dose of 2.5-5 mg and 5 needed prednisolones ≥5 mg daily. QoL improved by 50%. Total US halo thickness decreased in 38 arterial segments, median temporal artery Halo Score decreased from 11 to 0, axillary artery Halo Score remained stable. Median Total Vascular Score on FDG-PET/CT reduced from 11.5 to 6.5. In our experience, TCZ showed an excellent response with acceptable safety in GCA, with improvement on US and FDG-PET/CT imaging.

Halo score (temporal artery, its branches and axillary artery) as a diagnostic, prognostic and disease monitoring tool for Giant Cell Arteritis (GCA)

BACKGROUND

Giant cell arteritis (GCA) is a common large vessel vasculitis of the elderly, often associated with sight loss. Glucocorticoids (GC remain the mainstay of treatment, although biologic treatments have been approved. Biomarkers predicting disease severity, relapse rates and damage are lacking in GCA.EULAR recommends ultrasound (US) as the first investigation for suspected GCA. The cardinal US finding, a non-compressible halo, is currently categorised as either negative or positive. However, the extent and severity of this finding may vary.In this study, we hypothesise whether the extent and severity of the halo sign [calculated as a single composite Halo score (HS)] of temporal and axillary arteries may be of diagnostic, prognostic and monitoring importance; whether baseline HS is linked to disease outcomes, relapses and damage; whether HS can stratify GCA patients for individual treatment needs; whether HS can function as an objective monitoring tool during follow up.

METHODS

This is a prospective, observational study. Suspected GCA Participants will be selected from the GCA FTC at the participating centres in the UK. Informed consent will be obtained, and patients managed as part of standard care. Patients with GCA will have HS (temporal and axillary arteries) measured at baseline and months 1,3,6 and 12 long with routine clinical assessments, blood sampling and patient-reported outcomes (EQ5D). Non-GCA patients will be discharged back to the referral team and will have a telephone interview in 6 months.We aim to recruit 272 suspected GCA referrals which should yield 68 patients (25% of referrals) with confirmed GCA. The recruitment will be completed in 1 year with an estimated total study period of 24 months.

DISCUSSION

The identification of prognostic factors in GCA is both timely and needed. A prognostic marker, such as the HS, could help to stratify GCA patients for an appropriate treatment regimen. Tocilizumab, an IL-6R blocking agent, switches off the acute phase response (C-Reactive Protein), making it difficult to measure the disease activity. Therefore, an independent HS, and changes in that score during treatment and follow-up, maybe a more objective measure of response compare to patient-reported symptoms and clinical assessment alone.

SAT0249 A PROBABILITY-BASED DIAGNOSTIC ALGORITHM FOR SUSPECTED GCA

Background:

Clinical presentation of GCA is protean. It is vital to make a secure diagnosis, exclude mimics urgently and avoid inappropriate steroids to minimise side effects. Fast track GCA clinics (FTC) provide rapid specialist assessment with temporal and axillary US (1). EULAR recommendations support US as first-choice test. A pre-test probability score (PTPS) stratifies patients to low (LC), intermediate (IC) and high-risk (HC) categories.

Objectives:

To validate a diagnostic GCA algorithm based on stratification by PTPS, with sequential US and additional tests (AT), if necessary

Methods:

For the algorithm (Figure) retrospective data was extracted from case records of cases seen in 2019. PTPS overall showed median (Q2) score of 9,75thpercentile (Q3) score 12. Based on this and reported cut-off 9.5 (2) we classified LC as PTPS <9, IC 9-12 and HC >12 (Graph). GCA diagnosis was by modified GiACTA including US (Halo), CRP > 5 mg/L and AT if necessary. The algorithm performance was assessed overall and in individual categories.

Results:

Of 187 consecutive cases, 13 were excluded for incomplete data (tertiary referrals). In remaining 174, GCA confirmed 33%, mean age 72.4 years, 69% females,45% LC, 35% IC, and 20% HC. 130 (75%) had US whereas 44 did not (41 LC, 3 IC) (Figure)

In HC, 25/31 (81%) were US +ve, 19 treated as GCA without AT, 6 with AT (Table 2). Of 6 US -ve 3 had GCA confirmed by AT (PET-CT 2, TAB 1). US in HC showed sensitivity 89%, specificity 75%, accuracy 87%, GCA prevalence 87%, mean CRP 65.52 (SEM+/- 8.67).

Table 1.

US performance with PTPS

Category(n)USGCA, nNon-GCA, nSensitivity (%)Specificity (%)PPV (%)NPV(%)Prevalence (%)Accuracy(%)HC (31)+24124/27(89)3/4(75)24/25(96)3/6(50)27/31(87)(24 + 3)/31(87)-33IC (65)+30030/30(100)35/35(100)30/30(100)35/35(100)30/65(46)(30 + 35)/65(100)-035LC (78)+010/0 (undefined)77/78(99)0/1(0)77/77(100)0/78(0)(0 + 77)/78(99)-077Total (174)+54254/57(95)115/117(98)54/56(96)115/118(97)57/174(33)(54 + 115)/174(97)-3115

Abbreviations: GCA, Giant cell arteritis; NPV, Negative predictive value; PPV, Positive predictive value; US, Ultrasound

Table 2.

US, AT & confirmed diagnosis

CategoryUltrasoundNo of ATType of ATFinal Diagnosis+veNot done-veLC(78)1393871x TAB (-), CTB (-)Fibromyalgia1x TAB (-), MRA (-), MR neck (+)Tongue cancer1x CTA (+)Stroke1x CTCAP (-)IA1x PET (-)PMR1xTAB (-)NA AION1x PET (-)CVAIC(65)30332155x TAB (-), 2x PET (-)Not GCA2x TAB (+), 6x PET (+)GCAHC(31)2506101x PET (-)URTI1x TAB (-)NAAION2x PET (+)1x TAB (+)1x CTA (+)1x MRA (+)GCA1x PET (-)2x CTA (-)1x CTCAP (-)

Abbreviations: AT, Additional test; CTA, Computed tomography angiogram; CTB, Computed tomography of brain; CTCAP, Computed tomography of chest, abdomen and pelvis; GCA, Giant cell arteritis; IA, Inflammatory arthritis; MRA, Magnetic resonant angiogram; NA AION, Non arteritic anterior ischemic optic neuritis; PET, Position emission tomography; TAB, Temporal artery biopsy; URTI, Upper respiratory tract infection

In LC, 38 (49%) were US - ve, of whom 5 had AT. US not done on 39 (50%) for either PTPS very low or urgent alternative diagnosis. 1 went on to AT. 1 was US positive and had GCA excluded with AT. US in LC showed specificity 99%, sensitivity 0/0 (undefined), accuracy 99%, GCA prevalence 0%, mean CRP 21.79 (SEM+/- 3.80)

In IC, 30/65 (46%) were US +ve 8 had AT (all GCA confirmed) while on treatment. 32 (49%) US negative where 7 had AT (all GCA excluded). 3 did not have US. Sensitivity, specificity, accuracy of US was all 100%, GCA prevalence 46%, mean CRP 39.05 (SEM+/- 5.04)

US test performance overall sensitivity 95%, specificity 98%, accuracy 97%

Conclusion:

PTPS successfully stratifies GCA, excludes mimics and enhances US performance. The algorithm interprets correctly US findings and choice of AT.

References:

[1]Patil et al Clin Exp Rheumatol 2015;33(Suppl 89): S103–6.

[2]Laskou et al. Clin Exp Rheumatol. 2019 Feb 15

Disclosure of Interests:

Alwin Sebastian: None declared, Abdul Kayani: None declared, Chavini Ranasinghe: None declared, Bhaskar Dasgupta Grant/research support from: Roche, Consultant of: Roche, Sanofi, GSK, BMS, AbbVie, Speakers bureau: Roche

P04 A quality improvement initiative to improve influenza and pneumococcal vaccination rates in patients receiving biological DMARDS (bDMARDs) in the mid-west of Ireland

Background

bDMARDs have been the panacea for rheumatic diseases but their use may increase the risk of infection. Morbidity and mortality in patients with chronic disease can be prevented with influenza and pneumococcal (PCV) vaccinations.

Methods

We implemented a multifaceted quality improvement (QI) approach at our infusion unit using the Plan-Do-Study-Act methodology. Interventions included training of rheumatology nurses, individual patient consultations and distribution of Arthritis UK booklet on vaccination. During the first cycle, patients on bDMARDs attending the rheumatology infusion unit between January to April 2018 were recruited. Initial data included patients’ demographics, diagnosis, bDMARD, their influenza and PCV vaccination statuses with reasons for not having vaccination. The second cycle was carried out from January to April 2019.

Results

92 patients were recruited in the first cycle; mean age was 53.2 years with 63 (68.5%) females. The uptake of vaccination was 52 (56.5%) for influenza and 31 (33.7%) for PCV. More importantly, 39 (42.4%) patients did not receive either vaccination. Of the 18 (19.6%) patients aged ≥65 years, 5 (27.8%) received influenza vaccination alone and 8 (44.4%) received both. The most common diagnosis from our cohort was rheumatoid arthritis (37%), followed by spondylarthritis (13%), Behçet’s disease (9.8%) and others (40.2%). 48 (52.2%) were on rituximab, 37 (40.2%) on infliximab, 6 (6.5%) were on tocilizumab and 1 (1.1%) was on abatacept. 40 (43.5%) who did not receive the influenza vaccination stated that they were either unaware (45%), uninterested (25%), afraid of SEs (12.5%), forgotten (5%), unaware it was recommended (5%). Of the 61 (66.3%) patients who did not receive the PCV, 44 (72.1%) were unaware of its availability, 6 (9.8%) were uninterested, 8 (13.2%) were fearful of side effects (SEs) and 3 (4.9%) were unaware it was recommended. Patients who did not have vaccination were interviewed again during second cycle after QI interventions. There was satisfactory improvement in the vaccination rate of influenza vaccination (71.7%) and PCV (56.5%). The most common reason for the lack of vaccination were fear of SEs for influenza vaccination and unaware of its availability for PCV. 6 (9.7%) had serious infections in the preceding year requiring hospital admission; 3 had chest infections, 1 had urinary tract infection, 1 had cellulitis and 1 had necrotising fasciitis.

Conclusion

Although the baseline vaccination rate was suboptimal in our cohort, there was a significant improvement after the QI interventions. The lack of awareness is the main reason for failure to be vaccinated. There is a need of a more robust action plan involving both the rheumatology team and primary care physicians to ensure adequate vaccination in immunocompromised patients. In the next step, we also aim to implement these QI interventions to the immunocompromised patients attending outpatient clinics.

Disclosures

W. Ng None. A. Anjum None. A. Sebastian None. J. Devlin None. A. Fraser None.

P51 Serious pathology mimicking GCA: two cases of carcinoma tongue

Background

Jaw and tongue pain with constitutional symptoms and raised inflammatory markers are considered pathognomonic ischemic features of giant cell arteritis (GCA). Temporal artery ultrasound (US) (or biopsy) available in GCA fast-track clinics (FTC) for a rapid assessment of patients with suspected GCA. Atypical presentation and negative US or biopsy require further workup to look for an alternative diagnosis. ENT pathology can occur as a mimic of GCA. Herein we discuss two clinical cases of squamous cell cancer tongue presenting with signs and symptoms that resemble GCA.

Methods

We have put together a case report.

Results

Case-1: A 58-year-old male with a recent presumed diagnosis of relapsing GCA was referred with worsening visual symptoms and right eye pain despite ongoing steroid treatment (60mg), for consideration of Tocilizumab (TCZ). His initial presentation was 5 months ago with a right parietal and retro-orbital headache and blurred vision. He had a normal eye examination. His C-reactive protein (CRP) was raised (24). He was started on prednisolone 40 mg for GCA with complete resolution of symptoms with normalised CRP within weeks. Several weeks later, symptoms reoccurred. CT brain, abdomen and pelvis was normal and temporal artery biopsy negative. His prednisolone was increased to 60 mg. 6 months later, his jaw and tongue pain worsened, and he was treated with pulsed methylprednisolone. Due to partial response to steroids, he was referred to consider TCZ. He had tender left TMJ with normal temporal artery US. Urgent MRI head and neck revealed a left posterior tongue mass with the histology confirmed poorly differentiated squamous cell carcinoma. He was managed with chemo and radiotherapy.

Case-2: A 75 years old female, presented with right scalp pain, tongue pain, painful swallowing and chewing. Her blood investigations were normal except a raised ESR (48) and presumed GCA she was started on steroids (60 mg). she had initially good response but, within a few weeks, her symptoms returned. She was then referred to our FTC. Temporal artery US and biopsy were normal. MRI of the head and neck showed a large mass seen in the right half of the posterior tongue extending into the deep aspect of the anterior tongue. Histology confirmed poorly differentiated Squamous cell carcinoma. She was treated with a combination of chemotherapy and radiotherapy.

Conclusion

GCA mimics represent a major diagnostic dilemma. FTC helps to stratify the GCA from mimics. Careful evaluation of the history, examination as well as a temporal artery US helps to exclude GCA and aids prompt requesting of appropriate tests to find an alternative diagnosis such as tongue cancers as in our cases. We have now introduced negative weightage for consideration of alternative diagnoses in our GCA probability score.

Disclosures

A. Kayani None. A. Sebastian None. L. Borukhson None. M. Whitlock None. B. Dasgupta Consultancies; Roche, Sanofi. Grants/research support; Roche.

P190 Non-GCA diagnoses from a GCA fast track clinic: a single centre with four years' experience (2016-2019)

Background

Giant cell arteritis (GCA) has protean manifestations including temporal headache, visual disturbances, constitutional symptoms, jaw and tongue pain; symptoms which overlap with other conditions which mimic GCA. An important benefit of a fast-track clinic (FTC) is to rapidly exclude the diagnosis GCA to avoid inappropriate steroid exposure. We analysed data for patients referred with suspected GCA to our FTC where GCA diagnosis was subsequently excluded with fast-track ultrasound (US) and other investigations.

Methods

This retrospective data was extracted from the GCA fast-track electronic referral system at Southend University Hospital from January 2016 to July 2019.

Results

1,057 patients were seen at the fast-track clinic in this study period (Table 1). 690 (65.28%) were females. Only 15% (159) of the participants had a confirmed diagnosis of GCA (majority using US but also with other investigations such as biopsy or PET CT). Non-GCA patients accounted for 85% (898) and had a variety of differential diagnoses. In 222 (23.7%) no additional diagnosis was made after excluding GCA and patients were referred back for an expectant follow-up and assessment should any new features develop. In 204 (22.7%), polymyalgia rheumatica (PMR) was diagnosed with classical clinical symptoms and US of bilateral glenohumeral joints or response to a trial of low dose oral steroids. Another major group had different types of headaches 141 (15.71%) at presentation mimicking GCA. This included migraine 79 (56.0%), cervicogenic 58 (41.13%) and cluster headaches 4 (2.83%). Infectious causes were limited to head and neck infections 89 (9.91%) such as periorbital swelling, shingles and sinusitis. Neurological causes such as cervical spondylosis, cranial nerve palsy and TIA contributed to 7.9%. Chronic pain and other causes contributed 74 (8.24%) and 97 (10.8%) respectively. Other causes included medication-related (33), stress (21), cancer (4), RS3PE (4), glaucoma (2) and ANCA-associated vasculitis (33).

Conclusion

An FTP clinic not only diagnoses GCA rapidly but is also able to rapidly screen non GCA and prevent unnecessary steroid treatment. It also requires a screening tool like GCA probability score to triage referrals to enable a more efficient service.

Disclosures

A. kayani None. A. Sebastian None. C. Ranasinghe None. M. Whitlock None. H. Hussain None. B. Dasgupta Consultancies; Roche, Sanofi, GSK. Grants/research support; Roche.

Osteogenic preconditioning in perfusion bioreactors improves vascularization and bone formation by human bone marrow aspirates

Cell-derived extracellular matrix (ECM) provides a niche to promote osteogenic differentiation, cell adhesion, survival, and trophic factor secretion. To determine whether osteogenic preconditioning would improve the bone-forming potential of unfractionated bone marrow aspirate (BMA), we perfused cells on ECM-coated scaffolds to generate naïve and preconditioned constructs, respectively. The composition of cells selected from BMA was distinct on each scaffold. Naïve constructs exhibited robust proangiogenic potential in vitro, while preconditioned scaffolds contained more mesenchymal stem/stromal cells (MSCs) and endothelial cells (ECs) and exhibited an osteogenic phenotype. Upon implantation into an orthotopic calvarial defect, BMA-derived ECs were present in vessels in preconditioned implants, resulting in robust perfusion and greater vessel density over the first 14 days compared to naïve implants. After 10 weeks, human ECs and differentiated MSCs were detected in de novo tissues derived from naïve and preconditioned scaffolds. These results demonstrate that bioreactor-based preconditioning augments the bone-forming potential of BMA.

Signal and noise extraction from analog memory elements for neuromorphic computing

Dense crossbar arrays of non-volatile memory (NVM) can potentially enable massively parallel and highly energy-efficient neuromorphic computing systems. The key requirements for the NVM elements are continuous (analog-like) conductance tuning capability and switching symmetry with acceptable noise levels. However, most NVM devices show non-linear and asymmetric switching behaviors. Such non-linear behaviors render separation of signal and noise extremely difficult with conventional characterization techniques. In this study, we establish a practical methodology based on Gaussian process regression to address this issue. The methodology is agnostic to switching mechanisms and applicable to various NVM devices. We show tradeoff between switching symmetry and signal-to-noise ratio for HfO₂-based resistive random access memory. Then, we characterize 1000 phase-change memory devices based on Ge₂Sb₂Te₅ and separate total variability into device-to-device variability and inherent randomness from individual devices. These results highlight the usefulness of our methodology to realize ideal NVM devices for neuromorphic computing.

Memristive effects in oxygenated amorphous carbon nanodevices

Computing with resistive-switching (memristive) memory devices has shown much recent progress and offers an attractive route to circumvent the von-Neumann bottleneck, i.e. the separation of processing and memory, which limits the performance of conventional computer architectures. Due to their good scalability and nanosecond switching speeds, carbon-based resistive-switching memory devices could play an important role in this respect. However, devices based on elemental carbon, such as tetrahedral amorphous carbon or ta-C, typically suffer from a low cycling endurance. A material that has proven to be capable of combining the advantages of elemental carbon-based memories with simple fabrication methods and good endurance performance for binary memory applications is oxygenated amorphous carbon, or a-CO _x . Here, we examine the memristive capabilities of nanoscale a-CO _x devices, in particular their ability to provide the multilevel and accumulation properties that underpin computing type applications. We show the successful operation of nanoscale a-CO _x memory cells for both the storage of multilevel states (here 3-level) and for the provision of an arithmetic accumulator. We implement a base-16, or hexadecimal, accumulator and show how such a device can carry out hexadecimal arithmetic and simultaneously store the computed result in the self-same a-CO _x cell, all using fast (sub-10 ns) and low-energy (sub-pJ) input pulses.

Iron plaque decreases cadmium accumulation in Oryza sativa L. and serves as a source of iron

Cadmium (Cd) contamination occurs in paddy soils; hence it is necessary to reduce Cd content of rice. Application and mode of action of ferrous sulphate in minimizing Cd in rice was monitored in the present study. Pot culture with Indian rice variety Swarna (MTU 7029) was maintained in Cd-spiked soil containing ferrous sulphates, which is expected to reduce Cd accumulation in rice. Responses in rhizosphere pH, root surface, metal accumulation in plant and molecular physiological processes were monitored. Iron plaque was induced on root surfaces after FeSO4 application and the amount of Fe in plaque reduced with increases in Cd in the soil. Rhizosphere pH decreased during plaque formation and became more acidic due to secretion of organic acids from the roots under Cd treatment. Moreover, iron chelate reductase activity increased with Cd treatment, but in the absence of Cd, activity of this enzyme increased in plaque-induced plants. Cd treatment caused expression of OsYSL18, whereas OsYSL15 was expressed only in roots without iron plaque. Fe content of plants increased during plaque formation, which protected plants from Cd-induced Fe deficiency and metal toxicity. This was corroborated with increased biomass, chlorophyll content and quantum efficiency of photo-synthesis among plaque-induced plants. We conclude that ferrous sulphate-induced iron plaque prevents Cd accumulation and Fe deficiency in rice. Iron released from plaque via organic acid mediated dissolution during Cd stress.

De novo transcriptome assembly facilitates characterisation of fast-evolving gene families, MHC class I in the bank vole (Myodes glareolus)

The major histocompatibility complex (MHC) plays a central role in the adaptive immune response and is the most polymorphic gene family in vertebrates. Although high-throughput sequencing has increasingly been used for genotyping families of co-amplifying MHC genes, its potential to facilitate early steps in the characterisation of MHC variation in nonmodel organism has not been fully explored. In this study we evaluated the usefulness of de novo transcriptome assembly in characterisation of MHC sequence diversity. We found that although de novo transcriptome assembly of MHC I genes does not reconstruct sequences of individual alleles, it does allow the identification of conserved regions for PCR primer design. Using the newly designed primers, we characterised MHC I sequences in the bank vole. Phylogenetic analysis of the partial MHC I coding sequence (2-4 exons) of the bank vole revealed a lack of orthology to MHC I of other Cricetidae, consistent with the high gene turnover of this region. The diversity of expressed alleles was characterised using ultra-deep sequencing of the third exon that codes for the peptide-binding region of the MHC molecule. High allelic diversity was demonstrated, with 72 alleles found in 29 individuals. Interindividual variation in the number of expressed loci was found, with the number of alleles per individual ranging from 5 to 14. Strong signatures of positive selection were found for 8 amino acid sites, most of which are inferred to bind antigens in human MHC, indicating conservation of structure despite rapid sequence evolution.

Liver Transplantation in a Patient at Psychosocial Risk

Psychosocial assessment of transplant candidates is a challenging task. Securing adequate information is made more difficult when patients present with fulminant hepatic failure. When the patient cannot be interviewed and the family is reluctant to provide vital information, a comprehensive pretransplant psychosocial evaluation is virtually impossible. However, even the most difficult cases have the potential for a positive result when a good psychosocial profile of the patient is obtained after transplantation, a team treatment plan is developed and carried out which addresses current and anticipated problems, and the patient obtains mental health treatment.

Endogenous event-related potentials in patients with primary Sjögren's syndrome without central nervous system involvement

OBJECTIVES

Endogenous cognitive event-related potentials (CERPs) reflect higher-level processing of sensory information and can be used to evaluate cognitive functions. The aim of this paper was to determine whether there are any abnormalities in the electrophysiological parameters of CERPs in patients with primary Sjögren's syndrome (pSS) but without symptoms of central nervous system (CNS) involvement or mental disorder. The analysis of CERP parameters was then correlated with the clinical status of the patients and with some of the immunological parameters in the patient group.

METHOD

Thirty consecutive patients with pSS (29 females, one male) were included in the study. All the patients underwent CERP examination.

RESULTS

There was a significant prolongation of the latency of P300 and N200 potentials in patients with pSS. Abnormalities in electrophysiological parameters of CERPs correlated with the duration of the disease, salivary gland abnormalities, and elevated erythrocyte sedimentation rate (ESR) values. Patients with coexisting chronic fatigue syndrome (CFS) had larger P300 amplitudes. There were no statistically significant changes in the electrophysiological parameters of CERPs in patients with pSS dependent on the presence of peripheral nervous system (PNS) lesions, skin changes, arthritis, abnormalities in white blood cells and the immune system or the levels of blood lipids.

CONCLUSIONS

The results of the study suggest the presence of a minor cognitive dysfunction in patients with pSS without symptoms of CNS involvement or mental disorder. Cognitive dysfunction correlated with the disease duration time and the severity of inflammatory changes (salivary gland abnormalities and inflammatory markers in the blood). Further and larger longitudinal studies are necessary for confirmation of this correlation.

Arterialized venous bicarbonate is associated with lower bone mineral density and an increased rate of bone loss in older men and women

CONTEXT

Higher dietary net acid loads have been associated with increased bone resorption, reduced bone mineral density (BMD), and increased fracture risk.

OBJECTIVE

The objective was to compare bicarbonate (HCO3) measured in arterialized venous blood samples to skeletal outcomes.

DESIGN

Arterialized venous samples collected from participants in the Health, Aging and Body Composition (Health ABC) Study were compared to BMD and rate of bone loss.

SETTING

The setting was a community-based observational cohort.

PARTICIPANTS

A total of 2287 men and women age 74 ± 3 years participated.

INTERVENTION

Arterialized venous blood was obtained at the year 3 study visit and analyzed for pH and pCO2. HCO3 was determined using the Henderson-Hasselbalch equation.

MAIN OUTCOME MEASURE

BMD was measured at the hip by dual-energy x-ray absorptiometry at the year 1 (baseline) and year 3 study visits.

RESULTS

Plasma HCO3 was positively associated with BMD at both year 1 (P = .001) and year 3 (P = .001) in models adjusted for age, race, sex, clinic site, smoking, weight, and estimated glomerular filtration rate. Plasma HCO3 was inversely associated with rate of bone loss at the total hip over the 2.1 ± 0.3 (mean ± SD) years between the two bone density measurements (P < .001). Across quartiles of plasma HCO3, the rate of change in BMD over the 2.1 years ranged from a loss of 0.72%/y in the lowest quartile to a gain of 0.15%/y in the highest quartile of HCO3.

CONCLUSIONS

Arterialized plasma HCO3 was associated positively with cross-sectional BMD and inversely with the rate of bone loss, implying that systemic acid-base status is an important determinant of skeletal health during aging. Ongoing bone loss was linearly related to arterialized HCO3, even after adjustment for age and renal function. Further research in this area may have major public health implications because reducing dietary net acid load is possible through dietary intervention or through supplementation with alkaline potassium compounds.

Established dietary estimates of net acid production do not predict measured net acid excretion in patients with Type 2 diabetes on Paleolithic-Hunter-Gatherer-type diets

BACKGROUND/OBJECTIVES

Formulas developed to estimate diet-dependent net acid excretion (NAE) generally agree with measured values for typical Western diets. Whether they can also appropriately predict NAE for 'Paleolithic-type' (Paleo) diets-which contain very high amounts of fruits and vegetables (F&V) and concurrent high amounts of protein is unknown. Here, we compare measured NAEs with established NAE estimates in subjects with Type 2 diabetes (T2D).

SUBJECTS/METHODS

Thirteen subjects with well-controlled T2D were randomized to either a Paleo or American Diabetes Association (ADA) diet for 14 days. Twenty-four hour urine collections were performed at baseline and end of the diet period, and analyzed for titratable acid, bicarbonate and ammonium to calculate measured NAE. Three formulas for estimating NAE from dietary intake were used; two (NAE_diet R or L) that include dietary mineral intake and sulfate- and organic acid (OA) production, and one that is empirically derived (NAE_diet F) only considering potassium and protein intake.

RESULTS

Measured NAE on the Paleo diet was significantly lower than on the ADA-diet (+31±22 vs 112±52 mEq/day, P=0.002). Although all formula estimates showed similar and reasonable correlations (r=0.52-0.76) with measured NAE, each one underestimated measured values. The formula with the best correlation did not contain an estimate of dietary OA production.

CONCLUSIONS

Paleo-diets are lower in NAE than typical Western diets. However, commonly used formulas clearly underestimate NAE, especially for diets with very high F&V (as the Paleo diet), and in subjects with T2D. This may be due to an inappropriate estimation of proton loads stemming from OAs, underlining the necessity for improved measures of OA-related proton sources.

Force modulation for enhanced nanoscale electrical sensing

Scanning probe microscopy employing conductive probes is a powerful tool for the investigation and modification of electrical properties at the nanoscale. Application areas include semiconductor metrology, probe-based data storage and materials research. Conductive probes can also be used to emulate nanoscale electrical contacts. However, unreliable electrical contact and tip wear have severely hampered the widespread usage of conductive probes for these applications. In this paper we introduce a force modulation technique for enhanced nanoscale electrical sensing using conductive probes. This technique results in lower friction, reduced tip wear and enhanced electrical contact quality. Experimental results using phase-change material stacks and platinum silicide conductive probes clearly demonstrate the efficacy of the proposed technique. Furthermore, conductive-mode imaging experiments on specially prepared platinum/carbon samples are presented to demonstrate the widespread applicability of this technique.