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

Protease production and molecular characterization of a protease dipeptidyl-aminopeptidase gene from different strains of Sordaria fimicola

The current research was designed to reach extracellular protease production potential in different strains of Sordaria fimicola which were previously obtained from Dr. Lamb (Imperial College, London) from North Facing Slope and South Facing Slope of Evolution Canyon. After initial and secondary screening, two hyper-producers strains S2 and N6 were selected for submerged fermentation and cultural conditions including temperature, pH, incubation period, inoculum size, substrate concentration, and different carbon and nitrogen sources were optimized for enzyme production. S2 strain showed maximum protease production of 3.291 U/mL after 14 days of incubation at 30 °C with 7 pH, 1% substrate concentration and 1 mL inoculum, While N6 strain showed maximum protease production of 1.929 U/mL under fermentation optimized conditions. Another aim of the present research was to underpin the biodiversity of genetics and post-translational modifications (PTMs) of protease DPAP (peptidyl-aminopeptidase) in Sordaria fimicola. Five polymorphic sites were observed in amino acid sequence of S. fimicola strains with reference to Neurospora crassa. PTMs prediction from bioinformatics tools predicted 38 phosphorylation sites on serine residues for protease peptidyl-aminopeptidase in S1 strain of S. fimicola while 45 phosphorylation sites on serine in N7 strain and 47 serine phosphorylation modifications were predicted in N. crassa. Current research gave an insight that change in genetic makeup effected PTMs which ultimately affected the production of protease enzyme in different strains of same organism (S. fimicola). The production and molecular data of the research revealed that environmental stress has strong effects on the specific genes through mutations which may cause genetic diversity. S. fimicola is non- pathogenic fungus and has a short life cycle. This fungus can be chosen to produce protease enzyme on a commercial scale.

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

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

Radiative Double-Electron Capture by Bare and One-Electron Ions on Gas Targets

Radiative double-electron capture (RDEC) involves the transfer of two electrons with the simultaneous emission of a single photon. This process, which can be viewed as the inverse of double photoionzation, has been studied for 2.11  MeV/u F^{9+} and F^{8+} ions striking gas targets of N_{2} and Ne. The existence of RDEC is conclusively shown for both targets and the results are compared with earlier O^{8+} and F^{9+} findings for thin-foil carbon and with theory. The data for the carbon target showed some evidence for the existence of RDEC, but the interpretation was clouded by high-probability, unavoidable multiple collisions causing the exiting charge state to be increased.

Domestic violence and consanguineous marriages - perspective from Rawalpindi, Pakistan

Domestic violence is globally endemic and adversely impacts the health and economic well-being of women and society. This study used the standardized and validated assessment instrument "Woman Abuse Screening Tool" to study the prevalence of various forms of domestic violence among married women. The relationship between domestic violence and consanguineous marriage was studied using the chi-squared test. Cumulatively, 1010 married women were interviewed. Emotional abuse was the most commonly reported abuse, reported by 721 (71.4%) women as either often or sometimes, followed by sexual abuse and physical abuse, reported by 527 (52.2%) and 511 (50.6%) respectively. Being married to one's cousin did not protect married women from being abused either emotionally or physically by their husbands; thsi was statistically significant. There is a need for better understanding of the magnitude and scale of domestic violence in Pakistan by using standardized assessment tools for meaningful comparisons across different parts of the country over time.

Band gap engineering of zinc selenide thin films through alloying with cadmium telluride

This work investigates band gap engineering of zinc selenide (ZnSe) thin films. This was achieved by mixing ZnSe with cadmium telluride (CdTe). The mass ratio (x) of CdTe in the starting material was varied in the range x = 0-0.333. The films were prepared using thermal evaporation. The chemical composition of the films was investigated through energy dispersive spectroscopy and Rutherford backscattering spectrometry. Structural analysis was carried out using X-ray diffraction and atomic force microscopy. Normal incidence transmittance and reflectance were measured over the wavelength range 300-1300 nm. The absorption coefficients and band gaps were determined from these spectrophotometric measurements. The band gap monotonically decreased from 2.58 eV (for x = 0) to 1.75 eV (for x = 0.333). Photocurrent measurements indicated that the maximum current density was obtained for films with x = 0.286. A figure of merit, based on crystallinity, band gap, and photocurrent, was defined. The optimum characteristics were obtained for the films with x = 0.231, for which the band gap was 2.14 eV.

Fatalism and its implications for risky road use and receptiveness to safety messages: a qualitative investigation in Pakistan

Given the increasing vehicle numbers and expanding road construction in developing countries, the importance of safe road user behaviour is critical. Road traffic crashes (RTCs) are a significant problem in Pakistan; however, the factors that contribute to RTCs in Pakistan are not well researched. Fatalistic beliefs are a potential barrier to the enhancement of road safety, especially participation in health-promoting and injury prevention behaviours, and also contribute to risk taking. Fatalistic beliefs relating to road safety have been found in some developing countries, although research is scarce and indicates that the nature and extent of fatalism differs in each country. Qualitative research was undertaken with a range of drivers, religious orators, police and policy makers to explore associations between fatalism, risky road use and associated issues. Findings indicate that fatalistic beliefs are pervasive in Pakistan, are strongly linked with religion, present a likely barrier to road safety messages and contribute to risky road use. Fatalism appears to be a default attribution of RTC and the intensity of belief in fate surpasses the kinds of fatalism noted in the limited existing literature. These findings have importance to developing road safety countermeasures in countries where fatalistic beliefs are strong.

PGC-1α transcriptional response and mitochondrial adaptation to acute exercise is maintained in skeletal muscle of sedentary elderly males

The aim of the present study was to examine the effects of ageing and training status on (1) markers of skeletal muscle mitochondrial content and (2) the ability to activate the acute signalling pathways associated with regulating exercise-induced mitochondrial biogenesis. Muscle biopsies were obtained from the vastus lateralis muscle of young untrained (24 ± 4 years, n = 6; YU), young trained (22 ± 3 years, n = 6; YT), old untrained (65 ± 6 years, n = 6; OU) and old trained (64 ± 3 years, n = 6; OT) healthy males before and after (3 h and 3 days post-exercise) completion of high-intensity interval cycling exercise. In resting muscle, lifelong training preserved mtDNA, PGC-1α and COXIV protein content such that muscles from OT individuals were comparable to muscles from both YU and YT individuals, whereas lifelong sedentary behaviour reduced such markers of mitochondrial content. Regardless of age or training status, acute exercise induced comparable increases in p38MAPK phosphorylation immediately post-exercise, PGC-1α and COXIV mRNA expression at 3 h post-exercise and COXIV protein at 3 days post-exercise. Data demonstrate that lifelong endurance training preserves skeletal muscle PGC-1α content and that despite the mitochondrial dysfunction typically observed with sedentary ageing, muscles from sedentary elderly individuals retain the capacity to activate the acute signalling pathways associated with regulating the early processes of mitochondrial biogenesis. We consider our data to have immediate translational potential as they highlight the potential therapeutic effects of exercise to induce skeletal muscle mitochondrial biogenesis persist late in adulthood, even after a lifetime of physical inactivity.

Effect of xanthine oxidase-generated extracellular superoxide on skeletal muscle force generation

Skeletal muscle contractions increase superoxide anion in skeletal muscle extracellular space. We tested the hypotheses that 1) after an isometric contraction protocol, xanthine oxidase (XO) activity is a source of superoxide anion in the extracellular space of skeletal muscle and 2) the increase in XO-derived extracellular superoxide anion during contractions affects skeletal muscle contractile function. Superoxide anion was monitored in the extracellular space of mouse gastrocnemius muscles by following the reduction of cytochrome c in muscle microdialysates. A 15-min protocol of nondamaging isometric contractions increased the reduction of cytochrome c in microdialysates, indicating an increase in superoxide anion. Mice treated with the XO inhibitor oxypurinol showed a smaller increase in superoxide anions in muscle microdialysates following contractions than in microdialysates from muscles of vehicle-treated mice. Intact extensor digitorum longus (EDL) and soleus muscles from mice were also incubated in vitro with oxypurinol or polyethylene glycol-tagged Cu,Zn-SOD. Oxypurinol decreased the maximum tetanic force produced by EDL and soleus muscles, and polyethylene glycol-tagged Cu,Zn-SOD decreased the maximum force production by the EDL muscles. Neither agent influenced the rate of decline in force production when EDL or soleus muscles were repeatedly electrically stimulated using a 5-min fatiguing protocol (stimulation at 40 Hz for 0.1 s every 5 s). Thus these studies indicate that XO activity contributes to the increased superoxide anion detected within the extracellular space of skeletal muscles during nondamaging contractile activity and that XO-derived superoxide anion or derivatives of this radical have a positive effect on muscle force generation during isometric contractions of mouse skeletal muscles.