AB1237 COMPARISON BETWEEN ENZYME IMMUNOASSAY AND CHEMILUMINESCENCE TO DETERMINE THE CONCENTRATION OF SERUM CALPROTECTIN AND ITS ASSOCIATION WITH CLINICAL VARIABLES IN PEDIATRIC RHEUMATOLOGY

Background

Serum calprotectin (SC) is an emerging biomarker in the measurement of inflammation. It can be determined by different techniques, such as enzyme immunoassay (EIA) or chemiluminescence (CLIA). However, there are no studies comparing whether there is a correlation between the two diagnostic methods in paediatric rheumatologic diseases.

Objectives

(i) To assess whether there are differences between serum calprotectin (SC) levels determined by EIA (Bühlmann) method and CLIA (QUANTA Flash) in pediatric age patients with systemic autoimmune rheumatic disease (SARD). (ii) To evaluate which clinical and analytical variables are associated with an increase of SC in each method.

Methods

Analytical cross-sectional study that included patients from a pediatric rheumatology specialized unit between 02/2017 and 05/2021. We included 41 patients with SARD who had at least one SC analysis determined by EIA in their routine controls (144 serum) and afterwards had SC determined again, this time using the CLIA method.

The collected variables were sex, age, remission according to clinical judgment, swollen joint count according to physical examination (PE Count) and ultrasound (US Count), Juvenile Arthritis Disease Activity Score according to physical examination (PE JADAS-27) and ultrasound (US JADAS-27), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR).

As for the statistical analysis, intraclass correlation (ICC) and paired samples t-test were performed to compare the two methods. Univariate linear regression was performed to study the association between EIA, CLIA and both clinical and analytical variables.

Results

We included 41 patients, 50.1% were women with a mean age (± SD) of 13.1 (± 3.8) years. The details of their descriptive characteristics were: mean SC (EIA) of 3.1 (±1.8) µg/ml, mean SC (CLIA) of 2.5 (±1.6) µg/ml, mean CRP of 2.6 (± 6.5) mg/l, mean ESR of 10.1 (± 11) mm/h, and mean PE JADAS-27 of 2.8 (± 8). Most frequent diagnosis was oligoarticular juvenile idiopathic arthritis (JIA) (24.4%), followed by enthesitis-related (ERA) JIA (12.2%) and polyarticular JIA (12.2%), familial Mediterranean fever (FMF) (9.8%), psoriatic JIA (4.9%), systemic JIA (4.9%) and syndrome of periodic fever, aphtous stomatitis, pharyngitis, and cervical adenitis (PFAPA) (4.9%), vasculitis (4.8%), and undifferentiated JIA (2.4%). Clinical diagnosis was unspecific in 9.8% of the patients. In our sample, 66.7% were in clinical remission at the discretion of the specialist.

A statistically significant Pearson’s CCI of 0.77 (95%CI 0.70-0.83; p=0.00) was observed as a single measure between EIA and CLIA and with an average of 0.87 (95%CI=0.82-0.91; p=0.000). Figure 1 shows the dispersion of this correlation.

On the other hand, we observed a statistically significant difference in the mean between both methods of 0.58 (95%CI=0.40-0.77; p=0.000), observing a greater difference in SC (EIA) > 4 µg/ml.

A significant association was observed between EIA and clinical remission, joint count, JADAS and CRP; and also between CLIA and clinical remission, JADAS and CRP. The analysis performed is shown in Table 1.

Table 1.

Association between EIA and CLIA with clinical and analytical variables.

RemissionPE CountUS CountPE JADASUS JADASbpbpbpbpbpSC(EIA)0.430.0110.140.0270.080.0240.090.0000.060.000SC(CLIA)0.530.000-0.000.9450.310.3200.050.0210.040.015SexGenderESRCRPbpbpbpbpSC(EIA)0.000.9970.050.2070.000.4870.050.027SC(CLIA)-0.240.3620.010.7950.020.1050.080.000

b, regression coefficient; p, statistical significance.

Conclusion

There is a good correlation between EIA and CLIA methods to determine SC in pediatric patients with SARD. Significant differences were observed between both methods above the value of 4 µg/ml. This fact could be explained by methodological differences, since CLIA discriminates better at higher values than EIA.

An association was observed between both methods and variables of remission or disease activity.

Disclosure of Interests

None declared

Optical Entanglement of Distinguishable Quantum Emitters

Solid-state quantum emitters are promising candidates for the realization of quantum networks, owing to their long-lived spin memories, high-fidelity local operations, and optical connectivity for long-range entanglement. However, due to differences in local environment, solid-state emitters typically feature a range of distinct transition frequencies, which makes it challenging to create optically mediated entanglement between arbitrary emitter pairs. We propose and demonstrate an efficient method for entangling emitters with optical transitions separated by many linewidths. In our approach, electro-optic modulators enable a single photon to herald a parity measurement on a pair of spin qubits. We experimentally demonstrate the protocol using two silicon-vacancy centers in a diamond nanophotonic cavity, with optical transitions separated by 7.4 GHz. Working with distinguishable emitters allows for individual qubit addressing and readout, enabling parallel control and entanglement of both colocated and spatially separated emitters, a key step toward scaling up quantum information processing systems.

Resting heart rate and cardiovascular outcomes in patients with atrial fibrillation: CODE-AF registry

Funding Acknowledgements

Type of funding sources: None.

Background

The prognostic significance of resting heart rate and its therapeutic target in atrial fibrillation (AF) is uncertain.

Purpose

The aim of this study was to investigate the relationships between resting heart rate and cardiovascular outcomes in patients with AF.

Methods

A total of 8,886 patients with AF was included from the COmparison study of Drugs for symptom control and complication prEvention of AF (CODE-AF) registry. Patients were categorized according to baseline heart rate, and cardiovascular outcomes were accessed during a median follow-up of 30 months. The primary outcome was a composite of cardiovascular death, hospitalization due to heart failure, and myocardial infarction/critical limb ischemia.

Results

Compared to heart rate ≥100 beats per minute (bpm), heart rate 80-99 bpm was associated with the lowest risk of primary outcome (adjusted hazard ratio [HR] 0.56, 95% confidence interval [CI] 0.40-0.79, p=0.001). In subgroup of patients with heart failure with preserved ejection fraction (HFpEF), heart rate between 80-99 bpm was associated with reduced risk of primary outcome compared to heart rate ≥100 bpm (HR 0.40, 95% CI 0.16-0.98, p=0.045). However, in patients with heart failure with reduced ejection fraction (HFrEF), there was no association between resting heart rate and cardiovascular outcomes (P for interaction 0.001).

Conclusion

Resting heart rate was associated with cardiovascular outcomes in patients with AF, and those with a resting heart rate between 80-99 bpm had the lowest risk of adverse events. The impact of resting heart rate on adverse events persisted in patients with concomitant HFpEF but was not apparent in those with concomitant HFrEF.

Measurement of Differential Branching Fractions of Inclusive B→X_{u}ℓ^{+}ν_{ℓ} Decays

The first measurements of differential branching fractions of inclusive semileptonic B→X_{u}ℓ^{+}ν_{ℓ} decays are performed using the full Belle data set of 711  fb^{-1} of integrated luminosity at the ϒ(4S) resonance and for ℓ=e, μ. With the availability of these measurements, new avenues for future shape-function model-independent determinations of the Cabibbo-Kobayashi-Maskawa matrix element |V_{ub}| can be pursued to gain new insights in the existing tension with respect to exclusive determinations. The differential branching fractions are reported as a function of the lepton energy, the four-momentum-transfer squared, light-cone momenta, the hadronic mass, and the hadronic mass squared. They are obtained by subtracting the backgrounds from semileptonic B→X_{c}ℓ^{+}ν_{ℓ} decays and other processes, and corrected for resolution and acceptance effects.

Precise Measurement of the D^{0} and D^{+} Lifetimes at Belle II

We report a measurement of the D^{0} and D^{+} lifetimes using D^{0}→K^{-}π^{+} and D^{+}→K^{-}π^{+}π^{+} decays reconstructed in e^{+}e^{-}→cc[over ¯] data recorded by the Belle II experiment at the SuperKEKB asymmetric-energy e^{+}e^{-} collider. The data, collected at center-of-mass energies at or near the ϒ(4S) resonance, correspond to an integrated luminosity of 72  fb^{-1}. The results, τ(D^{0})=410.5±1.1(stat)±0.8(syst)  fs and τ(D^{+})=1030.4±4.7(stat)±3.1(syst)  fs, are the most precise to date and are consistent with previous determinations.

Search for B^{+}→K^{+}νν[over ¯] Decays Using an Inclusive Tagging Method at Belle II

A search for the flavor-changing neutral-current decay B^{+}→K^{+}νν[over ¯] is performed at the Belle II experiment at the SuperKEKB asymmetric energy electron-positron collider. The data sample corresponds to an integrated luminosity of 63  fb^{-1} collected at the ϒ(4S) resonance and a sample of 9  fb^{-1} collected at an energy 60 MeV below the resonance. Because the measurable decay signature involves only a single charged kaon, a novel measurement approach is used that exploits not only the properties of the B^{+}→K^{+}νν[over ¯] decay, but also the inclusive properties of the other B meson in the ϒ(4S)→BB[over ¯] event, to suppress the background from other B meson decays and light-quark pair production. This inclusive tagging approach offers a higher signal efficiency compared to previous searches. No significant signal is observed. An upper limit on the branching fraction of B^{+}→K^{+}νν[over ¯] of 4.1×10^{-5} is set at the 90% confidence level.

Measurements of the Branching Fractions of the Semileptonic Decays Ξ_{c}^{0}→Ξ^{-}ℓ^{+}ν_{ℓ} and the Asymmetry Parameter of Ξ_{c}^{0}→Ξ^{-}π^{+}

Using data samples of 89.5 and 711  fb^{-1} recorded at energies of sqrt[s]=10.52 and 10.58 GeV, respectively, with the Belle detector at the KEKB e^{+}e^{-} collider, we report measurements of branching fractions of semileptonic decays Ξ_{c}^{0}→Ξ^{-}ℓ^{+}ν_{ℓ} (ℓ=e or μ) and the CP-asymmetry parameter of Ξ_{c}^{0}→Ξ^{-}π^{+} decay. The branching fractions are measured to be B(Ξ_{c}^{0}→Ξ^{-}e^{+}ν_{e})=(1.31±0.04±0.07±0.38)% and B(Ξ_{c}^{0}→Ξ^{-}μ^{+}ν_{μ})=(1.27±0.06±0.10±0.37)%, and the decay parameter α_{Ξπ} is measured to be 0.63±0.03±0.01 with much improved precision compared with the current world average. The corresponding ratio B(Ξ_{c}^{0}→Ξ^{-}e^{+}ν_{e})/B(Ξ_{c}^{0}→Ξ^{-}μ^{+}ν_{μ}) is 1.03±0.05±0.07, which is consistent with the expectation of lepton flavor universality. The first measured asymmetry parameter A_{CP}=(α_{Ξ^{-}π^{+}}+α_{Ξ[over ¯]^{+}π^{-}})/(α_{Ξ^{-}π^{+}}-α_{Ξ[over ¯]^{+}π^{-}})=0.024±0.052±0.014 is found to be consistent with zero. The first and the second uncertainties above are statistical and systematic, respectively, while the third ones arise due to the uncertainty of the Ξ_{c}^{0}→Ξ^{-}π^{+} branching fraction.

Ammonium-free medium is critical for regeneration of shoot tips of the endangered species Pogostemon yatabeanus cryopreserved using droplet-vitrification

BACKGROUND

Pogostemon yatabeanus, synonym Dysophylla yatabeana, (Labiatae) is an endangered wild species in Korea. It has has a limited natural habitat and requires urgent conservation measures.

OBJECTIVE

To develop an efficient cryopreservation protocol using in vitro shoot tips to complement traditional conservation approaches in case seeds are unavailable, or insufficient in number for conservation programs.

MATERIALS AND METHODS

Node-cutting induced shoot tips of in vitro plants were produced and cryopreserved using a droplet-vitrification method following improvements in preculture, osmoprotection, vitrification solution (VS) and regrowth treatments. The starting protocol included preculture with 10% sucrose for 31 h, followed by osmoprotection with C4-35% (17.5% glycerol + 17.5% sucrose) for 40 min, and cryoprotection with A3-80% (33.3% glycerol + 13.3% DMSO + 13.3% EG + 20.1% sucrose) for 60 min on ice, cooling and warming using aluminum foil strips, and regrowth in MS hormone-free medium.

RESULTS

Shoot tips of Pogostemon yatabeanus were sensitive to the osmotic stress evidenced by low survival after step-wise preculture with 17.5% sucrose and cryopreservation without osmoprotection. Among VS tested, including PVS2, PVS3 and their alternatives, A3-80% on ice for 60 min resulted in the highest post-cryopreservation survival (80%) and regeneration (20%). Post-cryopreservation regeneration significantly improved (up to 73%) by incubation of cryopreserved shoot tips on ammonium-free medium followed by GA X₃-containing medium and medium without growth regulators.

CONCLUSION

Cryopreservation of in vitro shoot tips using droplet-vitrification was developed as a complementary conservation approach for D. yatabeana. Adjustment of medium composition during the recovery stage was important for regeneration of healthy plants from both cryoprotected-control and cryopreserved shoot tips.

The Safety of Intra-arterial Tirofiban during Endovascular Therapy after Intravenous Thrombolysis

BACKGROUND AND PURPOSE

The safety and efficacy of tirofiban during endovascular therapy in patients undergoing intravenous thrombolysis with recombinant IV tPA remain unclear. This study aimed to investigate the safety and efficacy of intra-arterial tirofiban use during endovascular therapy in patients treated with IV tPA.

MATERIALS AND METHODS

Using a multicenter registry, we enrolled patients with acute ischemic stroke who underwent endovascular therapy. Safety outcomes included postprocedural parenchymal hematoma type 2 and/or thick subarachnoid hemorrhage, intraventricular hemorrhage, and 3-month mortality. Efficacy outcomes included the successful reperfusion rate, postprocedural reocclusion, and good outcomes at 3 months (mRS scores of 0-2). The tirofiban effect on the outcomes was evaluated using a multivariable analysis while adjusting for potential confounders.

RESULTS

Among enrolled patients, we identified 314 patients with stroke (279 and 35 patients in the no tirofiban and tirofiban groups, respectively) due to an intracranial artery occlusion who underwent endovascular therapy with intravenous thrombolysis. A multivariable analysis revealed no association of intra-arterial tirofiban with postprocedural parenchymal hematoma type and/or thick subarachnoid hemorrhage (adjusted OR, 1.07; 95% CI, 0.20-4.10; P = .918), intraventricular hemorrhage (adjusted OR, 0.43; 95% CI, 0.02-2.85; P = .467), and 3-month mortality (adjusted OR, 0.38; 95% CI, 0.04-1.87; P = .299). Intra-arterial tirofiban was not associated with good outcome (adjusted OR, 2.22; 95% CI, 0.89 -6.12; P = .099).

CONCLUSIONS

Using intra-arterial tirofiban during endovascular therapy after IV tPA could be safe.

AB0804 ONE YEAR FOLLOW-UP SAFETY AND EFFICACY RESULTS OF VACCINATION PROTOCOL FROM A RHEUMATOLOGY CLINIC

Background:

Patients with autoimmune inflammatory rheumatic diseases (AIIRD) have a higher burden of infectious diseases compared to the general population. This could be explained by the disturbances in their immune system response, comorbidities and immunosuppressive treatment.Vaccination is the most effective measure to prevent infections.

Objectives:

To describe a cohort of patients with AIIRD referred to the infectious disease´s unit according to the vaccination protocol.

Methods:

Restrospective and descriptive study of a cohort of 286 patients with AIIRD who were evaluated in the rheumatology service of a tertiary hospital in Barcelona and referred to the infectious disease´s unit according to the vaccination protocol among 1 year,between January 1rst December 31st, 2019. The vaccination protocol included serologies of human immunodeficiency virus,hepatitis A,B and C, varicella zoster,tuberculosis,measles,mumps and rubella virus.The recommended vaccines were H.influenzae b,S.pneumonia,influenza,hepatitis A and B(immunity absence),meningococcus c,tetanus – diphtheria (low antigenic load),poliomyelitis and human papillomavirus (not vaccinated).The patients included were diagnosed with a rheumatologic condition under immunosuppressive therapy. Demographic variables,diagnosis,treatment,vaccines administered,infections and adverse effects were collected.

Results:

Of 286 patients reviewed the mean age was 61, 4 (±14.4) years. The characteristics of the cohort are shown in Table 1. Most of the patients used csDMARDs 149 (52.1%), 77(26.9%) patients used combined treatment. Measles and rubella are part of the triple virus vaccines included in the systematic Spanish vaccination schedule, in our cohort 20 (7%) patients had negative serologies for measles and 26 (9%) for rubella. 57 (20%) patients had latent TB with positive Quantiferon.Forty-one (14.3%) were vaccinated before receiving immunosuppressive treatment. The less administered vaccine was influenza with 44.9% (vaccination rate in Spain in healthy population, in 2019-2020 was 51.2%).No serious adverse effects were reported in relation to the vaccination. The infectious complications during the follow-up period were bronchopneumonia in a patient with RA treated with certolizumab (1), herpes zoster infection in RA on adalimumab(1), recurrent otitis in RA on adalimumab(1), mycobacterium avium infection in RA on etanercept(1), TB reactivation in RA with GCs and csDMARDs(1) and Papilloma virus infection in SpA on ustekinumab (1).

Table 1.

CHARACTERISTICS OF COHORT OF PATIENTS

Sex n % (women/men)193/93 (67,5/32,5)Age, years ± DE61.4 ± 14.4Diagnoses AIIRD, n (%)Rheumatoid arthritis n (%)164 (57.3)Systemic lupus erythematosus n (%)6 (2.1)Sjögren´s syndrome n (%)9 (3.1)Systemic sclerosis n (%)1 (0.35)Inflammatory myopathie n (%)5 (1.7)Vasculitis n (%)36 (12.6)Polymyalgia rheumatica n (%)4 (1.4)Spondyloarthropathy n (%)46 (16.1)Others n (%)15 (5.2)Treatment AIIRDGCs n (%)116 (40.7)csDMARDs n (%)149 (52.1)bDMARDs n (%)80 (27.8)tsDMARDs n (%)7 (2.4)Others1 n (%)12 (4.2)GCs + csDMARDs n (%)59 (21)GCs + bDMARDs n (%)14 (4.9)GCs + csDMARDs + bDMARDs n (%)4 (1.4)VaccinesPCV 13 n (%)283 (99)PPSV23 n (%)265 (93)HiB n (%)265 (93)NM n (%)247 (86.7)Influenza n (%)128 (44.9)HBV n (%)121 (42.3)Vaccination before IS n (%)41 (14.3)Vaccination with IS n (%)244 (85.3)

Other: Behcet,Adult Stills,Relapsing polychondritis,IGg4 related disease,Sarcoidosis

Others1: Mycophenolic acid,cyclosporine and tacrolimus

Conclusion:

In our cohort, the vaccination protocol proved to be a good tool to improve the vaccination rate of rheumatological patients, despite this, the vaccination of Hepatitis B and specially of influenza, continues to have a lower prevalence to general population.The vaccines were effective since none of the preventable infections occurred during follow up, despite the use of an immunosuppressant. Vaccination showed a good safety profile, without reported serious adverse effects or worsening of the underlying disease.

Disclosure of Interests:

None declared

AB0129 IL-6R GENETIC VARIANTS AS PREDICTORS OF CLINICAL RESPONSE TO TOCILIZUMAB IN RHEUMATOID ARTHRITIS PATIENTS

Background:

Rheumatoid arthritis (RA) is a chronic, systemic, inflammatory autoimmune disease of unknown etiology. Tocilizumab (TCZ) is a first-line biological disease-modifying anti-rheumatic drug (bDMARD) which inhibits Interleukin 6 (IL-6) pathway through blockade of its receptor. At present, there is a lack of evidence to recommend the treatment of one bDMARD over another.(1) Seeking for genetic biomarkers to predict response to treatment could be key towards a personalized treatment strategy in rheumatology.(2)

Objectives:

We aimed to evaluate whether functional single nucleotide polymorphisms (SNPs) in the IL6R gene could predict response and/or toxicity to TZC in Caucasian patients diagnosed with RA.

Methods:

Retrospective analytical preliminar study of a cohort of 31 patients diagnosed with RA (ACR/EULAR 2010 criteria) who received treatment with TCZ within the last 10 years. Epidemiological, clinical and laboratory data were collected. DNA was extracted from EDTA blood samples. Three SNPs in the IL-6 receptor gene (rs12083537, rs2228145, rs4329505) were genotyped by real-time PCR with TaqMan probes. The associations between polymorphisms and clinicopathological features were evaluated using parametric tests. Efficacy was assessed as the difference of DAS-28 CRP at 6 months. The toxicities recorded were hepatotoxicity, infections, hypersensibility, gastrointestinal, hematological and dyslipidemia.

Results:

The 31 DNA samples from patients included were mainly female (83.9%) and had a mean age at diagnosis of 46.8 years. The mean duration of treatment was 51.3 months and, previously to initiate TCZ, they received a mean of 2,6 csDMARD and 1,7 bDMARD.

The more frequent adverse effects were hypertransaminasemia (22.6%) and neutropenia (32.3%). Most relevant epidemiologic and clinical data is shown in Table 1.

Table 1.

Clinical characteristics. RA=Rheumatoid Arthritis. CCP= anti-Cyclic Citrullinated Peptides. RF=Rheumatoid factor. csDMARDs= conventional synthetic Disease-modifying antirheumatic drug. bDMARD= biological Disease-modifying antirheumatic drug. BMI=Body Mass Index. Sc=subcutaneous. Ev=endovenous. DAS28= Disease Activity Score in 28 joints

Sex (n=31), n (% women/men) 26/5 (83,9%/16,1%)Age at diagnosis (n=31), years +- SD 46,8+- 12,8Erosive RA (n=31), n(%) 14 (45,2%)Anti-CCP positive (n=31), n(%)UI+- SD 23 (74,2%)259,7 +- 137,3RF positive (n=31), n (%)UI+-SD 21 (67,7%)189,4+- 114Previous csDMARD (n=31), n°+-SD2,6 +-1,3Previous bDMARD (n=31), n°+- SD1,7 +- 1,4BMI (n=29), mean +- SD29,3+- 5,1Duration of treatment (n=31), months +-SD51,3 +- 36,3-Active treatment (n=12)-80,9+- 18,3-Finished treatment (n=19)-32,6+- 32,2Route of administration (n=31), n (%) sc/ev 11/20 (35,5/64,5)Basal DAS28 (n=30), mean+- SD5,3 +- 1,1DAS28 reduction at 6 months (n=28), mean+-SD2,9 +-1,1

The univariate analyses showed that the rs2228145 variant was statistically associated with differences in DAS28 reduction at 6 months (p=0.042). Regarding efficacy, we also found a trend with the SNP rs4329505 (p=0.173), which could achieve statistical significance with the projected inclusion of more patients. No associations were found regarding adverse effects.

Conclusion:

The rs2228145 polymorphisms in the IL6R gene may be considered as a pharmacogenetic biomarker of TCZ response in RA patients. More studies are required in order to investigate the clinical use of pharmacogenetic biomarkers in rheumatic diseases.

References:

[1]Smolen, Josef S., Robert B., et al. 2020. “EULAR Recommendations for the Management of Rheumatoid Arthritis with Synthetic and Biological Disease-Modifying Antirheumatic Drugs: 2019 Update.” Annals of the Rheumatic Diseases 79 (6): 685–99.

[2]Tarnowski, Maciej, Agnieszka Paradowska-Gorycka, et al. 2016. “The Effect of Gene Polymorphisms on Patient Responses to Rheumatoid Arthritis Therapy.” Expert Opinion on Drug Metabolism & Toxicology 12 (1): 41–55.

Disclosure of Interests:

None declared

POS0827 HEPATOTROPIC VIRUSES WITH HIGHER RHEUMATOID FACTOR, BUT NOT RHEUMATIC DISEASES LINK TO PREVALENT CRYOGLOBULINEMIA. CORRELATION OF CLINICAL AND SEROLOGICAL MARKERS WITH ETIOLOGICAL CAUSES

Background:

Cryoglobulinemia (CG) is a rare phenomenon, which is defined as the persistent presence in serum of abnormal immunoglobulins (Igs) that precipitate in vitro at less than 37°C and dissolve when the temperature rises again. Is related to hematological disorders, infections and autoimmunes diseases.

Objectives:

To describe the differential clinical features, serological and demographics in a cohort of patients diagnosed with CG.

Methods:

We describe a retrospective cohort of 252 cryoglobulin (Cg) positive samples, obtained from a database from the immunology laboratory of a tertiary hospital (November 2018-November 2019). We obtained 182 patients with CG, classified according to their etiology into 4 groups: 1)Rheumatic diseases (RD) that includes rheumatoid arthritis, Systemic lupus erythematosus, Sjögren´s syndrome and Systemic scleroderma, 2)Hepatotropic viruses (HV) with patients diagnosed with Hepatitis C virus, B virus and both, 3)Hematological diseases (HD) and 4)Essential cryoglobulinemia (CGE). Demographic variables, clinical and serological data were collected. A comparative analysis was performed with the Mann-Whitney U test and the multivariate Kruskal-Wallis test, nonparametric variables were compared using a Wilcoxon test. Ten patients, with more than one disease from 4 groups, were excluded from the study.

Results:

Out of 182 reviewed patients, 172 were included in the study. Mean age at diagnosis was 59.7(±14.0). Demographic, clinical and laboratory characteristics are described in table 1. Mixed CG was the predominant subtype, in 116 (67.4%) patients. The most prevalent CG-associated diseases were HV infection with 91(53%) patients. CGE mostly presented with cutaneous manifestations (p=0.0001), particularly purpura. In RD group the presence of Raynaud and non-erosive arthritis (p=0.0001) was relevant. Laboratory findings showed that CG titration varies according to the etiology, being HD the one with the highest values with 292.2 (±546.2). There is significant difference in terms of the average of rheumatoid factor (RF) being higher in the group by CGE. On other hand, the group HV presented more consumption of complement, and showed the lowest average p=0.0001, without more severe clinical manifestations.

RD (n=47)HV (n=91)HD (n=17)CGE (n=17)Gender,n(%) F42 (89.4)57 (62.6)7 (41.2)11 (64.7)Age at dg, years, (± SD)60.6 (±14)59.6 (±13.1)61.1(±16.6)56.3(±20.8)p=0.8CLINICAL CHARACTERISTICSSkin n (%)18 (38.3)10 (11.0)2 (11.8)9 (52.9)p<0.001Raynaud n (%)14 (29.8)1 (5.9)3 (17.6)p<0.001Purpura n (%)6 (12.8)9 (9.9)2 (11.8)6 (35.3)p=0.04Acrocyanosis n (%)6 (12.8)1 (5.9)p=0.0033Ulcers n (%)3 (6.4)2 (2.2) -2 (11.8)p=0.19Peripheric Neuro n (%)10 (21.3)9 (9.9)1 (5.9)4 (23.5)p=0.13N-E arthritis n (%)22 (46.8)8 (8.8)1 (5.9)4 (23.5)p<0.001GMN n (%)5 (10.6)3 (3.3)1 (5.9)3 (17.6)p=0.11LABORATORYCg (mg/dL) x (± SD)26.7 (±63.2)65.8 (±256.5)292.4 (±546.2)47.59 (±79.1)p<0.001Isotype IgG, n (%)G+M 26 (55.3)G+M 72 (79.1)M 8 (47.1)G+M 12 (70.6)β2M (≥1.8 mg/L), n (%)7/40 (17.5%)1/5 (20.0%)3/12 (25.0%)-p= 0.44RCP (mg/L) p 5010.3 (±26.2)3.9 (±3.0)13.4 (±18.3)8.5 (±12.0)p= 0.47ESR (mm/h) p5040.0 (±28.5)20.3 (±20.2)35.4 (±35.1)24.5 (±25.0)p= 0.0003RF + (>20UI/mL), n (%)19/46 (41.3)44/86 (51.2)5/11 (45.5)7/17 (41.2)p= 0.09p5090.6 (±175.9)161.0 (±219.5)94.8 (±135.6)284.5 (±619.3)p<0.001C3 (<85mg/dL), n %)20 (42.6)47 (51.6)3 (17.6)3 (17.6)p= 0.13x (± SD)90.1 (±28.6)68.5 (±10.8)99.1 (±29.0)114.8 (±12.7)p<0.001C4 (<12mg/dL), n (%)17 (36.2)36 (39.6) -3 (17.6)p= 0.02x (± SD)15.6 (±9.0)7.6 (±3.5)20.4 (±7.4)21.1 (±9.5)p<0.001

Conclusion:

In our cohort, not all patients with CG presented clinical manifestations being those associated with CGE and RD those with the highest skin and joint expression. The most prevalent association of CG continues to be the HV and we confirmed the characteristic decrease in C3 and C4 complement levels, together with the positivity for RF.

Disclosure of Interests:

None declared

AB0643 IL-1 BLOCKAGE WITH ANAKINRA IN GOUT PATIENTS. SCOPING REVIEW OF THE PUBLISHED LITERATUR

Background:

Gout is the most common inflammatory arthritis in adults. It is caused by the chronic deposition of monosodium urate crystals in joints. Hypertension, diabetes mellitus, chronic kidney disease (CKD) and cardiovascular disease are highly prevalent in gout patients.

Nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids or colchicine are the first line therapeutic agents for flares. These drugs can be contraindicated in a large group of gout patients. Off label prescription of IL-1 receptor blockage with anakinra can be an alternative for this complex patients.

Objectives:

The main objective of this study is to perform a scoping review about patient characteristics, comorbidity, effectivity and safety profile of patients with gout treated with anakinra.

Methods:

A total of 1119 citations were screened. The reviewers performed a two-stage screening by title/abstract and full-text screening. Thirty six articles that finally met selection criteria, were included for data extraction and synthesis. Treatment duration of ≥12 weeks was considered chronic.

Results:

Four hundred forty three patients were included in the study. 20 patients (4,5%) received chronic treatment and 423 (95,5%) flare treatment. Outcomes from 496 flares were finally analyzed.

The mean age of the patients was 63.6 years and 84% were men. The clinical presentation was polyarticular in 47.9% and tophaceous gout in 66.5%. Some of these patients presented atypical forms of the disease such as spinal gout, autoinflammatory syndromes or sternoclavicular joint arthritis.

Most of the patients presented comorbidities, the most prevalent being arterial hypertension in 127 (70.5%) and chronic kidney disease (≥ 3 stage) in 220 (51.8%). History of transplant in 37 (14.6%) with stem cell, kidney, heart, and liver transplant. More than half of patients had more than one associated comorbidity. Demographic and clinical characteristics of gouty arthritis patients are presented in Table 1. Flare was present in admitted patients in 260 (57.5%). Anakinra was administered in 52 patients with an active infection.

Different treatment regimens were described. Daily administration was used in 98% of the patients. 92.8% of the flares were treated seven days or less, being the three days regimen the most prevalent. In the chronic group the longest treatment reported was 5 years.

Efficacy of treatment with anakinra was evidenced, in flare 426 patients (93%) and chronic 19 patients (91%). Overall, anakinra was well tolerated. In the case of flares, thirty-three (7.9%) adverse effects related to anakinra administration were registered: seven (1.6%) site injection reactions, five (1.1%) reversible hematological alterations and five acute infections (H1N1, herpes zoster, severe cold, pulmonary abscess and nosocomial pyelonephritis). In chronic treated patients, adverse infectious events were more prevalent, seven (32%) infections (Staphylococcus aureus tophus (2), Staphylococcus aureus lung abscess, erysipela of the leg, Streptococcus B urinary tract infection, Staphylococcus aureus knee arthritis and tuberculous cervical lymphadenitis).

Conclusion:

Anakinra has been shown to be effective and safe in treatment for flares in gout complex or resistant patients. It has been shown in multiples scenarios like active infections, dialysis, transplants, chronic kidney disease, tophi and polyarticular disease refractory to standard treatment. It has also shown its effectiveness as chronic treatment, but there are more concerns about its safety. These findings need to be confirmed with controlled clinical trials for anakinra inclusion in treatment recommendations in special situations of flares in complex or resistant gout patients.

Disclosure of Interests:

None declared.

Test of Lepton-Flavor Universality in B→K^{*}ℓ^{+}ℓ^{-} Decays at Belle

We present a measurement of R_{K^{*}}, the branching fraction ratio B(B→K^{*}μ^{+}μ^{-})/B(B→K^{*}e^{+}e^{-}), for both charged and neutral B mesons. The ratio for the charged case R_{K^{*+}} is the first measurement ever performed. In addition, we report absolute branching fractions for the individual modes in bins of the squared dilepton invariant mass q^{2}. The analysis is based on a data sample of 711  fb^{-1}, containing 772×10^{6}  BB[over ¯] events, recorded at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. The obtained results are consistent with standard model expectations.

A compact and stable incidence-plane-rotating second harmonics detector

We describe a compact and stable setup for detecting the optical second harmonics, in which the incident plane rotates with respect to the sample. The setup is composed of rotating Fresnel rhomb optics and a femtosecond ytterbium-doped fiber laser source operating at the repetition frequency of 10 MHz. The setup including the laser source occupies an area of 1 m² and is stable so that the intensity fluctuation of the laser harmonics can be less than 0.2% for 4 h. We present the isotropic harmonic signal of a gold mirror of 0.5 pW and demonstrate the integrity and sensitivity of the setup. We also show the polarization-dependent six-fold pattern of the harmonics of a few-layer WSe₂, from which we infer the degree of local-field effects. Finally, we describe the extensibility of the setup to investigate the samples in various conditions such as cryogenic, strained, ultrafast non-equilibrium, and high magnetic fields.

Evidence for X(3872)→J/ψπ^{+}π^{-} Produced in Single-Tag Two-Photon Interactions

We report the first evidence for X(3872) production in two-photon interactions by tagging either the electron or the positron in the final state, exploring the highly virtual photon region. The search is performed in e^{+}e^{-}→e^{+}e^{-}J/ψπ^{+}π^{-}, using 825  fb^{-1} of data collected by the Belle detector operated at the KEKB e^{+}e^{-} collider. We observe three X(3872) candidates, where the expected background is 0.11±0.10 events, with a significance of 3.2σ. We obtain an estimated value for Γ[over ˜]_{γγ}B(X(3872)→J/ψπ^{+}π^{-}) assuming the Q^{2} dependence predicted by a cc[over ¯] meson model, where -Q^{2} is the invariant mass squared of the virtual photon. No X(3915)→J/ψπ^{+}π^{-} candidates are found.

Risk factors for local recurrence and long term survival after minimally invasive intersphincteric resection for very low rectal cancer: Multivariate analysis in 161 patients

INTRODUCTION

Intersphincteric resection (ISR) is the ultimate anal-sparing technique as an alternative to abdominoperineal resection in selected patients. Oncological safety is still debated. This study analyses long-term oncological results and evaluates risk factors for local recurrence (LR) and overall survival (OS) after minimally-invasive ISR.

MATERIALS AND METHODS

Retrospective single-center data were collected from a prospectively maintained colorectal database. A total of 161 patients underwent ISR between 2008 and 2018. OS and local recurrence-free survival (LRFS) were assessed using Kaplan-Meier analysis (log-rank test). Risk factors for OS and LRFS were assessed with Cox-regression analysis.

RESULTS

Median follow-up was 55 months. LR occurred in 18 patients. OS and LRFS rates at 1, 3, and 5 years were 96%, 91%, and 80% and 96%, 89%, and 87%, respectively. Tumor size (p = 0.035) and clinical T-stage (p = 0.029) were risk factors for LRFS on univariate analysis. On multivariate analysis, tumor size (HR 2.546 (95% CI: 0.976-6.637); p = 0.056) and clinical T-stage (HR 3.296 (95% CI: 0.941-11.549); p = 0.062) were not significant. Preoperative CEA (p < 0.001), pathological T-stage (p = 0.033), pathological N-stage (p = 0.016) and adjuvant treatment (p = 0.008) were prognostic factors for OS on univariate analysis. Preoperative CEA (HR 4.453 (95% CI: 2.015-9.838); p < 0.001) was a prognostic factor on multivariate analysis.

CONCLUSIONS

This study confirms the oncological safety of minimally-invasive ISR for locally advanced low-lying rectal tumors when performed in experienced centers. Despite not a risk factor for LR, tumor size and, locally advanced T-stage with anterior involvement should be carefully evaluated for optimal surgical strategy. Preoperative CEA is a prognostic factor for OS.

Developing a predictive model for distinguishing invasive nail unit melanoma from nail unit melanoma in situ

BACKGROUND

Clinical information that distinguishes invasive nail unit melanoma from nail unit melanoma in situ before surgery would aid physicians in the decision-making process and estimating prognosis. However, limited information is available on the detailed demographic and dermoscopic features of invasive nail unit melanoma and nail unit melanoma in situ for differential diagnosis.

OBJECTIVE

This study aimed to investigate the demographic data and dermoscopic features of invasive nail unit melanoma and nail unit melanoma in situ and establish a predictive model for differentiating these two forms of nail unit melanoma.

METHODS

A retrospective observational study of ninety-seven patients diagnosed with nail unit melanoma (59 in situ and 38 invasive cases) in four healthcare centres in South Korea (three tertiary referral hospitals and one second referral hospital) from March 2014 to December 2019.

RESULTS

A multivariable analysis revealed that ulcer (odds ratio = 21.6, confidence interval = 2.1-219.8, P = 0.009), total melanonychia (odds ratio = 17.6, confidence interval = 3.0-104.0, P = 0.002), nail plate destruction (odds ratio = 10.9, confidence interval = 2.0-59.4, P = 0.006) and polychromia (odds ratio = 5.3, confidence interval = 1.36-20.57, P = 0.016) were distinctive dermoscopic features of invasive nail unit melanoma. A predictive model with scores ranging from 0 to 6 points demonstrated a reliable diagnostic value (C-statistic = 0.902) in differentiating invasive nail unit melanoma from nail unit melanoma in situ.

CONCLUSIONS

Invasive nail unit melanoma and nail unit melanoma in situ have different dermoscopic features. A predictive model based on morphologic dermoscopic features could aid in differentiating invasive nail unit melanoma from nail unit melanoma in situ.

Search for Axionlike Particles Produced in e^{+}e^{-} Collisions at Belle II

We present a search for the direct production of a light pseudoscalar a decaying into two photons with the Belle II detector at the SuperKEKB collider. We search for the process e^{+}e^{-}→γa, a→γγ in the mass range 0.2<m_{a}<9.7  GeV/c^{2} using data corresponding to an integrated luminosity of (445±3)  pb^{-1}. Light pseudoscalars interacting predominantly with standard model gauge bosons (so-called axionlike particles or ALPs) are frequently postulated in extensions of the standard model. We find no evidence for ALPs and set 95% confidence level upper limits on the coupling strength g_{aγγ} of ALPs to photons at the level of 10^{-3}  GeV^{-1}. The limits are the most restrictive to date for 0.2<m_{a}<1  GeV/c^{2}.

Frontal plane dynamics of the centre of mass during quadrupedal locomotion on a split-belt treadmill

Our previous study of cat locomotion demonstrated that lateral displacements of the centre of mass (COM) were strikingly similar to those of human walking and resembled the behaviour of an inverted pendulum (Park et al. 2019 J. Exp. Biol.222, 14. (doi:10.1242/jeb.198648)). Here, we tested the hypothesis that frontal plane dynamics of quadrupedal locomotion are consistent with an inverted pendulum model. We developed a simple mathematical model of balance control in the frontal plane based on an inverted pendulum and compared model behaviour with that of four cats locomoting on a split-belt treadmill. The model accurately reproduced the lateral oscillations of cats' COM vertical projection. We inferred the effects of experimental perturbations on the limits of dynamic stability using data from different split-belt speed ratios with and without ipsilateral paw anaesthesia. We found that the effect of paw anaesthesia could be explained by the induced bias in the perceived position of the COM, and the magnitude of this bias depends on the belt speed difference. Altogether, our findings suggest that the balance control system is actively involved in cat locomotion to provide dynamic stability in the frontal plane, and that paw cutaneous receptors contribute to the representation of the COM position in the nervous system.

Conducting a national burden of disease study in South Korea: from past to present

South Korea has been measuring its own burden of disease since the early 2000s and has developed a methodology for its calculation. Since 2012, South Korea has been carrying out disease burden research through the Research and Development Project, supported by the Ministry of Health and Welfare. Because the Korean health insurance system covers the entire population of the country, the Korean National Burden of Disease (KNBD) study is based on individual claims data. Disease prevalence, incidence, and mortality rates, which are the epidemiologic indicators used to calculate burden of disease, are based on actual data, and the incidence-based approach is used for Years Lived with disability (YLD), Years of Life Lost (YLL), and Disability Adjusted Life Year (DALY). The KNBD study is conducted for 260 diseases and injuries and subdivided into sub-national levels. Disability weights (DW) are calculated to reflect the sociocultural characteristics of a disease. For cause-specific DWs, we conducted a self-administered web-based survey for medical doctors and students. Using a ranking method, we calculated cause-specific DWs. For this reason, KNBD study results cannot be directly compared with GBD results.

The major findings of the KNBD study are as follows. In Korea, the DALY rate (per 100,000 people) steadily increased for all income levels. The higher the income, the lower the burden of disease; low-income people had a higher burden of disease than high-income people. However, thyroid cancer, refraction and accommodation disorders had a high burden of disease in the high-income group. Growth in the YLD rate was faster than in the YLL rate. In 2016 the leading causes of disease burden were diabetes mellitus, low back pain, and chronic obstructive pulmonary disease.

We will present South Korea's disease burden calculation methodology and its results and share the efforts to calculate disease burden in other countries.

Variation in training requirements within general surgery: comparison of 23 countries

Background

Many differences exist in postgraduate surgical training programmes worldwide. The aim of this study was to provide an overview of the training requirements in general surgery across 23 different countries.

Methods

A collaborator affiliated with each country collected data from the country's official training body website, where possible. The information collected included: management, teaching, academic and operative competencies, mandatory courses, years of postgraduate training (inclusive of intern years), working‐hours regulations, selection process into training and formal examination.

Results

Countries included were Australia, Belgium, Canada, Colombia, Denmark, Germany, Greece, Guatemala, India, Ireland, Italy, Kuwait, the Netherlands, New Zealand, Russia, Saudi Arabia, South Africa, South Korea, Sweden, Switzerland, UK, USA and Zambia. Frameworks for defining the outcomes of surgical training have been defined nationally in some countries, with some similarities to those in the UK and Ireland. However, some training programmes remain heterogeneous with regional variation, including those in many European countries. Some countries outline minimum operative case requirement (range 60–1600), mandatory courses, or operative, academic or management competencies. The length of postgraduate training ranges from 4 to 10 years. The maximum hours worked per week ranges from 38 to 88 h, but with no limit in some countries.

Conclusion

Countries have specific and often differing requirements of their medical profession. Equivalence in training is granted on political agreements, not healthcare need or competencies acquired during training.

AB0770 DESCRIBING A COHORT OF PATIENTS WITH PSORIATIC ARTHRITIS ACCORDING TO THE BODY MASS INDEX: EXPERIENCE IN A JOINT RHEUMATOLOGY-DERMATOLOGY CLINIC

Background:

Obesity is a predictor for the development of psoriatic arthritis (PsA) with a negative prognostic impact.

Objectives:

We aimed to describe and characterize patients with PsA according to the Body Mass Index (BMI) in a joint Rheumatology-Dermatology unit (PAIDER).

Methods:

We retrospectively reviewed patients diagnosed with PsA according to CASPAR criteria visited between May 2012 and May 2019 at the PAIDER clinic of our center. Data on demographic and anthropometric features, serologic findings, source of referral, cardiovascular risk factors and biological treatment were collected from clinical records. Patients were classified according to the WHO International Classification of nutritional status in normal weight (BMI 18.5-24.9 Kg/m2), overweight (BMI 25-29.9 Kg/m2) and obesity (BMI≥30 Kg/m2). A descriptive analysis was performed, and the differences between groups were evaluated using Chi2, T-Student and ANOVA tests. P-values <0.05 were accepted as significant.

Results:

During the study period 393 patients (50.6% women) with a mean age of 52.47 ± 13.21 years were evaluated. Baseline characteristics are shown in table 1.

Table 1.Baseline characteristicsTotaln=393Female, n (%)199 (50,6)Age, yrs, mean ±SD52,47 (13,21)Source of referral, n (%) Dermatology117 (29,8) Rheumatology219 (55,7) Primary Care and Others22 (5,6)Smoker, n (%)97 (25,8)High Blood Pressure (HBP), n (%)106 (27,7)Diabetes, n (%)48 (12,5)Hypercholesterolemia, n (%)98 (25,8)Hyperuricemia, n (%)32 (8,6)HLA-B27 positive, n (%)68 (21,6)BMI, Kg/m2, mean ±SD28,15 (5,87)Biological treatment, n (%)166 (43,2)

The mean BMI was 28.15 ± 5.87 kg/m2. 112 patients (32%) were overweight with a mean BMI of 27.46 ± 1.55 kg/m2and 118 patients (34%) were obese with a mean BMI of 34.42 ± 5.08 kg/m2. Of the obese patients, 80 (67.8%) had obesity grade 1, 28 (23.7%) grade 2 and 10 (8.5%) grade 3.

Characteristics of the patients according to BMI categories are shown in Table 2.

Table 2.Characteristics according to BMINormal weightn= 118Overweightn= 112Obesityn=118P valueFemale, n (%)66 (55,9)52 (46,4)62 (52,5)nsAge, yrs, mean ±SD47,92 (14,08)54,71 (11,75)54,48 (11,54)<0,001Source of referral, n (%)Ns Dermatology35 (33,7)37 (35,2)34 (30,9) Rheumatology63 (60,6)61 (58,1)70 (63,6) Primary Care and Others6 (5,8)7 (6,7)6 (5,5)Smoker, n (%)37 (33)23 (21,1)31 (26,7)nsHigh Blood Pressure (HBP), n (%)12 (10,5)37 (34,3)41 (35)<0,001Diabetes, n (%)7 (6)9 (8,3)30 (25,6)<0,001Hypercholesterolemia, n (%)19 (17)24 (22,2)45 (38,5)0,001Hyperuricemia, n (%)5 (4,4)7 (6,8)19 (16,7)0,004HLA-B27, n (%)27 (28,7)17 (17,9)13 (12,6)0,016BMI, Kg/m2, media ±DE22,58 (1,78)27,46 (1,55)34,42 (5,08)-Biological treatment, n (%)47 (41,2)45 (40,9)66 (55,9)0,032

We observed that mean age was significantly higher in obese patients (p <0.001), as well as the prevalence of cardiovascular risk factors such as HBP (p <0.001), Diabetes (p <0.001), dyslipidemia (p = 0.001) and hyperuricemia (p = 0.004). Obese patients also received more biological therapy (p=0.032). A higher prevalence of HLA-B27 was observed in patients with normal weight (p=0.016). No differences were found according to BMI regarding gender and source of referral.

Conclusion:

- Almost 70% of patients with PsA visited in the PAIDER clinic of our center have a BMI above normal and more than a third of them are obese, mostly grade 1.

- In our joint clinic there are no differences in BMI regarding the source of referral of the patients.

- Patients with obesity are older, have more cardiovascular comorbidities and receive more biological treatment significantly, which increases the complexity of their management and worsens the prognosis.

Disclosure of Interests:

Andrea García-Guillén: None declared, Ana Laiz: None declared, Anna Lopez-Ferrer: None declared, HyeSang Park: None declared, Patricia Moya: None declared, Berta Magallares: None declared, Ivan Castellví Consultant of: Boehringer Ingelheim, Actelion, Kern Pharma, Speakers bureau: Boehringer Ingelheim, Actelion, Bristol-Myers Squibb, Roche, Ana Milena Millán Arciniegas: None declared, Cesar Díaz-Torné: None declared, Sicylle Jeria: None declared, Hector Corominas: None declared

AB0997 IS HEIGHT ADJUSTMENT NECESSARY IN PEDIATRIC DENSITOMETRY IN ALL CHILDREN?

Background:

The current guidelines of the International Society for Clinical Densitometry (1) recommend that in children with linear growth or maturational delay, Z score results should be adjusted. Height for age Z score (HAZ) adjustment is valid and can be calculated using the formula the formula proposed by Zemmel et al(2).

It is possible that pediatric populations without linear growth or maturational delay, also benefit from HAZ, to prevent bone size from influencing the final Z score.

Objectives:

To evaluate Z score variability adjusted and without adjusting for height for age.

Methods:

We analysed data from densitometry performed on patients 2-20 years of age, from 2016 to 2018, assessed in the pediatric rheumatology office of our hospital for presenting risk factors for low bone mass/osteoporosis. The HAZ was calculated according to Zemel’s formula.

Results:

Data from 103 patients are presented. Its characteristics are summarized in Table 1

Table 1.Mean age9,8 yearsFemale52,4%Height Percentil ≤ 36,8%Height Percentil ≥ 974,9%LBM (Z score ≤ -2) spine8,2%LBM HAZ spine6,4%LBM whole body10,5%LBM HAZ whole body7,2%

The table shows that the proportion of patients with BMD decreases in both the spine region and the whole body when adjusting for HAZ.

When evaluating the relationship between densitometric measurements we found that spine Z score (ZsS) and whole body Z score (ZsWB) had a correlation coefficient of 0,73 (p<0,001). There were no differences between their averages (p=0,170).

At the LBM cut-off point (Z score ≤ -2) there were discrepancies in 7%, where 5% presented LBM in ZsWB but not in ZsS. The concordance index at this point was 0,557.

When comparing these measures with their HAZ adjusted equivalents, we observe:

Conclusion:

There are discrepancies at the LBM cut-off point depending on the HAZ adjustment.

The pediatric population without linear growth or maturational delay, can also benefit from HAZ adjustment, especially those with high height percentiles in which their size can hide a diagnosis of LBM.

References:

[1]Weber DR, Boyce A, Gordon C, Hogler W, Kecskemethy HH, Misra M, et al. The Utility of DXA Assessment at the Forearm, Proximal Femur, and Lateral Distal Femur, and Vertebral Fracture Assessment in the Pediatric Population: 2019 ISCD Official Position. Journal of clinical densitometry: the official journal of the International Society for Clinical Densitometry. 2019;22(4):567-89.

[2]Zemel BS, Leonard MB, Kelly A, Lappe JM, Gilsanz V, Oberfield S, et al. Height adjustment in assessing dual energy x-ray absorptiometry measurements of bone mass and density in children. The Journal of clinical endocrinology and metabolism. 2010;95(3):1265-73.

Disclosure of Interests:

None declared