Effects of type of substrate and dilution rate on fermentation in serial rumen mixed cultures

Forages and concentrates have consistently distinct patterns of fermentation in the rumen, with forages producing more methane (CH4) per unit of digested organic matter (OM) and higher acetate to propionate ratio than concentrates. A mechanism based on the Monod function of microbial growth has been proposed to explain the distinct fermentation pattern of forages and concentrates, where greater dilution rates and lower pH associated with concentrate feeding increase dihydrogen (H2) concentration through increasing methanogens growth rate and decreasing methanogens theoretically maximal growth rate, respectively. Increased H2 concentration would in turn inhibit H2 production, decreasing methanogenesis, inhibit H2-producing pathways such as acetate production via pyruvate oxidative decarboxylation, and stimulate H2-incorporating pathways such as propionate production. We examined the hypothesis that equalizing dilution rates in serial rumen cultures would result in a similar fermentation profile of a high forage and a high concentrate substrate. Under a 2 × 3 factorial arrangement, a high forage and a high concentrate substrate were incubated at dilution rates of 0.14, 0.28, or 0.56 h-1 in eight transfers of serial rumen cultures. Each treatment was replicated thrice, and the experiment repeated in two different months. The high concentrate substrate accumulated considerably more H2 and formate and produced less CH4 than the high forage substrate. Methanogens were nearly washed-out with high concentrate and increased their initial numbers with high forage. The effect of dilution rate was minor in comparison to the effect of the type of substrate. Accumulation of H2 and formate with high concentrate inhibited acetate and probably H2 and formate production, and stimulated butyrate, rather than propionate, as an electron sink alternative to CH4. All three dilution rates are considered high and selected for rapidly growing bacteria. The archaeal community composition varied widely and inconsistently. Lactate accumulated with both substrates, likely favored by microbial growth kinetics rather than by H2 accumulation thermodynamically stimulating electron disposal from NADH into pyruvate reduction. In this study, the type of substrate had a major effect on rumen fermentation largely independent of dilution rate and pH.

MGRN1 depletion promotes intercellular adhesion in melanoma by upregulation of E-cadherin and inhibition of CDC42

Mahogunin Ring Finger 1 is an E3-ubiquitin ligase encoded by the color gene MGRN1. Our previous in vitro and in vivo studies demonstrated that Mgrn1 deletion in mouse melanoma cells induced cell differentiation and adhesion, and decreased cell motility and invasion on collagen I, and lung colonization in an in vivo model. Here, we investigated the role of MGRN1 on human melanoma cell morphology, adhesion and expression of genes/proteins involved in an EMT-like transition. We demonstrated that wild-type BRAF human melanoma cells adopted a clustering-like morphology on collagen I, with permanent MGRN1 abrogation resulting in bigger cell clusters. Enhanced intercellular adhesion was mostly mediated by induction of E-cadherin and higher co-localization with β-catenin. Transcriptional upregulation of E-cadherin likely occurred through downregulation of the ZEB1 repressor. Finally, pulldown assays showed reduced activation of CDC42 in the absence of MGRN1, which was reverted after E-cadherin silencing. Overall, these findings highlight a new MGRN1-dependent pathway regulating melanoma cell shape, motility, and invasion potential.

Long-term outcomes of the global tuberculosis and COVID-19 co-infection cohort

BACKGROUND

Longitudinal cohort data of patients with tuberculosis (TB) and coronavirus disease 2019 (COVID-19) are lacking. In our global study, we describe long-term outcomes of patients affected by TB and COVID-19.

METHODS

We collected data from 174 centres in 31 countries on all patients affected by COVID-19 and TB between 1 March 2020 and 30 September 2022. Patients were followed-up until cure, death or end of cohort time. All patients had TB and COVID-19; for analysis purposes, deaths were attributed to TB, COVID-19 or both. Survival analysis was performed using Cox proportional risk-regression models, and the log-rank test was used to compare survival and mortality attributed to TB, COVID-19 or both.

RESULTS

Overall, 788 patients with COVID-19 and TB (active or sequelae) were recruited from 31 countries, and 10.8% (n=85) died during the observation period. Survival was significantly lower among patients whose death was attributed to TB and COVID-19 versus those dying because of either TB or COVID-19 alone (p<0.001). Significant adjusted risk factors for TB mortality were higher age (hazard ratio (HR) 1.05, 95% CI 1.03-1.07), HIV infection (HR 2.29, 95% CI 1.02-5.16) and invasive ventilation (HR 4.28, 95% CI 2.34-7.83). For COVID-19 mortality, the adjusted risks were higher age (HR 1.03, 95% CI 1.02-1.04), male sex (HR 2.21, 95% CI 1.24-3.91), oxygen requirement (HR 7.93, 95% CI 3.44-18.26) and invasive ventilation (HR 2.19, 95% CI 1.36-3.53).

CONCLUSIONS

In our global cohort, death was the outcome in >10% of patients with TB and COVID-19. A range of demographic and clinical predictors are associated with adverse outcomes.

Use of direct oral anticoagulants and low molecular weight heparin in venous thromboembolism associated with cancer: real-world evidence in Argentina

BACKGROUND

Venous thromboembolism (VTE) and major bleeding (MB) are common in cancer patients. Reduced-doses of antithrombotics as secondary prophylaxis have limited data. This work aims to describe and to compare treatments and outcomes for cancer-associated VTE.

RESEARCH DESIGN AND METHODS

Retrospective study. Adults with cancer-associated VTE were included. After 3-6 months of full-doses of anticoagulants, three strategies were considered: A) lowering the doses; B) maintaining full-doses; C) stopping treatment. The strategy and medication used were shown in a descriptive analysis and the rate of bleeding and VTE-recurrence between those in a comparative analysis.

RESULTS

A total of 420 patients were included, 56.2% received DOACs, 43.8% enoxaparin. Strategy was defined in 257 patients: A (50.2%), B (46.3%), and C (3.5%). Forty-one (9.8%) had VTE-recurrence and 15 (3.6%) had MB or clinically relevant non-major bleeding (CRNMB).According to strategy, recurrent-VTE was 8.5% (A), 4.2% (B), and 11.1 (C) (p = 0.22), MB or CRNMB was 0.8% (A), 1.7% (B), and 0% (C) (p = 0.64).

CONCLUSIONS

DOACs and strategy A were the most frequently used agent and strategy, respectively. There were no differences between medications or strategies used. The results must be interpreted with caution, and it is a retrospective single-center study, probably with information and selection bias.

Subclinical hearing loss associated with aging

Objective

Contribute to clarifying the existence of subclinical hearing deficits associated with aging.

Design

In this work, we study and compare the auditory perceptual and electrophysiological performance of normal-hearing young and adult subjects (tonal audiometry, high-frequency tone threshold, a triplet of digits in noise, and click-evoked auditory brainstem response).

Study sample

45 normal hearing volunteers were evaluated and divided into two groups according to age. 27 subjects were included in the "young group" (mean 22.1 years), and 18 subjects (mean 42.22 years) were included in the "adult group."

Results

In the perceptual tests, the adult group presented significantly worse tonal thresholds in the high frequencies (12 and 16 kHz) and worse performance in the digit triplet tests in noise. In the electrophysiological test using the auditory brainstem response technique, the adult group presented significantly lower I and V wave amplitudes and higher V wave latencies at the supra-threshold level. At the threshold level, we observed a significantly higher latency in wave V in the adult group. In addition, in the partial correlation analysis, controlling for the hearing level, we observed a relationship (negative) between age and speech in noise performance and high-frequency thresholds. No significant association was observed between age and the auditory brainstem response.

Conclusion

The results are compatible with subclinical hearing loss associated with aging.

Prediction of nitrogen excretion from data on dairy cows fed a wide range of diets compiled in an intercontinental database: A meta-analysis

Manure nitrogen (N) from cattle contributes to nitrous oxide and ammonia emissions and nitrate leaching. Measurement of manure N outputs on dairy farms is laborious, expensive, and impractical at large scales; therefore, models are needed to predict N excreted in urine and feces. Building robust prediction models requires extensive data from animals under different management systems worldwide. Thus, the study objectives were (1) to collate an international database of N excretion in feces and urine based on individual lactating dairy cow data from different continents; (2) to determine the suitability of key variables for predicting fecal, urinary, and total manure N excretion; and (3) to develop robust and reliable N excretion prediction models based on individual data from lactating dairy cows consuming various diets. A raw data set was created based on 5,483 individual cow observations, with 5,420 fecal N excretion and 3,621 urine N excretion measurements collected from 162 in vivo experiments conducted by 22 research institutes mostly located in Europe (n = 14) and North America (n = 5). A sequential approach was taken in developing models with increasing complexity by incrementally adding variables that had a significant individual effect on fecal, urinary, or total manure N excretion. Nitrogen excretion was predicted by fitting linear mixed models including experiment as a random effect. Simple models requiring dry matter intake (DMI) or N intake performed better for predicting fecal N excretion than simple models using diet nutrient composition or milk performance parameters. Simple models based on N intake performed better for urinary and total manure N excretion than those based on DMI, but simple models using milk urea N (MUN) and N intake performed even better for urinary N excretion. The full model predicting fecal N excretion had similar performance to simple models based on DMI but included several independent variables (DMI, diet crude protein content, diet neutral detergent fiber content, milk protein), depending on the location, and had root mean square prediction errors as a fraction of the observed mean values of 19.1% for intercontinental, 19.8% for European, and 17.7% for North American data sets. Complex total manure N excretion models based on N intake and MUN led to prediction errors of about 13.0% to 14.0%, which were comparable to models based on N intake alone. Intercepts and slopes of variables in optimal prediction equations developed on intercontinental, European, and North American bases differed from each other, and therefore region-specific models are preferred to predict N excretion. In conclusion, region-specific models that include information on DMI or N intake and MUN are required for good prediction of fecal, urinary, and total manure N excretion. In absence of intake data, region-specific complex equations using easily and routinely measured variables to predict fecal, urinary, or total manure N excretion may be used, but these equations have lower performance than equations based on intake.

Prediction of enteric methane production and yield in dairy cattle using a Latin America and Caribbean database

Successful mitigation efforts entail accurate estimation of on-farm emission and prediction models can be an alternative to current laborious and costly in vivo CH₄ measurement techniques. This study aimed to: (1) collate a database of individual dairy cattle CH₄ emission data from studies conducted in the Latin America and Caribbean (LAC) region; (2) identify key variables for predicting CH₄ production (g d^-1) and yield [g kg^-1 of dry matter intake (DMI)]; (3) develop and cross-validate these newly-developed models; and (4) compare models' predictive ability with equations currently used to support national greenhouse gas (GHG) inventories. A total of 42 studies including 1327 individual dairy cattle records were collated. After removing outliers, the final database retained 34 studies and 610 animal records. Production and yield of CH₄ were predicted by fitting mixed-effects models with a random effect of study. Evaluation of developed models and fourteen extant equations was assessed on all-data, confined, and grazing cows subsets. Feed intake was the most important predictor of CH₄ production. Our best-developed CH₄ production models outperformed Tier 2 equations from the Intergovernmental Panel on Climate Change (IPCC) in the all-data and grazing subsets, whereas they had similar performance for confined animals. Developed CH₄ production models that include milk yield can be accurate and useful when feed intake is missing. Some extant equations had similar predictive performance to our best-developed models and can be an option for predicting CH₄ production from LAC dairy cows. Extant equations were not accurate in predicting CH₄ yield. The use of the newly-developed models rather than extant equations based on energy conversion factors, as applied by the IPCC, can substantially improve the accuracy of GHG inventories in LAC countries.

AB0560 CLINICAL, SEROLOGICAL AND IMAGING CHARACTERISTICS OF LATIN AMERICAN PATIENTS WITH LUPUS MYOCARDITIS: A CASE-CONTROL STUDY

Background

Lupus myocarditis (LM) is an uncommon manifestation of systemic lupus erythematosus (SLE),

with a prevalence of 9% that tends to be lower in recent studies; it can range from subclinical to life-threatening manifestations (1). The clinical and immunological characteristics of LM have not been established in Latin American patients.

Objectives

To determine the clinical, serological, and imaging characteristics of patients with LM.

Methods

We conducted a single-center, case-control study that enrolled hospitalized patients between 2012 and 2020 in Colombia. Fifteen LM patients (cases) were matched by age and sex with thirty non-LM patients (controls). Descriptive, comparative, and logistic regression analyses were performed.

Results

Patients with LM were mostly females (93.3%) with a mean age of 28.2 years. The major affected clinical domains associated was renal (80%). Myocardial involvement occurred after SLE diagnosis with a mean of 5.1 years. Dyspnea (73.3%) was the main clinical manifestation. Troponin was high in 92.3% and echocardiographic findings included decreased left ventricular ejection fraction (LVEF) in the 60% of cases (mean 40%), diastolic dysfunction (61.5%), left ventricular dilatation (53.3%) and global hypokinesia 35.7%. The most common valvulopathy was mild mitral regurgitation. Nine LM patients underwent cardiac magnetic resonance. In this modality, mean LVEF was 38%, increased regional intensity on T2-weighted images, increased myocardial potentiation ratio on T1, and non-ischemic enhancement (mainly epicardial) was presented on 85.7%, 60%, and 57.1%, respectively. All patients received glucocorticoids and cyclophosphamide. Comparisons of the demographic, clinical, serological between LM and non-LM groups are shown in Table 1.

Table 1.

Demographic, clinical and serological characteristics.

VariableLM (n=15)Non-LMP-valueFemale93.3%100%0.333Age SLE24.9 (SD 12)28.3 (SD 13.9)0.515Clinical domainsCutaneous46.7%90%0.003Articular60%76.7%0.245Hematological60%83.3%0.086Serosal53.3%36.7%0.227Renal80%76.7%0.560Neuropsyquiatric6.7%26.7%0.115Vascular13.3%50%0.017PCR mg/dL10.1 (SD 9.3)2.8 (SD 4.6)0.0004Erythrocyte sedimentation rate mm/H52.9 (SD 25.7)43.9 (SD 32.9)0.267Creatinine mg/dL1.4 (SD 0.9)1.9 (SD 2.5)0.294C3 mg/dL57.4 (SD 22.4)86.2 (SD 29.9)0.002C4 mg/dL9.6 (SD 8.3)16.4 (SD 9.3)0.009Anti-dsDNA86.7%52.4%0.034SLEDAI score14.7 (SD 5.7)6.8 (SD 7.6)0.0003

SD: Standard deviation

Bivariate logistic regression showed that LM was independently associated with anti-dsDNA (OR 1.17, IC 1.04 – 1.31, p= 0.004), higher SLEDAI score (OR 1.17, IC 1.04 – 1.31, p=0,006), higher RCP (OR 1.21, IC 1.04 – 1.4, p=0.013), lower C3 (OR 0.96, IC 0.93 – 0.98, p:0,06) and lower C4 (OR 0.90 IC 0.82 – 0.99 P=0,036), highlighting its relationship with disease activity.

Conclusion

LM is a potentially severe manifestation and occurs in patients with higher disease activity, as was evidenced in the present study by low complement, anti-dsDNA and SLEDAI score. In the proper clinical context, noninvasive diagnostic tests should detect myocardial involvement in SLE.

References

[1]du Toit, Riette et al. “Outcome of clinical and subclinical myocardial injury in systemic lupus erythematosus - A prospective cohort study.” Lupus vol. 30,2 (2021): 256-268. doi:10.1177/0961203320976960

Disclosure of Interests

None declared

AB0527 DIFFUSE ALVEOLAR HEMORRHAGE IN LATIN AMERICAN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS: A CASE-CONTROL STUDY

Background

Diffuse alveolar hemorrhage (DAH) is an uncommon and life-threatening complication of systemic lupus erythematosus (SLE) with a high mortality rate (estimated average 50%). The presence of respiratory symptoms (dyspnea, cough, hemoptysis), a new drop in hemoglobin levels, and diffuse infiltrates on chest imaging should raise suspicion of this complication.

Objectives

We aimed to describe DAH-SLE patients and compare them with non-DAH SLE patients.

Methods

We conducted a single-center, case-control study that enrolled hospitalized patients between 2012 and 2020 in Colombia. Twenty-three DAH-SLE patients (cases) were matched by age and sex with 23 non-DAH-SLE patients (controls). Descriptive, comparative, and logistic regression analyses were performed.

Results

In seven (30.4%) patients, DAH was the initial manifestation of SLE; 69.5% of DAH-SLE patients were females with a mean age of 35 years. Lupus nephritis was present in 65% of cases, mean hemoglobin decrease was 2.22 g/l [standard deviation (SD) 0.92 g/L], and 78% had hemosiderophages in bronchoalveolar lavage. All patients received intravenous (IV) pulses of methylprednisolone followed by high-dose steroids, 87.0% IV cyclophosphamide pulses, 60.8% plasmapheresis, 21.7% IV immunoglobulin, and 8.7% rituximab. Comparisons between DAH and non-DAH groups are shown in Table 1. Bivariate logistic regression analysis showed that male sex (OR 9.625 CI95% 1.07 - 86.17; p=0.043), higher SLEDAI-2K score (OR 1. 28 CI95% 1.10 - 1.48; p=0.001), and higher C-reactive protein (CRP) levels (OR 1.09 CI95% 1.01 - 1.18; p=0.016) were independently associated with the occurrence of DAH, whereas prior use of corticosteroids (OR 0.029 CI95% 0.003 - 0.25; p=0.001) and antimalarials (OR 0.121 CI95% 0.03 - 0.45; p=0.002), higher hemoglobin levels (OR 0.457 CI95% 0.29 - 0.71; p=0.001), higher C3 (OR 0.94 CI95% 0.91 - 0.97; p<0.0001) and higher C4 levels (OR 0.87 CI95% 0.80 - 0.95; p=0.002) were negatively associated with DAH occurrence (Graph).

Table 1.

Demographic, clinical, serological, and therapeutic characteristics in DAH-SLE patients and non-DAH-SLE patients

VariableNon-DHA SLE (n = 23)DHA SLE (n = 23)Female95.6%69.5%Age (years)27.9 (SD 12.8)34.82 (SD 17.3)Hospital stay (days)*20.7 (SD 29.1)34.39 (24.4)SLEDAI-2K*6.17 (SD 5.9)21.77 (12.5)Creatinine (mg/dL)*2.5 (SD 3.7)4.23 (SD 5.2)Leucocyte (cell/mm3)8907 (5668)9408 (5477)Neutrophil (cell/mm3)7112 (5595)8063 (5456)Lymphocyte (cell/mm3)1236 (759)952 (425)Hemoglobin (g/L)10.5 (2.6)6.9 (1.5)Ureic nitrogen (mg/dL)*33.79 (SD 28.87)45.73 (SD 25.64)ESR (mm/Hour)51.5 (35.72)64.65 (47.50)CPR (mg/dL)*5.21 (SD 8.16)12.42 (9.63)Ferritina (ng/mL)509 (526)891 (856)Lactate dehydrogenase (U/L)*314 (SD 114)503 (SD 357)C3 (mg/dL)*84.8 (SD 23.07)44.84 (SD 27.91)C4 (mg/dL)*20.5 (10.3)9.5 (8.2)Anti-dsDNA42.8%71.4%Anti-Ro38.8%38.8%Anti-La11.1%10.5%Anti-RNP44.4%47.3%Anti- Sm38.8%35%IgG ACL09%IgM ACL10.5%13.6%Lupus anticoagulant33.3%33.33%Mucocutaneous involvement78.2%69.5%Articular involvement73.9%60.8%Hematological involvement86.9%69.5%Renal involvement91.3%86.9%Serosal involvement34.7%26.1%Prior glucocorticoid*95.6%39.1%Prior antimalarial*69.5%21.7%Dead4.3%21.7%

*P value < 0.05

Conclusion

In about one-third of patients diagnosed with DAH, this life-threatening complication was the initial presentation of SLE. Male sex, higher SLEDAI-2K scores, and higher CRP levels were associated with DAH occurrence, whereas higher hemoglobin levels, elevated complement levels, prior use of glucocorticoids, and antimalarial treatment were negatively associated with the occurrence of DAH.

Figure 1.

Forest plot of factors associated with DHA-SLE patients. *

*The Forest plot graph does not include the male sex variable due to its wide confidence intervals.

Disclosure of Interests

None declared

3-Nitrooxypropanol substantially decreased enteric methane emissions of dairy cows fed true protein- or urea-containing diets

Methane is a potent but short-lived greenhouse gas targeted for short-term amelioration of climate change, with enteric methane emitted by ruminants being the most important anthropogenic source of methane. Ruminant production also releases nitrogen to the environment, resulting in groundwater pollution and emissions of greenhouse gas nitrous oxide. We hypothesized that inhibiting rumen methanogenesis in dairy cows with chemical inhibitor 3-nitrooxypropanol (3-NOP) would redirect metabolic hydrogen towards synthesis of microbial amino acids. Our objective was to investigate the effects of 3-NOP on methane emissions, rumen fermentation and nitrogen metabolism of dairy cows fed true protein or urea as nitrogen sources. Eight ruminally-cannulated cows were fed a plant protein or a urea-containing diet during a Control experimental period followed by a methanogenesis inhibition period with 3-NOP supplementation. All diets were unintentionally deficient in nitrogen, and diets supplemented with 3-NOP had higher fiber than diets fed in the Control period. Higher dietary fiber content in the 3-NOP period would be expected to cause higher methane emissions; however, methane emissions adjusted by dry matter and digested organic matter intake were 54% lower with 3-NOP supplementation. Also, despite of the more fibrous diet, 3-NOP shifted rumen fermentation from acetate to propionate. The post-feeding rumen ammonium peak was substantially lower in the 3-NOP period, although that did not translate into greater rumen microbial protein production nor lesser nitrogen excretion in urine. Presumably, because all diets resulted in low rumen ammonium, and intake of digestible organic matter was lower in the 3-NOP period compared to the Control period, the synthesis of microbial amino acids was limited by nitrogen and energy, precluding the evaluation of our hypothesis. Supplementation with 3-NOP was highly effective at decreasing methane emissions with a lower quality diet, both with true protein and urea as nitrogen sources.

Feeding Strategies to Mitigate Enteric Methane Emission from Ruminants in Grassland Systems

Ruminants produce approximately 30% of total anthropogenic methane emissions globally. The objective of this manuscript was to review nutritional enteric methane abatement practices for ruminants that are applicable under grazing conditions. A total of 1548 peer-reviewed research articles related to the abatement of enteric methane emissions were retrieved and classified into four categories: non-experimental, in vitro, in vivo confined, and in vivo grazing. The methane abatement strategies for grazing systems were arranged into grazing management and supplementation practices. Only 9% of the retrieved papers have been conducted under grazing conditions. Eight grazing management practices have been evaluated to reduce methane emissions. Decreasing the pre-grazing herbage mass reduced the methane emission per unit of product. Other grazing management practices such as increased stocking rate, decreased forage maturity, rotational stocking, and incorporating tannin-containing or non-tannin-containing feeds showed contradictory results. Nitrogen fertilization or silvopastoral systems did not modify methane emissions. Conversely, supplementation practices in grazing conditions showed contradictory responses on methane emissions. Lipid supplementation showed promising results and suggests applicability under grazing conditions. Identifying and implementing grazing strategies and supplementation practices under grazing conditions is required to increase efficiency and reduce the environmental impact of these systems.

Current Perspectives on Achieving Pronounced Enteric Methane Mitigation From Ruminant Production

Limiting global warming to 1.5°C above pre-industrial levels by 2050 requires achieving net zero emissions of greenhouse gases by 2050 and a strong decrease in methane (CH4) emissions. Our aim was to connect the global need for mitigation of the emissions of greenhouse gases and enteric CH4 from ruminant production to basic research on the biological consequences of inhibiting rumen methanogenesis in order to better design strategies for pronounced mitigation of enteric CH4 production without negative impacts on animal productivity or economic returns. Ruminant production worldwide has the challenge of decreasing its emissions of greenhouse gases while increasing the production of meat and milk to meet consumers demand. Production intensification decreases the emissions of greenhouse gases per unit of product, and in some instances has decreased total emissions, but in other instances has resulted in increased total emissions of greenhouse gases. We propose that decreasing total emission of greenhouse gases from ruminants in the next decades while simultaneously increasing meat and milk production will require strong inhibition of rumen methanogenesis. An aggressive approach to pronounced inhibition of enteric CH4 emissions is technically possible through the use of chemical compounds and/or bromoform-containing algae, but aspects such as safety, availability, government approval, consumer acceptance, and impacts on productivity and economic returns must be satisfactorily addressed. Feeding these additives will increase the cost of ruminant diets, which can discourage their adoption. On the other hand, inhibiting rumen methanogenesis potentially saves energy for the host animal and causes profound changes in rumen fermentation and post-absorptive metabolism. Understanding the biological consequences of methanogenesis inhibition could allow designing strategies to optimize the intervention. We conducted meta-regressions using published studies with at least one treatment with &gt;50% inhibition of CH4 production to elucidate the responses of key rumen metabolites and animal variables to methanogenesis inhibition, and understand possible consequences on post-absorptive metabolism. We propose possible avenues, attainable through the understanding of biological consequences of the methanogenesis inhibition intervention, to increase animal productivity or decrease feed costs when inhibiting methanogenesis.

Long-Term and Carryover Effects of Supplementation with Whole Oilseeds on Methane Emission, Milk Production and Milk Fatty Acid Profile of Grazing Dairy Cows

Research is ongoing to find nutritional methane (CH4) mitigation strategies with persistent effects that can be applied to grazing ruminants. Lipid addition to dairy cow diets has shown potential as means to decrease CH4 emissions. This study evaluated the effects of oilseeds on CH4 emission and production performance of grazing lactating dairy cows. Sixty Holstein Friesian cows grazing pasture were randomly allocated to 1 of 4 treatments (n = 15): supplemented with concentrate without oilseeds (CON), with whole cottonseed (CTS), rapeseed (RPS) or linseed (LNS). Oilseeds were supplemented during weeks 1-16 (spring period) and 17-22 (summer period), and the autumn period (wk 23-27) was used to evaluate treatment carryover effects. Cows fed CTS decreased CH4 yield by 14% compared to CON in spring, but these effects did not persist after 19 weeks of supplementation (summer). Compared to CON, RPS decreased milk yield and CTS increased milk fat concentration in both spring and summer. In summer, CTS also increased milk protein concentration but decreased milk yield, compared to CON. In spring, compared to CON, CTS decreased most milk medium-chain fatty acids (FA; 8:0, 12:0, 14:0 and 15:0) and increased stearic, linoleic and rumenic FA, and LNS increased CLA FA. There were no carry-over effects into the autumn period. In conclusion, supplementation of grazing dairy cows with whole oilseeds resulted in mild effects on methane emissions and animal performance. In particular, supplementing with CTS can decrease CH4 yield without affecting milk production, albeit with a mild and transient CH4 decrease effect. Long term studies conducted under grazing conditions are important to provide a comprehensive overview of how proposed nutritional CH4 mitigation strategies affect productivity, sustainability and consumer health aspects.

On how trap positioning affects phlebotomine sand fly density estimations

There is a need for standardizing sand fly sampling methodology and guidance on trap positioning for quantitative sand fly studies. We investigated differences in sand fly density with 'sticky' interception and CO₂ -light attraction traps, in relation to trap distance to the ground and the presence or absence of a continuous or discontinuous (wire mesh) vertical surface adjacent to the trap. The study, conducted in a dog kennel in southeast Spain, lasted 48 days and collected 692 Phlebotomus papatasi, P. perniciosus, P. ariasi and Sergentomyia minuta specimens. There were no significant differences between species with respect to trap position. Overall, density in sticky traps was highest closest to the ground and next to the continuous vertical surface, followed sequentially by traps similarly placed adjacent to the wire mesh and those hanging from a rope across the kennel yard. In contrast, density in CO₂ -light traps was highest in traps hanging from the rope near the ground, followed by those next to the continuous vertical surface. The overall negative relationship between sand fly density and ground distance was not significant for CO₂ -light traps next to the continuous vertical surface. Modelling also suggested that sand flies do not use the wire mesh to move vertically.

POS0770 DIFFERENTIAL CLINICAL PRESENTATION BETWEEN SLE RUPHUS PATIENTS AND SLE NON-RHUPUS PATIENTS: A CASE-CONTROL STUDY

Background:

Rhupus is a term that describe the coexistence of systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Rhupus patients have symmetrical, erosive arthritis, characteristic SLE manifestations and an array of autoantibodies including rheumatoid factor (RF), anti-cyclic citrullinated peptides (anti-CCP), anti-dsDNA, and anti-Sm.1 Joint involvement is common in SLE patients (90%), but only 1% to 9,7% have rhupus.2 Due to its low prevalence, there is still a lack of evidence on its presentation and differences with other SLE patients without rhupus.

Objectives:

To examine the rhupus prevalence and to compare the clinical and serological characteristics between rhupus, and non-rhupus SLE patients (SLE with arthritis (SLEa), and SLE without arthritis (SLEwa)).

Methods:

We performed a case-control study. Rhupus patients (cases) were matched 1:1 with non-rhupus SLE patients (controls). Descriptive statistics were calculated and rhupus, SLEa, and SLEwa were compared.

Results:

A total of 72 patients were included, 24 patients in each group; most were female (87.5%). The median age at rhupus onset was 36.5 years (IQR 30-42.5). RA preceded rhupus in half of the patients, 29% were initially diagnosed as SLE, and 21% were initially diagnosed as rhupus. The median duration of RA was 66 months (IQR 30-144).

In the descriptive analysis of rhupus patients, the most affected joints were the proximal interphalangeal and metacarpophalangeal joints (87.5%), followed by the wrists (79.1%). Regarding immunological findings, RF and anti-CCP were positive in 87.5% and 50% of the patients, respectively. As to radiographic findings, the median number of erosions in the hands and wrists was 2 (IQR 0-5) and the median number of joints with narrowed joint space was 7 (IQR: 1.5 - 13.5). In terms of treatment, 95.8% received corticosteroids (median 10 mg/day), 91.6% antimalarials, 79.1% methotrexate, 41.6% leflunomide, and 25.0% rituximab.

Patients with rhupus were older and had less renal and hematological involvement than patients with SLEa and SLEwa. SLEa patients had higher seropositivity for anti-RNP and anti-Sm, higher neurological involvement, and higher SLEDAI-2K scores than rhupus patients. Comparisons of other clinical and serological variables between SLE rhupus and non-ruphus patients are shown in table 1 and figure 1.

Table 1.

Clinical and serological manifestations in rhupus, articular SLE, and non-articular SLE

VariablesRHUPUSM (IQR)SLE with arthritisM (IQR)SLE without arthritisM (IQR)P value RHUPUS vs. SLE with arthritisp value RHUPUSvs. SLE without arthritisAge (years) M (IQR)40 (31.5 – 49)29 (21.5 – 45)33 (19.5 – 37.5)0.0430.013CPR M (IQR)2.3 (1– 8.5)1.6 (0.3– 3.6)0.9 (0.2– 2.5)0.3370.032Positive anti-RNP N (%)7 (29.1%)14 (58.3%)7 (29.1%)0.0421.000Positive anti-Sm N (%)5 (20.8%)15 (62.5%)6 (25%)0.0030.500SLEDAI – 2K score M (IQR)4.5 (1 – 7)9 (2 – 18)7 (3.5 – 15)0.0450.082Figure 1.

Differences in the frequencies of organic alterations. w/o: without.

Conclusion:

Patients with rhupus were older and had lower SLEDAI-2K scores compared with those non-rhupus. Furthermore, renal, neurological, and hematological manifestations were more common in non-rhupus patients than in rhupus patients.

References:

[1]Antonini L, et al. Rhupus: a systematic literature review. Autoimmun Rev. 2020;19(9):102612.

[2]Tani C, et al. Rhupus syndrome: Assessment of its prevalence and its clinical and instrumental characteristics in a prospective cohort of 103 SLE patients. Autoimmun Rev. 2013; 12:537–41.

Disclosure of Interests:

None declared

AB0374 CHARACTERISTICS OF A GIANT CELL ARTERITIS COHORT IN LATINOAMERICA

Background:

Giant cell arteritis (GCA) is a large vessel vasculitis (LVV) that affects mostly the elderly (1). Temporal artery biopsy (TAB) has been defined as the gold standard, although this has come to question (3). EULAR guidelines recommended non-invasive imaging techniques such as the temporal artery Doppler ultrasound to aid in LVV diagnosis (2). The characterization of GCA in Latin American countries, and specifically in Colombia, is scarce.

Objectives:

To perform a clinical, demographical, histopathological, and radiological characterization of

Colombian GCA patients.

Methods:

Retrospective data from GCA patients at two teaching hospitals in Medellín, Colombia, was collected. A bioethics committee previously approved the research protocol. Inclusion criteria: diagnosis of GCA, based on clinical characteristics or imaging/biopsy findings. Exclusion criteria: HIV diagnosis, paraneoplastic large vessel vasculitis. Clinical, radiological, and histopathological variables were selected based on the clinicians’ expertise and the 2018 EULAR recommendations for a core data set to support observational research and clinical care in giant cell arteritis (3). The data were analyzed in SPSS v22.0 (IBM, USA).

Results:

Twenty-two patients were collected. Demographical and clinical characteristics are summarized in Table 1. Most patients were women (68.1%), with a mean age of 71.8 years, mean duration of symptoms of 5.3 months. In the cranial form of the disease, the most common symptoms were headache and jaw claudication (95% and 68%). Six patients experienced visual loss: complete unilateral visual loss in two, partial unilateral in two, complete bilateral in one, and partial bilateral in one patient.

Sixteen patients (72.7%) underwent TAB; the most common finding was mononuclear infiltrate and internal elastic fragmentation in 43.7% of the biopsies. Giant cells were observed in 6 biopsies (37.5%). Doppler ultrasound was performed in 19 patients (86.35%), finding intima-media thickening and the halo sign t in 7 patients (36.8%).

Table 1.

Demographical and clinical characteristics

Characteristicn = 22Mean age (years SD)71.8 (10.6)Female sex n (%)15 (68.1%)Mean symptoms duration (months ± SD)5.3 ± 6.8Mestizo n (%)20 (90%)Headache n (%)21 (95.4%)Jaw claudication n (%)15 (68.1%)Weight loss n (%)13 (59%)Scalp sensitivity n (%)11 (50%)Fever n (%)8 (36.3%)Presence of polymyalgia rheumatica n (%)7 (31.8%)Visual loss n (%)6 (27.2%)Amaurosis fugax n (%)1 (4.5%)Glucocorticoids n (%)22 (100%)Pulse n (%)8 (36.3%)Mean dose (mg ± SD)47.1 ± 16.7Methotrexate n (%)17 (77.7%)Azathioprine n (%)2 (9%)Tocilizumab n (%)1 (4.5%)

Conclusion:

In this GCA cohort, the main phenotype was cranial GCA, with 95% of the patients presenting with headache. The most common imaging study performed was Doppler ultrasound of temporal arteries, with intima-media thickening and halo sign being the most common findings. The mainstay of treatment was glucocorticoids with methotrexate as a sparing agent. To our knowledge, this study is the first to perform a specific characterization of GCA patients in the Colombian population, and it can represent the foundation of further research for these patients.

References:

[1]Lazarewicz K, Watson P. Giant cell arteritis. BMJ. 2019 May 30;365:l1964.

[2]Dejaco C, Ramiro S, Duftner C, Besson FL, Bley TA, Blockmans D, et al. EULAR recommendations for the use of imaging in large vessel vasculitis in clinical practice. Ann Rheum Dis. 2018 May;77(5):636–43.

[3]Ehlers L, Askling J, Bijlsma HWJ, Cid MC, Cutolo M, Dasgupta B, et al. 2018 EULAR recommendations for a core data set to support observational research and clinical care in giant cell arteritis. Ann Rheum Dis. 2019;78(9):1160–6.

Disclosure of Interests:

None declared

Penicillin desensitization in allergic pregnant women with syphilis. Report of two cases

Syphilis during pregnancy has a high risk of congenital transmission with disastrous fetal consequences. Penicillin (PNC) is the only effective antimicrobial for the treatment of pregnant women with syphilis. Chilean guidelines do not consider desensitization to PNC in these women. We report two cases of pregnant women aged 32 and 23 years, with immediate allergy to PNC and syphilis who were safely and successfully desensitized using a four-hour intravenous protocol in the critical care unit and who subsequently received benzathine G PNC. An electronic survey was conducted among approximately 100 Clinical Pharmacists (CP) in the country. Of these, 16 answered and 13 reported having experience in drug desensitization, in at least five cases with PNC and none reported deaths or cardiorespiratory arrest. Desensitization to PNC can be carried out safely and in Chile, this alternative should be incorporated to the management of pregnant women with syphilis and immediate allergy to PNC, instead of using erythromycin.

ARCHITECT Chagas® as a single test candidate for Chagas disease diagnosis: evaluation of two algorithms implemented in a non-endemic setting (Barcelona, Spain)

OBJECTIVES

To evaluate two algorithms for the diagnosis of chronic and congenital Chagas disease (CD), both including the chemiluminescent microparticle immunoassay ARCHITECT Chagas® (CMIA) as a single test but with an amended signal-to-cut-off ratio (S/CO) of ≥6, instead of an S/CO of ≥1 as indicated by the manufacturer.

METHODS

The study encompassed two panels of retrospective samples: 831 sera from 786 adolescents and adults (panel A), and 96 sera from 35 newborn infants with CD-infected mothers (panel B). A CMIA-negative result was deemed conclusive, whereas samples with an S/CO ≥ 0.8 were confirmed by a second test (BioELISA Chagas, ELISAr).

RESULTS

In panel A, seropositivity was 13% (102/786); 10 samples gave discordant results for CMIA and ELISAr, all of which were CMIA positive and had CD confirmed through a previous diagnosis by two positive serological tests. In panel B, all newborns were considered non-infected based on both a progressive decrease in antibody titres over time and negative real-time PCR results. CMIA still gave positive results in two infants aged 10 months but no S/CO values ≥6 were observed from 4 months on.

CONCLUSIONS

CMIA is a firm candidate for use as a single CD diagnostic test in non-endemic countries. The algorithm with the ≥6 S/CO is as an efficient method for chronic CD diagnosis. CMIA could also be used as a single test to screen infants for congenital infection at the age of 10 months or even earlier if applying the corrected cut-off ratio, although further studies are required.

Microplastic identification and quantification from organic rich sediments: A validated laboratory protocol

Plastic pollution presents a global environmental concern with potentially widespread ecological, socio-economic and health implications. Methodological advances in microplastic extraction, quantification and identification from sediments have been made. However, integrating these fragmentary advances into a holistic, cost-effective protocol and applying it to organic rich sediments with fine grain size remains a challenge. Nonetheless, many hot spots of microplastic contamination such as harbour and estuarine sediments are characterised by such sediments. We conducted a series of experiments to integrate methodological advances, and clarify their applicability to organic rich sediments with fine grain size. The resulting protocol consisted of three stages. First, pre-treatment with Fenton's reagent was found to be efficient in reducing organic matter content, compatible with later Fourier Transform-Infrared Spectroscopy (FT-IR) for polymer identification, although it did affect the size of polyethylene (PE) and polyethylene terephthalate (PET). Secondly, a novel density separation column with a top overflow (the OC-T) obtained recovery rates above 90% for microplastics present in a ZnCL₂ solution. Finally, automated epifluorescence microscopic image analysis of Nile Red stained filters with selected validation of polymer identities using FT-IR revealed 91.7% of stained particles to be plastics. A case study on estuarine sediments demonstrated a high extraction efficiency with quantification possible down to 125 μm and detection possible down to 62.5 μm. This makes this protocol suitable for large scale monitoring of microplastics in sediments of estuarine origin provided polymer specific recovery rates, background contamination and uncertainty in Nile Red identification is accounted for. Subject to further validation, the protocol could also offer a solution to similar organic rich sediments with fine grain size, such as some soils and sludge, to improve our ability to conduct cost-effective, large scale monitoring of microplastic contamination.

Laparoscopic Liver Resection: A South American Experience with 2887 Cases

BACKGROUND

Laparoscopic liver resections (LLR) have been increasingly performed in recent years. Most of the available evidence, however, comes from specialized centers in Asia, Europe and USA. Data from South America are limited and based on single-center experiences. To date, no multicenter studies evaluated the results of LLR in South America. The aim of this study was to evaluate the experience and results with LLR in South American centers.

METHODS

From February to November 2019, a survey about LLR was conducted in 61 hepatobiliary centers in South America, composed by 20 questions concerning demographic characteristics, surgical data, and perioperative results.

RESULTS

Fifty-one (83.6%) centers from seven different countries answered the survey. A total of 2887 LLR were performed, as follows: Argentina (928), Brazil (1326), Chile (322), Colombia (210), Paraguay (9), Peru (75), and Uruguay (8). The first program began in 1997; however, the majority (60.7%) started after 2010. The percentage of LLR over open resections was 28.4% (4.4-84%). Of the total, 76.5% were minor hepatectomies and 23.5% major, including 266 right hepatectomies and 343 left hepatectomies. The conversion rate was 9.7%, overall morbidity 13%, and mortality 0.7%.

CONCLUSIONS

This is the largest study assessing the dissemination and results of LLR in South America. It showed an increasing number of centers performing LLR with the promising perioperative results, aligned with other worldwide excellence centers.

Real-world effectiveness and safety of apremilast in psoriasis at 52 weeks: a retrospective, observational, multicentre study by the Spanish Psoriasis Group

BACKGROUND

Little has been published on the real-world effectiveness and safety of apremilast in psoriasis.

OBJECTIVES

To evaluate the effectiveness, safety and drug survival of apremilast at 52 weeks in patients with moderate to severe plaque psoriasis or palmoplantar psoriasis in routine clinical practice.

METHODS

Retrospective, multicentre study of adult patients with moderate to severe plaque psoriasis or palmoplantar psoriasis treated with apremilast from March 2016 to March 2018.

RESULTS

We studied 292 patients with plaque psoriasis and 85 patients with palmoplantar psoriasis. The mean (SD) Psoriasis Area and Severity Index (PASI) score was 10.7 (7.0) at baseline and 3.0 (4.2) at 52 weeks. After 12 months of treatment, 73.6% of patients had a PASI score of 3 or less. In terms of relative improvement by week 52, 49.7% of patients achieved PASI-75 (≥75% reduction in PASI score) and 26.5% achieved PASI-90. The mean physician global assessment score for palmoplantar psoriasis fell from 4.2 (5.2) at baseline to 1.3 (1.3) at week 52. Overall drug survival after 1 year of treatment with apremilast was 54.9 %. The main reasons for treatment discontinuation were loss of efficacy (23.9%) and adverse events (15.9%). Almost half of the patients in our series (47%) experienced at least one adverse event. The most common events were gastrointestinal problems.

CONCLUSIONS

Apremilast may be a suitable alternative for the treatment of moderate to severe psoriasis and palmoplantar psoriasis. Although the drug has a good safety profile, adverse gastrointestinal effects are common.

A spatial ecology study in a high-diversity host community to understand blood-feeding behaviour in Phlebotomus sandfly vectors of Leishmania

Molecular studies indicate that Phlebotomine sandflies (Diptera: Psychodidae) blood feed on many vertebrate species, of which only a few are proven parasite reservoirs. Investigating sandfly vector feeding preferences is therefore important and requires taking into account the availability and accessibility of host species. In terms of the latter, it is necessary to consider the metabolic cost to the insect of reaching the host and moving on to a suitable breeding site. The present study used statistical modelling to compare the feeding patterns of Phlebotomus perniciosus (n = 150), Phlebotomus papatasi (n = 35) and Phlebotomus ariasi (n = 7) on each of an average of 30 host species in a wildlife park in Murcia, Spain. Sandfly feeding movement costs were estimated as a function of the distance and altitude gradients saved by the insect, assuming that they displayed 'site fidelity'. Most (87%) engorged females were caught <100 m from the host on which they had fed. Although the percentage of bloodmeals was highest on fallow deer (Dama dama) (30%) and red deer (Cervus elaphus) (26%), the predicted feeding probability after considering movement cost was highest for red deer and common eland (Taurotragus oryx), and positively associated with host census. These results suggest that, under similar circumstances, sandflies prefer to feed on some host species more than on others.

AB0538 PREGNANCY OUTCOMES IN PATIENTS WITH TAKAYASU’S ARTERITIS: CASE SERIES

Background:

Takayasu’s arteritis (TA) is most prevalent in women of childbearing age. Although its activity and risk of relapse are low during pregnancy, up to 40% of patients may have unfavorable obstetric outcomes and therefore it is important to know their clinical behavior.

Objectives:

To describe the clinical features and obstetric outcomes of pregnant women with TA treated in a tertiary center.

Methods:

Retrospective evaluation of medical records of 6 pregnancies in 6 women with TAs treated in a tertiary center in Medellin, Colombia between 2011-2018.

Results:

Six women who were 17.5 (RI 9.25) years old at diagnosis and 24 (RI 8.25) years old at delivery, their disease duration were 5.5 (RI 10.5) years. Three patients had extensive aortic involvement classified as Numano type V, two as type IIB and one as type I. At delivery, three patients were active and required immunosuppressants, five had high blood pressure, one developed preeclampsia in the second trimester, one had severe mitral and tricuspid insufficiency with decreased ejection fraction of the left ventricle; two had aneurysms (left subclavian artery and ascending aorta). There were two fetal deaths, one due to intrauterine growth restriction and placental insufficiency and another of unknown etiology; both patients with disease activity, extensive aortic condition and arterial hypertension; no pregnancy resulted in abortion or preterm birth. Five deliveries were by caesarean section by maternal indication; there was no aortic dissection, aneurismal rupture or cerebral hemorrhage (table).

Table

Patient’s characteristics

PatientAge at diagnosisAge at deliveryClinical featuresHata-Numano classificationMaternal outcomeFetal outcome1617HT, absence of left brachial and radial pulses, L carotid and subclavian murmurs, LVEF 47%VHT, C-sectionTerm delivery, SGA22226HT, abscence of L brachial and radial pulses, L carotid and subclavian murmurs, dyspnea, anginaV(plus pulmonary)HT, vaginal birthPlacental insufficiency, IUGR, fetal death31438HT, abscence of L brachial and radial pulses, L carotid and subclavian murmurs, intermittent claudication, dyspnea, aortic regurgitationIIBHT, C-sectionTerm delivery, SGA41824HT, malaise,, abscence of L brachial and radial pulses, intermittent claudication, arthralgiaIIBPreeclampsia, C-sectionTerm delivery, SGA51722Fever, malaise, intermittent claudication, arthralgiaIC-sectionTerm delivery, SGA62124HT, abscense of bilateral femoral, popliteal, tibial and pedial pulses, headache, dizziness, amaurosisVHT, C-sectionFetal death

HT: hypertension; L: left; LVEF: left ventricular ejection fraction; C-section: cesarean section; SGA: small for gestational age; IUGR: intrauterine growth restriction

Conclusion:

Pregnant women with active disease and extensive aortic condition presented unfavorable obstetric results, suggesting that an inadequate control of vasculitis may lead to greater maternal-fetal complications.

References:

[1]Assad APL, da Silva TF, Bonfa E, Pereira RMR. Maternal and Neonatal Outcomes in 89 Patients with Takayasu Arteritis (TA): Comparison Before and After the TA Diagnosis. J Rheumatol. 2015 Oct;42(10):1861–4.

[2]Hidaka N, Yamanaka Y, Fujita Y, Fukushima K, Wake N. Clinical manifestations of pregnancy in patients with Takayasu arteritis: experience from a single tertiary center. Arch Gynecol Obstet. 2012 Feb;285(2):377–85.

Disclosure of Interests:

None declared

FRI0222 MAGNETIC RESONANCE IMAGING OF MUSCLE INVOLVEMENT IN POLYARTERITIS NODOSA

Background:

muscle involvement is frequently reported in polyarteritis nodosa (PAN), mostly as myalgia, muscle swelling, and gait difficulty due to intramuscular arteries involvement, peripheral neuropathy, or myositis with slightly or no elevation of muscle enzymes. Magnetic resonance imaging (MRI) findings of compromised muscles have been reported in isolated cases, mainly as a limited form of PAN, however, muscular involvement patterns in MRI of patients with PAN have been recently described

Objectives:

to describe MRI of legs findings in patients with PAN in a tertiary center from Medellin-Colombia.

Methods:

it was performed a retrospective cross-sectional descriptive study of 15 adult patients who were clinically assessed as having PAN and who had undergone MRI of legs between January 2011 and December 2019. Characteristics already informed in previous studies, affected structures (muscle, subcutaneous tissue, and bone) and pattern of hyperintensities were described as diffuse pattern (signal alterations affecting the entire area of the involved muscle), patched pattern (areas of hyperintensities alternating areas of normal muscle signal intensity), and fluffy nodular pattern or cotton-wool appearance (round hyperintense lesions with fluffy margins centered on blood vessels).

Results:

clinical characteristics:myalgia, especially calf pain, was the most frequent muscular complaint; other clinical manifestations were: constitutional symptoms (80%), arthralgias or arthritis (50%), mono/polyneuropathy (33%), subcutaneous nodules (33%), livedo reticularis (20%), lower limbs ulcers (13%), abdominal symptoms (13%), and purpura (7%).MRI findings:bilateral muscular edema was found in all patients (100%), fatty infiltration (20%), edema of the subcutaneous cellular tissue (20%), and muscular atrophy (13%) were also described. A diffuse pattern occurred in 46% (n=7) of patients (figure panel A), a patched pattern (figure panel B) in 46% (n=7), and a fluffy nodular pattern or cotton-wool appearance (figure panel C) in 6% (n=1). The most frequently affected muscular group was gastrocnemius and soleus (67%), followed by anterior tibialis (27%), plantar, long peroneus, first finger flexors, and long flexors only affected in 7%. Bone involvement was found in 53%, being the tibia the most affected, followed by the fibula and the calcaneus. MRI led to guide the site of muscle biopsy to prove histological medium-size vasculitis in half of the patients.

Conclusion:

in patients with PAN suspicion who have muscular complaints, especially calf pain, MRI arises as an important diagnostic tool, and also as a guide to muscular biopsy to prove vasculitis. The patterns associated with PAN are diffuse, patched or fluffy nodular hyperintensities in gastrocnemius and soleus with or without bone compromise.

References:

[1]Kang, Y. et al. Muscle involvement in polyarteritis nodosa: Report of eight cases with characteristic contrast enhancement pattern on MRI. Am. J. Roentgenol. 206, 378–384 (2016).

[2]Hofman DM, Lems WF, Witkamp TD, Putte VD, Bijlsma JW. Demonstration of calf abnormalities by magnetic resonance imaging in polyarteritis nodosa. Clin Rheumatol 1992; 11:402–404.

Figure

Disclosure of Interests:

None declared

AB0487 TAKAYASU’S ARTERITIS: RECOGNIZING AN OLD ENEMY

Background:

Takayasu’s arteritis (AT) is a systemic vasculitis that affects large vessels, mainly the aorta, its branches and the pulmonary arteries. There are few data on their behavior in our region.

Objectives:

to describe the clinical and angiographic characteristics and outcomes of a group of patients with AT.

Methods:

a cross-sectional, retrospective study based on a secondary source taken from two high complexity hospitals in Medellin - Colombia between August 2011 and December 2018.

Results:

medical records of 41 patients were evaluated, 87.5% met the 1990 ACR criteria of AT. The majority were women (95.1%), with a median age at the time of diagnosis of 22 years (IR 52), 11 patients (26.8%) were over 40 years old at debut. The median delay in diagnosis was 12 months (IR: 167). Systemic symptoms included general malaise (29.3%), weight loss (29.3%) and fever (19.5%); the main vascular manifestations were hypertension and blood pressure difference (61%), headache (39%), upper limb claudication (31.7%), dyspnea (29.3%), angina (26.8%) and carotidinia (22%). Most frequent findings on physical examination were pulse absence or decrease (78%) and subclavian murmur (53.7%). ESR and CRP were found high in 85.3% and 22%, respectively. Angiographic studies revealed stenosis or occlusion in multiple arterial territories, being the stenosis of the left subclavian artery the most frequent lesion (68.3%), followed by the involvement of the abdominal aorta (58.5%) and thoracic (51%). The distribution according to Hata-Numano classification was: type V (58.5%), type I (17.1%) and type IIa (7.3%), indicating complex vascular lesions and associated serious complications. Abnormalities of the renal arteries, pulmonary arteries involvement, and aortic insufficiency were present in 39%, 14.6%, and 7.3% respectively. Seventy-five percent of patients had active disease, glucocorticoids were the main treatment in 90.2% of the cases, used isolated (2.4%) or in combination with other immunosuppressants (87.8%), including methotrexate (75.6%), azathioprine (26.8%) and cyclophosphamide (14.6%); vascular interventions were performed in 11 patients (26.8%). Most relevant vascular complications were renovascular hypertension (26.8%), stroke (19.5%), chronic kidney disease (19.5%) and chronic heart failure (17.1%). From the clinical point of view, our findings were similar to those shown in series from Brazil, Japan, and Turkey. Contrary to what was reported in other series, carotidinia was a finding that occurred in almost a quarter of our patients (23%) and maybe one of the initial symptoms of the disease. The findings of the vascular physical examination are similar to those reported by the IRAVAS group, where the asymmetry of the pulses was most frequent, followed by the presence of murmurs and the difference in blood pressure, claudication being less frequent in the upper and lower limbs.

Conclusion:

patients in this series are characterized by having an extensive disease partly due to a late diagnosis, with a high percentage of complications associated with vascular stenotic compromise, which generates morbidity and impact on the quality of life.

References:

[1]Sato EI, et al. Takayasu arteritis. Treatment and prognosis in a university center in Brazil, Int J Cardiol. 2000; 75 Suppl 1: S163-6.

[2]Arnaud L, et al. Takayasu arteritis in France: a single-center retrospective study of 82 cases comparing white, North African, and black patients. Medicine (Baltimore). 2010; 89(1): 1-17.

Disclosure of Interests: :

None declared

AB0535 ARE THE NEUTROPHIL/LYMPHOCYTE RATIO (NLR) AND PLATELET/LYMPHOCYTE RATIO (PLR) USEFUL TO COMPARED WITH ACUTE PHASE REACTANTS (ESR/CRP) FOR DIAGNOSIS AND PROGNOSIS OF PATIENTS WITH ACTIVE TAKAYASU’S ARTERITIS (TAK)?: AN ANALYSIS BASED ON ROC AND KAPLAN-MEIER CURVES IN A LATIN AMERICAN POPULATION

Background:

The NIH criteria are the main measure to determine activity in TAK. NLR and PLR appear promising to predict disease activity(1). TAK is one of the most frequent vasculitis in Colombia with a prevalence of 13.3%; however, in more recent years the information is sparse about TAK clinical behavior in our region, which leads to a late diagnosis. Although survival has improved with immunosuppressive treatment, relapses remain high especially in the first year of diagnosis

Objectives:

Compare NLR and PLR with ESR/CRP to predict TAK activity

Show survival and relapse in patients with TAK followed to 7 y

Methods:

Retrospective cohort of 43 patients with TAK between 2011-2018 with prospective follow-up of relapses and mortality. 88% fulfilled the ACR 1990 criteria. The disease activity was determined according to NIH criteria: active disease (n=34) and inactive disease (n=9). Through bivariate analysis, we compared the clinical and radiologic characteristics between age groups (table 1) using the Pearson test and Wilcoxon range test. Value of p <0.05 was statistically significant. Survival and relapse analysis were performed using Kaplan-Meier plots. Sensitivity (Sn), specificity (Sp) and area under the curve (AUC) were determined for NLR, PLR, ESR and CRP by receiver-operating curves (ROC) compared to NIH criteria.

Table 1.

Comparison of Clinical Features in Patients with TAK

No (%) of PatientsAge at diagnosis≤40 y (n=32)Age at diagnosis≥40 y(n=11)P valueFemale30 (94)11 (100)0.39Age at symptom onset (years), median: (Interquartile range –IQR-)20 (17-25)52 (47-57)0.110Time from symptom onset to diagnosis (months) median (IQR)9.5 (2-15)36 (1.5-24)0.774Smoking2 (6)6 (54)0.002Dyslipidemia7 (22)6 (54)0.042ACR Criteria 1990Claudication of extremities14 (43)5 (45)0.922Upper extremities blood pressure discrepancy > 10 mmHg19 (59)6 (54)0.779Decreased brachial artery pulse24 (75)9 (82)0.644Subclavian artery or aorta bruit19 (59)6 (54)0.774Arteriographic abnormality27/27 (100)11/11 (100)1.0ESR (mm/h), median (IQR)56 (23-115)38 (33-76)0.011CRP (mg/dL), median (IQR)1.35 (0.4-3.4)3 (1.49-18.5)0.020Creatinine (mg/dL), median (IQR)0.72 (0.6-0.83)0.84 (0.75-1)0.007Hata-Numano classification I15%18% IIa6%9% IIb6% III6% IV3%9% V59%64%

Results:

41 patients were women (96%) with a median age at diagnosis of 22 y and an interval from the onset of disease to diagnosis of 12 months (IR:1-168 m). The population over 40 years had a greater comorbidities burden (54% had history of smoking and dyslipidemia) and a major interval between the onset of disease and the diagnosis (36 months vs 9.5 months). Most frequent vascular phenotypes were types V (62%) and I (16%). NLR and PLR showed poor performance to predict activity compared with CRP; NLR level of 1.74 showed to be the predictive cut-off value for active TAK (Sn: 85.3%, Sp: 37.5%, AUC = 0.563). PLR level of 112.5 was found to be the predictive cut-off value for active TAK (Sn: 76.5%, Sp: 50%, AUC = 0.517). The CRP was the most accurate biomarker (Sn: 79.4%, Sp: 75%, AUC = 0.761) while the ESR was lower to predict activity (Sn: 63.6%, Sp: 75%, AUC = 0.598) (figure 1). At 5 years, survival was 83% and 50% of patients had presented at least one relapse (figure 2)

Conclusion:

Our data does not support the use of NLR or PLR to differentiate relapse and remission in TAK. CRP had better diagnostic performance than ESR in the prediction of activity compared to NIH criteria. The 5-year survival in this cohort is below that reported after 1985 (reported survival: 90-96%)(2)

References :

[1]Pan L, et al. Platelet-to-lymphocyte ratio and neutrophil-to-lymphocyte ratio associated with disease activity in patients with Takayasu’s arteritis: a case-control study. BMJ Open 2017; 7: e014451

[2]Schmidt J, et al. Diagnostic features, treatment, and outcomes of Takayasu arteritis in a US cohort of 126 patients, Mayo Clin Proc. 2013; 88(8): 822-30

Disclosure of Interests:

None declared

AB0514 CALF PAIN, KEY POINT IN THE DIAGNOSIS OF POLYARTERITIS NODOSA

Background:

polyarteritis nodosa (PAN) is a primary systemic vasculitis that is becoming a rare disease in part by the decrease in hepatitis B virus (HBV) infection due to widespread vaccination. It is characterized by a full vast constellation of nonspecific clinical manifestations, which sometimes delays and makes it difficult to diagnose. Still, muscle involvement is a feature that could guide the clinician.

Objectives:

to describe the main clinical and laboratory characteristics of patients with PAN and to confirm the frequency of muscle involvement.

Methods:

retrospective cross-sectional descriptive study of 23 adult patients diagnosed with PAN between January 2011 and December 2018 in two high complexity hospitals in Medellin-Colombia.

Results:

twenty-three patients met ACR 1990 classification criteria for PAN, 52% were men with a median age of 51 (IR 36-60), 78.3% were newly diagnosed, and only two patients (8.7%) had HBV infection. General symptoms (found in 95% of the patients), cutaneous (82%), and articular (56%) were the most frequent manifestations. Among systemic symptoms, myalgia, especially calf pain, was the most common characteristic (78.3%), followed by weight loss (73.9%), fatigue (69.3%), and fever (59.3%). Laboratory findings and severity scores are shown in the table. Angiography was performed in 27.3% of patients, finding splanchnic (renal, hepatic and splenic) microaneurysms (17.4%), stenosis (13%), and renal infarction (4.3%). Fourteen patients (61%) had at least one positive biopsy documenting medium-sized artery vasculitis, mainly skin, muscle, nerve, or both; 9 (39%) had normal or inconclusive biopsy findings. All patients received high daily doses of prednisolone (50 ± 16 mg); 52.2% required cyclophosphamide, 30.4% azathioprine, 17.4% methotrexate, 8.7% rituximab, 4.3% dapsone and 4.3% plasmapheresis; acetylsalicylic acid was given to half of the patients and only one required antiviral therapy for HBV. With treatment, 87% improved; 22.7% had an infection, and 8.7% of patients died.

Conclusion:

myalgia was the main characteristics of our PAN patients, especially in calves, and its presence in patients with other general, skin or articular symptoms should raise the suspect of this vasculitis.

References:

[1]Karadag O, Jayne DJ. Polyarteritis nodosa revisited: a review of historical approaches, subphenotypes and a research agenda. Clin Exp Rheumatol. 2018;36 Suppl 111(2):135–142.

[2]Pagnoux C, Seror R, Henegar C, et al. Clinical features and outcomes in 348 patients with polyarteritis nodosa: a systematic retrospective study of patients diagnosed between 1963 and 2005 and entered into the French Vasculitis Study Group Database. Arthritis Rheum. 2010;62(2):616–626.

TableCharacteristicPAN patients (n=23)CRP (mean and SD in mg/dl)6.3 ± 8.51ESR (mean and SD in mm/h)84 ± 38CPK (median and IR in U/L) normal value < 18076 (66)FFS (mean)1BVAS (median and IR)17 (7)

PAN: polyarteritis nodosa; CRP: C-reactive protein; ESR: erythrocyte sedimentation rate; CPK: creatine phosphokinase; FFS: five factor score; BVAS: Birmingham Vasculitis Activity Score; SD: standard desviation; IR (interquartile range)

Disclosure of Interests:

None declared

FRI0468 SYSTEMIC AND CUTANEOUS POLYARTERITIS NODOSA IN COLOMBIAN PEDIATRIC PATIENTS: CUTANEOUS POLYARTERITIS IS NOT SO BENIGN

Background:

Polyarteritis nodosa (PAN) is the third most frequent vasculitis in pediatrics, Cutaneous PAN (CPAN) being more common that Systemic PAN (SPAN). CPAN is frequently described as a benign disease. In children, PAN onset is frequent between 9 and 11 years of age, with no sex differences, and its clinical features may be nonspecific.

Objectives:

To characterize pediatric patients who were diagnosed with CPAN and SPAN and to compare their clinical features, treatments, and outcome.

Methods:

A descriptive study was conducted in two centers from Medellin- Colombia, using retrospective data from January 2010 to December 2019. Patients under 18 years of age classified as PAN according to EULAR/PRINTO/PRES(1) criteria were included. CPAN patients were defined according to EULAR/PRES definition (2). Data from medical records were registered, and were expressed in median and ranges and mean and standard deviation (SD) according to their distribution. A univariate analysis was carried out by comparing signs, symptoms, and treatment between CPAN and SPAN, and ap-value < 0,05was considered as significant.

Results:

Twenty patients were included. The median age at diagnosis was ten years. 60% were boys. The median follow-up period was 27 months. CPAN was diagnosed in 11 (55%) and SPAN in 9 patients (45%). The most frequent symptoms were cutaneous manifestations (95%), fever (60%) and Calf Pain (55%). Mucosal ulcers were described in four patients; 3 of them were defined as CPAN. Lingual necrosis was present in two CPAN, and peripheral nervous system involvement was found in one SPAN and two CPAN patients in skin affected with lesions; even though, no significant statistical differences between CPAN and SPAN were found in constitutional, cutaneous, muscle-skeletal symptoms, and acute phase reactants. Arteriographic anomalies as hepatic and renal microaneurysms, carotidal aneurysms without aortic involvement, and renal infarction were found in one patient each. Skin Biopsy was performed in 18 patients, being compatible with PAN in 16. All PAN patients (CPAN and SPAN) required treatment with glucocorticoids. None of the patients died during the follow-up period.

Conclusion:

In this Colombian pediatric cohort of PAN patients, the disease was more common in boys than girls, and CPAN was more frequent than SPAN, as already been described. As is evident in this cohort, although CPAN has been considered a benign disease, these patients may be severely ill, requiring glucocorticoid treatment. Pediatric CPAN patients should be strictly followed with particular attention to identify systemic involvement, considering that constitutional, cutaneous, and muscle-skeletal features may be very similar between CPAN and SPAN.

References:

[1]Ozen S, Pistorio A, Iusan S, et al. EULAR/PRINTO/PRES criteria for Henoch-Schönlein purpura, childhood polyarteritis nodosa, childhood Wegener granulomatosis and childhood Takayasu arteritis: Ankara 2008. Part II: Final classification criteria. Ann Rheum Dis. 2010 May;69(5):798–806.

[2]Ozen S, Ruperto N, Dillon M, et al. EULAR/PReS endorsed consensus criteria for the classification of childhood vasculitides. Ann Rheum Dis. 2006;65(7):936–41.

Disclosure of Interests:

None declared

Inhibiting Methanogenesis Stimulated de novo Synthesis of Microbial Amino Acids in Mixed Rumen Batch Cultures Growing on Starch but Not on Cellulose

Ameliorating methane (CH₄) emissions from ruminants would have environmental benefits, but it is necessary to redirect metabolic hydrogen ([H]) toward useful sinks to also benefit animal productivity. We hypothesized that inhibiting rumen methanogenesis would increase de novo synthesis of microbial amino acids (AA) as an alternative [H] sink if sufficient energy and carbon are provided. We examined the effects of inhibiting methanogenesis with 9, 10-anthraquione (AQ) on mixed rumen batch cultures growing on cellulose or starch as sources of energy and carbon contrasting in fermentability, with ammonium (NH₄⁺) or trypticase (Try) as nitrogen (N) sources. Inhibiting methanogenesis with AQ inhibited digestion with cellulose but not with starch, and decreased propionate and increased butyrate molar percentages with both substrates. Inhibiting methanogenesis with 9, 10-anthraquinone increased de novo synthesis of microbial AA with starch but not with cellulose. The decrease in the recovery of [H] caused by the inhibition of methanogenesis was more moderate with starch due to an enhancement of butyrate and AA as [H] sinks. There may be an opportunity to simultaneously decrease the emissions of CH₄ and N with some ruminant diets and replace plant protein supplements with less expensive non-protein nitrogen sources such as urea.

Efficacy of extended infusion of β-lactam antibiotics for the treatment of febrile neutropenia in haematologic patients: protocol for a randomised, multicentre, open-label, superiority clinical trial (BEATLE)

Background

Febrile neutropaenia (FN) is a very common complication in patients with haematological malignancies and is associated with considerable morbidity and mortality. Broad-spectrum antipseudomonal β-lactam antibiotics (BLA) are routinely used for the treatment of cancer patients with FN. However, the clinical efficacy of BLA may be diminished in these patients because they present with pathophysiological variations that compromise the pharmacokinetic (PK) parameters of these antibiotics. Optimised administration of BLA in prolonged infusions has demonstrated better clinical outcomes in critically ill patients. However, there is a paucity of data on the usefulness of this strategy in patients with FN.

The aim of this study is to test the hypothesis that the administration of BLA would be clinically more effective by extended infusion (EI) than by intermittent infusion (II) in haematological patients with FN.

Methods

A randomised, multicentre, open-label, superiority clinical trial will be performed. Patients with haematological malignancies undergoing chemotherapy or haematopoietic stem-cell transplant and who have FN and receive empirical antibiotic therapy with cefepime, piperacillin-tazobactam or meropenem will be randomised (1:1) to receive the antibiotic by EI (during half the time of the dosing interval) in the study group, or by II (30 min) in the control group.

The primary endpoint will be clinical efficacy, defined as defervescence without modifying the antibiotic treatment administered within the first 5 days of therapy. The primary endpoint will be analysed in the intention-to-treat population. The secondary endpoints will be pharmacokinetic/pharmacodynamic (PK/PD) target achievement, bacteraemia clearance, decrease in C-reactive protein, overall (30-day) case-fatality rate, adverse events and development of a population PK model of the BLA studied.

Discussion

Data on the usefulness of BLA administration in patients with FN are scant. Only three clinical studies addressing this issue have been published thus far, with contradictory results. Moreover, these studies had some methodological flaws that limit the interpretation of their findings. If this randomised, multicentre, phase IV, open-label, superiority clinical trial validates the hypothesis that the administration of BLA is clinically more effective by EI than by II in haematological patients with FN, then the daily routine management of these high-risk patients could be changed to improve their outcomes.

Trial registration

European Clinical Trials Database: EudraCT 2018–001476-37.

ClinicalTrials.gov, ID: NCT04233996.

Academically Oriented Activity Breaks for First-Grade Chilean Students: Development and Pilot Testing Effectiveness

We developed and pilot tested the effectiveness of a physically active academic program, Active Breaks (AB), whose objective is to increase school time moderate/vigorous physical activity (MVPA) among first graders, through daily 15-minute bouts of MVPA, at the beginning of the first lesson. Initially, 240 cards including one game each were developed and tested in first-grade students from 16 schools in Santiago. Trained observers and school teachers assessed the time, ease, and feasibility of implementation for each card. Barriers and facilitators to implementation were obtained from semistructured interviews to 14 teachers (out of 16). In eight schools (n = 556 students), we compared school time MVPA (with accelerometers) at baseline and follow-up, using test of proportions. One-hundred and twenty cards (games) complied with all aspects. AB were implemented 50% of the time with a duration of 14 minutes (SD = 5). More than 90% of the time, teachers felt competent to conduct AB, and children understood the instructions and enjoyed the activity. The main facilitators included teachers liking physical activity and considering it important, support of principal and school staff, and conducting AB inside the classroom. Barriers included teacher's workload and having to conduct AB during the first lesson. During the 4-month period of implementation, MVPA increased by 1.5 and 1.2 percentage points in boys and girls, respectively. The set of 120 cards is easy and feasible to implement. Moreover, preliminary results suggest they could be effective in increasing MVPA during school time, although studies with longer follow-ups are needed to assess the validity of these findings.

Bisphenol A induces coronary endothelial cell necroptosis by activating RIP3/CamKII dependent pathway

Epidemiological studies link long term exposure to xenoestrogen Bisphenol-A to adverse cardiovascular effects. Our previous results show that BPA induces hypertension by a mechanism involving CamKII activation and increased redox stress caused by eNOS uncoupling. Recently, CamKII sustained activation has been recognized as a central mediator of programmed cell death in cardiovascular diseases, including necroptosis. However, the role of necroptosis in cardiac response to BPA had not yet been explored. Mice exposed to BPA for 16 weeks showed altered heart function, electrical conduction, and increased blood pressure. Besides, a stress test showed ST-segment depression, indicative of cardiac ischemia. The hearts exhibited cardiac hypertrophy and reduced vascularization, interstitial edema, and large hemorrhagic foci accompanied by fibrinogen deposits. BPA initiated a cardiac inflammatory response, up-regulation of M1 macrophage polarization, and increased oxidative stress, coinciding with the increased expression of CamKII and the necroptotic effector RIP3. In addition, cell death was especially evident in coronary endothelial cells within hemorrhagic areas, and Evans blue extravasation indicated a vascular leak in response to Bisphenol-A. Consistent with the in vivo findings, BPA increased the necroptosis/apoptosis ratio, the expression of RIP3, and CamKII activation in endothelial cells. Necrostatin-1, an inhibitor of necroptosis, alleviated BPA induced cardiac dysfunction and prevented the inflammatory and hemorrhagic response in mice. Mechanistically, silencing of RIP3 reversed BPA-induced necroptosis and CamKII activation in endothelial cells, while inhibition of CamKII activation by KN-93 had no effect on RIP3 expression but decreased necroptotic cell death suggesting that BPA induced necroptosis is mediated by a RIP 3/CamKII dependent pathway. Our results reveal a novel pathogenic role of BPA on the coronary circulation. BPA induces endothelial cell necroptosis, promotes the weakening of coronary vascular wall, which caused internal ventricular hemorrhages, delaying the reparative process and ultimately leading to cardiac dysfunction.

The Value of Pre-Screening in the Alzheimer's Prevention Initiative (API) Autosomal Dominant Alzheimer's Disease Trial

The Alzheimer's Prevention Initiative (API) Autosomal Dominant Alzheimer's Disease (ADAD) trial evaluates the anti-amyloid-β antibody crenezumab in cognitively unimpaired persons who, based on genetic background and age, are at high imminent risk of clinical progression, and provides a powerful test of the amyloid hypothesis. The Neurosciences Group of Antioquia implemented a pre-screening process with the goals of decreasing screen failures and identifying participants most likely to adhere to trial requirements of the API ADAD trial in cognitively unimpaired members of Presenilin1 E280A mutation kindreds. The pre-screening failure rate was 48.2%: the primary reason was expected inability to comply with the protocol, chiefly due to work requirements. More carriers compared to non-carriers, and more males compared to females, failed pre-screening. Carriers with illiteracy or learning/comprehension difficulties failed pre-screening more than non-carriers. With the Colombian API Registry and our prescreening efforts, we randomized 169 30-60 year-old cognitively unimpaired carriers and 83 non-carriers who agreed to participate in the trial for at least 60 months. Our findings suggest multiple benefits of implementing a pre-screening process for enrolling prevention trials in ADAD.

Longitudinal monitoring of anti-saliva antibodies as markers of repellent efficacy against Phlebotomus perniciosus and Phlebotomus papatasi in dogs

A 2-year longitudinal study of enzyme-linked immunosorbent assay (ELISA) antibodies against Phlebotomus perniciosus and Phlebotomus papatasi (Diptera: Psychodidae) sandfly saliva was performed in 32 Beagle dogs treated preventively with an imidacloprid-permethrin topical insecticide in an endemic area in Spain. Dogs were grouped into three sandfly exposure groups according to the time of inclusion in the study. Assays analysed immunoglobulin G (IgG) against salivary gland homogenates (SGH) of both species and recombinant P. papatasi rSP32 and P. perniciosus rSP03B proteins in serum. The dogs were participating in a Leishmania infantum (Kinetoplastida: Trypanosomatidae) vaccine trial and were experimentally infected with the parasite in the second year. No dog acquired natural L. infantum infections during the first year, but most developed anti-saliva antibodies, and median log-transformed optical densities (LODs) were seasonal, mimicking those of local sandflies. This indicates that the repellent efficacy of the insecticide used is below 100%. Multi-level modelling of LODs revealed variability among dogs, autocorrelation and differences according to the salivary antigen and the dog's age. However, dog seroprevalence, estimated using pre-exposure LODs as cut-offs, was relatively low. This, and the fact that dogs did not become naturally infected with L. infantum, would support the efficacy and usefulness of this imidacloprid-permethrin topical insecticide in canine leishmaniasis control.

How does descending aorta geometry change when it dissects?

OBJECTIVES

Thoracic endovascular aortic repair is the treatment of choice in complicated acute type B aortic dissection. How to infer predissection aortic diameter is not well understood. Our aim was to delineate changes in descending aortic geometry due to dissection.

METHODS

Five tertiary centres reviewed their acute aortic dissection type B databases containing 802 patients. All patients who had undergone computed tomography angiography less than 2 years before and immediately after aortic dissection onset were included. We compared the aortic geometry before and after the dissection onset.

RESULTS

Altogether 25 patients were included [median age 60 (first quartile 52, third quartile 72) years; 60% men]. In all except 1 patient, the maximum descending aortic diameter was less than 45 mm before aortic dissection onset. The largest increase in diameter induced by the dissection was observed in the proximal descending aorta 28.2 (25.1, 32.1) vs 34.6 (31.3, 39.1) mm (+6.4 mm; +23%; P < 0.001). The thoracic descending aortic length increased after the dissection onset [253.3 (229.3, 271.9) vs 261.3 (247.9, 285.4) mm; P = 0.003]. The predissection aortic diameter of the proximal thoracic descending aorta was 7.9 (5.2, 10.7) mm larger (P < 0.001) than the post-dissection area-derived true-lumen diameter and 2.5 (1.3, 6.1) mm larger than the maximum true-lumen diameter (P < 0.001).

CONCLUSIONS

Type B aortic dissection increases the diameter, length and volume of the descending thoracic aorta. The predissection aortic diameter most closely resembles the post-dissection maximum diameter of the true lumen.

Seroprevalence of canine Leishmania infantum infection in the Mediterranean region and identification of risk factors: The example of North-Eastern and Pyrenean areas of Spain

The Mediterranean basin is an endemic region for canine leishmaniosis (CanL), where it represents a major veterinary problem and raises human health concerns. However, the distribution of the disease is heterogeneous and not all countries and locations have been equally studied and characterized. This work describes the situation of CanL in Girona province (Catalonia, Spain), for which no data has been previously reported, and presents a relevant study to exemplify other areas with similar characteristics across the region. Four cross-sectional seroprevalence surveys were performed from 2012 to 2016 throughout the province, including 36 sampling stations in 26 localities and a total of 593 dogs. For each animal, individual and location variables were also collected. Additionally, each dog owner answered a questionnaire about their knowledge of CanL and preventive methods used. Blood samples were analysed by an in-house ELISA and a mixed logistic regression model was used to assess the relationship between pre-determined variables and dog seropositivity. A Spearman's correlation was used to assess the association between dog owners' perceived risk of CanL and Leishmania infantum seropositivity in dogs at a given location. The overall true seroprevalence estimated for Girona province was 19.5% (95%CI: 15.5-23.5), of which only 6.8% (10/146) were considered symptomatic. Age of the dog [OR = 1.21 (95%CI: 1.11-1.31); p < 0.001] and altitude [OR = 0.02 (95%CI: 0.001-0.19); p = 0.001] were identified as risk factors for the infection. The results obtained in this study are expected to aid in the implementation of directed control programmes in CanL endemic areas throughout Europe, as well as to provide suitable data for the design of better risk assessment maps of the disease.

Clinical and immunological profile of children aged 5-9 years with persistent egg allergy before oral immunotherapy with egg. A multicenter, randomized controlled trial of the Spanish Society of Pediatric Allergy, Asthma and Clinical Immunology (SEICAP)

BACKGROUND

In children with egg protein allergy (EA), the probability of overcoming the allergy decreases with age, and the possibility of suffering severe adverse reactions as a consequence of dietetic transgressions results in worsened quality of life. One treatment option in such cases is oral immunotherapy (OIT) with foods.

METHODS

We present a cohort of children with EA scheduled for OIT with pasteurized raw egg white, describing their clinical and allergic characteristics before the start of OIT.

RESULTS

The median age was six years, and 93% of the patients also suffered other allergies (58% asthma and 38.6% allergy to more than two food groups). In the last year, 14.8% had suffered a severe reaction due to dietetic transgression with egg. The median IgE specific of egg white titer was 38.5kU/l. A double-blind placebo-controlled food challenge with cooked egg white was performed, and if the test proved positive, it was repeated with pasteurized raw egg white. The mean symptoms-provoking dose was 1.26g and 0.55g for cooked egg white and raw egg white, respectively. An IgE specific of ovomucoid titer of <2.045kU/l differentiated those patients that tolerated cooked egg white.

CONCLUSIONS

OIT with egg is regarded as an option in patients with persistent egg allergy. In the previous challenge test, an IgE specific of ovomucoid titer of <2.045kU/l differentiates those patients that tolerate cooked egg white.