POS0359 MOLECULAR PROFILING OF RADIOGRAPHIC AXIAL SPONDYLOARTHRITIS PATIENTS REVEALS AN ASSOCIATION BETWEEN INNATE AND ADAPTIVE CELL POPULATIONS AND THERAPEUTIC RESPONSE TO ADALIMUMAB

Background:

The response to treatment in spondylarthropaties is heterogeneous, due to factors yet to be better described. For that reason, it is important to find tools that might help clinicians to decide what is the best available therapeutic option for each patient.

Objectives:

The goal of this study is to use comprehensive molecular profiling to characterize clinical response to therapy in a real-world setting. Specifically, to identify molecular biomarkers differentiating good responders and non-responders to TNF inhibitors (TNFi) treatment, using adalimumab, in radiographic axial spondyloarthritis | ankylosing spondylitis (r-axSpA|AS) patients context.

Methods:

Whole-blood mRNA and plasma proteins were measured in a cohort of biologic naïve r-axSpA|AS patients (n = 35) from the Bioefficacy study (Biomarkers identification of anti-TNF alpha agent efficacy in AS patients using RNA sequencing and mass spectrometry), pre and post (14 weeks) TNFi treatment using adalimumab. Response to treatment was categorized according to ASAS20. Results of differential expression analysis were used to identify the most enriched pathways and in predictive models to distinguish responses to TNFi.

Results:

A treatment-related signature, independent of the type of response, suggests a reduction in inflammatory disease activity. We found genes and proteins robustly differentially expressed between baseline and week 14 in responders, including the GWAS AS-associated genes TNFRSF1A, FCGR2A, TYK2, TBKBP1, IL1R1, IL6R, ICOSLG, IL7R, HHAT and LTBR. Moreover, CRP and HP proteins showed strong and early decrease in the plasma of AS patients, while a cluster of apolipoproteins (APO1, APO2, APO3) showed an increased expression at week 14. Good responders to TNFi treatment tend to have higher expression of innate immunity genes at baseline, and lower expression of markers associated with adaptive immunity, particularly B-cells. A logistic regression model incorporating ASDAS-CRP, gender and Gene x, the top differentially expressed gene at baseline between responders and non-responders, enabled an accurate prediction of response to adalimumab in our cohort (AUC=0.97).

Conclusion:

Differences in disease activity and/or innate/adaptive immune cell type composition at baseline may be a major contributor to response to adalimumab in r-axSpA|AS. Alternatively, a model including clinical and gene expression variables could be considered, particularly in patients with mild disease activity.

Disclosure of Interests:

None declared

AB0015 IDENTIFICATION OF KEY GENES TO SUPPORT SYSTEMIC LUPUS ERYTHEMATOSUS, RHEUMATOID ARTHRITIS AND ANKYLOSING SPONDYLITIS DIAGNOSIS BY TRANSCRIPTOMIC APPROACH

Background:

Early diagnosis of inflammatory rheumatic diseases (IRD), as Systemic Lupus Erythematosus (SLE), Rheumatoid Arthritis (RA) and axial Spondyloarthritis (axSpA) represents in our days a major clinical challenge. Increasing evidence has determined that early diagnosis, prompt treatment initiation and early achievement of remission are the best predictors of long-term clinical, functional and radiographic outcomes. Therefore, identification of sensitive biomarkers to support an early diagnosis to enable early therapy is of utmost importance [1,2].

Objectives:

This study aims to identify novel genes that may improve the current clinical diagnosis approach for early SLE, RA and axSpA.

Methods:

A cross-sectional study was conducted on 44 participants, 12 with axSpA (according to ASAS criteria), 11 with RA (according to ACR/EULAR criteria for RA), 10 with SLE (according to ACR classification criteria for SLE) and 11 Healthy Controls (HC), gender and age matched. Patients with co-occurrence of other IRD or having received biological therapies were excluded. Peripheral blood samples were collected into PAXgene tubes and stored in -80°C. mRNA profiling by RNA-seq was performed. Unpaired t-tests with multivariate permutation correction were applied to identify differentially expressed genes (DEGs) between patients and HC for each disease and within diseases. Enrichment analysis, Gene ontology (GO) and Kyoto Enrichment of Genes and Genomes (KEGG) analysis were also performed. DEGs that allow to distinguish each disease from HC and between diseases. The top DEGs (axSpA n=2, RA n=2, SLE n=3) identified were confirmed by quantitative RT-PCR.

Results:

For axSpA, genes involved in negative regulation of cytokines by JAK/STAT pathway and in osteoblast differentiation through STAT3 pathway, were confirmed. In SLE, genes involved in trap for immune complexes in peripheral blood and involved in nucleosome regulation, were also confirmed. Regarding RA, no genes were confirmed.

Conclusion:

Our work provides new insights into IRD pathogenesis, and discloses new biomarkers, which may be useful as either predictive biomarkers for diagnosis or therapeutic targets to improve IRD approach.Further validation are needed in different cohorts.

References:

[1]Monti, S. et al. (2015) ‘Rheumatoid arthritis treatment: The earlier the better to prevent joint damage’, RMD Open, 1(Suppl 1), pp. 1–5. doi: 10.1136/rmdopen-2015-000057.

[2]Oglesby, A. et al. (2014) ‘Impact of early versus late systemic lupus erythematosus diagnosis on clinical and economic outcomes.’, Applied health economics and health policy, 12(2), pp. 179–90. doi: 10.1007/s40258-014-0085-x.

Acknowledgments:

To all patients and healthy controls who participated in the study

Disclosure of Interests:

Atlas Mashayekhi Sardoo: None declared, Paul Leo: None declared, Mariana Santos: None declared, Tiago Costa: None declared, Sergio Fernandes Almeida: None declared, Sara Maia: None declared, Vladimir Benes: None declared, Mattew Brown Speakers bureau: MSD, Pfizer, Novartis, Jaime Branco Speakers bureau: Vitoria, Fernando Pimentel dos Santos Speakers bureau: Novartis, Pfizer, Biogen, Vitoria,

Characterization of hLF1-11 immobilization onto chitosan ultrathin films, and its effects on antimicrobial activity

hLF1-11 (GRRRRSVQWCA) is an antimicrobial peptide (AMP) with high activity against methicillin-resistant Staphylococcus aureus (MRSA), the most prevalent species in implant-associated infection. In this work, the effect of the surface immobilization on hLF1-11 antimicrobial activity was studied. Immobilization was performed onto chitosan thin films as a model for an implant coating due to its reported osteogenic and antibacterial properties. Chitosan thin films were produced by spin-coating on gold surfaces. hLF1-11 was immobilized onto these films by its C-terminal cysteine in an orientation that exposes the antimicrobial activity-related arginine-rich portion of the peptide. Two levels of exposure (with and without a polyethylene glycol (PEG) spacer) were analyzed. Covalent immobilization was further compared with the AMP physical adsorption onto chitosan films. Surfaces were characterized using ellipsometry, contact angle measurements, atomic force microscopy, infrared and X-ray photoelectron spectroscopies and using a fluorimetric assay for hLF1-11 quantification. Surface antimicrobial activity was assessed through surface adhesion and viability assays using an MRSA (S. aureus ATCC 33591). The incorporation of hLF1-11 increased significantly bacterial adhesion to chitosan films. However, the presence of hLF1-11, namely when immobilized through a PEG spacer, decreased the viability of adherent bacteria with regard to the control surface. These results demonstrated that hLF1-11 after covalent immobilization by its cysteine can maintain activity, particularly if a spacer is applied. However, further studies, exploring the opposite orientation or the same C-terminal orientation, but non-cysteine related, can help to clarify the potential of the hLF1-11 immobilization strategy.

The role of targeted BRCA1/BRCA2 mutation analysis in hereditary breast/ovarian cancer families of Portuguese ancestry

We report the analysis of altogether 1050 suspected hereditary breast/ovarian cancer (HBOC) families, 524 fully screened for BRCA1/BRCA2 mutations and 526 tested only for the most common mutations. Of the 119 families with pathogenic mutations, 40 (33.6%) had the BRCA2 c.156_157insAlu rearrangement and 15 (12.6%) the BRCA1 c.3331_3334del mutation, the former being specific of Portuguese ancestry and the latter showing a founder effect in Portugal. Interestingly, the two most common mutations were found in a significant proportion of the HBOC families with an a priori BRCAPRO mutation probability <10%. We recommend that all suspected HBOC families from Portugal or with Portuguese ancestry, even those fulfilling moderately stringent clinical-criteria for genetic testing, should be specifically analyzed for the two most common BRCA1/BRCA2 founder mutations, and we here present a simple method for this first tier test. Screening of the entire coding regions of BRCA1 and BRCA2 should subsequently be offered to those families with a mutation probability ≥10% if none of those founder mutations are found.

Selective albumin-binding surfaces modified with a thrombin-inhibiting peptide

Blood-contacting medical devices have been associated with severe clinical complications, such as thrombus formation, triggered by the activation of the coagulation cascade due to the adsorption of certain plasma proteins on the surface of biomaterials. Hence, the coating of such surfaces with antithrombotic agents has been used to increase biomaterial haemocompatibility. Biomaterial-induced clotting may also be decreased by albumin adsorption from blood plasma in a selective and reversible way, since this protein is not involved in the coagulation cascade. In this context, this paper reports that the immobilization of the thrombin inhibitor D-Phe-Pro-D-Arg-D-Thr-CONH2 (fPrt) onto nanostructured surfaces induces selective and reversible adsorption of albumin, delaying the clotting time when compared to peptide-free surfaces. fPrt, synthesized with two glycine residues attached to the N-terminus (GGfPrt), was covalently immobilized onto self-assembled monolayers (SAMs) having different ratios of carboxylate-hexa(ethylene glycol)- and tri(ethylene glycol)-terminated thiols (EG6-COOH/EG3) that were specifically designed to control GGfPrt orientation, exposure and density at the molecular level. In solution, GGfPrt was able to inactivate the enzymatic activity of thrombin and to delay plasma clotting time in a concentration-dependent way. After surface immobilization, and independently of its concentration, GGfPrt lost its selectivity to thrombin and its capacity to inhibit thrombin enzymatic activity against the chromogenic substrate n-p-tosyl-Gly-Pro-Arg-p-nitroanilide. Nevertheless, surfaces with low concentrations of GGfPrt could delay the capacity of adsorbed thrombin to cleave fibrinogen. In contrast, GGfPrt immobilized in high concentrations was found to induce the procoagulant activity of the adsorbed thrombin. However, all surfaces containing GGfPrt have a plasma clotting time similar to the negative control (empty polystyrene wells), showing resistance to coagulation, which is explained by its capacity to adsorb albumin in a selective and reversible way. This work opens new perspectives to the improvement of the haemocompatibility of blood-contacting medical devices.

[Radiation exposure of surgical staff during sentinel node surgery. Is there a risk for the surgeon and his team?]

OBJECTIVE

Assess the radiation exposure of surgical staff during sentinel node surgery in gynecology using a radiotracer, the (99m)Tc-microalbumin.

MATERIALS AND METHODS

A monocentric, prospective study was conducted during 3 months representing 40 sentinel node surgical procedures with different dosimetric measurements. Dosimeters were used to evaluate the whole body and the fingers radiation exposure for all exposed workers (surgeon, nurse and surgical assistant). Another dosimeter was used to estimate the atmospheric radiation level. The activity of (99m)Tc-microalbumin was 50.1±2.4MBq when the surgery was performed the same day and 90.4±3.2MBq when the surgery was performed the day after.

RESULTS

Radioactive doses received during each procedure by the surgeon, surgical assistant and nurse are 5, 3.75 and 0μSv for whole body exposure and 17.5, 15.6 and 16.2μSv for extremities respectively. Atmosphere dosimeter does not detect any radiation over this period. On average, 200 procedures are performed each year in our hospital by 7 surgeons. Surgeon's radiation exposure remains below the threshold of 1mSv annual for whole body and 50mSv annual for fingers set for public by the International Commission on Radiological Protection.

DISCUSSION AND CONCLUSIONS

During sentinel node surgery radiation exposure of surgical staff is weak. Everyone, including the surgeon, receives a dose below the limits of the public radiation exposure. There is no need for special dosimetric monitoring or use radiation protective devices during the sentinel node surgery using (99m)Tc-microalbumin injection.

A novel microdeletion syndrome at 3q13.31 characterised by developmental delay, postnatal overgrowth, hypoplastic male genitals, and characteristic facial features

BACKGROUND

Congenital deletions affecting 3q11q23 have rarely been reported and only five cases have been molecularly characterised. Genotype-phenotype correlation has been hampered by the variable sizes and breakpoints of the deletions. In this study, 14 novel patients with deletions in 3q11q23 were investigated and compared with 13 previously reported patients.

METHODS

Clinical data were collected from 14 novel patients that had been investigated by high resolution microarray techniques. Molecular investigation and updated clinical information of one cytogenetically previously reported patient were also included.

RESULTS

The molecular investigation identified deletions in the region 3q12.3q21.3 with different boundaries and variable sizes. The smallest studied deletion was 580 kb, located in 3q13.31. Genotype-phenotype comparison in 24 patients sharing this shortest region of overlapping deletion revealed several common major characteristics including significant developmental delay, muscular hypotonia, a high arched palate, and recognisable facial features including a short philtrum and protruding lips. Abnormal genitalia were found in the majority of males, several having micropenis. Finally, a postnatal growth pattern above the mean was apparent. The 580 kb deleted region includes five RefSeq genes and two of them are strong candidate genes for the developmental delay: DRD3 and ZBTB20.

CONCLUSION

A newly recognised 3q13.31 microdeletion syndrome is delineated which is of diagnostic and prognostic value. Furthermore, two genes are suggested to be responsible for the main phenotype.

[Situation of supply and boom of PET imaging: what is the future for technetium-99m in nuclear medicine?]

Molecular imaging has shown its interest in the diagnosis, staging and therapy monitoring of many diseases, especially in the field of cancer. This imaging modality can detect non-invasively early molecular changes specific to these diseases. Its expansion includes two aspects linked firstly with the advanced techniques of imaging modalities and secondly with the development of tracers as radio pharmaceuticals for imaging new molecular targets. Technetium-99m ((99m)Tc), because of its physical characteristics, its widespread availability and low cost, is the most used radionuclide in molecular imaging with the technique of single photon emission computed tomography (SPECT). Nevertheless, the current difficulty concerning the supply and the great interest of Positron Emission Tomography (PET), the "competitor" imaging modality-using molecules labelled with fluorine-18 ((18)F), legitimates the question about the future of (99m)Tc, its supremacy and the emergence of new tracer labelled with (99m)Tc. Focusing on the actual and future supply situation, the place of SPECT imaging in nuclear medicine, as well as the development of new molecules labelled with (99m)Tc is necessary to show that this radionuclide will remain essential for the speciality in the next years.

Latent tuberculosis infection among undergraduate medical students in Rio de Janeiro State, Brazil

SETTING

Five medical schools in three cities with different tuberculosis (TB) incidence rates in Rio de Janeiro State, Brazil.

OBJECTIVE

To estimate prevalence of and associated factors for latent tuberculosis infection (LTBI) among medical students.

DESIGN

A cross-sectional survey was conducted among undergraduate students in pre-clinical, early and late clinical years from schools in cities with low (28/100,000), intermediate (63/100,000) and high (114/100,000) TB incidence rates. Information on socio-demographic profile, previous BCG vaccination, potential TB exposure, co-morbidity and use of respiratory protective masks was obtained. A tuberculin skin test (TST) was performed using the Mantoux technique by an experienced professional. A positive TST, defined as induration > or = 10 mm, was considered LTBI.

RESULTS

LTBI prevalence was 6.9% (95%CI 5.4-8.6). In multivariate analysis, male sex (adjusted odds ratio [aOR] 1.8; 95% CI 1.1-3.0), late clinical years (aOR 1.9; 95% CI 1.01-3.5), intermediate TB incidence (aOR 4.3; 95% CI 1.3-14.6) and high TB incidence in the city of medical school (aOR 5.1; 95% CI 1.6-16.8) were significantly associated with LTBI.

CONCLUSIONS

The higher prevalence of LTBI in late clinical years suggests that medical students are at increased risk for nosocomial Mycobacterium tuberculosis infection. The implementation of a TB control program may be necessary in medical schools, particularly in cities with higher TB incidence.

Discrimination of multidrug-resistant Mycobacterium tuberculosis IS6110 fingerprint subclusters by rpoB gene mutation analysis

The rpoB gene mutations in a 69-bp region of the gene, resulting in resistance to rifampin, were used to discriminate between Mycobacterium tuberculosis IS6110 fingerprint subclusters. These subclusters exhibited identical IS6110 fragments or had one or two additional fragments. In the two major subclusters all the analyzed strains have the same variant rpoB allele but are different from each other, suggesting the occurrence of independent outbreaks.

The heroin epidemic in New York City: current status and prognoses

Since 1989, heroin production worldwide has risen; in New York City, as its purity rose and prices fell, street-level markets were restructured and offered heroin in addition to cocaine and crack (which had been popular during the 1980s). While officials estimate that there are between 500,000 and one million hard-core, chronic heroin users nationwide, evidence of supplemental users heralding another heroin era includes: more overdoses and overdose deaths, greater demand for treatment, larger seizures of heroin at all levels of distribution and related arrests, and broader media coverage. In this article, the authors describe the characteristics of populations in which there may have been a percentage increase of new users, such as young middle- or upper-class European-Americans, young Puerto Ricans and recent Haitian and Russian immigrants. The abstinence of young African-Americans is also noted. The article ends with a preliminary needs assessment of the new users in the areas of health (including AIDS), housing, employment, treatment, arrest and imprisonment.