Bone mineral density in adults with arthrogryposis multiplex congenita: a retrospective cohort analysis

The primary objective of this study was to evaluate the prevalence of low femoral and lumbar spine bone mineral density (BMD) in adults with arthrogryposis multiplex congenita (AMC). We performed a retrospective cohort analysis of adults with AMC who were enrolled in the French Reference Center for AMC and in the Pediatric and Adult Registry for Arthrogryposis (PARART, NCT05673265). Patients who had undergone dual-energy X-ray absorptiometry (DXA) and/or vitamin D testing were included in the analysis. Fifty-one patients (mean age, 32.9 ± 12.6 years) were included; 46 had undergone DXA. Thirty-two (32/51, 62.7%) patients had Amyoplasia, and 19 (19/51, 37.3%) had other types of AMC (18 distal arthrogryposis, 1 Larsen). Six patients (6/42, 14.3%) had a lumbar BMD Z score less than - 2. The mean lumbar spine Z score (- 0.03 ± 1.6) was not significantly lower than the expected BMD Z score in the general population. Nine (9/40, 22.5%) and 10 (10/40, 25.0%) patients had femoral neck and total hip BMD Z scores less than - 2, respectively. The mean femoral neck (- 1.1 ± 1.1) and total hip (- 1.2 ± 1.2) BMD Z scores in patients with AMC were significantly lower than expected in the general population (p < 0.001). Femoral neck BMD correlated with height (rs = 0.39, p = 0.01), age (rs = - 0.315, p = 0.48); total hip BMD correlated with height (rs = 0.331, p = 0.04) and calcium levels (rs = 0.41, p = 0.04). Twenty-five patients (25/51, 49.0%) reported 39 fractures. Thirty-one (31/36, 86.1%) patients had 25-hydroxyvitamin D levels less than 75 nmol/l, and 6 (6/36, 16.7%) had 25-hydroxyvitamin D levels less than 75 nmol/l. Adults with AMC had lower hip BMD than expected for their age, and they more frequently showed vitamin D insufficiency. Screening for low BMD by DXA and adding vitamin D supplementation when vitamin D status is insufficient should be considered in adults with AMC, especially if there is a history of falls or fractures.

Presence of ectopic germinal center structures in autoimmune hepatitis

Autoimmune tissues may contain ectopic germinal centers (EGCs). However, these structures have never been described in the liver of patients suffering from autoimmune hepatitis (AIH). We retrospectively reviewed histological features of 120 definite AIH cases, and found 10 cases harboring markers of EGCs. In these cases, CD21+ follicular dendritic cells were intermixed with CD3+ T and CD20+ B lymphocytes. The latter expressed the GC-specific marker bcl6, and some were proliferative as assessed by Ki67 expression. Antibody-secreting cells (ASCs) defined by expression of the mum-1 transcription factor and presence of cytoplasmic IgMs were usually present in the periphery of these structures, but some were also present within the EGCs. Notably, some ASCs were IgG-switched. Common treatment applied to AIH patients achieved biochemical normalization as efficiently as in patients without EGCs. In the present study, we provide the proof for the occurrence of functional EGCs enabling differentiation of B cells into ASCs and occurrence of immunoglobulin switch in AIH livers.

Septins as membrane influencers: direct play or in association with other cytoskeleton partners

The cytoskeleton comprises three polymerizing structures that have been studied for a long time, actin microfilaments, microtubules and intermediate filaments, plus more recently investigated dynamic assemblies like septins or the endocytic-sorting complex required for transport (ESCRT) complex. These filament-forming proteins control several cell functions through crosstalks with each other and with membranes. In this review, we report recent works that address how septins bind to membranes, and influence their shaping, organization, properties and functions, either by binding to them directly or indirectly through other cytoskeleton elements.

Meeting report - the ever-fascinating world of septins

Septins are GTP-binding proteins that assemble into hetero-oligomers. They can interact with each other end-to-end to form filaments, making them the fourth element of the cytoskeleton. To update the current knowledge on the ever-increasing implications of these fascinating proteins in cellular functions, a hundred expert scientists from across the globe gathered from 12 to 15 October 2021 in Berlin for the first hybrid-format (on site and virtual) EMBO workshop Molecular and Cell Biology of Septins.

Cytoskeleton and Associated Proteins: Pleiotropic JNK Substrates and Regulators

This review extensively reports data from the literature concerning the complex relationships between the stress-induced c-Jun N-terminal kinases (JNKs) and the four main cytoskeleton elements, which are actin filaments, microtubules, intermediate filaments, and septins. To a lesser extent, we also focused on the two membrane-associated cytoskeletons spectrin and ESCRT-III. We gather the mechanisms controlling cytoskeleton-associated JNK activation and the known cytoskeleton-related substrates directly phosphorylated by JNK. We also point out specific locations of the JNK upstream regulators at cytoskeletal components. We finally compile available techniques and tools that could allow a better characterization of the interplay between the different types of cytoskeleton filaments upon JNK-mediated stress and during development. This overview may bring new important information for applied medical research.

Cdc42 and its BORG2 and BORG3 effectors control the subcellular localization of septins between actin stress fibers and microtubules

Cell resistance to taxanes involves several complementary mechanisms, among which septin relocalization from actin stress fibers to microtubules plays an early role. By investigating the molecular mechanism underlying this relocalization, we found that acute paclitaxel treatment triggers the release from stress fibers and subsequent proteasome-mediated degradation of binder of Rho GTPases 2 (BORG2)/Cdc42 effector protein 3 (Cdc42EP3) and to a lesser extent of BORG3/Cdc42EP5, two Cdc42 effectors that link septins to actin in interphase cells. BORG2 or BORG3 silencing not only caused septin detachment from stress fibers but also mimicked the effects of paclitaxel by triggering both septin relocalization to microtubules and significant drug resistance. Conversely, BORG2 or BORG3 overexpression retained septins on actin fibers even after paclitaxel treatment, without affecting paclitaxel sensitivity. We found that drug-induced inhibition of Cdc42 resulted in a drop in BORG2 level and in the relocalization of septins to microtubules. Accordingly, although septins relocalized when overexpressing an inactive mutant of Cdc42, the expression of a constitutively active mutant acted locally at actin stress fibers to prevent septin release, even after paclitaxel treatment. These findings reveal the role of Cdc42 upstream of BORG2 and BORG3 in controlling the interplay between septins, actin fibers, and microtubules in basal condition and in response to taxanes.

Stress-induced phosphorylation of CLIP-170 by JNK promotes microtubule rescue

The stress-induced c-Jun N-terminal kinase (JNK) controls microtubule dynamics by enhancing both microtubule growth and rescues. Here, we show that upon cell stress, JNK directly phosphorylates the microtubule rescue factor CLIP-170 in its microtubule-binding domain to increase its rescue-promoting activity. Phosphomimetic versions of CLIP-170 enhance its ability to promote rescue events in vitro and in cells. Furthermore, while phosphomimetic mutations do not alter CLIP-170’s capability to form comets at growing microtubule ends, both phosphomimetic mutations and JNK activation increase the occurrence of CLIP-170 remnants on the microtubule lattice at the rear of comets. As the CLIP-170 remnants, which are potential sites of microtubule rescue, display a shorter lifetime when CLIP-170 is phosphorylated, we propose that instead of acting at the time of rescue occurrence, CLIP-170 would rather contribute in preparing the microtubule lattice for future rescues at these predetermined sites.

SAT0364 DATA TO BE COLLECTED FOR AN OPTIMAL MANAGEMENT OF AXIAL SPONDYLOARTHRITIS IN DAILY PRACTICE: PROPOSAL FROM AN EVIDENCE BASED AND CONSENSUAL APPROACHES

Background:

Standardization of clinical practice has been proven to be effective in management of chronic diseases. This is particularly true at the time where the concept of treat to target is becoming more and more important in the field of axial spondyloarthritis (ax-SpA).

Objectives:

To propose a list of variables to be collected at the time of the diagnosis and over the follow-up of patients with axial spondyloarthritis (ax-SpA) for an optimal management in daily practice.

Methods:

The process comprised (1) the evaluation of the interest of 51 variables proposed for the assessment of axSpA via a systematic literature research, (2) a consensus process involving 78 hospital-based or office-based rheumatologists, considering the collection of the variable in a 4 grade scale from ”potentially useful” to “mandatory”, (3) a consensus on optimal timeline for periodic assessment of the selected variables on a 5 grade scale from “at each visit” to “never to be re-collected”.

Results:

The systematic literature research retrieved a total of 14,133 abstracts, of which 213 were included in the final qualitative synthesis. Concerning the data to be collected at the time of the diagnosis and during follow-up, we proposed to differentiate the results based on a) the way of collection of the variables (e.g. questionnaires by the patient, interview by the physician, physical examination, investigations) b) the usefulness these variables in daily practice based on the opinion of the rheumatologists ” c) the optimal timeline between 2 evaluations of the variable based on the opinion of the rheumatologists. In the initial systematic review, symptoms of heart failure history of inflammatory bowel disease, psoriasis or uveitis, patient global visual analogic scale, spine radiographs, modified Schöber test, coxo-femoral rotations, swollen joint count, urine strip test, BASDAI and ASDAS global scores were considered very useful and nocturnal back pain/morning stiffness, sacro-iliac joints radiographs and CRP were considered mandatory (Figure 1). Timeline between 2 evaluations of variables to collect in the periodic review are summarized inFigure 2.

Figure 1.

Core sets of items to collect and report in the systematic review in axial spondyloarthritis management in daily practice ASDAS=Ankylosing Spondylitis Disease Activity Score, BASDAI=Bath Ankylosing Spondylitis Disease Activity Index, BASFI=Bath Ankylosing Spondylitis Functionnal Index, BASMI=Bath Ankylosing Spondylitis Metrology Index, CRP=C Reactive Protein, CT=computerized tomography, FIRST=Fibromyalgia Rapid Screening Tool, HLA=Human Leukocyte Antigen, MRI=Magnetic resonance imaging, PET=positron emission tomography.

Figure 2.

Periodic review timeline of variables to collectASDAS=Ankylosing Spondylitis Disease Activity Score, BASDAI=Bath Ankylosing Spondylitis Disease Activity Index, Spondylitis Metrology Index, CRP=C Reactive Protein, IBD = inflammatory bowel diseases, PRO = Patient Reported Outcomes

Conclusion:

Using an evidence-based and an expert consensus approaches, this initiative defined a core set of variables to be collected and reported at the time of the diagnosis and during follow-up of patients with ax-SpA in daily practice.

Acknowledgments:

this study has been conducted in two parts: the first one (evidence-based) was conducted thanks to a support from Abbvie France. AbbVie did not review the content or have influence on this manuscript. The second part of this initiative (consensus) has been conducted thanks to a support from the scientific non-profit organization: Association de Recherche Clinique en Rhumatologie

Disclosure of Interests:

Athan Baillet Consultant of: Athan BAILLET has received honorarium fees from Abbvie for his participation as the coordinator of the systematic literature review, Xavier Romand Consultant of: Xavier ROMAND has received honorarium fees from Abbvie, Arnaud Pfimlin Consultant of: Arnaud PFIMLIN has received honorarium fees from Abbvie, Mickael Dalecky Consultant of: Mickael DALECKY has received honorarium fees from Abbvie, Maxime Dougados Grant/research support from: AbbVie, Eli Lilly, Merck, Novartis, Pfizer and UCB Pharma, Consultant of: AbbVie, Eli Lilly, Merck, Novartis, Pfizer and UCB Pharma, Speakers bureau: AbbVie, Eli Lilly, Merck, Novartis, Pfizer and UCB Pharma

THU0370 CLUSTER-RANDOMIZED PRAGMATIC CLINICAL TRIAL EVALUATING THE POTENTIAL BENEFIT OF A TIGHT-CONTROL AND TREAT-TO-TARGET STRATEGY IN AXIAL SPONDYLOARTHRITIS: THE RESULTS OF THE TICOSPA TRIAL

Background:

Current recommendations for axial spondyloarthritis (axSpA) management include tight control and treat-to-target (TC) strategies, but no study has evaluated its potential benefit

Objectives:

To evaluate the benefit of TC strategies in comparison to usual care (UC) in patients with axSpA.

Methods:

Study design:Pragmatic, prospective, cluster-randomized controlled (2 arms), one-year trial (NCT03043846).Centers: 18 axSpA expert centers randomly allocated (1:1) to the treatment arm: TC vs. UC.Patients: axSpA diagnosis and ASAS criteria, non-optimally treated with NSAIDs, bDMARD-naïve, and ASDAS > 2.1 at inclusion.Study treatment:a) TC arm: the strategy was pre-specified by the scientific committee based on current axSpA recommendations and aiming at a target (ASDAS <2.1); visits every 4w;b) UC arm:treatment decisions were at the rheumatologist’s discretion with visits every 12w.Outcomes:the % of patients with a significant (>30%) improvement in the ASAS-HI score over one-year follow-up was the main outcome. Other outcomes (disease activity, quality of life, treatment, …) over follow-up were evaluated (Table 1). The number/type of adverse events were collected.Statistical analysis: this was an intention-to-treat analysis. To take into account the cluster-randomization design, for all outcomes, two models were performed: first a two-level mixed model with 2 random effects was used to estimate the % of responders/the change of the outcome over follow-up (i.e. mod1); in a second step, the imbalanced variables observed at baseline were included in the model (i.e.mod2). Cost-effectiveness was assessed by estimating the (baseline- and cluster-adjusted) incremental cost per quality-adjusted life-year (QALY) gained for TC vs. UC.

Estimated outcomes at week 48Cluster-adjusted (mod1)Cluster and imbalance-adjusted (mod2)TCUCASDAS LDA*76.5%59.5%<0.010.03ASDAS ID25.9%18.7%--ASDAS CII61.2%46.0%<0.010.02ASDAS MI16.5%14.9%--ASAS4052.3%34.7%<0.010.01ASAS2094.9%85.9%<0.010.03BASDAI 5079.0%43.8%0.010.03Physician Global (0-10)2.0 (0.2)1.8 (0.2)--CRP (mg/L)3.9(1.4)3.5 (1.5)--BASG (0-10)2.6 (0.5)3.4 (0.5)0.09-BASFI (0-10)1.7(0.5)2.4 (0.5)--ASAS HI SMD47.3%36.1%--EQ5D0.7(0.1)0.8(0.1)0.02-ASAS-NSAID score1.5(2.2)- 4.9 (2.9)--

Results:

160 patients were included (80 in TC and 80 in UC). Mean age was 37.9(11.0) years with a disease duration of 3.7(6.2) years, 51.2% were males. A radiographic damage of the SI-joints, a (ever) positive MRI sacroiliitis and HLA-B27+ were seen in 46.9%, 81.9% and 75.0% patients respectively. Mean ASDAS at inclusion was 3.0 (0.7) and mean ASASHI was 8.6 (3.7). 72 patients per group attended the one-year visit. Although 47.3% vs. 36.1% patients in the TC and UC arms achieved a significant improvement in ASASHI at the one-year visit, the difference was not statistically significant, with either model. Across all other outcomes a trend was observed in favor of the TC arm (Table 1). The number of bDMARDs was significantly higher in TC arm (56.2% vs. 27.2%). The number of infections was comparable in both groups (15 vs. 16 in the TC and UC, respectively), with only 2 severe infections occurring in the UC arm. From a societal perspective, TC resulted in an additional 0.04 QALY and saved €265 when compared to UC and a 67% probability of being cost-effective at a cost-effectiveness threshold of €20,000 per QALY.

Conclusion:

In this setting of SpA expert centers, UC resulted in a good outcome in a substantial number of patients but the TC was not superior for the primary outcome despite a greater number of bDMARDs prescription. Nevertheless, a general trend in favor of the tight control was observed, with a comparable safety profile and was found to be favorable from a societal health economic perspective.

Acknowledgments:

this trial has been conducted thanks to an unrestricted grant from UCB

Disclosure of Interests:

Anna Moltó Grant/research support from: Pfizer, UCB, Consultant of: Abbvie, BMS, MSD, Novartis, Pfizer, UCB, Clementina López-Medina: None declared, Filip van den Bosch Consultant of: AbbVie, Celgene Corporation, Eli Lilly, Galapagos, Janssen, Novartis, Pfizer, and UCB, Speakers bureau: AbbVie, Celgene Corporation, Eli Lilly, Galapagos, Janssen, Novartis, Pfizer, and UCB, Annelies Boonen Grant/research support from: AbbVie, Consultant of: Galapagos, Lilly (all paid to the department), Casper Webers: None declared, Emmanuelle Dernis Speakers bureau: Lilly, Novartis, Floris A. van Gaalen: None declared, Martin SOUBRIER: None declared, Pascal Claudepierre Speakers bureau: Janssen, Novartis, Lilly, Athan Baillet Consultant of: Athan BAILLET has received honorarium fees from Abbvie for his participation as the coordinator of the systematic literature review, Mirian Starmans-Kool: None declared, Désirée van der Heijde Consultant of: AbbVie, Amgen, Astellas, AstraZeneca, BMS, Boehringer Ingelheim, Celgene, Cyxone, Daiichi, Eisai, Eli-Lilly, Galapagos, Gilead Sciences, Inc., Glaxo-Smith-Kline, Janssen, Merck, Novartis, Pfizer, Regeneron, Roche, Sanofi, Takeda, UCB Pharma; Director of Imaging Rheumatology BV, Maxime Dougados Grant/research support from: AbbVie, Eli Lilly, Merck, Novartis, Pfizer and UCB Pharma, Consultant of: AbbVie, Eli Lilly, Merck, Novartis, Pfizer and UCB Pharma, Speakers bureau: AbbVie, Eli Lilly, Merck, Novartis, Pfizer and UCB Pharma

OP0031 AN INCREASE IN SERUM CALPROTECTIN LEVEL IN ANCA-ASSOCIATED VASCULITIDES PATIENTS DURING MAINTENANCE THERAPY IS ASSOCIATED WITH MORE RELAPSE AND ACCELERATED RENAL FUNCTION DECLINE

Background:

Calprotectin (S100A8/A9), a protein secreted by activated neutrophils and monocytes in inflammatory conditions, is upregulated in active ANCA-associated vasculitides. Serum calprotectin level variation during induction therapy is associated with disease relapse in PR3-ANCA-associated vasculitides (1). However, the place of this biomarker during maintenance therapy is unknown.

Objectives:

To demonstrate whether variation in serum calprotectin level during maintenance therapy could be used as a biomarker predicting subsequent relapse in ANCA-associated vasculitides.

Methods:

Patients with ANCA-associated vasculitides in complete remission (BVAS=0) after induction therapy with cyclophosphamide and included in the MAINRITSAN trial (2) were analyzed. Patients were randomized to receive rituximab or azathioprine as maintenance therapy. Relapse was defined as the re-occurrence or new onset of disease attributable to active vasculitis. Accelerated decline renal function (estimated Glomerular Filtration Rate (eGFR) assessed using the MDRD equation) was defined in concordance with NICE 2015 guideline (3) as “a decrease in eGFR of 25% or more and a change in GFR category or a sustained decrease in eGFR of 15 ml/min/1.73m2over 12 months”. Calprotectin was assessed in the serum at inclusion and 6 months by ELISA (IDK® Calprotectin ELISA kit, Immunodiagnostik). We defined an increase in serum levels of calprotectin as a positive variation of calprotectin level at M6 compared to baseline.

Results:

Of all, 96 patients (female 45.8%, mean age 55.3±13.5, 69.8% PR3+, 62.5% ANCA positive at inclusion) had at least a calprotectin dosage (86 at baseline, 86 at M6 and 76 patients at this 2 time-point). Calprotectin level at baseline or 6 months was not significantly different between relapsing patients and those without relapse after 18 months of follow-up, whereas the calprotectin variation at M6 compared to baseline was higher in relapsing patients (n=10) (mean (SD) 17991 (±28972) ng/ml) than in patients not experiencing any relapse (n=66) (9419 (±50002) ng/mL; p=0.03). An increase in serum calprotectin level at 6 months was significantly associated with an increased risk of relapse in PR3-ANCA patients (OR=5.6 (95%CI, 1.0-31.3; p=0,049) but not in the whole study group (OR=3.3 (95%CI, 0.8-14.1; p=0.1), and identified patients with accelerated renal function decline (all cohort: OR=10.6 (95%CI, 2.9-39.6; p=0.002; PR3+ patients: OR=5.909 (95%CI, 2.9-39.6; p=0.01)), whereas calprotectin level did not correlate with glomerular filtration rate (r = -0.07, p=0.35).

Conclusion:

An increase in serum calprotectin during the first 6 months of maintenance therapy in ANCA-associated vasculitides is a useful biomarker predicting vasculitis relapse and accelerated renal function deterioration in the following 12 months.

Increase calprotectin serum at 6 months identify relapser and accelerated decline renal function at 1 year.Kaplan-Meier survival curves of ANCA-associated vasculitis patients with an increase in serum calprotectin at 6 months (solid line) or not (dotted line) remaining total relapse-free or accelerated decline renal function-free. Gehan-Beslow-Wilcoxon test.

References:

[1]Pepper RJ et al. Arthritis Rheumatol. 2017;69(1):185-93.

[2]Guillevin L et al. N Engl J Med. 2014;371(19):1771-80.

[3]NIH. Chronic kidney disease 2014.

Acknowledgments:

Supported by a grant from the Programme Hospitalier de Recherche Clinique, French Ministry of Health (2008-002846-51).

Disclosure of Interests:

Xavier Romand Consultant of: Xavier ROMAND has received honorarium fees from Abbvie, Anais Courtier: None declared, Minh Vu Chuong Nguyen: None declared, Marie-Hélène Paclet: None declared, Philippe Gaudin Speakers bureau: Lilly, Loïc Guillevin: None declared, Benjamin Terrier: None declared, Athan Baillet Consultant of: Athan BAILLET has received honorarium fees from Abbvie for his participation as the coordinator of the systematic literature review

AB0665 VALVULOPATHY, SYSTOLIC AND DIASTOLIC DYSFUNCTION IN AXIAL SPONDYLOARTHRITIS: A SYSTEMATIC REVIEW AND META-ANALYSIS

Background:

Axial Spondyloarthritis (ax-SpA) displays an increased cardiovascular disease (CVD) risk compared with the general population. Although ischemic cardiac manifestations are well known, prevalence of non-ischemic manifestations such as myocardial dysfunction and valvulopathy is less clear.

Objectives:

To compare prevalence of myocardial dysfunction and valvulopathy by ultrasound in ax-SpA patients and versus healthy controls.

Methods:

Two investigators independently searched for studies indexed in PUBMED, Cochrane Library and EMBASE databases and published before January 17th 2020. The search was focused on ultrasound evaluation of myocardial function and valvulopathy, with two-dimensional, Doppler, tissue Doppler, and speckle tracking echocardiography. We included for meta-analysis all controlled studies including ax-SpA without previous cardiovascular disease. Data were pooled using appropriate random or fixed effects model.

Results:

Literature search retrieved of 186 abstracts. A total of 31 papers were included in the systematic review and 27 papers were analyzed in the meta-analysis (1,494 ax-SpA patients and 1,091 healthy controls). Studies displayed cross-sectional design and included ax-SpA without prevalent cardiovascular disease.

Ax-SpA was defined according to the modified New York criteria (24 studies) followed or the ASAS criteria (2 studies). HLA B27+ positivity ranged from 51 to 100%, mean age ranged from 26.7 to 55.7 years, disease duration ranged from 3.2 to 23.3 years and mean BASDAI ranged from 1.24 to 5.6.

Patients with ax-SpA displayed a lower diastolic function with a lower E/A ratio, a higher deceleration time, a higher isovolumetric relaxation time and a lower systolic function with a lower ejection fraction (figure 1). Left-ventricular end diastolic and systolic diameters were higher in ax-SpA patients with respectively mean difference 0.55 mm [CI95%; 0.19, 0.91] and 0.79 mm [CI95%; 0.40, 1.17]. We did not find any difference for left and posterior ventricular thickness, left atrial dimension, and left ventricular mass index.

Figure 1.

Systolic and diastolic dysfunction is slightly altered in ax-SpA patients compared to healthy individuals Diastolic dysfunction was assessed by (A) E/A ratio (m/s), (B) deceleration time (ms), (C) Isovolumetric relaxation time (ms) and (D) systolic function was assessed by ejection fraction (%).

A total of 15 articles reported prevalence of valvulopathy in ax-SpA. Prevalence of mitral regurgitation and aortic regurgitation were similar in ax-SpA patients and healthy individuals: OR=1.13 [CI95% 0.76, 1.68] and OR=1.18 [CI95% 0.68, 2.04].

Conclusion:

Prevalence of valvulopathy was similar in ax-SpA and healthy individuals. Diastolic and systolic function seems to be slightly altered in ax-SpA compared to healthy controls. However, this difference is unlikely clinically relevant. Usefulness of systematic echography remains to be determined in future longitudinal studies.

Disclosure of Interests:

Fanny Adeline: None declared, Xavier Romand Consultant of: Xavier ROMAND has received honorarium fees from Abbvie, Mickael Dalecky Consultant of: Mickael DALECKY has received honorarium fees from Abbvie, Arnaud Pfimlin Consultant of: Arnaud PFIMLIN has received honorarium fees from Abbvie, Daniel Wendling: None declared, Philippe Gaudin Speakers bureau: Lilly, Pascal Claudepierre Speakers bureau: Janssen, Novartis, Lilly, Maxime Dougados Grant/research support from: AbbVie, Eli Lilly, Merck, Novartis, Pfizer and UCB Pharma, Consultant of: AbbVie, Eli Lilly, Merck, Novartis, Pfizer and UCB Pharma, Speakers bureau: AbbVie, Eli Lilly, Merck, Novartis, Pfizer and UCB Pharma, Athan Baillet Consultant of: Athan BAILLET has received honorarium fees from Abbvie for his participation as the coordinator of the systematic literature review

FRI0095 SARILUMAB IMPROVED PATIENT-PERCEIVED IMPACT OF RHEUMATOID ARTHRITIS WHATEVER THE BASELINE DISEASE ACTIVITY: FIRST RESULTS FROM AN INTERVENTIONAL NON CONTROLLED STUDY: SARIPRO, IN MODERATE AND SEVERE RHEUMATOID ARTHRITIS PATIENTS

Background:

Sarilumab, an anti-IL-6R antibody, is approved for the treatment of moderate to severe RA and shown efficacy on disease activity and patient-reported outcomes (PROs). Detailed analyses of drug efficacy from the patient point of view is important. SariPRO is a pragmatic interventional study close to the daily practice.

Objectives:

To assess the effectiveness of sarilumab on several PROs using the RAID (Rheumatoid Arthritis Impact of Disease) score.

Methods:

The SariPRO study (NCT 03449758) was a French multicenter interventional study assessing the effects of sarilumab 200 mg on PROs in patients with moderately to severely active RA with an inadequate response or intolerance to conventional synthetic or biologic DMARDs. The primary endpoint was change in total RAID score from baseline to week 24 (RAID ranges 0-10 where 10 is maximal impact). Changes from baseline for RAID, DAS28-ESR and CDAI according to baseline disease activity were analyzed as secondary outcomes. Safety was assessed by monitoring adverse events (AE). All statistical analyses were descriptive, 95% CI was given when appropriate.

Results:

84 patients were included in 31 centers and 62 were evaluable and analyzed for effectiveness. They had similar characteristics to the 84 patients at baseline and were as expected for an RA population initiating a biologic: mean (SD) age: 59.9 (12.4) years, 71.0% female, disease duration 9.7 (10.3) years, rheumatoid factor positivity 82.5%, ACPA positivity 86.4%, and DAS28=4.9 (11). Total RAID score decreased significantly from 5.7 (2.0) at baseline to 3.3 (2.5) at W24; mean change was -2.4 [95% CI: -3.0; -1.8]. Furthermore, this improvement was noted both for highly and less active patients at baseline: for patients with DAS28-ESR < 5.1 (n=31), mean change was -1.56 [-2.28; -0.83] and for patients with DAS28-ESR≥5.1 (n=27), mean change was -1.98 [-2.91; -1.05]. Changes in DAS28-ESR and CDAI were significant (-2.8 [-3.2; -2.4] and -15.2 [-18.5; -11.8], respectively). AEs were consistent with the safety profile of anti-IL-6R antibodies and with results from RCTs (data not shown).

Conclusion:

In this real world study, treatment with sarilumab during 24 weeks in RA patients led to an improvement in the total RAID score irrespective of baseline levels of disease activity. This is the first time RAID score is used as the primary endpoint in a study.

References:

[1]Study was sponsored by Sanofi Genzyme

Disclosure of Interests:

Laure Gossec Grant/research support from: Lilly, Mylan, Pfizer, Sandoz, Consultant of: AbbVie, Amgen, Biogen, Celgene, Janssen, Lilly, Novartis, Pfizer, Sandoz, Sanofi-Aventis, UCB, René-Marc Flipo Consultant of: Johnson and Johnson, MSD France, Novartis, Sanofi, Speakers bureau: Johnson and Johnson, MSD France, Novartis, Sanofi, Thierry Schaeverbeke: None declared, Christine Albert: None declared, Athan Baillet Consultant of: Athan BAILLET has received honorarium fees from Abbvie for his participation as the coordinator of the systematic literature review, marie-Christophe Boissier: None declared, Cyrille Confavreux: None declared, Gregoire CORMIER: None declared, Emmanuelle Dernis Speakers bureau: Lilly, Novartis, Elisabeth Gervais Solau: None declared, Sophie Godot: None declared, Jacques-Eric Gottenberg Grant/research support from: BMS, Pfizer, Consultant of: BMS, Sanofi-Genzyme, UCB, Speakers bureau: Abbvie, Eli Lilly and Co., Roche, Sanofi-Genzyme, UCB, Philippe Goupille Grant/research support from: AbbVie, Amgen, Biogen, BMS, Celgene, Chugai, Lilly, Janssen, Medac, MSD France, Nordic Pharma, Novartis, Pfizer, Sanofi and UCB, Consultant of: AbbVie, Amgen, Biogen, BMS, Celgene, Chugai, Lilly, Janssen, Medac, MSD France, Nordic Pharma, Novartis, Pfizer, Sanofi and UCB, Speakers bureau: AbbVie, Amgen, Biogen, BMS, Celgene, Chugai, Lilly, Janssen, Medac, MSD France, Nordic Pharma, Novartis, Pfizer, Sanofi and UCB, Slim Lassoued: None declared, Thierry Lequerre: None declared, Frederic Lioté Consultant of: CME: Nordic Pharma, Christian Marcelli: None declared, Yves Maugars: None declared, Minh Nguyen: None declared, Aleth Perdriger: None declared, Yves-Marie Pers: None declared, Edouard Pertuiset: None declared, Lucile Poiroux: None declared, Carole Rosenberg: None declared, Christian Roux: None declared, Adeline Ruyssen-Witrand Grant/research support from: Abbvie, Pfizer, Consultant of: Abbvie, BMS, Lilly, Mylan, Novartis, Pfizer, Sandoz, Sanofi-Genzyme, Martin SOUBRIER: None declared, Pascale Vergne-Salle: None declared, Charles Zarnitsky: None declared, Eric Fakra Consultant of: Janssen, Lundbeck, Otsuka, Sanofi, Hubert MAROTTE Grant/research support from: Bristol Myers Sqibb, Lilly France, MSD, Novartis, Nordic Pharma, Pfizer, SanofiAventis, Consultant of: AbbVie, Amgen, Bristol Myers Sqibb, Lilly France, MSD, Novartis, Nordic Pharma, Pfizer, SanofiAventis, Paid instructor for: Sanofi-Aventis, Speakers bureau: Sanofi-Aventis, Florence E Lévy-Weil Employee of: Sanofi Genzyme employee

Moderate alcohol consumption is associated with increased radiological progression in women, but not in men, with early rheumatoid arthritis: results from the ESPOIR cohort (Étude et Suivi des Polyarthrites Indifférenciées Récentes)

OBJECTIVE

We conducted this study to determine whether alcohol consumption influences radiological progression in early rheumatoid arthritis (RA).

METHOD

Patients fulfilling the European League Against Rheumatism/American College of Rheumatology 2010 criteria in the early arthritis cohort ESPOIR (Étude et Suivi des Polyarthrites Indifférenciées Récentes) were included in this study. Alcohol consumption was collected at baseline and at each visit. We classified alcohol consumption into three groups: abstinent (0 g/day), moderate (≤ 20 g/day for women, ≤ 30 g/day for men), and abuse (> 20 g/day for women, > 30 g/day for men). The primary outcome was the occurrence of radiological progression, defined as an increase ≥ 5 points in the total Sharp/van der Heijde score. We investigated whether alcohol consumption is predictive of radiological progression at 1, 3, and 5 years by univariate and multivariate analysis adjusted for age, baseline erosion, rheumatoid factor, anti-citrullinated peptide antibody, smoking status, body mass index, and treatment with leflunomide or methotrexate and biologics.

RESULTS

The study included 596 patients. When considering the influence of gender on the interaction between alcohol consumption and radiological progression, we showed a deleterious effect of moderate consumption in women [odds ratio (OR) = 1.73, 95% confidence interval (CI) 1.01; 2.96, p = 0.045] and a trend towards a protective effect of moderate consumption in men (OR = 0.50, 95% CI 0.21; 1.16, p = 0.106) in multivariate analysis.

CONCLUSION

Our data suggest a deleterious effect of moderate consumption of alcohol on radiological progression in women, but not in men, with early RA.

Cancer-Related Functions and Subcellular Localizations of Septins

Since the initial discovery of septin family GTPases, the understanding of their molecular organization and cellular roles keeps being refined. Septins have been involved in many physiological processes and the misregulation of specific septin gene expression has been implicated in diverse human pathologies, including neurological disorders and cancer. In this minireview, we focus on the importance of the subunit composition and subcellular localization of septins relevant to tumor initiation, progression, and metastasis. We especially underline the importance of septin polymer composition and of their association with the plasma membrane, actin, or microtubules in cell functions involved in cancer and in resistance to cancer therapies. Through their scaffolding role, their function in membrane compartmentalization or through their protective function against protein degradation, septins also emerge as critical organizers of membrane-associated proteins and of signaling pathways implicated in cancer-associated angiogenesis, apoptosis, polarity, migration, proliferation, and in metastasis. Also, the question as to which of the free monomers, hetero-oligomers, or filaments is the functional form of mammalian septins is raised and the control over their spatial and temporal localization is discussed. The increasing amount of crosstalks identified between septins and cellular signaling mediators reinforces the exciting possibility that septins could be new targets in anti-cancer therapies or in therapeutic strategies to limit drug resistance.

ANSO study: evaluation in an indoor environment of a mobile assistance robotic grasping arm

OBJECTIVE

To evaluate the reliability and functional acceptability of the ‘‘Synthetic Autonomous Majordomo’’ (SAM) robotic aid system (a mobile Neobotix base equipped with a semi-automatic vision interface and a Manus robotic arm).

MATERIALS AND METHODS

An open, multicentre, controlled study. We included 29 tetraplegic patients (23 patients with spinal cord injuries, 3 with locked-in syndrome and 4 with other disorders; mean SD age: 37.83 13.3) and 34 control participants (mean SD age: 32.44 11.2). The reliability of the user interface was evaluated in three multi-step scenarios: selection of the room in which the object to be retrieved was located (in the presence or absence of visual control by the user), selection of the object to be retrieved, the grasping of the object itself and the robot’s return to the user with the object. A questionnaire was used to assess the robot’s user acceptability.

RESULTS

The SAM system was stable and reliable: both patients and control participants experienced few failures when completing the various stages of the scenarios. The graphic interface was effective for selecting and grasping the object – even in the absence of visual control. Users and carers were generally satisfied with SAM, although only a quarter of patients said that they would consider using the robot in their activities of daily living.

Reactive oxygen species, AMP-activated protein kinase, and the transcription cofactor p300 regulate α-tubulin acetyltransferase-1 (αTAT-1/MEC-17)-dependent microtubule hyperacetylation during cell stress

Beyond its presence in stable microtubules, tubulin acetylation can be boosted after UV exposure or after nutrient deprivation, but the mechanisms of microtubule hyperacetylation are still unknown. In this study, we show that this hyperacetylation is a common response to several cellular stresses that involves the stimulation of the major tubulin acetyltransferase MEC-17. We also demonstrate that the acetyltransferase p300 negatively regulates MEC-17 expression and is sequestered on microtubules upon stress. We further show that reactive oxygen species of mitochondrial origin are required for microtubule hyperacetylation by activating the AMP kinase, which in turn mediates MEC-17 phosphorylation upon stress. Finally, we show that preventing microtubule hyperacetylation by knocking down MEC-17 affects cell survival under stress conditions and starvation-induced autophagy, thereby pointing out the importance of this rapid modification as a broad cell response to stress.

Incorporation of triterpenic derivatives within an o/w/o multiple emulsion: structure and release studies

Triterpenic derivatives stimulate the total collagen synthesis of skin fibroblasts. Their incorporation within an o/ w/o multiple emulsion should protect them against oxidation, particularly for unsaturated derivatives and should lead to a modulated release after topical application. The influence of the incorporation of madecassic acid, asiaticoside and asiatic acid on the viscosity and the stability of a multiple o/w/o emulsion was studied. Rheological analyses were carried out by flow experiments in order to obtain the apparent viscosity and by the oscillatory technique to calculate the basic visceolastic parameters. The comparative stability study was assessed by the tracer release method with phthalic acid diethyl ester previously incorporated in the internal phase of the emulsions. Six months storage at room temperature and at 40 degrees C did not affect the stability of emulsions with triterpenic substances. The in vitro percutaneous absorption of triterpenic derivatives was investigated by Franz diffusion cells in hairless rats. Triterpenic derivatives were analysed in stratum corneum, epidermis and dermis, by liquid chromatography. Correlations were established between the triterpenic derivatives structure (glycosylated or not) and their percutaneous absorption. O/w/o multiple emulsion seems to be an efficient vehicle to preserve these active substances and to control their distribution in the skin.

Modulation of septin and molecular motor recruitment in the microtubule environment of the Taxol-resistant human breast cancer cell line MDA-MB-231

Cell resistance to low doses of paclitaxel (Taxol) involves a modulation of microtubule (MT) dynamics. We applied a proteomic approach based on 2-DE coupled with MS to identify changes in the MT environment of Taxol-resistant breast cancer cells. Having established a proteomic pattern of the microtubular proteins extracted from MDA-MB-231 cells, we verified by Western blotting that in resistant cells, α- and β-tubulins (more specifically the βIII and βIV isotypes) increased. Interestingly, four septins (SEPT2, 8, 9 and 11), which are GTPases involved in cytokinesis and in MT/actin cytoskeleton organization, were overexpressed and enriched in the MT environment of Taxol-resistant cells compared to their sensitive counterpart. Changes in the MT proteome of resistant cells also comprised increased kinesin-1 heavy chain expression and recruitment on MTs while dynein light chain-1 was downregulated. Modulation of motor protein recruitment around MTs might reflect their important role in controlling MT dynamics via the organization of signaling pathways. The identification of proteins previously unknown to be linked to taxane-resistance could also be valuable to identify new biological markers of resistance.

[Management of nasolabial clefts: the issue in Dakar]

The management of patients with a cleft lip in developing countries is often the prerogative of humanitarian missions from developed countries. The goal of our work is to conduct a first epidemiological, clinical and therapeutic assessment of the management of cleft lips by a local team and to evidence the difficulties faced by us in our working conditions. In a retrospective study covering a period of about five years (January 2004 to March 2009), 205 cases of nasolabial clefts are assembled. The mean age at the time of the first visit is 17 months. A slight female predominance is observed. The majority of patients are from the capital city. A close relative with a cleft is found in 6.8% of them. In 44.9% of cases, it is a simple cleft lip. A cleft palate is associated in 47.8% of cases. Associated malformations are observed in 10.5% of cases. We operated on 110 patients. The mean age at the first surgery is two years. Millard's technique is our technique of choice. No operative mortality is observed. In 17.4% of cases, operative morbidity occurred in the form of suppuration with partial or complete early suture release. The esthetic result is satisfactory in 67.7% of cases. This management could be improved by creating a multidisciplinary team including--in addition to surgeons--dentists, speech-language pathologists, psychologists, etc.

The ins and outs of tubulin acetylation: more than just a post-translational modification?

Microtubules are highly dynamic polymers of α/β tubulin heterodimers that play key roles in cell division and in organizing cell cytoplasm. Although they have been discovered more than two decades ago, tubulin post-translational modifications recently gained a new interest as their role was increasingly highlighted in neuron differentiation and neurodegenerative disorders. Here, we specifically focus on tubulin acetylation from its discovery to recent studies that provide new insights into how it is regulated in health and disease and how it impacts microtubule functions. Even though new mechanisms involving tubulin acetylation are regularly being uncovered, the molecular links between its location inside the microtubule lumen and its regulators and effectors is still poorly understood. This review highlights the emerging roles of tubulin acetylation in multiple cellular functions, ranging from cell motility, cell cycle progression or cell differentiation to intracellular trafficking and signalling. It also points out that tubulin acetylation should no longer be seen as a passive marker of microtubule stability, but as a broad regulator of microtubule functions.

[S100A8, S100A9 and S100A12 proteins in rheumatoid arthritis]

Although S100 proteins represent 40% of the neutrophil cytoplasmic proteins, their physiological and pathological functions are still unclear. S100A8, S100A9 and S100A12 protein concentrations are dramatically enhanced in synovial fluid and synovium of patients suffering from rheumatoid arthritis. Their expression seems to correlate with disease activity and joint damage. These proteins are likely involved in rheumatoid arthritis pathogenesis by enhancing extracellular matrix proteolysis, autoimmunity and inducing the pseudotumoral phenotype of the synoviocytes in rheumatoid arthritis. S100A8, S100A9 and S100A12 assessment will probably constitute a relevant tool for rheumatoid arthritis diagnosis and will improve inflammatory arthritides management.

Basal endothelial nitric oxide synthase (eNOS) phosphorylation on Ser(1177) occurs in a stable microtubule- and tubulin acetylation-dependent manner

To better understand the relationship between the subcellular compartmentalization of endothelial nitric oxide synthase (eNOS) and its function in endothelial cells, we addressed the roles of the microtubule network and of its dynamics in organizing Golgi-bound eNOS. We found that part of Golgi-bound eNOS localizes to the trans-Golgi network and/or to trans-Golgi network-derived vesicles and membrane tubules that are organized preferentially by stable microtubules. Also, while most of cellular eNOS was recovered in a detergent-resistant microtubule-enriched subcellular fraction, its recovery was impaired after total microtubule disassembly, but not after selective disassembly of dynamic microtubules or after microtubule stabilization. Basal eNOS phosphorylation on Ser(1177) further required the association of the trans-Golgi network to stable microtubules and was enhanced by microtubule stabilization. We finally show that the involvement of stable microtubules in basal eNOS phosphorylation involved alpha-tubulin acetylation. Microtubule-dependent organization of subcellular eNOS and control over its phosphorylation would thus be essential for endothelial cells to maintain their basal eNOS function.

Tubulin acetylation favors Hsp90 recruitment to microtubules and stimulates the signaling function of the Hsp90 clients Akt/PKB and p53

Involved in a wide range of cellular processes such as signal transduction, microtubules are highly dynamic polymers that accumulate various post-translational modifications including polyglutamylation, polyglycylation, carboxyterminal cleavage and acetylation, the functions of which just begin to be uncovered. The molecular chaperone Hsp90, which is essential for the folding and activity of numerous client proteins involved in cell proliferation and apoptosis, associates with the microtubule network but the effects of tubulin post-translational modifications on its microtubule binding has not yet been investigated. Herein, we show that both the constitutive (beta) and the inducible (alpha) Hsp90 isoforms bind to microtubules in a way that depends on the level of tubulin acetylation. Tubulin acetylation also stimulates the binding and the signaling function of at least two of its client proteins, the kinase Akt/PKB and the transcription factor p53. This study highlights the role of tubulin acetylation in modulating microtubule-based transport of Hsp90-chaperoned proteins and thus in regulating signaling dynamics in the cytoplasm.

Apolipoprotein A-I and platelet factor 4 are biomarkers for infliximab response in rheumatoid arthritis

OBJECTIVES

The use of biologicals such as infliximab has dramatically improved the treatment of rheumatoid arthritis (RA). However, factors predictive of therapeutic response need to be identified. A proteomic study was performed prior to infliximab therapy to identify a panel of candidate protein biomarkers of RA predictive of treatment response.

METHODS

Plasma profiles of 60 patients with RA (28 non-responders (as defined by the American College of Rheumatology 20% improvement criteria (ACR20)) negative and 32 responders (ACR70 positive) to infliximab) were studied by surface enhanced laser desorption/ionisation time-of-flight mass spectrometry (SELDI-TOF MS) technology on two types of arrays, an anion exchange array (SAX2) and a nickel affinity array (IMAC3-Ni). Biomarker characterisation was carried out using classical biochemical methods (purification by ammonium sulfate precipitation or metal affinity chromatography) and identification by matrix assisted laser desorption/ionisation time-of-flight (MALDI-TOF) MS analysis.

RESULTS

Two distinct protein profiles were observed on both arrays and several proteins were differentially expressed in both patient populations. Five proteins at 3.86, 7.77, 7.97, 8.14 and 74.07 kDa were overexpressed in the non-responder group, whereas one at 28 kDa was increased in the responder population (sensitivity>56%, specificity>77.5%). Moreover, combination of several biomarkers improved the sensitivity and specificity of the detection of patient response to over 97%. The 28 kDa protein was characterised as apolipoprotein A-I and the 7.77 kDa biomarker was identified as platelet factor 4.

CONCLUSIONS

Six plasma biomarkers are characterised, enabling the detection of patient response to infliximab with high sensitivity and specificity. Apolipoprotein A-1 was predictive of a good response to infliximab, whereas platelet factor 4 was associated with non-responders.

Role of ceramide structure and its microenvironment on the conformational order of model stratum corneum lipids mixtures: an approach by FTIR spectroscopy

The aim of this study is to investigate the influence of ceramide head group architecture and free fatty acid (another main class of stratum corneum lipids) or protein (keratin), on the lamellar organization of the ceramide auto-associated in model films mimicking lipid organization within the stratum corneum. FTIR spectroscopy is a powerful technique for investigating the structure of such systems. This technique has already been used to characterize phase transitions of the SC and of related model systems. As temperature is known to modify the conformational order of lipids, we used it as a variable parameter to monitor the differences in the conformational stability of ceramides. Our study included four ceramides: ceramide 2, 3, 5 and 6 which differ by their head group architecture. Two kinds of lipid-lipid interactions were studied: non-polar and polar. We noted some structural factors which participated to the organizational behavior: insaturation of alkyl chain, alpha-hydroxyl on fatty acid moiety and sphingosine or phytosphingosine head group. There is a direct interaction of palmitic acid on alkyl chains organization and a weak interaction with polar head group in presence of keratin, both provoking a destabilization of the ceramidic orthorhombic organization.

Liquid chromatography on porous graphitic carbon with atmospheric pressure photoionization mass spectrometry and tandem mass spectrometry for the analysis of glycosphingolipids

The study of several structural variations (the length, the degree of unsaturation and hydroxylation of the alkyl chains, the number and nature of osidic residues) helped understand the behaviour of neutral glycosphingolipids (GSLs) on porous graphitic carbon stationary phase (PGC). Atmospheric pressure photoionization mass spectrometry (APPI) and tandem mass spectrometry were used to perform the detection and the identification of molecular species in positive mode where [M+H](+) and [M-H(2)O+H](+) ions provided structural information on the fatty acid and the sphingoid base. The retention of GSLs increased with the hydrocarboneous volume of their alkyl chains and with the number of osidic residues in agreement with hydrophobic properties and polar retention effect of graphite, respectively. The presence of polar groups, such as OH-group or double bond within alkyl chains, decreased their retention. The coupling of chromatography on PGC with APPI tandem mass spectrometry detection appeared a powerful technique to discriminate isobaric molecules. Isobaric solutes differing by the position of two double bonds or by the repartition of hydrocarboneous skeleton were discriminated according to their chromatographic comportment or their mass spectrum, respectively. Among isobaric molecules, only few structures differing by the nature of osidic residue were not discriminated (i.e. glucosylceramide and galactosylceramide with similar ceramide skeleton were co-eluted and no difference in mass spectra was observed).

Fluorescence probe assisted post-column detection for lipid analysis in microbore-LC

A general approach, still few exploited so far and never associated with microbore-LC, consisting of detection of various lipid classes (i.e. phospholipids, triglycerides, ceramides and glycosphingolipids) by non-covalent association with 1,6-diphenyl-1,3,5-hexatriene (DPH) fluorescence probe is developed. This mode of detection was coupled with non-aqueous reversed-phase microbore-LC (C18) by using classical post-column fluorescence detection. The classical LC system was first adapted to microbore-chromatography (internal diameter 1 mm) without apparatus miniaturization of the solvent delivery system and the detection cell. For this purpose, the detection parameters (probe concentration, post-column flow rate, post-column reactor length and post-column system temperature) were optimized by a central composite design (CCD) using a mixture of phosphatidylcholine (PC) species as a lipid model and DPH (lambda(ex) = 350 nm, lambda(em) = 430 nm) as a fluorescence probe. The optimal conditions of detection for the various molecular species of PC were determined for a DPH concentration of 3.35 micromol/L, a post-column flow rate of 0.5 mL/min, a reactor length of 1.4 m and a temperature of 35 degrees C. The fluorescence response was linear over a wide range of PC species from 5 microg/mL to 100 microg/mL and the lower limit of detection (signal/noise = 3) was about 1 microg/mL, that is equivalent to evaporative light scattering detection (ELSD). Others molecular species of various classes of lipids, i.e. triglycerides, ceramides and glycosphingolipids were also easily detected. Thus, this study demonstrated the versatility of the proposed system of detection which was shown to be sensitive, easy to perform, non-destructive and allowed, in contrast to ELSD, for a linear response with various polarity lipid classes.

ATR-FTIR spectroscopy: a chemometric approach for studying the lipid organisation of the stratum corneum

The barrier function of skin resides in the lipid components of the stratum corneum, particularly their spatial organisation. FTIR spectroscopy has already been used as a relevant tool to study this lipid organisation: IR vibration band shifts have been attributed to the variations in lipid organisation induced by temperature. Our study included a stratum corneum model, composed of the three main lipids: palmitic acid as an example of fatty acids, cholesterol and ceramide III as an example of ceramide. Different films with various ratios of these lipids were studied. In our analytical strategy, the interest of using a chemometric analysis of global data obtained from ATR-FTIR spectra to highlight the main interactions involved in the molecular organisation of lipids has been demonstrated. Two kinds of interaction between the three main lipids have been shown: a non polar interaction between the long hydrocarbon chains and a polar interaction as the hydrogen bonding between polar functional groups. By varying the lipid ratio, we have shown first that the relative importance of each interaction was modified, second, that the induced modification of organisation can be detected by chemometric analysis of the ATR-FTIR spectra. The role of each kind of lipid in the organisation has been discussed. In conclusion, associating the ATR-FTIR with chemometric treatment is a promising tool: firstly, to understand the consequence of lipid relative compositions on the structural organisation of the stratum corneum, secondly, to show the relationship between lipid organisation and percutaneous penetration data. Indeed, this methodology will be transposed to in vivo studies with IR measurements through a probe.

Optimisation of the separation of four major neutral glycosphingolipids: application to a rapid and simple detection of urinary globotriaosylceramide in Fabry disease

A simple method for the separation of the four major neutral glycosphingolipids, present in all human tissue, was developed. This gradient normal phase-HPLC method utilises a polyvinyl alcohol bonded stationary phase and an evaporative light-scattering detection (ELSD). Screening pure solvents in a binary gradient elution mode allowed, in a first step, to assess the behaviour of the studied solutes and to select the solvents for further mobile phase optimisation. The proportion of the remaining solvents was defined to reach a maximal resolution. The reduction of the analysis time and the enhancement of the signal were obtained by optimising the gradient slope and the flow-rate. Optimal levels of triethylamine and formic acid (TEA-FA) for the enhancement of the evaporative light scattering detector response were established at 0.1% (v/v). Thus, the optimal conditions for the separation of the four glycosphingolipids was obtained with a gradient elution from a 100% chloroform to a 100% acetone:methanol (90:10 (v/v)) mobile phase at 0.2 ml min-1, using a 10% min-1 gradient slope. Finally, this method was applied to detect the excess of one of the neutral sphingolipids, namely globotriaosylceramide (Gb3) in the urine of patients affected with Fabry disease. A liquid-liquid extraction of the sediments obtained from an aliquot of only ten ml of urine proved sufficient to detect the excess of Gb3 present in both hemizygote and heterozygote patients. In all, the ability of our method to detect abnormal amounts of Gb3 in urinary sediments could allow the diagnosis of weakly symptomatic Fabry patients in large screening programs

Peroxisome proliferator-activated receptor alpha physically interacts with CCAAT/enhancer binding protein (C/EBPbeta) to inhibit C/EBPbeta-responsive alpha1-acid glycoprotein gene expression

Recently, the role of the peroxisome proliferator-activated receptor alpha (PPARalpha) in the hepatic inflammatory response has been associated to the decrease of acute phase protein transcription, although the molecular mechanisms are still to be elucidated. Here, we were interested in the regulation by Wy-14643 (PPARalpha agonist) of alpha1-acid glycoprotein (AGP), a positive acute phase protein, after stimulation by Dexamethasone (Dex), a major modulator of the inflammatory response. In cultured rat hepatocytes, we demonstrate that PPARalpha inhibits at the transcriptional level the Dex-induced AGP gene expression. PPARalpha exerts this inhibitory effect by antagonizing the CCAAT/enhancer binding protein (C/EBPbeta) transcription factor that is involved in Dex-dependent up-regulation of AGP gene expression. Overexpression of C/EBPbeta alleviates the repressive effect of PPARalpha, thus restoring the Dex-stimulated AGP promoter activity. Furthermore, glutathione-S-transferase GST pull-down and coimmunoprecipitation experiments evidenced, for the first time, a physical interaction between PPARalpha and the C-terminal DNA binding region of C/EBPbeta, thus preventing it from binding to specific sequence elements of the AGP promoter. Altogether, these results provide an additional molecular mechanism of negative regulation of acute phase protein gene expression by sequestration of the C/EBPbeta transcription factor by PPARalpha and reveal the high potency of the latter in controlling inflammation.

Retinoids increase alpha-1 acid glycoprotein expression at the transcriptional level through two distinct DR1 retinoic acid responsive elements

In the present study, we analyzed the influence of retinoic acids on the expression of alpha-1 acid glycoprotein (AGP). We show that in rat primary hepatocytes, 9-cis retinoic acid and all-trans retinoic acid increase AGP gene expression at the transcriptional level. Transient transfections of rat primary hepatocytes with a reporter construct driven by the rat AGP gene promoter indicated that retinoids regulate AGP gene expression via the -763/-138 region of the AGP promoter. Furthermore, cotransfection experiments with retinoic acid receptor alpha (RARalpha) and retinoid X receptor alpha (RXRalpha) expression vectors in NIH3T3 cells demonstrated that both RXRalpha/RXRalpha homodimer and RXRalpha/RARalpha heterodimer are competent for ligand-induced transactivation of the AGP promoter. Unilateral deletion and site-directed mutagenesis identified two retinoic-acid responsive elements (RARE), RARE-I and RARE-II, which interestingly correspond to a direct repeat of two TGACCT-related hexanucleotides separated by a single bp only (DR1-type response element). Cotransfection assays showed that RXRalpha and RARalpha activate AGP gene transcription through these two elements either as a homodimer (RXRalpha/RXRalpha) or as a heterodimer (RXRalpha/RARalpha). The RXRalpha/RXRalpha homodimer acts most efficiently through the RARE-I response element to promote AGP transactivation, whereas the RXRalpha/RARalpha heterodimer mediates transactivation better via the RARE-II responsive element.

The benefit of the retrofitting of a conventional LC system to micro LC: a practical evaluation in the field of bioanalysis with fluorimetric detection

The interests in liquid micro-chromatography (higher column efficiencies, increase in sensitivity) are now well established. The enhancement of fluorimetric response induced by the reduction of the inner diameter of columns (4.6, 3.0, 1.0 and 0.3 mm respectively) coupled with adapted detection cells to control the loss of efficiency (8 micro L for the two first columns and 100 nL for the two smaller ones) has been studied in the bioanalytical field, using the plasma determination of native fluorescent antibacterial agents: fluoroquinolones. Ten-fold enhancement of the signal can easily be obtained when substituting a 0.3 mm i.d. column and 100 nL detection cell for a 4.6 mm i.d. column, and 8 micro L detection cell. In addition to inner diameter reduction, the detection cell geometry appears to be an essential parameter to obtain the best enhancement of the recorded signal. Hence, the enhancement of signal with micro-chromatography with fluorimetric detection appears to be a compromise between column inner diameter and flow cell volume reduction.

Assessment of the retention properties of poly(vinyl alcohol) stationary phase for lipid class profiling in liquid chromatography

Potentialities of polymerized vinyl alcohol on silica gel were assessed for class separation of simple lipids, sphingolipids, glyceroglycolipids and phospholipids by high-performance liquid chromatography. A screening of pure solvents in binary gradient elution and a chemometric approach was used to define a rugged two segment linear gradient formed from four solvents for total lipid class separation. Triethylamine and formic acid were added in all mobile phase components for acidic phospholipid separation and evaporative light scattering response enhancement. Simple analytical procedures are described for the analysis of complex lipid materials.

Structural analysis of commercial ceramides by gas chromatography-mass spectrometry

A simple method using gas chromatography-mass spectrometry was applied to analyse structures of ceramides. Identification of trimethylsilylated ceramides were obtained in short analysis times (derivatization of ceramides in 30 min at room temperature and 20 min gas chromatography mass spectrometry run) even for complex mixtures. For example in ceramide Type III, 18 peaks were observed which represent 27 various structures. The coeluted compounds were ceramides containing the same functional groups and the same carbon number but with a different distribution on the two alkyl chains of the molecule. They were accurately differentiated by mass spectrometry. Therefore, 83 structures of trimethylsilylated ceramides were identified in 11 different commercial mixtures. For 52 structures of these, mass spectral data were not described in the literature, neither full mass spectra nor characteristic fragments.

Retention behaviour of ceramides in sub-critical fluid chromatography in comparison with non-aqueous reversed-phase liquid chromatography

This study was devoted to the development of an analytical method for ceramide analysis in packed subcritical fluid chromatography (pSubFC). Monofunctional grafted silica support was found to be more suitable for ceramide analysis. Five Kromasil columns were coupled and the parameters, temperature, pressure and percentage of organic modifier in CO2 were optimised, considering selectivity and analysis time. The final conditions were 31 degrees C, 6% of methanol (MeOH) and 13 MPa. In these conditions the selectivity for structural differences (methylene group, unsaturation or two different bases) were studied. As classically observed, the methylene selectivity decreased with the increase of the eluotropic strength. Moreover, unlike in non-aqueous reversed-phase liquid chromatography (NARP-LC), adding a further unsaturation and two further methylene groups on ceramide results to an increase of retention in pSubFC. Moreover, this last technique allowed to separate ceramides with the same total number of carbons containing unsaturated fatty acids, when the distribution of carbon number of the two chain is very different. These results had enabled to plot retention chart in order to predict ceramide structure in view to identify additional ceramide. This retention chart was finally compared with the one already obtained in NARP-LC.

Modulated release of triterpenic compounds from a O/W/O multiple emulsion formulated with dimethicones: infrared spectrophotometric and differential calorimetric approaches

From the use of silicones within O/W/O multiple emulsions, we can expect, two principal advantages: (1) the silicones with the lowest molecular weight decrease the oily touch; (2) due to the large range of viscosity, this excipient should influence the skin distribution of actives after topical application. The purpose of our work is to highlight these advantages. Multiple emulsions were formulated with several dimethicones and with drug model. Firstly, the effects of different dimethicones incorporated within multiple emulsions were studied, through in vitro penetration results. Secondly, we investigated the residual film on the skin by Differential Scanning Calorimetry (DSC) and by Fourier Transform Infrared (FTIR) to determine its structure. Correlations were established between the silicone structure and the distribution of drugs in different skin levels or between the silicone structure and the percutaneous penetration. The incorporation of silicones within O/W/O multiple emulsions seems to be an efficient means of modulating the penetration and the distribution of drugs in the skin.

Quantitative HPLC analysis of sunscreens and caffeine during in vitro percutaneous penetration studies

This report describes rapid analytical HPLC for the quantification of five UV filters (octyl methoxycinnamate, benzophenone-3, benzophenone-4, octyl triazone and octocrylene) and of caffeine in various skin layers (stratum corneum, dermis, epidermis and receptor fluid) and in cosmetic preparations. The predominant purpose of the study was to establish standard operating procedures for rapid analysis of the compounds in various skin samples. Particular attention was paid to the preparation of biological samples whose natural constitution could interfere with the quantitative analysis. Our methods used the isocratic chromatographic mode in an RP-HPLC with UV detection and did not involve centrifugation or evaporation. Our results were validated in terms of specificity, linearity, precision, accuracy and limits of detection and quantification. The first results, obtained after in vitro experiments, are presented in this report.