Predicting Response to Immunotargeted Therapy in Endometrial Cancer via Tumor Immune Microenvironment: A Multicenter, Observational Study

Only one-third of patients with advanced MSS/pMMR endometrial cancer exhibit a lasting response to the combination treatment of Pembrolizumab and Lenvatinib. The combined administration of these two drugs is based on Lenvatinib's ability to modulate the tumor microenvironment, enabling Pembrolizumab to exert its effect. These findings underscore the importance of exploring tumor microenvironment parameters to identify markers that can accurately select candidates for this type of therapy. An open non-randomized observational association study was conducted at six clinical centers, involving a total of 28 patients with advanced MSS/pMMR endometrial cancer who received Pembrolizumab and Lenvatinib therapy. Using TSA-associated multiplex immunofluorescence, we analyzed the proportion of CD8+ T lymphocytes, CD20+ B lymphocytes, FoxP3+ T regulatory lymphocytes, and CD163+ macrophages in tumor samples prior to immunotargeted therapy. The percentage of CD20+ B lymphocytes and the CD8-to-CD20 lymphocytes ratio was significantly higher in patients who responded to treatment compared to non-responders (responders vs. non-responders: 0.24 (0.1-1.24)% vs. 0.08 (0.00-0.15)%, p = 0.0114; 1.44 (0.58-2.70) arb. unit vs. 19.00 (3.80-34.78) arb. unit, p = 0.0031). The sensitivity and specificity of these biomarkers were 85.71% and 70.59%, and 85.71% and 85.71%, respectively. The proportion of CD20+ B lymphocytes and the CD8-to-CD20 lymphocytes ratio in the stroma of endometrial cancer serves as both a prognostic marker of response to immunotargeted therapy and a prognostic factor for progression-free survival in patients.

Recurrent meningitis caused by Salmonella enterica Paratyphi B var. Java in a 3-month-old infant complicated by dilation of subarachnoid spaces, subdural effusion and right-sided hemiparesis

A 3-month-old female infant with meningo-encephalitis caused by Salmonella enterica Paratyphi B var. Java is described. The aetiological agent was confirmed in six CSF samples; however, none of the blood or faecal samples was positive for the same pathogen. The presence of the bacteria was confirmed in the CSF by culture, serology and Multiplex PCR assay. The infant developed dilated subarachnoid spaces and right-sided hemiparesis associated with the persistent bacterial meningo-encephalitis. She was re-admitted 2 weeks after recovery and initial discharge from hospital owing to recurrence of S. enterica Paratyphi B bacteria in the CSF and the development of large bilateral subdural effusions in the brain. Computed tomography and the clinical course confirmed dynamically progressive meningo-encephalitis. Following further parenteral antibiotics and symptomatic treatment, the child's condition improved. After a total of 24 days in the PICU, she was sufficiently improved to be discharged with a residual right-sided hemiparesis. However, sadly she died a week after discharge.Abbreviation: ALT: alanine aminotransferase; API: analytical profile index 20 E-test; AST: aspartate aminotransferase; CRP: C-reactive protein; CSF: cerebrospinal fluid; CT: computed tomography; EUCAST: European Committee on Antimicrobial Susceptibility Testing; MDCT: multi-detector computed tomography; PCR: polymerase chain reaction; PICU: paediatric intensive care unit; RBC: red blood cells; VITEK: automated instrument for identification/antimicrobial susceptibility testing; WBC: white blood cells.

AB0349 ANALYSIS EFFICACY OF ABATACEPT TREATMENT IN BIOLOGIC-NAÏVE AND BIOLOGIC-EXPERIENCED PATIENTS

Background

Despite the high efficacy of rheumatoid arthritis (RA) therapy, in routine clinical practice, clinicians face questions about the choice of a second biologics, as well as the possibility of biologics monotherapy. Therefore, the specialties of biologics use in these categories of patients are of great clinical interest. This work is devoted to the study of the effectiveness of abatacept (ABA) therapy in biologic-naïve and biologic-experienced patients and in the subgroup of ABA monotherapy.

Objectives

To evaluate the effectiveness of ABA therapy between biologic-naïve and patients who had experienced an inadequate response to biological agents and in the subgroup of ABA monotherapy.

Methods

We prospectively enrolled and followed 91 patients with high RA activity (SDAI=28±13.4, CDAI=25±12) and an inadequate response of conventional synthetic DMARDs (mainly methotrexate, 70.3%) and biologics (mainly TNF-α blockers, 93%) were included in the study. Most of the patients were middle-aged (49±13.5), positive for RF (72.5%) and ACCP (77%) with moderate functional impairment - 1.4 (0.9-2). Patients were divided into two groups: biologic-naïve (48.4%, n=44) and biologic-experienced patients (51.6%, n=47). 18% (n=17) of patients had a history of an inadequate response of 2 or more biologics. The ABA monotherapy group (13%, n=12) was assessed separately. ABA were administered IV, 10 mg/kg according to the standard scheme. The evaluation of the effectiveness of the therapy was carried out according to the EULAR/ACR 2011 criteria using the intention-to-treat approach and SDAI, CDAI and the functional state using the HAQ.

Results

ABA led to a significant (p<0.05) decrease in RA activity after 3 months of ABA therapy in all groups. After 6 months of treatment, there was a tendency towards an increase in the number of patients who achieved remission and low RA activity in the group of biologic-naïve patients, which continued to 12 months of therapy. So, after 6 months and 12 months in the group of biologic-naïve patients, the frequency of remission and low disease activity was 71% (n=25) and 76% (n=19) by SDAI, 75.6% (n=28) and 81.5% (n=24) by CDAI, respectively. Whereas, in the group of biologic-experienced patients - SDAI - 61.8% (n=21) and 69.2% (n=18), CDAI - 64.8% (n=22) and 77.8% (n=21), respectively. However, these differences didn’t reach significance. Similar results were obtained according to the EULAR criteria: after 12 months of treatment, the percentage of patients with a good response in both groups did not differ, 38% (n=14) in biologic-naïve and 38.4% (n=15) in biologic-experienced patients. ABA significantly improved functional status of patients, after 12 months the median HAQ of biologic-naïve and biologic-experienced patients were 0.7 (0.2–0.8) and 1.18 (0.7–1.6), respectively. More biologic-naïve patients achieved functional remission by HAQ after 6 and 12 months compared with biologic-experienced patients: 67% (n=23) vs. 33% (n=17), 62.5% (n=11) vs. 37.5% (n=9), respectively, but these differences didn’t reach significance. In the ABA monotherapy group after 6 months treatment, a good response by EULAR criteria was achieved in 10% (n=1) patients, while in the group of ABA+csDMARDs therapy in 43.5%, p=0.04. After 12 months the trend towards a more pronounced response in the combination therapy group persisted (11%, n=1 and 42%, n=28, respectively), but no significant differences were obtained.

Conclusion

Abatacept has shown significant improvement clinical and functional status in all studied groups. There were no significant differences in response to ABA therapy between biologic-naïve and biologic-experienced patients. ABA monotherapy were significantly worse compared with the combination therapy of ABA and csDMARDs after 6 months. After 12th month observation, this tendency continued, but no significant differences were achieved. This is probably due to the small number of patients on ABA monotherapy and, as a result, to the insufficient statistical representativeness of the sample.

Disclosure of Interests

None declared

AB0170 AMCV POSITIVITY AND HIGHER SERUM IP-10 (CXCL-10) LEVEL ARE ASSOCIATED WITH A MORE PRONOUNCED EFFECT OF ABATACEPT THERAPY

Background

With the advent of medications with different mechanisms of action in the treatment of rheumatoid arthritis (RA), clinicians face the challenge of personalizing the approach to the treatment of RA patients. One of the steps in this direction is to identify predictors of the effectiveness of the therapy. This work is devoted to the identification of predictors of the therapy effectiveness with the blocker of T cells co-stimulation - abatacept (ABA).

Objectives

Search for clinical and immunological predictors of the effectiveness of ABA therapy.

Methods

91 patients were included in the study, most of them women, with high disease activity of RA (DAS28=5.1±1.0, SDAI=28±13.4, CDAI=25±12) and failure of previous biologics (51, 6%) and DMARDs (100%). Moreover, in 20% (n=18) of patients the inefficiency more than 2 biologics were recorded. The average duration of the disease was 3.0 (1.4–12) years, most patients were positive for RF 72.5%, ACCP 77%, AMCV 86%. In 44 patients the levels of RF, ACCP, AMCV and MMP-3 were assessed after 24 weeks of ABA therapy. In 36 patients enzyme-linked immunoassay was used to measure serum concentrations of biomarkers IL-1β, IL-6, IL-17AF, TNF-α, VEGF-A, IP-10, YKL-40 at baseline and after 24 weeks of ABA therapy. The effectiveness of therapy was assessed according to the EULAR criteria. ABA IV infusions were performed according to the standard schedule. Methods of parametric and non-parametric statistics were used in statistical analysis.

Results

ABA treatment led to a significant decrease of disease activity assessed by DAS28, SDAI, CDAI starting from 3 months of therapy (p<0.05). More than half of the patients were in remission and had low disease activity according to the DAS28 (65.7%, n=35) after 48 weeks of treatment. After 48 weeks, the highest percentage of patients with RA remission was registered by the DAS28 (37.4%, n=20), the lowest — SDAI (21.6%, n=11). After 24 weeks of therapy, ABA led to a significant decrease in the serum levels of IL-6 from 2.4 [1.1 - 6,4] to 1.29 [0.9-2.2] pg/ml, (p=0.0006), IP-10 from 21 [12,9-49,8] to 14 [7.5-28] pg/ml, (p=0.007) and matrix metalloproteinase 3 (MMP3) from 30.1 [13-82] pg/ml to 10 [7.4-55] pg/ml, (p = 0.0003). A decrease in the serum level of IL-6 significantly correlated with a decrease in the DAS28 and SDAI (r=0.5 and r=0.479, p<0.05), IP-10 with DAS28 (r=0.326, p<0.05). Initially, the serum level of TNF-α was significantly lower in patients who achieved low disease activity by the SDAI (72.6%, n=37) after 48 weeks of therapy, compared with the rest. On the contrary, a significantly higher level of IP-10 before treatment was recorded in patients with a good response according to the EULAR criteria (39%, n=29) after 48 weeks of ABA treatment (Figure 1). The ROC-analysis revealed that an initially high concentration of TNF-α may indicate with 71% sensitivity and 77% specificity about the possible ineffectiveness of ABA therapy after 48 weeks of treatment, the area under the curve was 0.7, 95% CI (0.5– 0.9). In patients initially positive for AMCV, low RA activity by SDAI was significantly more often registered after 24 (p=0.04) and 48 weeks. (p=0.01). 89% (n=34) of AMCV-positive patients achieved low disease activity after 48 weeks therapy by the SDAI and CDAI. It is noteworthy that a cohort of patients with insufficient effect after 48 weeks consisted entirely of AMCV-negative patients.

Conclusion

ABA therapy led to a significant decrease in disease activity according to the main indices (DAS28, SDAI, CDAI). During ABA treatment, there was a decrease of important immunoinflammatory markers - IL-6, IP-10, MMP-3. AMCV positivity is significantly associated with higher efficacy of ABA therapy. Also, a high basal concentration of TNF-α could use as a predictor of possible failure of ABA therapy, and a high initial level of IP-10, on the contrary, indicates the possible efficacy of ABA therapy.

References

None

Disclosure of Interests

None declared

AB1475 SERUM LEVELS OF INFLAMMATORY BOWEL DISEASE-SPECIFIC ANTIBODIES IN ANKYLOSING SPONDYLITIS

Background

Ankylosing spondylitis (AS) is an immune-mediated inflammatory disease of the musculoskeletal system, that is often accompanied with a subclinical intestinal inflammation. Inflammatory bowel diseases (IBD), including, Crohn’s disease (CD) and ulcerative colitis (UC), are the most frequent extra-articular manifestation in patients (pts) with AS. Several autoantibodies and antimicrobial antibodies are used as additional non-invasive serological markers for the diagnosis of CD and UC [1]. The evaluation of IBD-associated antibodies in AS pts provided conflicting results [2, 3].

Objectives

The aim of the study was to determine the serum levels of IBD-specific antibodies in AS.

Methods

We studied 51 pts with AS fulfilled modified New York criteria (1984); (40M/11F); median and interquartile range (25th—75th percentile) of age 44.0; 34.0-49.0 years; disease duration 12.0; 5.0-20.0 years; BASDAI - 5.3; 4.5-6.4; ASDAS ESR - 3.6; 3.0-4.4; ASDAS CRP - 3.7; 2.8-4.5; 40% HLA-27 positive. In 22% of pts with AS, IBD (CD and UC) were diagnosed. The control group included 44 healthy donors (HC). Atypical perinuclear anti-neutrophil cytoplasmic antibodies (pANCA) were detected using indirect immunofluorescence. The serum levels of IgA/IgG antibodies to Saccharomyces cerevisiae (ASCA), IgA/IgG antibodies to glycoprotein 2 (GP2), IgG antibodies to cathepsin G, lactoferrin, elastase and bactericidal permeability-increasing protein (BPI) were detected by ELISA.

Results

AS pts without signs of IBD and AS with IBD (AS/IBD) pts had significantly higher serum levels of IgA ASCA, IgA anti-GP2, anti-elastase antibodies than HC (4.5; 2.6-6.4 U/ml and 4.9; 3.7-7.3 U/ml vs 1.9; 0.6-2.6 U/ml, p=0.0008, p=0.001; 1.2; 0.8-5.5 U/ml and 1.2; 0.9-11.8 U/ml vs 0.7; 0.6-1.3 U/ml, p=0.007, p=0.02; 8.2; 5.9-9.9 U/ml and 9.1; 8.5-10.5 U/ml vs 5.6; 4.7-8.3 U/ml, p=0.01, p=0.003). The median concentration of anti-cathepsin G antibodies was greater for AS/IBD pts than AS pts (0.8; 0.5-1.0 U/ml vs 0.4; 0.3-0.6 U/ml, p=0.02). In AS and AS/IBD, the occurrence of anti-elastase antibodies (23.0%, 33.0%) was higher than for HC (0%, p=0.05, p=0.01). The positivity rate of IgA anti-GP2 in AS/IBD exceeded that in HC (27.0% vs 0%, p=0.025). AS/IBD pts demonstrated a higher prevalence of pANCA (36.0%), and anti-BPI antibodies (36.0%), when compared to AS alone (4.8%, p=0.005, and 8.0%, p=0.02) and HC (0%, p=0.0001, and 0%, p=0.008).

Conclusion

Our findings indicate that elevated serum levels of IgA ASCA, IgA anti-GP2, anti-elastase antibodies in AS did not differ from those in AS/IBD and may serve as potential biomarkers for predicting intestinal inflammation at an early stage. For AS/IBD, the most useful diagnostic markers were atypical pANCA, IgA ASCA, IgA anti-GP2, anti-elastase and anti-BPI antibodies.

References

[1]Prideaux L, De Cruz P, Ng SC, Kamm MA. Serological antibodies in inflammatory bowel disease: a systematic review. Inflamm Bowel Dis. 2012; 18(7):1340-55.

[2]Benfaremo D, Luchetti M, Gabrielli A. Biomarkers in inflammatory bowel disease-associated spondyloarthritis: state of the art and unmet needs. J Immunol Res. 2019 May 30; 2019:8630871.

[3]De Vries M, Van Der Horst-Bruinsma I, Van Hoogstraten I., et al. pANCA, ASCA, and OmpC antibodies in patients with ankylosing spondylitis without inflammatory bowel disease. J Rheumatol. 2010; 37(11):2340–4.

Disclosure of Interests

None declared

AB0837 SERUM YKL-40 LEVELS IN PATIENTS WITH EARLY RHEUMATOID ARTHRITIS: RELATION TO DISEASE ACTIVITY AND JOINT DESTRUCTION

Background:

YKL-40 (chitinase-3-like 1 protein, human cartilage glycoprotein 39) is one of the major proteins secreted locally in the arthritic joint by activated macrophages, chondrocytes, synoviocytes and neutrophils, YKL-40 an important marker for inflammation, cartilage remodelling and synovial hyperplasia is recognized as a possible auto-antigen in rheumatoid arthritis (RA).

Objectives:

The aims of the study were to determine the serum level of YKL-40 in early RA and investigate his relationship with biomarkers of disease activity and joint destruction.

Methods:

We studied 22 patients with early RA (ACR/EULAR 2010 classification criteria); 4 males, 18 females; median and interquartile range (25th—75th percentile) of age 55,0 (43,0-64,0) years, disease duration 7,0 (5,0-11,0) months, DAS28 4,9 (4,3-5,8); 86% IgM rheumatoid factor (IgM RF) +; 91% anti-cyclic citrullinated peptide antibody (anti-CCP) +. All patients were treated with methotrexate (MTX). Three (14 %) patients received low oral doses of steroids and intra-articular injections. The control group included 22 healthy donors (HC). Radiographs were scored according to the van der Heijde-modified Sharp score. YKL-40, matrix metalloproteinase-3 (MMP-3), anti-CCP were detected using commercially available enzyme-linked immunosorbent assays (ELISA). The serum levels of IgM RF, C-reactive protein (CRP), serum amyloid A (SAA) were measured by immunonephelometry.

Results:

RA patients had significantly higher serum level of YKL-40 than HC (92,1; 68,5-153,1 pg/ml vs 54,0; 41,7-83,2 pg/ml, p<0.01). Serum YKL-40 concentration was positively correlated with DAS 28 (r=0,5; p<0,05), erythrocyte sedimentation rate (ESR) (r=0,5; p<0,05), CRP (r=0,8; p<0,05), SAA (r=0,6; p<0,05) and MMP-3 (r = 0,6; p<0,05). We found no relationship between the level of YKL-40 and articular radiographic changes.

Conclusion:

Elevated serum concentration of YKL-40 in early RA is associated with clinical and laboratory indicators of disease inflammatory activity and increased level of MMP-3 - an immunological marker of joint destruction.

Disclosure of Interests:

Elena Aleksandrova: None declared, Alexander Novikov: None declared, Elena Luchikhina Speakers bureau: Abbvie, Roche, Pfizer, Biocad, MSD, Sanofi, Johnson & Johnson, Glaxo, UCB, Celgene, Novartis, Consultant of: Abbvie, Biocad, Sanofi, Celgene, Dmitriy Karateev Speakers bureau: Abbvie, Roche, Pfizer, Biocad, MSD, Sanofi, Johnson & Johnson, Glaxo, UCB, Celgene, Novartis, Lilly, Bayer, Paid instructor for: Abbvie, Pfizer, Biocad, Sanofi, Novartis, Lilly, Galina Lukina Speakers bureau: Abbvie, Roche, Pfizer, Biocad, MSD, Sanofi, Johnson & Johnson, Glaxo, UCB, Celgene, Novartis, Paid instructor for: Abbvie, Biocad, Sanofi, Celgene

FRI0564 SERUM LEVELS OF IL-6 AND IL-8 IN ANKYLOSING SPONDYLITIS PATIENTS: ASSOCIATIONS WITH DISEASE ACTIVITY

Background:

Ankylosing spondylitis (AS) is a chronic inflammatory disease of the spine and sacroiliac joints characterized by new bone formation (syndesmophytes) and ankyloses. In AS cases, along with the damage to the musculoskeletal system, impairment of other organs and systems is often observed (uveitis, inflammatory bowel and heart diseases). Pro-inflammatory cytokines (TNF-α, IL-6,-17,-23,-21,-22,-31) and chemokines (IL-8) are key pathogenic markers in AS.

Objectives:

The aims of the study were to determine the serum levels of IL-6 and IL-8 in AS and investigate their relationship with disease activity.

Methods:

We studied 140 patients (pts) with AS fulfilled modified New York criteria (1984); (102M/38F); median and interquartile range (25th—75th percentile) of age 43.0; 35.0-51.0 years; disease duration 6.0; 4.0-12.0 years; BASDAI - 5.4; 4.1-6.6; ASDAS ESR - 3.6; 2.6-4.4; ASDAS CRP - 3.8; 2.7-4.5; 86% HLA-27 positive. In 50% of pts with AS, inflammatory bowel diseases (IBD) (Crohn’s disease and ulcerative colitis) were diagnosed. The control group included 17 healthy donors (HC). The serum concentrations of IL-6 and IL-8 were detected by chemiluminescence immunoassay using IMMULATE 1000 analyzer (Siemens Healthcare Diagnostics, USA).

Results:

AS pts had significantly higher serum level of IL-6 than HC (4.3; 0.1-8.0 pg/ml vs 2.3; 0.1-2.7 pg/ml, p <0.006). The median concentration of IL-8 didn’t differ between AS pts and HC (10.5; 8.3-18.0 pg/ml vs 11.9; 8.2-18.3 pg/ml, p>0.05). The same levels of IL-6 and IL-8 were detected in AS with IBD and AS without signs of IBD (p>0.05). In AS pts, serum IL-6 concentration was positively correlated with ASDAS ESR (r = 0.3), ASDAS CRP (r = 0.3), ESR (r = 0.3) and CRP (r = 0.5) (p <0.05); IL-8 was negatively associated with presence of fecal calprotectin (r = -0.3) (p <0.05).

Conclusion:

Elevated serum concentration of IL-6 in AS is associated with clinical and laboratory markers of high inflammatory activity of the disease. The levels of IL-8 in the sera of AS patients were negatively correlated with the concentration of fecal calprotectin. Data on the relationship of IL-8 with the activity of the pathological process in AS require further study.

Disclosure of Interests:

Elena Aleksandrova: None declared, Alexander Novikov: None declared, Polina Kulakova: None declared, Aleksey Dorofeev: None declared, Nadezhda Savenkova: None declared, Evgeniy Volnukhin: None declared, Anton Kovshik: None declared, Galina Lukina Speakers bureau: Novartis, Pfizer, UCB, Abbvie, Biocad, MSD, Roche

FRI0541 TEN-YEAR OUTCOME OF DIFFERENT SUBTYPES OF UNDIFFERENTIATED INFLAMMATORY ARTHRITIS

Background:

A group of patients with recent onset of arthritis always presents a certain difficulty for the practitioner due to its marked heterogeneity. This especially concerns the patients with undifferentiated inflammatory arthritis (UIA).

Objectives:

To characterize the long-term nosological outcome of clinical and immunological subtypes of early UIA.

Methods:

A cohort study of patients with recent onset of arthritis with a duration of not more than 12 months (n = 761, 82.8% females, 55.2% RF +) was initiated in 2003. All patients were referred to rheumatologist from GP with suspicion on inflammatory arthritis. Inclusion criteria: age 18 years or more, at least 1 swollen joint at 1stvisit and/or positive squeeze test or morning stiffness for at least 30 minutes. 243 patients were initially classified as having UIA: 46 (18,9%) males, 197 (81,1%) females, age (median, quartiles)- 44 [29;53] years, duration of symptoms- 3 [2;5] months, swollen joints count (66/68)- 2 [1;4], tender joints count 3 [2;6], 85 (35%) rheumatoid factor (RF)+, 63 (25,9%) anti-CCP+. Patients with UIA were followed up for at least 10 years.

Results:

28 (11,5%) of patients were lost to follow up. Long-term observation was conducted in 215 patients. 22 (10,2%) of them developed persistent spontaneous (without use of DMARDs) remission. Other patients were finally classified as having: rheumatoid arthritis (RA) 138 (64,2%) and non-RA (25,6%). The spectrum of diagnoses in non-RA group included: ankylosing spondylitis, osteoarthritis, gout, psoriatic arthritis, polymyalgia rheumatica, systemic lupus, mixed connective tissue disease, sarcoidosis, paraneoplastic syndromes. The following characteristics at baseline positively correlated with the development of RA: arthritis of 3 or more joints (p=0,011), arthritis of hand (p=0,005), high ESR (p<0,001), high CRP (p=0,003), PF-positivity (p<0,001), anti-CCP-positivity (p<0,001), older age of onset (p=0,019), higher levels of RF IgM (p=0,027) and anti-CCP (p<0,001). Development of persistent spontaneous remission negatively correlated with polyarthritis (p=0,033), PF-positivity (p=0,034), anti-CCP-positivity (p=0,001). Positive seroconversion was observed: of RF in 10 (4,7%) patients, 8 developed RA, of anti-CCP – in 3 (1,4%) patients, all developed RA.

Table.

Outcome of different subtypes of patients with UA after 10 years of follow up (n=215).

Subtypes of UAOutcomeP (Pearson chi-squared test)Non-RA (n=55)RA (n=138)Spontaneous remission (n=22)Mono- and oligo arthritis (n=140)40 (28,6%)81 (57,9%)19 (13,6%)0,016Polyarthritis (n=75)15 (20%)57 (76%)3 (4%)RF-negative AND anti-CCP-negative (n=90)34 (37,8%)41 (45,6%)15 (16,7%)<0,001RF+ OR anti-CCP+ OR low levels (<3 ULN) (n=92)20 (21,7%)65 (70,7%)7 (7,6%)High RF+ AND High anti-CCP+ (n=33)1 (3%)32 (97%)0

Conclusion:

Seronegative oligoarticular disease and highly seropositive disease are different subtypes of UIA. Combination of seronegativity and oligoarticular disease (n=52) associated with relatively rare development of RA (36,2%) and high proportion of spontaneous remission (22,4%). Patients who were highly positive (>3 ULN) for both RF and anti-CCP developed RA in 97% of cases and never remitted spontaneously.

Disclosure of Interests:

Elena Luchikhina Consultant of: Abbvie, Biocad, Sanofi, Celgene, Speakers bureau: Abbvie, Roche, Pfizer, Biocad, MSD, Sanofi, Johnson & Johnson, Glaxo, UCB, Celgene, Novartis, Dmitry Karateev Consultant of: Abbvie, Pfizer, Biocad, Sanofi, Novartis, Lilly, Speakers bureau: Abbvie, Roche, Pfizer, Biocad, MSD, Sanofi, Johnson & Johnson, Glaxo, UCB, Celgene, Novartis, Lilly, Bayer, Alexander Novikov: None declared, Galina Lukina Speakers bureau: Novartis, Pfizer, UCB, Abbvie, Biocad, MSD, Roche, Elena Aleksandrova: None declared, Natalia Demidova: None declared

[MICROSATELLITE INSTABILITY IN ENDOMETRIAL CANCER]

Microsatellite instability (MSI) is involved in the pathogenesis of about 30% of endometrial cancer cases. In accumulating data from the past few years MSI is shown to have both clinical and prognostic value. In the present work we are discussing the components and molecular mechanisms of functioning of the mismatch repair system (MMR). MSI is a hallmark of endometrial tumors with DNA MMR deficiency. We summarized the main pathways for accumulating mutations in coding and non-coding DNA sequences, which is a result of errors during replication of microsatellite tandem repeats. A few studies rising valuable conclusions about the correlation between MSI and endometrial cancer are revised.

Spatial distribution and dynamics of proton conductivity in fuel cell membranes: potential and limitations of electrochemical atomic force microscopy measurements

The proton conductivity of a Nafion 112 membrane is measured with a high spatial resolution using electrochemical atomic force microscopy. Image analysis reveals an inhomogeneous conductivity distribution which is attributed to the limited connectivity of hydrophilic domains. This information relates to the micro-morphology which is due to phase separation of the hydrophobic polymer backbone and the hydrophilic pendant groups. The direct images relate to a different length scale and are complementary to the x-ray diffraction investigations which provide only average information. Furthermore, the measured current values reveal an interesting correlation with the size of the conductive areas. A bimodal conductivity distribution suggests that there are different mechanisms which contribute to the proton current in Nafion. Additionally, time dependence in local conductivity is found and interpreted in terms of redistribution of water in the membrane. A statistical analysis of the current distribution is performed and compared with theoretical simulations. Evidence is found for the existence of a critical current density. On a timescale of seconds the response of the conductive network is probed by applying voltage steps to the atomic force microscope tip.

Electrochemical atomic force microscopy study of proton conductivity in a Nafion membrane

High membrane conductivity is one of the key parameters in polymer electrolyte fuel cell applications. We introduce an electrochemical atomic force microscopy method that provides simultaneously the surface topography of a Nafion 112 membrane and the conductivity of ion channels with an unprecedented resolution of ca. 10 nm. For given conditions, a large fraction of the channel ports is found to conduct exactly the same number of protons per unit time. This is taken as evidence for an optimum pore size and structure for proton conduction, or alternatively, for an efficient connectivity of the ion channel network, so that the same conductivity is measured at all exit pores. The time response following a potential step and the influence of the relative humidity on the transport properties is investigated. The method will be of relevance for tailoring the production technology to yield an optimised micromorphology, and it permits detailed tests of membrane models and provides data for theoretical modelling of proton conductivity.

[The feeding of newborns with low birth weight with milk formula "Nenatal" and "Nutrilon-premium"]

The aim of the study is to make retrospective analysis of 9 years experience in the feeding of praematuries and high risk newborn in that ward in First City Hospital-Sofia with formula milks "Nenatal" and "Nutrilon-premium". 721--42.4% from all babies in this period were feed with those formulas. With Nenatal only--11.8%, with Nutrilon-premium 88.2%. This the fact is due that all babies under 2000 gr. were fed with Nenatal, and after reaching 2000 gr.--with Nutrilon-premium. The results confirm that Nenatal is right formula for feeding of low and very low birth weight infant, due to its special content and qualities. The results from Nutrilon-premium illustrated that mean gain weight is the biggest in I grade of prematurity--33 grams, followed by matures--30 gr, after them II grade--29 gr., III grade--27 gr., IV grade--26 gr. As a conclusion we may say that mean gain weight for all groups is 29 grams. Consuming all gain weight of the babies feeding with Nutrilon-premium data appear that the biggest is in III of prematurity--1499 grams, followed by IV grade--1418 gr., I grade--1341 spama, II grade--1219 gr., and last matures--745 gr.