Acquired enamel pellicle and biofilm engineering with a combination of acid-resistant proteins (CaneCPI-5, StN15, and Hemoglobin) for enhanced protection against dental caries - in vivo and in vitro investigations

OBJECTIVE

This study was designed in two-legs. In the in vivo, we explored the potential of a rinse solution containing a combination (Comb) of 0.1 mg/mL CaneCPI-5 (sugarcane-derive cystatin), 1.88 × 10- 5M StN15 (statherin-derived peptide) and 1.0 mg/mL hemoglobin (Hb) to change the protein profile of the acquired enamel pellicle(AEP) and the microbiome of the enamel biofilm. The in vitro, was designed to reveal the effects of Comb on the viability and bacterial composition of the microcosm biofilm, as well as on enamel demineralization.

MATERIALS AND METHODS

In vivo study, 10 participants rinsed (10mL,1 min) with either deionized water (H2O-control) or Comb. AEP and biofilm were collected after 2 and 3 h, respectively, after rinsing. AEP samples underwent proteomics analysis, while biofilm microbiome was assessed via 16 S-rRNA Next Generation Sequencing(NGS). In vitro study, a microcosm biofilm protocol was employed. Ninety-six enamel specimens were treated with: 1)Phosphate-Buffered Solution-PBS(negative-control), 2)0.12%Chlorhexidine, 3)500ppmNaF and 4)Comb. Resazurin, colony-forming-units(CFU) and Transversal Microradiography(TMR) were performed.

RESULTS

The proteomic results revealed higher quantity of proteins in the Comb compared to control associated with immune system response and oral microbial adhesion. Microbiome showed a significant increase in bacteria linked to a healthy microbiota, in the Comb group. In the in vitro study, Comb group was only efficient in reducing mineral-loss and lesion-depth compared to the PBS.

CONCLUSIONS

The AEP modification altered the subsequent layers, affecting the initial process of bacterial adhesion of pathogenic and commensal bacteria, as well as enamel demineralization.

CLINICAL RELEVANCE

Comb group shows promise in shaping oral health by potentially introducing innovative approaches to prevent enamel demineralization and deter tooth decay.

Acquired Pellicle and Biofilm engineering by rinsing with hemoglobin solution

INTRODUCTION

The identification of acid-resistant proteins, including hemoglobin (Hb), within the acquired enamel pellicle (AEP) led to the proposition of the "acquired pellicle engineering" concept, which involves the modification of the AEP by incorporating specific proteins, presenting a novel strategy to prevent dental demineralization.

OBJECTIVE

Combining in vivo and in vitro proof-of-concept protocols we sought to reveal the impact of AEP engineering with Hb protein on the biofilm microbiome and enamel demineralization.

METHODS

In the in vivo studies, 10-volunteers, in 2 independent experiments, rinsed (10mL,1min) with: deionized water-negative control or 1.0mg/mL Hb. The AEP and biofilm formed along 2 or 3h, respectively, were collected. AEP was analyzed by quantitative shotgun-label-free proteomics and biofilm by 16S-rRNA Next-Generation-Sequencing (NGS). In vitro study, a microcosm biofilm protocol was employed. Seventy-two bovine enamel specimens were treated with: 1)Phosphate-Buffered Solution-PBS, 2)0.12% Chlorhexidine, 3)500ppm NaF; 4)1.0mg/mL Hb; 5)2.0mg/mL Hb, and 6)4.0mg/mL Hb. The biofilm was cultivated for 5-days. Resazurin, colony-forming-units(CFU) and Transversal Microradiography(TMR) were performed.

RESULTS

Proteomics and NGS analysis revealed that Hb increased proteins with antioxidant, antimicrobial, acid-resistance, hydroxyapatite-affinity, calcium-binding properties and showed a reduction in oral pathogenic bacteria. In vitro experiments demonstrated that the lowest Hb concentration was the most effective in reducing bacterial activity, CFU and enamel demineralization compared to PBS.

CONCLUSION

These findings suggest that Hb could be incorporated into anticaries dental products to modify the oral microbiome and control caries, highlighting its potential for AEP and biofilm microbiome engineering.

Stereotactic Body Reirradiation in Gynaecological Cancer: Outcomes and Toxicities from a Single Institution Experience

AIMS

To report toxicity profile, outcomes and quality of life (QoL) data in patients with recurrent gynaecological cancer who underwent stereotactic body radiotherapy (SBRT) retreatment.

MATERIALS AND METHODS

Data from patients' folders were retrospectively extracted, focusing on the primary neoplasm, previous systemic therapies and previous radiotherapy. Concerning SBRT, the total dose (five daily fractions) was delivered with a linear accelerator using intensity-modulated radiotherapy techniques. Acute and late toxicities were assessed by the CTCAE 4.03 scale. QoL was evaluated according to the Cancer Linear Analogue Scale [CLAS1 (fatigue), CLAS2 (energy level), CLAS3 (daily activities)].

RESULTS

Between December 2005 and August 2021, 23 patients (median age 71 years, range 48-80) with 27 lesions were treated. Most patients had endometrial (34.8%), ovarian (26.1%) and cervical cancer (26.1%) as the primary tumour. The most common SBRT schedules in five fractions were 30 Gy (33.3%), 35 Gy (29.6%) and 40 Gy (29.6%). The median follow-up was 32 months (range 3-128). There were no patients reporting acute or late toxicities higher than grade 2, except for a bone fracture. One- and 2-year local control was 77.9% and 70.8%, respectively. One- and 2-year overall survival was 82.6% and 75.1%, respectively. The overall response rate was 96.0%. Regarding QoL, no statistically significant difference was identified between the baseline and follow-up values: the median CLAS1, CLAS2 and CLAS3 scores for each category were 6 (range 4-10) at baseline and 6 (range 3-10) 1 month after SBRT.

CONCLUSIONS

This preliminary experience suggests that SBRT retreatment for recurrent gynaecological cancer is a highly feasible and safe treatment with limited side-effects and no short-term QoL impairment.

Antimicrobial Peptide Arsenal Predicted from the Venom Gland Transcriptome of the Tropical Trap-Jaw Ant Odontomachus chelifer

With about 13,000 known species, ants are the most abundant venomous insects. Their venom consists of polypeptides, enzymes, alkaloids, biogenic amines, formic acid, and hydrocarbons. In this study, we investigated, using in silico techniques, the peptides composing a putative antimicrobial arsenal from the venom gland of the neotropical trap-jaw ant Odontomachus chelifer. Focusing on transcripts from the body and venom gland of this insect, it was possible to determine the gland secretome, which contained about 1022 peptides with putative signal peptides. The majority of these peptides (75.5%) were unknown, not matching any reference database, motivating us to extract functional insights via machine learning-based techniques. With several complementary methodologies, we investigated the existence of antimicrobial peptides (AMPs) in the venom gland of O. chelifer, finding 112 non-redundant candidates. Candidate AMPs were predicted to be more globular and hemolytic than the remaining peptides in the secretome. There is evidence of transcription for 97% of AMP candidates across the same ant genus, with one of them also verified as translated, thus supporting our findings. Most of these potential antimicrobial sequences (94.8%) matched transcripts from the ant's body, indicating their role not solely as venom toxins.

Maquiberry Cystatins: Recombinant Expression, Characterization, and Use to Protect Tooth Dentin and Enamel

Phytocystatins are proteinaceous competitive inhibitors of cysteine peptidases involved in physiological and defensive roles in plants. Their application as potential therapeutics for human disorders has been suggested, and the hunt for novel cystatin variants in different plants, such as maqui (Aristotelia chilensis), is pertinent. Being an understudied species, the biotechnological potential of maqui proteins is little understood. In the present study, we constructed a transcriptome of maqui plantlets using next-generation sequencing, in which we found six cystatin sequences. Five of them were cloned and recombinantly expressed. Inhibition assays were performed against papain and human cathepsins B and L. Maquicystatins can inhibit the proteases in nanomolar order, except MaquiCPIs 4 and 5, which inhibit cathepsin B in micromolar order. This suggests maquicystatins' potential use for treating human diseases. In addition, since we previously demonstrated the efficacy of a sugarcane-derived cystatin to protect dental enamel, we tested the ability of MaquiCPI-3 to protect both dentin and enamel. Both were protected by this protein (by One-way ANOVA and Tukey's Multiple Comparisons Test, p < 0.05), suggesting its potential usage in dental products.

Transcriptomic and biochemical analysis from the venom gland of the neotropical ant Odontomachus chelifer

The genus Odontomachus is widely distributed in neotropical areas throughout Central and South America. It is a stinging ant that subdues its prey (insects) by injecting them a cocktail of toxic molecules (venom). Ant venoms are generally composed of formic acid, alkaloids, hydrocarbons, amines, peptides, and proteins. Odontomachus chelifer is an ant that inhabits neotropical regions from Mexico to Argentina. Unlike the venom of other animals such as scorpions, spiders and snakes, this ant venom has seldom been analyzed comprehensively, and their compositions are not yet completely known. In the present study, we performed a partial investigation of enzymatic and functional activities of O. chelifer ant venom, and we provide a global insight on the transcripts expressed in the venom gland to better understand their properties. The crude venom showed phospholipase A₂ and antiparasitic activities. RNA sequencing (Illumina platform) of the venom gland of O. chelifer generated 61, 422, 898 reads and de novo assembly Trinity generated 50,220 contigs. BUSCO analysis against Arthropoda_db10 showed that 92.89% of the BUSCO groups have complete gene representation (single-copy or duplicated), while 4.05% are only partially recovered, and 3.06% are missing. The 30 most expressed genes in O. chelifer venom gland transcriptome included important transcripts involved in venom function such as U-poneritoxin (01)-Om1a-like (pilosulin), chitinase 2, venom allergen 3, chymotrypsin 1 and 2 and glutathione S-transferase. Analysis of the molecular function revealed that the largest number of transcripts were related to catalytic activity, including phospholipases. These data emphasize the potential of O. chelifer venom for prospection of molecules with biotechnological application.

Volumetric Intensity-Modulated Arc Stereotactic Radiosurgery Boost in Oligometastatic Patients with Spine Metastases: a Dose-escalation Study

AIMS

To report the final results of a dose-escalation study of volumetric intensity-modulated arc stereotactic radiosurgery (VMAT-SRS) boost after three-dimensional conformal radiation therapy in patients with spine metastases.

MATERIALS AND METHODS

Oligometastatic cancer patients bearing up to five synchronous metastases (visceral or bone, including vertebral ones) and candidates for surgery or radiosurgery were considered for inclusion. 25 Gy was delivered in 10 daily fractions (2 weeks) to the metastatic lesion, affected vertebrae and adjacent ones (one cranial and one caudal vertebra). Sequentially, the dose to spinal metastases was progressively increased (8 Gy, 10 Gy, 12 Gy) in the patient cohorts. Dose-limiting toxicities were defined as any treatment-related non-hematologic acute adverse effects rated as grade ≥3 or any acute haematological toxicity rated as ≥ 4 by the Radiation Therapy Oncology Group scale.

RESULTS

Fifty-two lesions accounting for 40 consecutive patients (male/female: 29/11; median age: 71 years; range 40-85) were treated from April 2011 to September 2020. Most patients had a primary prostate (65.0%) or breast cancer (22.5%). Thirty-two patients received 8 Gy VMAT-SRS boost (total BED _α/β10: 45.6 Gy), 14 patients received 10 Gy (total BED _α/β10: 51.2 Gy) and six patients received 12 Gy (total BED _α/β10: 57.6 Gy). The median follow-up time was over 70 months (range 2-240 months). No acute toxicities > grade 2 and no late toxicities > grade 1 were recorded. The overall response rate based on computed tomography/positron emission tomography-computed tomography/magnetic resonance was 78.8%. The 24-month actuarial local control, distant metastases-free survival and overall survival rates were 88.5%, 27.1% and 90.3%, respectively.

CONCLUSION

A 12 Gy spine metastasis SRS boost following 25 Gy to the affected and adjacent vertebrae was feasible with an excellent local control rate and toxicity profile.

Transcriptomic analysis of Malpighian tubules from the stingless bee Melipona scutellaris reveals thiamethoxam-induced damages

The concern about pesticide exposure to neotropical bees has been increasing in the last few years, and knowledge gaps have been identified. Although stingless bees, (e.g.: Melipona scutellaris), are more diverse than honeybees and they stand out in the pollination of several valuable economical crops, toxicity assessments with stingless bees are still scarce. Nowadays new approaches in ecotoxicological studies, such as omic analysis, were pointed out as a strategy to reveal mechanisms of how bees deal with these stressors. To date, no molecular techniques have been applied for the evaluation of target and/or non-target organs in stingless bees, such as the Malpighian tubules (Mt). Therefore, in the present study, we evaluated the differentially expressed genes (DEGs) in the Mt of M. scutellaris after one and eight days of exposure to LC_50/100 (0.000543 ng a.i./μL) of thiamethoxam (TMX). Through functional annotation analysis of four transcriptome libraries, the time course line approach revealed 237 DEGs (nine clusters) associated with carbon/energy metabolism and cellular processes (lysosomes, autophagy, and glycan degradation). The expression profiles of Mt were altered by TMX in processes, such as detoxification, excretion, tissue regeneration, oxidative stress, apoptosis, and DNA repair. Transcriptome analysis showed that cell metabolism in Mt was mainly affected after 8 days of exposure. Nine genes were selected from different clusters and validated by RT-qPCR. According to our findings, TMX promotes several types of damage in Mt cells at the molecular level. Therefore, interference of different cellular processes directly affects the health of M. scutellaris by compromising the function of Mt.

Radical Nephroureterectomy Tetrafecta: A Proposal Reporting Surgical Strategy Quality at Surgery

Background

Standardized methods for reporting surgical quality have been described for all the major urological procedures apart from radical nephroureterectomy (RNU).

Objective

To propose a tetrafecta criterion for assessing the quality of RNU based on a consensus panel within the Young Association of Urology (YAU) Urothelial Group, and to test the impact of this tetrafecta in a multicenter, large contemporary cohort of patients treated with RNU for upper tract urothelial carcinoma (UTUC).

Design, setting, and participants

This was a retrospective analysis of 1765 patients with UTUC treated between 2000 and 2021.

Outcome measurements and statistical analysis

We interviewed the YAU Urothelial Group to propose and score a list of items to be included in the “RNU-fecta.” A ranking was generated for the criteria with the highest sum score. These criteria were applied to a large multicenter cohort of patients. Kaplan-Meier curves were built to evaluate differences in overall survival (OS) rates between groups, and a multivariable logistic regression model was used to find the predictors of achieving the RNU tetrafecta.

Results and limitations

The criteria with the highest score included three surgical items such as negative soft tissue surgical margins, bladder cuff excision, lymph node dissection according to guideline recommendations, and one oncological item defined by the absence of any recurrence in ≤12 mo. These items formed the RNU tetrafecta. Within a median follow-up of 30 mo, 52.6% of patients achieved the RNU tetrafecta. The 5-yr OS rates were significantly higher for patients achieving tetrafecta than for their counterparts (76% vs 51%). Younger age, lower body mass index, and robotic approach were found to be independent predictors of tetrafecta achievement. Conversely, a higher Eastern Cooperative Oncology Group score, higher clinical stage, and bladder cancer history were inversely associated with tetrafecta.

Conclusions

Herein, we present a “tetrafecta” composite endpoint that may serve as a potential tool to assess the overall quality of the RNU procedure. Pending external validation, this tool could allow a comparison between surgical series and may be useful for assessing the learning curve of the procedure as well as for evaluating the impact of new technologies in the field.

Patient summary

In this study, a tetrafecta criterion was developed for assessing the surgical quality of radical nephroureterectomy in patients with upper tract urothelial carcinoma. Patients who achieved tetrafecta had higher 5-yr overall survival rates than those who did not.

POS0824 SAFETY AND EFFICACY OF THE INTENSIFIED B CELL DEPLETION INDUCTION THERAPY FOR PATIENTS WITH ANCA-ASSOCIATED VASCULITIS AND SEVERE RENAL INJURY: A CONTROLLED STUDY

Background

Rituximab (RTX), an anti-CD20 monoclonal antibody, has shown to be an effective induction treatment for small-vessel vasculitides associated with antineutrophil cytoplasm antibodies (AAV) in both newly diagnosed and relapsing patients. However, the role of RTX in the management of the most severe cases of AAV remains to be fully elucidated.

Objectives

to assess both safety and efficacy of an intensified B-cell depletion therapy (IBCDT) protocol, including RTX, cyclophosphamide (CYC), and methylprednisolone pulses without additional maintenance immunosuppressive therapy compared to conventional therapy regimen based on oral CYC and steroids and prolonged maintenance therapy with azathioprine (AZA) in patients with AAV and severe renal injury.

Methods

A cohort of 15 AAV patients with the most severe features of AVV renal involvement (as <15 ml/min GFR and histological findings of paucimmune necrotizing glomerulonephritis with more than 50% crescents of non-sclerotic glomeruli at the renal biopsy) was treated IBCDT and compared to compared toa control group of 10 patients with AAV treated with a conventional therapy regimen based on oral CYC and steroids and prolonged maintenance therapy with azathioprine (AZA). Independently on the pharmacologic regimen, plasma exchange (7 procedures with 1-1.5 plasma volume replacement) was performed in the presence of 1. alveolar haemorrhage, and 2. more than 50% florid crescents in the nonsclerotic glomeruli, or 3. dialysis dependence.

Results

Complete clinical remission (BVAS 0) was observed at 6 months in 14 of 15 patients (93%). All cases treated with IBCDT who achieved a complete clinical remission experienced a depletion of peripheral blood B cells at the end of therapy. Of the 10 dialysis dependent patients at onset, 6 subjects (60%) experienced a functional recovery allowing the suspension of dialysis treatment. When compared to the control group, no statistically significant difference was observed in patients treated with IBCDT in terms of overall survival, 6-month therapeutic response rate, and 6-, and 12-month functional renal recovery. The cumulative total dose of CYC in the case group was on average 1 g/patient while in the control group on average 8.5 g / patient (p = 0.00008). Plasmapheresis sessions were performed at part of the induction therapy among 13 patients (87%) in the case group and 8 (80%) in the control group.

Conclusion

The results of this study showed that IBCDT appeared to be safe and has the same efficacy profile when compared to conventional therapy with CYC plus AZA in the management of the most severe patients with AAV. Additionally, this avoids the need of prolonged maintenance therapy for long, and limits the exposure to CYC with consequent reduced toxicity and drug-related side effect rates.

Disclosure of Interests

None declared

Stereotactic radiosurgery for bone metastases in oligometastatic prostate cancer patients: DESTROY-2 clinical trial subanalysis

INTRODUCTION

Aim of this analysis was to report toxicity and clinical outcomes in oligorecurrent prostate cancer (PCa) patients treated with single fraction stereotactic radiosurgery (SRS) for bone metastases.

METHODS

We separately analyzed clinical data of PCa patients with bone oligometastases enrolled in a prospective phase I trial (DESTROY-2). DESTROY-2 was based on SRS delivered using volumetric modulated arc therapy in patients with primary or metastatic tumors in several extra-cranial body sites. Acute and late toxicity, biochemical tumor response, local control (LC), distant metastases-free (DPFS), progression-free (PFS), time to next-line systemic treatment-free (NEST-FS), and overall survival (OS) were calculated.

RESULTS

Data on 37 PCa patients, carrying out 50 bone metastases, candidates for curative-intent treatment and treated with SRS at our Institution were collected. SRS dose ranged between 12 and 24 Gy. One grade 1 acute skin toxicity in one patient treated on the hip (24 Gy) and one grade 1 late skin toxicity in a patient with a scapular lesion (24 Gy) were recorded. No cases of bone fracture were registered in the treated population. With a median follow-up of 25 months (range 3-72 months) 2-year actuarial LC, DPFS, PFS, and OS were 96.7%, 58.1%, 58.1%, and 95.8%, respectively. Median and 2-year NEST-FS were 30 months (range 1-69 months) and 51.2%, respectively.

CONCLUSIONS

Data analysis showed few toxicity events, high local control rate and prolonged NEST-FS after linear accelerator-based radiosurgery of bone oligometastases from PCa. The possibility of postponing systemic treatments in patients with oligometastatic PCa by means of SRS should be taken into account. Further prospective studies on larger series are needed to confirm the reported results.

Three phylogenetically distinct and culturable diazotrophs are perennial symbionts of leaf-cutting ants

The obligate mutualistic basidiomycete fungus, Leucocoprinus gongylophorus, mediates nutrition of leaf-cutting ants with carbons from vegetal matter. In addition, diazotrophic Enterobacteriales in the fungus garden and intestinal Rhizobiales supposedly mediate assimilation of atmospheric nitrogen, and Entomoplasmatales in the genus Mesoplasma, as well as other yet unidentified strains, supposedly mediate ant assimilation of other compounds from vegetal matter, such as citrate, fructose, and amino acids. Together, these nutritional partners would support the production of high yields of leafcutter biomass. In the present investigation, we propose that three phylogenetically distinct and culturable diazotrophs in the genera Ralstonia, Methylobacterium, and Pseudomonas integrate this symbiotic nutrition network, facilitating ant nutrition on nitrogen. Strains in these genera were often isolated and directly sequenced in 16S rRNA libraries from the ant abdomen, together with the nondiazotrophs Acinetobacter and Brachybacterium. These five isolates were underrepresented in libraries, suggesting that none of them is dominant in vivo. Libraries have been dominated by four uncultured Rhizobiales strains in the genera Liberibacter, Terasakiella, and Bartonella and, only in Acromyrmex ants, by the Entomoplasmatales in the genus Mesoplasma. Acromyrmex also presented small amounts of two other uncultured Entomoplasmatales strains, Entomoplasma and Spiroplasma. The absence of Entomoplasmatales in Atta workers implicates that the association with these bacteria is not mandatory for ant biomass production. Most of the strains that we detected in South American ants were genetically similar with strains previously described in association with leafcutters from Central and North America, indicating wide geographic dispersion, and suggesting fixed ecological services.

Is thulium laser vapoenucleation of the prostate equally safe and effective in elderly patients? A propensity score matched analysis of early perioperative and functional outcomes

PURPOSE

To evaluate if thulium laser vapoenucleation of the prostate (ThuVEP) is equally safe and effective in a selected cohort of elderly patients when compared to "younger" patients.

MATERIALS AND METHODS

We performed a retrospective analysis of consecutive patients who underwent ThuVEP between September 2018 and February 2020. After application of the inclusion/exclusion criteria, patients were stratified according to the 75 years-old cut-off point suggested by the WHO. Group A included patients < 75 years-old; Group B included patients > 75 years-old. Preoperative assessment included urological consultation, prostate specific antigen (PSA), International Prostate Symptom Score (IPSS) and quality of life index, transrectal ultrasound to estimate prostate volume (PVol), and uroflowmetry to assess preoperative Qmax, Qave and post-void residual volume (PVR). Perioperative and postoperative data were analyzed during 3-month follow-up.

RESULTS

After propensity-score analysis, 51 versus 51 patients were 1:1 matched according to PVol, PSA, Qmax, IPSS and QoL. Patients were comparable at baseline excluding age (65 (IQR 59-70) versus 79 (IQR 77-82) years, Group A versus B, respectively, p-value < 0.001). No differences were found in terms of hemoglobin drop, complications rate, catheterization time and length of hospital stay. Group A (younger) patients had more significant improvement in 30-days absolute Qmax, Qave and ΔQmax. At 90-days follow-up, the differences between the groups disappeared. Within the 90-days follow-up, no significant differences were found in the readmission rate, with no need of reinterventions.

CONCLUSIONS

In our hands, even in elderly patients affected by BPH, ThuVEP appears to be a safe and effective treatment option.

POS0704 LONG-TERM CLINICAL OUTCOMES OF PATIENTS WITH LUPUS NEPHRITIS TREATED WITH AN INTENSIFIED B-CELL DEPLETION PROTOCOL: A PROSPECTIVE STUDY

Background:

B cells play a key role In the pathogenesis of Lupus Nephritis (LN).

Objectives:

we aim to investigate the safety and efficacy of an intensified B-cell depletion induction therapy (IBCDT)without immunosuppressive maintenance regimen compared to standard of care in biopsy-proven LN.

Methods:

Thirty patients were administered an IBCDT (4 weekly Rituximab 375mg/m2 and 2more doses after 1&2 months;2 infusions of 10 mg/kg cyclophosphamide (CYC),3 methylprednisolone pulses), followed by oral prednisone (tapered to 5 mg/day by the 3rd month). No immunosuppressive maintenance therapy was given. Thirty patients matched for LN class and age were selected as controls: 20 received 3 methylprednisolone pulses days followed by oral prednisone and mycophenolate mofetil (MMF) 2-3 g/day, while 10 were given the Euro Lupus CYC.

Results:

At 12 months, complete renal remission was observed in 93% of patients on IBCDT, in 62.7% on MMF, and in 75% on CYC (p=0,03); the dose of oral prednisone was lower in the IBCDT group (mean±SD 2.9±5.0mg/dl) than MMF (10.5±8.0 mg/day,p<0.01) or CYC group (7.5±9.0mg/day,p<0.01). Mean follow-up after treatment was 44.5 months (IQR 36–120months), 48.6 months (IQR36–120months), and 45.3 (IQR36–120months) for IBCDT, MMF and CYC, respectively. At their last follow-up visit, we observed no significant differences in proteinuria and serum creatinine, nor in the frequency of new flares among the three groups.

Conclusion:

In biopsy proven LN, the IBCDT without further immunosuppressive maintenance therapy was shown to be as effective as conventional regimen of MMF or CYC followed by a 3-year maintenance MMF regimen. Moreover, the use of IBCDT was associated with a marked reduction of glucocorticoid cumulative dose.

Disclosure of Interests:

None declared

POS0504 IS BIOELECTRICAL PHASE ANGLE ASSOCIATED WITH FUNCTIONAL STATUS AND DISEASE IMPACT IN PATIENTS WITH RHEUMATOID ARTHRITIS?

Background:

Rheumatoid arthritis (RA) is a chronic inflammatory disease in which an abnormal body composition was reported to be highly prevalent. (1) Bioelectrical phase angle (PhA) is a measure of the relationship between electric resistance and reactance obtained via bioelectrical impedance analysis (BIA). (2) As an indicator of cellular health, PhA has been described as a predictor of worse clinical outcome and higher mortality in various conditions. (3) Since there is evidence that PhA is related to disease progression and prognosis when considering chronic inflammatory conditions, a lower PhA may also be considered an indicator of a worse prognosis in RA. (1)

Objectives:

To study the association between PhA, functional status and impact of disease in RA patients.

Methods:

Observational and cross-sectional study, including 53 patients with RA diagnosis according to the ACR/EULAR 2010 criteria. Each patient demographic data was recorded, and body composition, including PhA by BIA, was obtained. BIA was performed using Bodystat QuadScan 4000 equipment. Functional status and impact of disease were assessed using the Health Assessment Questionnaire (HAQ) and the Rheumatoid Arthritis Impact of Disease (RAID) scores, respectively. PhA was stratified by tertiles (lowest, middle and highest) to create groups of patients. Statistical analysis was performed using student’s t-test (IBM SPSS version 26) for comparisons between groups.

Results:

A total of 53 patients with RA (81.1% women) with an average age of 62.2 ± 10.2 years were assessed. Mean PhA was 5.8 ± 1.7 °. A PhA lower than 5.2 ° (lowest tertile) was recorded in 17 patients; A PhA ranging from 5.2 ° to 6.0 ° (middle tertile) was observed in 18 patients; A PhA greater than 6.0 ° (highest tertile) was seen in 18 patients. Mean HAQ score was 1.43 ± 0.61 in the lowest tertile, 0.85 ± 0.57 in the middle tertile and 0.67 ± 0.57 in the highest tertile. Mean RAID score was 5.86 ± 1.69 in the lowest tertile, 4.73 ± 2.05 in the middle tertile and 3.00 ± 1.94 in the highest tertile. The statistical analysis showed significant differences in both HAQ and RAID scores between the lowest and the highest tertiles (p=0.001 and p <0.001, respectively). Significant differences were also found between the lowest and the middle tertile for HAQ score (p=0.007) and between the middle and the highest tertile for RAID score (p=0.017).

Conclusion:

In our cohort a lower PhA was significantly associated with higher HAQ and RAID scores, indicating higher disease impact and higher disability in RA patients with lower PhA. These results support the hypothesis that PhA may be investigated as a possible indicator of disease prognosis in RA.

References:

[1]Pineda-Juárez JA, Lozada-Mellado M, Ogata-Medel M, Hinojosa-Azaola A, Santillán-Díaz C, Llorente L, et al. Body composition evaluated by body mass index and bioelectrical impedance vector analysis in women with rheumatoid arthritis. Nutrition. 2018;53:49–53.

[2]Rinaldi S, Gilliland J, O’Connor C, Chesworth B, Madill J. Is phase angle an appropriate indicator of malnutrition in different disease states? A systematic review. Clin Nutr ESPEN. 2019;29:1–14.

[3]Norman K, Stobäus N, Pirlich M, Bosy-Westphal A. Bioelectrical phase angle and impedance vector analysis - Clinical relevance and applicability of impedance parameters. Clin Nutr. 2012;31(6):854–61.

Disclosure of Interests:

None declared