The interferon in idiopathic inflammatory myopathies: Different signatures and new therapeutic perspectives. A literature review

Idiopathic inflammatory myopathies (IIM), even though sharing common clinical manifestations, are characterized by diversified molecular pathogenetic mechanisms which may account for the partial inefficacy of currently used immunomodulatory drugs. In the last decades, the role of interferon (IFN) in IIM has been extensively elucidated thanks to genomic and proteomic studies which have assessed the molecular signature at the level of affected tissues or in peripheral blood across distinct IIM subtypes. A predominant type I IFN response has been shown in dermatomyositis (DM), being especially enhanced in MDA5+ DM, while a type 2 IFN profile characterizes anti-synthetase syndrome (ASyS) and inclusion body myositis (IBM); conversely, a less robust IFN footprint has been defined for immune-mediated necrotizing myopathy (IMNM). Intracellular IFN signaling is mediated by the janus kinase/signal transducer and activator of transcription (JAK/STAT) through dedicated transmembrane receptors and specific cytoplasmic molecular combinations. These results may have therapeutic implications and led to evaluating the efficacy of new targeted drugs such as the recently introduced janus kinase inhibitors (JAKi), currently approved for the treatment of rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis. In this review we aim to summarize the most significant evidence of IFN role in IIM pathogenesis and to describe the current state of the art about the ongoing clinical trials on IFN-targeting drugs, with particular focus on JAKi.

Sodium glucose co-transporter 2 inhibition prevents muscle energy metabolism changes in infarcted rats

Introduction

Skeletal muscle energy metabolism is commonly altered in heart failure patients, with a metabolic shift from oxidative to glycolytic muscle fiber. These changes contribute to reduced functional capacity. Sodium glucose co-transporter type 2 (SGLT2) inhibitors improve cardiovascular outcomes in both diabetic and non-diabetic patients, as well as those with and without heart failure. However, the effects of SGLT2 inhibitors on skeletal muscle during heart failure have not been established. The aim of this study was to assess the metabolic effect of empagliflozin (EMPA) on skeletal muscle of rats with myocardial infarction (MI)-induced heart failure.

Methods

One week after MI induction or simulated surgery, male Wistar rats were divided into four groups: Sham (n=10), Sham+Empa (n=12), MI (n=10), and MI+Empa (n=09). EMPA was added to rat chow (5 mg/kg/day). Rats were supplied with ad libitum water and chow for 12 weeks. Infarct size was measured by histological analysis. Metabolic enzyme activity in the soleus muscle was assessed by spectrophotometry. Statistical analysis: ANOVA and Tukey, and Student's t tests.

Results

Only rats with infarction size greater than 35% of total left ventricle area were included in this study. Infarction size did not differ between infarcted groups (MI 41.8±4.2; MI+Empa 40.7±5.7 of total left ventricle area). In the MI soleus muscle, metabolic enzyme activity of glucose-6-phosphate-dehydrogenase, citrate synthase and beta-hydroxy-acyl-dehydrogenase was higher than the Sham group. These changes were not observed in the MI+Empa group. MI+Empa had lower hexokinase, phosfructokinase, and pyruvate kinase activity (glycolytic metabolism enzymes), and lower citrate synthase and glucose-6-phosphate-dehydrogenase activity than MI.

Conclusion

Chronic treatment with SGLT2 inhibitor empagliflozin prevents metabolic abnormalities in skeletal muscle in infarcted rats.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): CAPES, CNPq, FAPESP

Influence of long-term sodium-glucose cotransporter 2 inhibition on cardiac remodeling in rats with type 1 diabetes mellitus

Background

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have beneficial effects on the cardiovascular system in diabetes mellitus (DM) patients. However, as most clinical trials were performed in type 2 DM, the effects of SGLT2 inhibitors in patients with type 1 DM still need further clarification. In this study, we evaluated the effects of long-term treatment with the SGLT2 inhibitor dapagliflozin on cardiac remodeling, myocardial function, and energy metabolism in rats with type 1 DM.

Methods

Male Wistar rats were divided into three groups: control (C, n=15); DM (n=15); and DM treated with dapagliflozin (DM+DAPA, n=15) for 30 weeks. DM was induced by streptozotocin; DAPA was added to the rat chow (5 mg/kg/day). Cardiac performance was evaluated by echocardiogram and myocardial function in isolated left ventricular (LV) papillary muscle preparations. Myocardial energy metabolism enzyme activities were evaluated by spectrophotometry. Statistical analyzes: ANOVA and Tukey or Kruskal-Wallis and Dunn.

Results

DM+DAPA had lower glycemia than DM [C 112 (108–116); DM 531 (522–535)*; DM+DAPA 267 (179–339) mg/dL; p<0.05 vs C and DM+DAPA]. Echocardiogram showed that DM and DM+DAPA had left atrium and left ventricle dilatation with systolic and diastolic dysfunction; in DM+DAPA, the changes were attenuated in relation to DM. Developed tension and +dT/dt were higher in DM+DAPA than DM in basal condition. After inotropic stimulation with post-pause contraction, extracellular calcium concentration elevation, and isoproterenol addition to the nutrient solution, +dT/dt and –dT/dt were higher in DM+DAPA than DM. Hexokinase, phosphofructokinase, and pyruvate kinase activity was lower in DM than the C. Phosphofructokinase and pyruvate kinase activity was higher in DM+DAPA than DM.

Conclusion

Long-term dapagliflozin treatment attenuates cardiac remodeling and myocardial dysfunction and preserves hexokinase, phosphofructokinase and pyruvate kinase activity in rats with type 1 diabetes mellitus.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): CNPq - National Council for Scientific and Technological Developmentdoctor

AB0441 PREDICTORS OF CLASI RESPONSE OVER TIME IN A MULTICENTRIC REAL LIFE COHORT OF SLE PATIENTS TREATED WITH BELIMUMAB

Background

Over 80% of patients affected with SLE experience skin involvement. The anti-BLyS drug belimumab was shown effective in ameliorating mucocutaneous SLE manifestations in clinical trials and real-life studies. Cutaneous response is quantified through the CLASI (cutaneous lupus erythematosus area and severity index). Clinically relevant improvements are defined as decreases of ≥50% (CLASI50) or 70% (CLASI70) from baseline values.

Objectives

To assess rates and predictors of CLASI50 and CLASI70 in the Berliss multicentric SLE cohort1 of patients treated with belimumab.

Methods

Baseline and ongoing features of patients with baseline active skin involvement (CLASI>0) were assessed in relationship to the chosen outcomes CLASI50 and CLASI70 at 24 and 52 weeks. A subanalysis on patients with CLASI≥5 was as well conducted. Logistic regression was employed to identify predictors of response.

Results

172 patients displayed skin involvement at baseline (CLASI>0). Of those, 124 displayed at least a 12-month-follow-up and were included in the analysis. Seventy-seven (62.1%) patients reached CLASI50 at 24 weeks and 91 (77.8%) at 52 weeks; 87 (70.2%) reached CLASI70 at 24 and 99 (79.8%) at 52 weeks. Baseline predictors of CLASI50 at 24 weeks were CLASI-damage (CLASI-d) (OR [95%CI], p; 0.79 [0.65-0.98] 0.03) and disease duration (0.93[0.86-0.99], 0.011). No baseline predictors of CLASI70 at 24 weeks emerged, however having achieved a CLASI50 response at 24 weeks portended CLASI50 and 70 response through week 52 (p<0.01, Table 1). In the subgroup of patients with CLASI≥5, longer disease and increased CLASI-d at baseline confirmed as negative predictors of CLASI50 at 24 weeks. In this subset, use of antimalarials and active smoking at baseline predicted CLASI70 at 24 weeks (Table 1).

Table 1.

Predictors of CLASI-A Response at Week 24 and 52 by Baseline CLASI-A at 50% and 70% Response Thresholds

TimepointOutcomeVariableOR[95%CI] pCLASI>024 weeksCLASI50CLASI-d0.79 [0.65-0.98] 0.030Disease duration0.93[0.86-0.99], 0.011CLASI70CLASI-d0.93 [0.74-1.16], 0.51Disease duration0.97 [0.97-1.02], 0.1852 weeksCLASI50CLASI50 at 24 weeks14.3[4.88-44.42], <0.001CLASI70CLASI50 at 24 weeks6.22 [2.00-19.34], 0.002CLASI≥524 weeksCLASI50CLASI-d0.72 [0.53-0.98], 0.037Disease duration0.93 [0.66-1.00], 0.071CLASI70Antimalarials6.61 [1.20-36.29] 0.032Smoking0.15 [0.03-0.83], 0.03452 weeksCLASI50CLASI50 at 24 weeks22.0 [2.47-196.05], 0.006CLASI70CLASI50 at 24 weeks1.24 [0.06-25.08], 0.88

CLASI, cutaneous lupus erythematosus area and severity index; CLASI-d, CLASI damage; CLASI50 and CLASI70: decrease ≥50% or ≥70% in CLASI from baseline. OR and 95%CIs are estimated using a logistic regression model with stratification factors as covariates (SLEDAI-2K at baseline, baseline prednisone dosage).

Conclusion

Earlier use of belimumab favors achievement of skin response among SLE patients and attainment of a prompt response predicts further response. Use of antimalarials reinforces while smoking hampers a more profound CLASI improvement over time.

References:

[1]Gatto M, et al. Arthritis Rheumatol. 2020 Aug;72(8):1314-1324

Disclosure of Interests

Mariele Gatto Speakers bureau: GSK, Grant/research support from: GSK, Roberto Depascale: None declared, Angela Tincani: None declared, Giacomo Emmi: None declared, Salvatore Scarpato: None declared, Fabrizio Conti: None declared, Marcello Govoni: None declared, Marta Mosca: None declared, Maria Gerosa: None declared, Enrica Bozzolo: None declared, Valentina Canti: None declared, Armando Gabrielli: None declared, Elisa Gremese: None declared, Salvatore De Vita: None declared, francesco ciccia: None declared, Carlo Salvarani: None declared, Maurizio Rossini: None declared, Paola Faggioli: None declared, Antonella Laria: None declared, Amato De Paulis: None declared, Roberto Gerli: None declared, Enrico Brunetta: None declared, Alessandro Mathieu: None declared, Carlo Selmi: None declared, Rossella De Angelis: None declared, Simone Negrini: None declared, Margherita Zen: None declared, Andrea Doria Speakers bureau: GSK, Eli Lilly, Roche, Grant/research support from: GSK, Luca Iaccarino Speakers bureau: GSK, Grant/research support from: GSK

POS0391 TRENDS IN THE DIAGNOSIS OF MYOSITIS AND ASSOCIATION WITH THE CORONAVIRUS-19 PANDEMIC AND VACCINES: DATA FROM THE VENETO RARE DISEASE REGISTRY, 2014-2021

Background

There are uncertainties regarding the occurrence of idiopathic inflammatory myopathies (IIM) after infection by Severe Acute Respiratory Syndrome (SARS)-CoronaVirus2(CoV2) or in recipients of Coronavirus disease-19 (Covid-19) vaccines.

Objectives

Herein, the main objective was to assess temporal trends of newly diagnosed IIM in the past eight years, including the effects of the Covid-19 pandemic.

Methods

We extracted data of IIM patients from the Veneto Rare Disease Registry from 01/01/2014 and 31/12/2021. This regional registry has to be considered comprehensive of all patients with IIM in a specific geographical area. Hence, we extracted the following information: age; sex; date of diagnosis; type of IIM including dermatomyositis (DM), polymyositis (PM), anti-synthetase syndrome (ASS), inclusion body myositis (IBM); place of residence. We restricted the analysis to IIM patients certified by expert rheumatologists belonging to the Regional Centre for Study and Treatment of Connective Tissue and other Rare Diseases at the Division of Rheumatology, University of Padua, Veneto, Italy. Finally, we compared new IIM cases before and after 04/01/2021 as the starting date for the vaccination campaign in Veneto. We reported descriptive statistics (median and interquartile range) and results of non-parametric tests to compare cases of IIM across the study period.

Results

Database extraction retrieved 192 people with IIM diagnosed during the study period (DM 85, PM 82, ASS 23, IBM 2; females 67.2%; median [25th-75th percentile] age at diagnosis 58.5 [49.6-68.5] years). There was a median of 2 [1-4] newly-diagnosed IIM monthly, with a non-significant increase in the post-pandemic two-year period 2020-2021 (Figure 1A). Numerically, 2020 had the most IIM diagnosis (N=30), mainly clustered in the second (N=12) and third (N=11) trimesters. Trends of new IIM diagnoses over one year course were similar during the study period, with visually identified higher IIM occurrence in February, April and September (Figure 1B). There was no difference in incident IIM cases in the 12 months before (N=31) and after (N=29) the initiation of the vaccination campaign (7 [5-9.8] vs 8 [3-12] new cases for each trimester; Mann-Whitney U test p=0.884). Finally, there was a significant trend for median age at diagnosis increasing by 6.46 years from 55.4 to 61.8 years between 2014 and 2021 (p=0.015, R2=0.344; repeated measures ANOVA with post test for linear trend).

Conclusion

We found no significant change in patterns of IIM diagnoses between 2014 and 2021 besides a slight numerical increase in the second and third trimesters of 2020. In addition, we noted no signals of increased IIM diagnoses after introducing Covid-19 vaccines. This data encourage further analyses of larger, multicentre datasets from other geographical areas to clarify whether there has been variation in specific myositis subtypes across new-onset IIM after the pandemic.

Acknowledgements

We acknowledge Dr Monica Mazzuccato and Registro Malattie Rare - Regione Veneto for providing data.

Disclosure of Interests

None declared

C24 TWIDDLER SYNDROME AND HEART FAILURE: INTEGRATION OF REMOTE MONITORING AND CARDIOLOGY TELECONSULTATION FOR OPTIMAL MANAGEMENT

The prevalence of heart failure in the population and the COVID pandemic have rendered increasingly necessary the integration of remote monitoring with cardiology teleconsultation. A patient with dilated cardimiopathy was subjected to ICD implantation (Boston Scientific Perciva DR) with remote monitoring (LatitudeTM). One month after implant, remote monitoring recorded an increase in the HeartLogicTM heart failure index, a decrease of right ventricular and atrial sensing, contextually to fluctuations of the impedance values of the two leads (Fig. 1). The patient reported having performed shoulder’s rehabilitation therapy with probable manipulation of the ICD pocket. Chest X–ray showed dislocation of both leads with distal end of right atrial catheter in superior vena cava and distal end of right ventricular catheter in right atrium (Fig. 2A) and kinking of proximal segments (Fig. 2B), a picture compatible with diagnosis of Twiddler‘s syndrome. Implant revision confirmed lead kinking in the subcutaneous pocket (Fig. 3A). The atrial catheter, given the amount of tissue deposited at its distal end (Fig.3B) which prevented its active fixation, was replaced. Following discharge, an increase in the HeartLogicTM Heart Failure Index was detected. The outpatient visit showed the presence of pleural effusion and medical therapy was therefore optimized. In order to avoid frequent ambulatory visits to the patient, a cardiology teleconsultation was planned, which enabled to verify the clinical benefit of therapy’s variation. Remote device monitoring confirmed HeartLogicTM Heart Failure Index normalization. In conclusion, the integration of remote monitoring with cardiology teleconsultation, enables to timely detect device malfunctions and prevent episodes of heart failure, avoiding further hospitalizations. This integration is even more useful and necessary in geographically disadvantaged areas, strengthening the link between the territory and the hospital, improving patients compliance and therapeutic adherence and thus allowing a progressive improvement of the symptoms and quality of life of heart failure patients.

Subgingival periodontal pathogens in Down syndrome children without periodontal breakdown. A case-control study on deciduous teeth

AIM

Down syndrome is the most common form of aneuploidia compatible with a long survival. The affected subjects are more susceptible to severe early-onset periodontal disease and show a lower risk to develop dental caries than the non-affected population. This study investigated the prevalence of periodontal pathogens in the subgingival plaque of deciduous teeth in children with Down syndrome without signs of periodontal breakdown.

METHODS

Thirty children suffering from Down syndrome and 46 matched healthy subjects were studied. A total of 228 subgingival plaque samples from deciduous teeth were separately collected and evaluated by polymerase chain reaction assays.

CONCLUSION

In absence of periodontal impairment, Down syndrome children display a clear presence of periodontal pathogens already in the deciduous dentition. The hypothesis of an intrinsic predisposing condition is here supported.

OP0186 CHANGES IN CIRCULATING B CELL LEVELS AND IMMUNOPHENOTYPE ARE ASSOCIATED WITH DEVELOPMENT OF ARTHRITIS FOLLOWING TREATMENT WITH CHECKPOINT INHIBITORS

Background:

Inflammatory arthritis (IA) is frequent among rheumatic side effects induced by checkpoint inhibitor (CPI) therapy for metastatic malignancies1. While T cells are likely to sustain the inflammatory process2, fewer data are available concerning the role of B cells3.

Objectives:

To investigate the phenotype of circulating B cells in patients who develop CPI-induced IA (CPI-IA) and to compare it with features of B cells in patients not developing immune-related adverse events (irAE) upon CPI treatment.

Methods:

B cell subsets at baseline (before CPI initiation) and during CPI treatment were analyzed in CPI-IA patients and in patients receiving CPI but who did not develop irAE (non-irAE). Peripheral blood mononuclear cells (PBMC) were analyzed by flow cytometry and B cells were identified as CD19+ and divided into naïve (CD27-IgD+), memory (CD27+IgD+/-), double negative (CD27-IgD-) and transitional (CD10+CD24+CD38+/hi) B cells. Levels of CD21, an activation marker on transitional B cells, were also analyzed. Non-parametric tests were used for analysis of differences between groups.

Results:

Six CPI-IA and 7 non-irAE patients matched for age, gender and CPI treatment were included, who had received CPI treatment due to metastatic melanoma. Flow cytometry revealed a significant increase of circulating B cells (p=0.002) (Figure 1A) and especially of transitional B cells in CPI-IA patients vs. non-irAE (median %, range: 7.8 (4.5-11.4) vs. 3.2 (1.6-4.3),p=0.007) (Figure 1B), while no remarkable changes were seen across other subsets. Transitional B cell levels significantly decreased from active to quiescent CPI-IA in all patients (p=0.008). In two CPI-IA patients for whom baseline sampling was available, the increase of transitional levels occurred early after CPI treatment and before CPI-IA onset. Levels of expression of CD21 on transitional B cells were increased in CPI-IA vs. non-irAE (p=0.01).

Conclusion:

Transitional B cells are expanded in CPI-IA patients and seem to increase early after start of CPI therapy. Monitoring this B cell subset might lead to closer follow-up and earlier diagnosis of CPI-IA.

References:

[1]Ramos-Casals M, Brahmer JR, Callahan MK, et al. Immune-related adverse events of checkpoint inhibitors. Nat Rev Dis Primers 2020;6:38

[2]Murray-Brown W, Wilsdon TD, Weedon H, et al. Nivolumab-induced synovitis is characterized by florid T cell infiltration and rapid resolution with synovial biopsy-guided therapy. J Immunother Cancer 2020;8:e000281

[3]Das R, Bar N, Ferreira M, et al. Early B cell changes predict autoimmunity following combination immune checkpoint blockade. J Clin Invest. 2018;128:715-2

Disclosure of Interests:

None declared

POS0693 EFFICACY AND SAFETY OF BELIMUMAB IN PATIENTS WITH LUPUS NEPHRITIS IN REAL-LIFE SETTING: RESULTS FROM A LARGE, NATIONWIDE, MULTICENTRIC, PROSPECTIVE COHORT

Background:

LN is still a severe manifestation of Systemic lupus erythematosus (SLE) and multitarget therapy is needed to control the disease especially in refractory cases.

Objectives:

To evaluate renal response in SLE patients with glomerulonephritis (GN) treated with Belimumab in real-life setting.

Methods:

Patients with proteinuria >0.5 g/24 h and/or active sediment at baseline enrolled in a multicentre Italian cohort of SLE patients (BeRLiSS study), treated with monthly iv Belimumab 10 mg/kg plus standard of care were considered in this study. Complete renal response (CRR) was defined as proteinuria <0.5 g/24 h, estimated glomerular filtration rate (eGFR)≥90ml/min/1.73m2 and no rescue therapy. Primary efficacy renal response (PERR) was defined as proteinuria ≤0.7 g/24 h, eGFR ≥60ml/min/1.73m2 and no rescue therapy. Prevalence and predictive factors of CRR and PERR at 12 and 24 months after Belimumab initiation were analyzed by multivariate logistic regression analysis.

Results:

A total of 91 patients were considered in this study, 79 female, mean age 40.51±9.03 years, mean disease duration 12.18±8.15 years, median follow-up time after Belimumab initiation 22 months. Twenty patients had baseline proteinuria ≥0.5 <1 g/day, 17 ≥1 <2 g/day, 13 ≥2 g/day. Belimumab was started at GN onset in 20 (22%) patients and at the time of a renal flare in all other cases. Seventy-five patients underwent a renal biopsy: 1 class I, 4 class II, 14 class III, 47 class IV and 9 class V. Baseline serum creatinine was 82.44±29.26 umol/L; 15 patients showed eGFR<60ml/min/1.73m2 at baseline. Immunosuppresants were taken by 70 (76.9%) patients: 47 micofenolate, 15 azathioprine and 5 ciclosporine. Sixty patients (65.9%) were on antimalarials. During follow-up 34 (37.4%) patients achieved CRR. Among them 5 (14.7%) patients relapsed and 29 (85.3%) patients maintained remission. Mean time to achieved CRR was 9.71±5.91 months.

High levels of baseline proteinuria were a negative independent predictor of CRR and PERR at 6 months (OR 0.044 CI95% 0.006-0.320 p=0.002 and OR 0.232 CI95% 0.091-0.596 p=0.002) and 12 months (OR 0.029 CI95% 0.002-0.556 p=0.019 and OR 0.056 CI95% 0.009-0.327 p=0.001). High levels of baseline creatinine were a negative independent predictor of renal response. Renal response at 6 months was a strong predictive factor of renal response at 12 and 24 months.

Conclusion:

Belimumab is an effective add-on therapy in the treatment of GN in real-life practice setting.

Disclosure of Interests:

None declared

Effects of late aerobic exercise on cardiac remodeling of rats with small myocardial infarction

Background

Physical exercise has been highlighted as an important non-pharmacological therapy for prevention and treatment of several cardiovascular diseases. However, its effects on hearts with minor cardiac remodeling are not clear.

Purpose

To evaluate the influence of aerobic physical exercise on functional capacity, cardiac structure, left ventricular (LV) function, and gene expression of NADPH oxidase subunits in rats with small-sized myocardial infarction (MI).

Methods

Three months after MI induction, Wistar rats were divided into three groups: Sham; sedentary MI (MI-SED); and aerobic exercised MI (MI-EA). Rats exercised three times a week for 12 weeks on a treadmill. Echocardiogram was performed before and after experimental period. Infarction size and cardiomyocyte diameters were evaluated by histology. Gene expression was assessed by RT-PCR.

Results

Only rats with MI size lower than 30% of LV total area were included in the study. Functional capacity was higher in MI-AE than the other groups. Infarction size did not differ between groups. Infarcted rats had increased LV diastolic and systolic diameter, left atrial diameter, and LV mass, with systolic dysfunction. LV diastolic posterior wall thickness was higher in MI-AE than Sham, and relative wall thickness was lower in MI-SED than MI-AE and Sham groups. Cardiomyocyte diameter was smaller in infarcted groups than Sham. Myocardial gene expression of the NADPH oxidase subunits NOX2, NOX4, p22phox, and p47phox did not differ between groups.

Conclusion

Small-sized myocardial infarction changes cardiac structures and left ventricular systolic function. Late aerobic physical exercise improves functional capacity and cardiac remodeling by preserving left ventricular geometry. NADPH oxidase subunits gene expression is not involved in cardiac remodeling or modulated by aerobic exercise in rats with small myocardial infarction.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): CNPq; CAPES

SARS-CoV-2 infection in patients with autoimmune rheumatic diseases in northeast Italy: A cross-sectional study on 916 patients

Background

Whether patients with autoimmune rheumatic diseases (ARD) have a higher risk for SARS-CoV-2 infection (COVID-19) and how SARS-CoV-2 pandemic impacts on adherence to therapy has not been fully elucidated. We assessed the rate and clinical presentation of COVID-19, and adherence to therapy in a large cohort of patients with ARD followed-up in a tertiary University-Hospital in Northeast Italy.

Methods

Between April 9th and April 25th^, 2020, after SARS-CoV-2 infection peak, a telephone survey investigating the impact of COVID-19 on patients with systemic lupus erythematosus (SLE), systemic sclerosis (SSc), rheumatoid arthritis (RA), ANCA-associated vasculitis (AAV), and idiopathic inflammatory myopathies (IIM) was administered. Demographics, disease activity status, therapy, occupational exposure, and adherence to social distancing advise were also collected.

Results

916 patients (397 SLE, 182 AAV, 176 SSc, 111 RA, 50 IIM) completed the survey. 148 patients developed at least one symptom compatible with COVID-19 (cough 96, sore throat 64, fever 64, arthromyalgias 59, diarrhea 26, conjunctivitis 18, ageusia/hyposmia, 18). Among the 916 patients, 65 (7.1%) underwent SARS-CoV-2 nasopharyngeal swab (18 symptomatic and 47 asymptomatic), 2 (0.21%) tested positive, a proportion similar to that observed in the general population of the Veneto region. No deaths occurred. 31 patients (3.4%) withdrew ≥1 medication, mainly immunosuppressants or biologics. Adoption of social distancing was observed by 860 patients (93.9%), including 335 (36.6%) who adopted it before official lockdown.

Conclusions

COVID-19 incidence seems to be similar in our cohort compared to the general population. Adherence to therapy and to social distancing advise was high.

•

SARS-CoV-2 infection rate in ARDs seems to be similar to that of the general population.

•

Adoption of social distancing measures was prevalent among different ARD groups.

•

Earlier social distancing was more common in unremitted patients, treated with multiple drugs.

•

Therapy discontinuation due to COVID-related concerns was rare, but undertaken even by active patients.

•

Therapeutic regimens based on ≥3 drugs were associated with therapy discontinuation in our cohort.

SAT0163 IMMUNOSUPPRESSANT WITHDRAWAL AFTER REMISSION ACHIEVEMENT IN LUPUS NEPHRITIS: EFFECT ON FLARE OCCURRENCE

Background:

Whether and when immunosuppressive therapy may be safely withdrawn in patients with lupus nephritis (LN) is still poorly defined. Indeed, there is no clear agreement about the optimal duration of maintenance treatment.

Objectives:

We aimed at assessing the rate and predictors of flare after IS withdrawal in patients with LN in remission.

Methods:

Patients with systemic lupus erythematosus (SLE) (ACR criteria) and biopsy-proven LN diagnosed between 1990 and 2019, ever treated with IS and currently in follow-up were considered. IS discontinuation was defined as the complete withdrawal of any immunosuppressive drug in patients in remission. Remission was defined as normal serum creatinine, proteinuria <0.5 g/24h, inactive urine sediment, and no extra-renal SLE activity (clinical SLE Disease Activity Index [c-SLEDAI]-2K=0) on a stable immunosuppressive and/or antimalarial therapy and/or on prednisone ≤5 mg/day. Flares were defined according to SLEDAI Flare Index; renal flare was defined as an increase of proteinuria >0.5 g/24h requiring an increase in corticosteroid therapy or the reintroduction of IS. Predictors of a subsequent flare were analyzed by multivariate logistic regression analysis.

Results:

Out of 456 SLE patients regularly followed-up, 206 (45.1%) had LN and were considered in our study. Eighty-three patients (40.3%) discontinued IS after remission achievement (Table 1). After stopping therapy, patients were followed for a mean±SD of 99±77 months (range 12-378). Nineteen patients (22.8%) developed a flare after IS discontinuation, after a mean±SD follow-up of 78±68 months (range 7-312), and were re-treated; among them, 6 patients (7.2%) experienced a renal and 13 (15.6%) an extra-renal flare. Compared to patients who flared, patients in persistent IS-free remission had longer remission before IS withdrawal (51.2±31.5 vs. 29.3±16.5 months, p<0.001), and continued antimalarials after IS discontinuation (p=0.005). No differences in flare occurrence according to the type of IS discontinued were found. At multivariate analysis, therapy with antimalarials was the strongest protective factor against disease flare (OR 0.06, 95% CI 0.11-0.41, p=0.004) (Table 2). At last follow-up, mean±SD SLEDAI-2K was 3.1±2.8 and 1.5±1.6 in patients who experienced or not a flare after IS discontinuation, respectively (p=0.058), Indeed, 10/19 patients (52.5%) who developed a flare re-achieved remission.

Table 1.

Characteristics of 83 patients with LN in remission who discontinued immunosuppressive therapy, overall and according to flare occurrence

Total patients (83)Patients with flare (19)Patients without flare (64)P valueFemale, N(%)72 (88.7)16 (84.2)56 (87.5)nsAge at 2019, years43±1139±11.545±10.40.049SLE duration at 2019, years18±916.7±9.018.6±8.6nsSLE duration at IS discontinuation, years9.7±7.67.1±6.110.5±7.8nsTime to achieve remission, months27±3722.1±35.628.5±37.6nsRemission duration at IS discontinuation, months46±3029 ±16.551±31.5<0.001IS therapy duration, years6.7±4.35.2±3.87.1±4.20.061Anti dsDNA, N(%)65 (78.3)18 (95)47 (73)0.059HCQ after IS discontinuation, N(%)67 (80.7)12 (63.1)55 (85.9)0.005

IS, immunosuppressant; HCQ, hydroxychloroquine

Table 2.

Multivariate logistic regression: predictors of flare occurrence

Dependent variable: flare occurrenceOR95% CIp valueNumber of ISs, ever3.2641.030-10.3420.044HCQ therapy after IS discontinuation0.0960.014-0.6520.017Remission duration at IS discontinuation0.9540.912-0.9970.037Cyclophosphamide, ever0.0650.008-0.5480.012

IS, immunosuppressant; HCQ, hydroxychloroquine

Conclusion:

Based on our experience, withdrawal of IS is feasible in selected patients with LN, i.e. patients who achieved stable remission and received maintenance therapy with antimalarials. Patients who experience new flares can re-achieve remission with an appropriate treatment.

Disclosure of Interests: :

Margherita Zen Speakers bureau: BMS, Ely Lilly, Janssen, GSK, Mariele Gatto Speakers bureau: GSK, Francesco Benvenuti: None declared, Francesca Saccon: None declared, Maddalena Larosa: None declared, Luca Iaccarino Speakers bureau: GSK, Pfizer, Janssen, Novartis, Andrea Doria Consultant of: GSK, Pfizer, Abbvie, Novartis, Ely Lilly, Speakers bureau: UCB pharma, GSK, Pfizer, Janssen, Abbvie, Novartis, Ely Lilly, BMS

THU0249 CLINICAL FEATURES AND RENAL PROGNOSIS IN LUPUS NEPHRITIS PATIENTS UNDERGOING A REPEATED BIOPSY: RESULTS OF 103 RE-BIOPSIES IN 438 PATIENTS

Background:

Indications to repeat renal biopsy (RB) in lupus nephritis (LN) are not unanimously acknowledged.

Objectives:

To evaluate the renal outcome of patients with LN undergoing a second RB.

Methods:

We retrospectively analyzed prospectively collected data of patients with LN followed up in four Italian referral centres for systemic lupus eryhtematosus. Serological and clinical information were retrieved according to a shared database. RB were classified according to ISN/RPS 2003 classification; chronicity (CI) and activity indexes (AI) were defined according to Austin et al. The primary renal outcome was renal failure, defined as serum creatinine (SCr)>1.0mg/dL with eGFR<60ml/min. Non-parametric tests were used for statistics. Patients repeating RB due to renal remission were excluded from the analysis.

Results:

Four-hundred and thirty-eight patients were recruited. One-hundred and three patients repeated RB after 6.1±4.7 (mean± SD) years from the first due to: protocol biopsy due to renal remission (Group 1, n=8); proteinuric flare (Group 2, n=51); worsened renal function (Group 3, n=26); partial renal response (Group 4 n=18). Patients undergoing a second RB were younger (p<0.001), had lower serum C3 at LN diagnosis (p<0.001) and displayed more frequently class IV and higher AI at first RB (p=0.0038 and p=0.043, respectively). At the end of follow-up, patients who repeated RB had more frequently renal failure (p=0.003). At the second RB, the histological class was unchanged in 55% of patients. CI increased at second RB compared to the first (3.6±2.4 vs.1.7±1.7; p<0.001). Overall, 26 out of 103 patients (25%) developed renal failure: 0 from group 1, 10 from group 2, 14 from group 3, 2 from group 4 (p<0.001). Uncontrolled hypertension at LN diagnosis, increased SCr and increased proteinuria at second RB predicted renal failure (Table).

Conclusion:

Patients undergoing a repeated RB had more aggressive clinical and histological features already at first RB and developed renal failure more frequently. Among baseline features, uncontrolled hypertension had the strongest association with renal failure, thus suggesting that control of blood pressure since early stages is highly advisable.

References:

[1]Austin HA, et al. Predicting renal outcomes in severe lupus nephritis: contributions of clinical and histologic data. Kidney Int 1994;45:544–50.

Table .

Comparison of patients undergoing 2nd RB according to development of renal failure

Renal failure (n=26)No renal failure (n=69)*pTotal FU (years), mean (SD)21 (10.4)16.5 (9.39)0.002SCr (mg/dl) at 2° RB, mean (SD)1.7 (1)0.98 (0.35)0.001Proteinuria (g/24h) at 2° RB, mean (SD)4.7 (3.9)2.99 (2.63)0.022Class IV and IV+V at 2° RB, %76.954.50.07Hypertension at onset, %84.632.4<0.001HCQ intake at 2° RB, %9.552<0.001Glucocorticoids at 2° RB %8487nsImmunosuppressants at 2° RB %4058nsAI at onset, mean (SD)7.14 (3.95)7.02 (3.86)nsAI at 2° RB, mean (SD)5.37 (4.12)4.02 (3.71)nsCI at onset, mean (SD)2.05 (1.88)1.56 (1.64)nsCI at 2° RB, mean (SD)3.87 (3.08)3.52 (2.16)nsYears between 2° RB and end of FU, mean (SD)14.1 (10.5)9.3 (8.84)ns

*Group 1 excluded

RB, renal biopsy; AI, activity index; CI, chronicity index; SCr serum creatinine; FU, follow-up; SD, standard deviation.

Disclosure of Interests:

Mariele Gatto Speakers bureau: GSK, Francesca Saccon: None declared, Francesca Radice: None declared, Paolo Gilles Vercelloni: None declared, Renato Alberto Sinico: None declared, Giulia Frontini: None declared, Valentina Binda: None declared, Piergiorgio Messa: None declared, Federico Alberici: None declared, Gabriella Moroni: None declared, Andrea Doria Consultant of: GSK, Pfizer, Abbvie, Novartis, Ely Lilly, Speakers bureau: UCB pharma, GSK, Pfizer, Janssen, Abbvie, Novartis, Ely Lilly, BMS

Diagnostic and prognostic role of renal histopathology in rheumatic diseases

The objective was to evaluate renal involvement in several rheumatic diseases (i.e. rheumatoid arthritis, systemic lupus erythematosus, Sjögren syndrome, systemic sclerosis, systemic vasculitides). The method chosen was to define histopathological profiles reported in renal biopsies performed on patients with renal involvement due to different rheumatic diseases. Renal involvement observed in patients with rheumatic disease can be the direct result of the disease per se and/or a complication of drugs used in the disease treatment. The clinical-pathological correlations derived from the study of renal tissues can be useful for differential diagnosis, prognosis assessment and therapeutic decisions. Renal biopsy should be considered as an important tool for the management of nephropathies in patients with systemic rheumatic diseases.

Participation of TLR2 and TLR4 in Cytokines Production by Patients with Symptomatic and Asymptomatic Chronic Chagas Disease

Chagas disease (CD), caused by the protozoan Trypanosoma cruzi, is a serious public health issue. Its evolution involves an acute stage, characterized by no specific symptoms, and the chronic stage during most individuals are asymptomatic, but about 30-40% of them become symptomatic presenting the cardiac or digestive disease. Host immune response mechanisms involved in symptomatic or asymptomatic chronic disease are not fully understood. The pro-inflammatory cytokines are crucial in host resistance. However, a fine control of this inflammatory process, by action of anti-inflammatory cytokines, is necessary to avoid tissue injury. This control was found to be responsible for no clinical manifestations in asymptomatic individuals. Toll-like receptors (TLRs) are extremely important in defining the cytokine profile released in response to a micro-organism. We found that patients with the cardiac form predominantly released the pro-inflammatory cytokines: IFN-γ, TNF-α and IL-17 with the involvement of both, TLR2 and TLR4. In contrast, patients with asymptomatic disease release predominantly the anti-inflammatory cytokines IL-10 and TGF-β, but also with TLR2 and TLR4 participation. The mechanisms by which stimulation of the same TLRs results in release of different pattern of cytokines, depending on the patients group that is being evaluated, are discussed.

17-β-estradiol affects BLyS serum levels and the nephritogenic autoantibody network accelerating glomerulonephritis in NZB/WF1 mice

Systemic lupus erythematosus (SLE) is an autoimmune disease that predominantly affects fertile women, suggesting sex hormones are involved in disease pathogenesis. B lymphocyte stimulator (BLyS) has been found to be elevated in SLE patients and to drive a lupus-like syndrome in transgenic mice. Our aim was to evaluate the effects of estrogen administration on BLyS and nephritogenic anti-C1q and anti-dsDNA antibodies in lupus-prone NZB/WF1 mice. We implanted pellets releasing 17-β-estradiol (18.8 µg/day) on the back side the ear of 10 NZB/WF1 mice (group 1), and compared them with 10 mice intraperitoneally injected with PBS 200 μl twice a week (group 2), as controls. We evaluated BLyS, anti-dsDNA and anti-C1q serum levels starting one week after pellet implantation. We also analyzed time to proteinuria onset, proteinuria-free survival and overall survival. Kidneys, spleen, liver and lungs were harvested for histological analysis. Mice were bred until natural death. BLyS serum levels were higher in group 1 than in group 2 mice at each evaluation. Group 1 mice developed nephritogenic antibodies and proteinuria significantly earlier and at higher levels than controls. Direct correlation between BLyS and anti-C1q (R (2 )= 0.6962, p < 0.0001) or anti-dsDNA (R (2 )= 0.5953, p < 0.0001), and between anti-C1q and anti-dsDNA autoantibodies (R (2 )= 0.5615, p < 0.0001) were found. Proteinuria-free and global survival rates were significantly lower in group 1 than in controls. Histological analyses showed more severe abnormalities in group 1 mice. Estrogen administration is associated with increased levels of BLyS as well as of anti-C1q and anti-dsDNA antibodies, leading to accelerated glomerulonephritis and disease progression in NZB/WF1 mice.

Value and goals of treat-to-target in systemic lupus erythematosus: knowledge and foresight

Treat-to-target is a therapeutic strategy aimed at improving disease outcome through the achievement of shared treatment goals, which has dramatically ameliorated the prognosis of widespread disorders, such as hypertension or diabetes. Conversely, efforts to delineate treat-to-target in systemic lupus erythematosus (SLE) have failed in pinpointing common goals and treatment strategies, probably because of disease heterogeneity and lack of measurable biomarkers predicting disease course and ensuring a safe treatment tapering during quiescence. Given the detrimental effects of persistent disease activity and protracted corticosteroid therapy on patients' outcome in lupus, disease remission should be pursued whenever possible. Fortunately, clinical remission is currently realistic for a greater number of patients than it was in the past, yet tight monitoring is required in order for patients to benefit from disease- and corticosteroid-free intervals, while minimizing the risk of disease flares. In everyday practice, patients should be brought to the lowest level of disease activity ensuring a significant benefit over a persistently active disease, being either clinical remission or low disease activity.

Gilles de la Tourette syndrome: clinical features of 75 cases from Argentina

A series of 75 cases of Gilles de la Tourette syndrome (GTS) from Argentina, whose ages ranged from 6 to 55 with a mean of 20.02, were evaluated to compare findings with those reported for other countries. Mean age at onset was 7.44 years and mean overall duration of symptoms was 12.58 years; 6.7% of cases were mild, 49% moderate and 44.3% severe. Most frequent presenting motor tics were excessive blinking in 41 followed by head jerking in 16 and eye winking in six, while phonic tics included coprolalia in 28.0%, echolalia in 17.5% and palilalia in 10.8%. Abnormal perinatal events were reported in 40.5%, while positive family history for tics was present in 26.66%. Obsessive-compulsive behaviour was evident in 66% and attention deficit disorder in 16% of cases. Self-injurious behaviour comprised onychophagia in 28 patients, lip-biting in seven and self-slapping in eight cases. Almost half of our patients were initially interpreted as having a psychogenic disorder indicating that GTS in Argentina is most likely underdiagnosed. It may be concluded that the overall pattern of GTS is not dissimilar to that described for European, Asian and American populations, thus highlighting the previously recognized cross-cultural uniformity.

Premature coronary heart disease in SLE: can we prevent progression?

Patients with systemic lupus erythematosus (SLE) have a higher prevalence of clinical and subclinical atherosclerosis compared with age- and sex-matched controls. Atherosclerosis progression is also accelerated in SLE, and coronary heart disease (CHD) is a major cause of morbidity and mortality.

Traditional cardiovascular (CV) risk factors, including hypertension, diabetes mellitus or dyslipidemia, are more prevalent in SLE patients than in the general population, but they cannot fully account for accelerated atherosclerosis in SLE. In fact, a number of nontraditional risk factors have been identified, including disease activity, damage and various treatments.

Preventive strategies for CHD are mandatory in SLE patients and should include giving up smoking; performing regular physical activity; managing metabolic abnormalities such as dyslipidemia, insulin resistance, and diabetes; treating persistent disease activity; and minimizing chronic exposure to corticosteroids. Low-dose aspirin, angiotensin-converting enzyme (ACE) inhibitors, vitamin D supplementation, antimalarials and, when indicated, some immunosuppressants such as mycophenolate mofetil should also be considered.

Nephritogenic-antinephritogenic antibody network in lupus glomerulonephritis

Lupus glomerulonephritis (LGN) is one of the most threatening manifestations of systemic lupus erythematosus (SLE) and a major predictor of poor prognosis. The mechanisms leading to kidney inflammation are not completely clear; however, autoantibodies seem to play a pivotal role. Apoptosis dysregulation in SLE is likely to trigger generation of autoantibodies, the released nucleosomes being the driving autoantigen for further epitope amplification and selection of DNA or nucleosome-specific B cells. Growing evidence supports a multistep path to LGN involving initial autoantibody binding to chromatin fragments in the mesangial matrix, where they can induce mesangial inflammation leading to a shut-down of the renal DNase gene, generation and deposition of secondary necrotic chromatin on the glomerular basement membrane favouring antibody binding, complement activation and development of membrano-proliferative glomerular lesions. Anti-DNA IgG antibodies display the major pathogenetic potential in LGN initiation; however, other isotypes (IgA or IgE) as well as autoantibodies targeting other molecules (e.g. anti-C1q, anti-C reactive protein) can perpetuate renal injury. Conversely, protective autoantibodies are also likely in SLE which can contain renal damage targeting either DNA (i.e. IgM anti-DNA) or other molecules (e.g. pentraxin 3). Thus, lupus nephritogenic-antinephritogenic antibodies orchestrate the balance between harm and defence of renal tissue.

Occupational exposure to styrene in the fibreglass reinforced plastic industry: comparison between two different manufacturing processes

BACKGROUND

Styrene is used in manufacturing fiberglass reinforced plastics: and occupational exposure was related to neurotoxicology and genotoxicity. The sum of the metabolites mandelic and phenylglyoxylic acids is the ACGIH biomarker for occupational exposure with a BEI of 400 mg/g of creatinine in end shift urine corresponding to a airborne styrene concentration of 85 mg/m3. There are two main molding processes, open and closed, the last more effective at controlling worker's styrene exposure.

OBJECTIVES

To compare the open molding process to the compression of fiber reinforced resin foils, a kind of closed molding, monitoring the styrene exposure of workers in two production sites (A and B).

METHODS

Environmental Monitoring was carried out by Radiello samplers and Biological Monitoring by means of the determination of MA and PGA with HPLC/MS/MS in 10 workers at Site A and 14 at Site B.

RESULTS

The median values for styrene exposure resulted 31.1 mg/m3 for Site A and 24.4 mg/m for Site B, while the medians for the sum of the two metabolites in the end shift urine were 86.7 e 33.8 mg/g creatinine respectively. There is a significant linear correlation between personal styrene exposure and the excretion of styrene metabolites (R = 0.74).

CONCLUSIONS

As expected the exposure markers of the workers of the two production sites resulted higher in the open process. The analytical results of both environmental and biological monitoring were all below the occupational exposure limits, confirming the efficacy of the protective devices.

Induction of the ‘ASIA’ syndrome in NZB/NZWF1 mice after injection of complete Freund’s adjuvant (CFA)

Adjuvants, commonly used in vaccines, may be responsible for inducing autoimmunity and autoimmune diseases, both in humans and mice. The so-called ‘ASIA’ (Autoimmune/inflammatory Syndrome Induced by Adjuvants) syndrome has been recently described, which is caused by the exposure to a component reproducing the effect of adjuvants. The aim of our study was to evaluate the effect of injection of complete Freund’s adjuvant (CFA) in NZB/NZWF1 mice, a lupus-prone murine model. We injected 10 NZB/NZWF1 mice with CFA/PBS and 10 with PBS, three times, 3 weeks apart, and followed-up until natural death. CFA-injected mice developed both anti-double-stranded DNA and proteinuria earlier and at higher levels than the control group. Proteinuria-free survival rate and survival rate were significantly lower in CFA-treated mice than in the control mice ( p = 0.002 and p = 0.001, respectively). Histological analyses showed a more severe glomerulonephritis in CFA-injected mice compared with the control mice. In addition, lymphoid hyperplasia in spleen and lungs, myocarditis, and vasculitis were observed in the former, but not in the latter group. In conclusion, the injection of CFA in NZB/NZWF1 mice accelerated autoimmune manifestations resembling ‘ASIA’ syndrome in humans.

Vaccination of patients with auto-immune inflammatory rheumatic diseases requires careful benefit-risk assessment

Will vaccination raise the incidence of autoimmune diseases, what is the impact of increasingly crowded vaccination schedules, the vaccination in age groups and the risk of coincidental temporal association? All these issues are still under debate. However, for the time being, to avoid confusion in the medical community and the media, we have to adhere to guidelines established consensually by experts while ensuring a strict surveillance and reporting possible side effects. Recommendation for vaccination in patients with autoimmune inflammatory rheumatic diseases (AIIRD) based on the currently available evidence and expert opinion were recently formulated by an EULAR task force. Major recommendations for AIIRD include: i) vaccination should ideally be administered during stable disease; ii) influenza vaccination and pneumococcal vaccination should be strongly considered; iii) vaccination can be administered during the use of DMARDs and TNF-inhibitors, but before starting rituximab; iv) live attenuated vaccines should be avoided whenever possible in immunosuppressed patients; v) BCG vaccination is not recommended.

Modelling cholera epidemics: the role of waterways, human mobility and sanitation

We investigate the role of human mobility as a driver for long-range spreading of cholera infections, which primarily propagate through hydrologically controlled ecological corridors. Our aim is to build a spatially explicit model of a disease epidemic, which is relevant to both social and scientific issues. We present a two-layer network model that accounts for the interplay between epidemiological dynamics, hydrological transport and long-distance dissemination of the pathogen Vibrio cholerae owing to host movement, described here by means of a gravity-model approach. We test our model against epidemiological data recorded during the extensive cholera outbreak occurred in the KwaZulu-Natal province of South Africa during 2000-2001. We show that long-range human movement is fundamental in quantifying otherwise unexplained inter-catchment transport of V. cholerae, thus playing a key role in the formation of regional patterns of cholera epidemics. We also show quantitatively how heterogeneously distributed drinking water supplies and sanitation conditions may affect large-scale cholera transmission, and analyse the effects of different sanitation policies.

Cholangiocarcinoma: risk factors and clinical presentation

Cholangiocarcinoma (CCA), a cancer originating from the neoplastic transformation of the biliary epithelium, is characterized by a progressive increase in incidence and prevalence. A number of risk factors have been identified including primary sclerosing cholangitis, liver fluke infestation, and hepatolithiasis. More recently, hepatitis viruses (HCV, HBV) have been taken into consideration as risk factors for the intrahepatic CCA and this could explain the increased incidence seen in the last two decades. All these risk factors induce chronic inflammation in the biliary epithelium together with partial bile obstruction. These two conditions are considered the background (chronic inflammation) favouring the cancer development. The only effective treatment is the radical surgical resection but, this is applicable in less than 40% of the patients since CCA is mostly diagnosed at an advanced stage. This mainly occurs because, in the majority of the cases, CCA is clinically silent, with symptoms only developing at an advanced stage but also for the lack of effective biomarkers to be used for a screening purpose. A number of serum and bile biomarkers have been recently proposed for the diagnosis of CCA but, their impact on the early diagnosis is still under the evaluation.

On spatially explicit models of cholera epidemics

We generalize a recently proposed model for cholera epidemics that accounts for local communities of susceptibles and infectives in a spatially explicit arrangement of nodes linked by networks having different topologies. The vehicle of infection (Vibrio cholerae) is transported through the network links that are thought of as hydrological connections among susceptible communities. The mathematical tools used are borrowed from general schemes of reactive transport on river networks acting as the environmental matrix for the circulation and mixing of waterborne pathogens. Using the diffusion approximation, we analytically derive the speed of propagation for travelling fronts of epidemics on regular lattices (either one-dimensional or two-dimensional) endowed with uniform population density. Power laws are found that relate the propagation speed to the diffusion coefficient and the basic reproduction number. We numerically obtain the related, slower speed of epidemic spreading for more complex, yet realistic river structures such as Peano networks and optimal channel networks. The analysis of the limit case of uniformly distributed population sizes proves instrumental in establishing the overall conditions for the relevance of spatially explicit models. To that extent, the ratio between spreading and disease outbreak time scales proves the crucial parameter. The relevance of our results lies in the major differences potentially arising between the predictions of spatially explicit models and traditional compartmental models of the susceptible-infected-recovered (SIR)-like type. Our results suggest that in many cases of real-life epidemiological interest, time scales of disease dynamics may trigger outbreaks that significantly depart from the predictions of compartmental models.

Size selectivity of fyke nets for European eel Anguilla anguilla

Size selectivity of fyke nets for European eels Anguilla anguilla was investigated by reviewing the results of published experimental studies. A general size selectivity model was then derived that can be easily incorporated into demographic models to simulate population dynamics, assess and monitor abundance and length structure of eel stocks and forecast the consequences of different management options.

Bile salts regulate proliferation and apoptosis of liver cells by modulating the IGF1 system

BACKGROUND

In different cell types, the insulin-like growth factor 1 and its receptor modulate growth, apoptosis and damage repair in cooperation with estrogen receptors.

AIM

To evaluate the involvement of the insulin-like growth factor 1 system and estrogen receptors in bile salts modulation of apoptosis/proliferation of hepatocytes and cholangiocytes. Primary cultures of rat hepatocytes and cholangiocytes were exposed to glycochenodeoxycholate or tauro-CDC in the presence or absence of insulin-like growth factor 1 receptor blocking antibody (alphaIR3), small interfering RNA for insulin-like growth factor 1, 17beta-estradiol or estrogen receptor antagonist (ICI 182,780). Proliferation was evaluated by proliferating cell nuclear antigen Western blot and apoptosis by measuring caspase-3 activity or annexin-V.

RESULTS

In hepatocytes, the insulin-like growth factor 1 receptor blocker enhanced glycochenodeoxycholate-induced apoptosis and caused tauro-CDC to promote apoptosis. 17Beta-estradiol or the estrogen receptor antagonist (ICI 182,780) did not influence the apoptotic effect of glycochenodeoxycholate. In cholangiocytes, both glycochenodeoxycholate and tauro-CDC induced proliferation at 100microM, while they induced apoptosis at 1mM with a more pronounced effect of glycochenodeoxycholate. Apoptosis induced by 1mM glycochenodeoxycholate or tauro-CDC in cholangiocytes was enhanced by blocking insulin-like growth factor 1 receptor or by silencing insulin-like growth factor 1. 17Beta-estradiol counteracts glycochenodeoxycholate-induced cholangiocyte apoptosis by enhancing insulin-like growth factor 1 secretion and activating the insulin-like growth factor 1 system.

CONCLUSIONS

Modulation of the IGF1 system could represent a potential strategy for the management of bile salts-induced liver injury.

Carbon emissions. The economic benefits of the Kyoto Protocol

The third Conference of the Parties in Kyoto set the target of reducing greenhouse-gas emissions by an average of 5.3% with respect to 1990 values by 2008-2012. One of the main objections to the protocol's ratification is that compliance would pose an unbearable economic burden on the countries involved. But we show here that this is not the case if costs apart from the direct costs of energy production are also considered. Costs are also incurred in rectifying damage to human health, material goods, agriculture and the environment related to greenhouse-gas emissions.

Quantifying the dynamics of prion infection: a bifurcation analysis of Laurent's model

Laurent (1996a, Médecine/sciences12, 774-785; 1996b, Biochem. J.318, 35-39; 1998, Bio-phys. Chem.72, 211-222) proposed a model for the dynamics of diseases of the central nervous system caused by prions. It is based on the protein-only hypothesis (Prusiner et al., 1981, Proc. Natl. Acad. Sci. U.S.A.78, 6675-6679), which assumes that infection can be spread by particular proteins (prions) that can exist in two forms that share the same sequence, but have a different structure. The normal form is harmless, while the infectious isoform of the prion protein catalyses a transconformation from the native isoform to itself within a specialized compartment of the brain cells. This paper systematically explores the model behavior with the aim of quantifying the fundamental parameters characterizing the dynamics of prion infection. To this end we use data from the literature to fix orders of magnitude for the rates of synthesis and degradation of the native form of prion protein and for the shape of the autocatalytic function. The dynamical behavior is classified with respect to two unknown parameters (bifurcation analysis): the rate of spontaneous transconformation and the rate of output of the infectious isoform from the specialized compartment. We thus find that the bistability properties evidenced by Laurent are confined to a certain range of parameters and that permanent oscillations of the two isoforms concentrations are possible. The bifurcation analysis allows us to estimate approximate ranges for the values of the two unknown parameters and consequently to derive incubation times and compare them with actual data for hamster. Also, our study predicts that the output rate of the infectious isoform is relatively insensitive to variations of model parameters.

Slow deep breathing prevents the development of tachygastria and symptoms of motion sickness

BACKGROUND

The purpose of this study was to see if slow deep breathing, a non-pharmacological procedure known to increase parasympathetic nervous system (PNS) activity, would prevent the development of gastric dysrhythmias and symptoms of motion sickness when subjects were exposed to a rotating optokinetic drum.

METHODS

Participating in this study were 46 healthy males and females aged 17-26 who were pre-tested in the rotating drum and found to be susceptible to motion sickness. They were randomly placed into one of the following three conditions: Slow Deep Breathing (n = 18), Counting Breaths (subjects were asked to count their breaths and asked for the count every 3 min, n = 16), and Control (subjects breathed normally, n = 12). Electrogastrograms were recorded from all subjects during a 6-min baseline and a 16-min rotation period. Subjects were asked about their symptoms every 3 min.

RESULTS

A significant difference in percent tachygastria from baseline to rotation was found between the three conditions. Percent tachygastria increased during rotation for the Counting Breaths group and the Control group, but remained the same as baseline for the Slow Deep Breathing group. The Slow Deep Breathing group (5.3) reported significantly fewer symptoms than the Counting Breaths group (9.0), but not the Control group (7.8).

CONCLUSION

In conclusion, slow deep breathing in a situation previously demonstrated to provoke tachygastria prevented the development of gastric dysrhythmias and decreased symptoms of motion sickness.

Effects of gender of subjects and experimenter on susceptibility to motion sickness

BACKGROUND

It has been reported that females are more susceptible to motion sickness than males, but these reports have failed to take into account the possible effects of the gender of the experimenter and the subjective nature of reports of symptoms of motion sickness. To deal with the first possible confound, we used male and female experimenters. To deal with the second issue, we recorded gastric myoelectric activity so as to be able to quantify gastric tachyarrhythmia, an objective measure that has been shown previously to correlate highly with severity of symptoms.

METHOD

There were 34 male and 34 female participants were assigned to either a male or female experimenter. Symptoms of motion sickness were induced by placing participants in an optokinetic drum for an 8-min baseline period followed by a 16-min rotation period. Electrogastrograms (EGGs) were continuously recorded, and reports of symptoms were obtained from the participants every 3 min during rotation.

RESULTS

Comparison of male and female subjects' symptom scores revealed that females had higher symptom scores than males; however, no significant main effects for gender of the subject or experimenter were found. However, on a post-session questionnaire, females reported experiencing significantly more GI symptoms than males. Gender comparisons of the change in gastric tachyarrhythmia power from baseline to rotation yielded no significant differences.

CONCLUSIONS

Females report more overall symptoms of motion sickness and significantly more GI symptoms than males, but do not show greater increases in gastric tachyarrhythmia during exposure to a rotating drum.

Evaluating a measure of everyday problem solving for use in African Americans

Results from previous research on everyday problem solving involving Caucasians suggests that it may be a useful concept in studying cognitive aging in African Americans. The purpose of this investigation was to examine: (1) the factor structure of an everyday problem solving in a sample of African Americans, (2) the internal consistency of everyday-problem solving in a sample of African Americans, and (3) the relationship of problem solving to demographic factors, physical functioning, and measures of fluid ability. The sample included subjects recruited from Baltimore, MD. The sample consisted of 249 community dwelling African-American adults with a mean age of 67.8 years (SD = 8.47). Variables included the Everyday Problem Solving Test (EPT), gender, age, education, physical functioning, and inductive reasoning. Everyday problem solving as a latent construct was confirmed and the split half reliability was high (.89). As in previous research, inductive reasoning and physical functioning were related to everyday problem solving abilities. We also found that certain domains of the EPT are more influenced by demographic factors than others. Our finding suggest that the Everyday Problems Test is appropriate for use with African American samples.

Acidic deposition, plant pests, and the fate of forest ecosystems

We present and analyze a nonlinear dynamical system modelling forest-pests interactions and the way they are affected by acidic deposition. The model includes mechanisms of carbon and nitrogen exchange between soil and vegetation, biomass decomposition and microbial mineralization, and defoliation by pest grazers, which are partially controlled by avian or mammalian predators. Acidic deposition is assumed to directly damage vegetation, to decrease soil pH, which in turn damages roots and inhibits microbial activity, and to predispose trees to increased pest attack. All the model parameters are set to realistic values except the inflow of protons to soil and the predation mortality inflicted to the pest which are allowed to vary inside reasonable ranges. A numerical bifurcation analysis with respect to these two parameters is carried out. Five functioning modes are uncovered: (i) pest-free equilibrium; (ii) pest persisting at endemic equilibrium; (iii) forest-pest permanent oscillations; (iv) bistable behavior with the system converging either to pest-free equilibrium or endemic pest presence in accordance with initial conditions; (v) bistable behavior with convergence to endemic pest presence or permanent oscillations depending on initial conditions. Catastrophic bifurcations between the different behavior modes are possible, provided the abundance of predators is not too small. Numerical simulation shows that increasing acidic load can lead the forest to collapse in a short time period without important warning signals.

Multicenter, double-blind, comparative clinical study on the efficacy and acceptability of a monthly injectable contraceptive combination of 150 mg dihydroxyprogesterone acetophenide and 10 mg estradiol enanthate compared to a monthly injectable contraceptive combination of 90 mg dihydroxyprogesterone acetophenide and 6 mg estradiol enanthate

Healthy, regularly menstruating women, aged 14-38 years, were enrolled in a comparative, double-blind, phase III, clinical trial to evaluate the contraceptive efficacy and acceptability of a combination of 90 mg dihydroxyprogesterone acetophenide with 6 mg estradiol enanthate compared to the commercially available contraceptive combination of 150 mg dihydroxyprogesterone acetophenide with 10 mg estradiol enanthate. Subjects received the contraceptive combination intramuscularly, between the 7th and 10th day of each menstrual cycle, during 12 consecutive menstrual cycles. Approximately 60% of the subjects in both groups completed the study. Principal reasons for discontinuation were personal, nonmedical reasons. Principal medical reasons for discontinuation were menstrual-related, irregular bleeding being the most frequent. Differences in menstrual patterns between the two groups did not lead to differences in discontinuation rates. Three contraceptive failures occurred during the trial, one in Group A (90/6 mg) and two in Group B (150/10 mg), indicating that the lower dose formulation is at least as efficient as the higher dose.

L-dopa malabsorption in a parkinsonian patient with Strongyloides stercoralis duodenitis

We report a parkinsonian patient initially responding to L-dopa who developed a severe loss of drug efficacy due to Strongyloides stercoralis duodenitis. The patient was put on mebendazole and metronidazole, and the parasitosis abated, allowing L-dopa reduction by 33%. Our patient illustrates the advisability of searching for Strongyloides stercoralis when L-dopa malabsorption is suspected in Parkinson's disease.

Bruxism secondary to chronic antidopaminergic drug exposure

Eight cases of diurnal bruxism (DB) secondary to long-term antidopaminergic drug exposure are reported. Five exhibited a grinding pattern, one a clenching form, and two a mixed type. An odontological etiology was absent throughout. EMG recordings disclosed two distinct patterns of muscle activity, one with brief rhythmic, forceful contractions and the other featuring sustained prolonged contractions. Surface EMG and EEG monitoring during a 24-h period confirmed the absence of bruxism during sleep. Several drug trials failed to provide relief. Our findings support DB as a focal tardive dystonia syndrome.

Hemiballism in a patient with partial motor status epilepticus treated with phenytoin

A 13-year-old girl developed left partial motor status epilepticus with severe postictal hemiparesis. Magnetic resonance imaging showed a right frontoparietal hyperintense T2 weighted signal. Treated with phenytoin, carbamazepine and phenobarbital, seizures subsided but left choreic-like flinging movements, consistent with hemiballism, presented 2 days later. On phenytoin withdrawal, symptoms gradually remitted with mild residual dystonia at 14 months follow-up. It is speculated that the lesion might have rendered the cortex more susceptible to phenytoin, inducing unilateral toxicity.

Chaotic population dynamics can result from natural selection

The question of whether animal populations display chaotic dynamics has motivated a thriving body of research for two decades. Yet unambiguous evidence for chaos in the wild remains scarce. Accordingly, it has been proposed that evolutionary forces act to preserve populations from chaos as well as oscillations. We have tested for this hypothesis by considering the dynamics associated with evolutionarily stable life histories (including age of maturity, adult survivorship and recruitment to adulthood) in a simple, but general, demographic model. Contrary to expectation, individual selection operating on demographic traits should often lead to oscillatory or chaotic dynamics for species with late feasible ages of maturity and many age classes. Also, the optimality of chaos is more likely whenever trade-offs constrain recruitment to rapidly decrease with increasing adult survival or decreasing age of maturity. Our results bring evolutionary support to the possibility that chaotic population dynamics might be much more widespread than inferred until now from data analyses. Furthermore, these findings provide novel support for the view that chaos could be an optimal regime for several biological systems.

Treatment of Tourette's syndrome with calcium antagonists

Six males and one female with chronic tic disorders, whose ages ranged from 12 to 31 years, were evaluated before treatment, after 1 month on placebo, after a single 10 mg nifedipine dose (three patients), and monthly while on flunarizine 10-15 mg (mean dose of 13 mg). None of the patients receiving nifedipine improved, but treatment with flunarizine significantly decreased both motor and phonic tic severity and frequency in all but one patient. Side effects included mild transient headaches in one patient, depression in one, and bradykinesia in two. Although a double-blind study is essential to validate our findings, results suggest that flunarizine is a useful drug in the treatment of Gilles de la Tourette syndrome.