Preliminary results of dialysis study: single pool variable-volume calcium kinetic model

Background: The primary aim of the international study DialysIS (Dialysis therapy between Italy and Switzerland) is the increased personalization of hemodialytic treatments through a modellistic approach. Within the DialysIS study, we investigated the use of a single-pool variable-volume Ca kinetic model to assess the intradialytic calcium mass balance (Ca2 + MB) in chronic and stable dialysis patients. Methods: 34 patients on thrice-weekly bicarbonate high-flux hemodialysis were studied during 240 dialysis sessions (mean 6.5 ± 1.9 for each patient; range 3–9). All patients were dialyzed with a nominal d[Ca] of 1.50 mmol/l. Ionized calcium concentrations of plasma water (Ca2 + pw) and dialysate (Ca2 + di) were determined at the beginning and end of each session; calcium dialysance (DCa) was estimated from conductivity dialysance. The most useful variable for validating this methodology was considered being the difference between end-dialysis ionized plasma water calcium concentration measured value, normalized to pH 7.40 (adjCa2 + pwtM), and predicted by the model (Ca2 + pwtP) applying: Ca2 + pwtP = 1/∙(Ca2 + di-(Ca2 + di–∙Ca2 + pw0)∙(VtCa/V0Ca) (DCa∙∙(1/Qfecv-1/Qpwi))) With  (Donnan’s factor) equal to 0.938. Results shown as mean ± standard deviation when normal, median (range) when non-normal. Results: A mean negative Ca2 + MB (–0.83 ± 1.33 mmol) and a statistically significant temporary parathyroid hormone (PTH) reduction was found (PTHt-PTH0: –128 (–488 ÷ 432) pg/ml p <0.01). Figure 1 shows the difference between the distribution of the predicted values, the adjusted values (Ca2+pwtP – adjCa2+pwtM: 0.016 (–0.08 ÷ 0.16) mmol/l)and the non-corrected values (Ca2+pwtP – Ca2+pwtM: 0.073 (–0.03 ÷ 0.20) mmol/l). Conclusions: The very low differences between predicted and adjusted Capwt suggest that it is possible to model and predict Ca2+MB during dialysis with a nominal dialysate calcium concentration of 1.5 mmol/l and a final calcium level in physiological range

Preliminary results of dialysis study: accuracy of a single pool variable-volume calcium kinetic model with different calcium dialysate concentrations

Background: The primary aim of the international study DialysIS (Dialysis therapy between Italy and Switzerland) is the increased personalization of hemodialytic treatments through a modellistic approach. Within the DialysIS study, we compare the accuracy of a single-pool variable volume calcium kinetic model (SPVV-CaKM) using two different dialysate calcium concentrations (CaD). Methods: Pre- and post-treatment relevant variables of 34 patients treated with nominal CaD of 1.5 mmol/l (Group 1) and 22 patients with nominal CaD of 1.75 mmol/l (Group 2) were analyzed. The accuracy was evaluated determining the difference between predicted (Ca2+pwtP) and measured (Ca2+pwt) plasma water ionized calcium concentrations at the end of the dialysis sessions. To account for the changes in blood pH during dialysis session, which is known to affect plasma water ionized calcium concentrations, Ca2+pwt values were normalized at pH of 7.40. Results: Fig. 1 indicate that the predicted values almost overlap t he normalized values for Group 1, while it’s significantly higher for Group 2. Conclusion: The SPVV-CaKM is accurate in Group 1 while it overestimates the Ca2+pwt Group 2. The Ca2+pwt of the two groups doesn’t seem to account for the increased CaD. This suggests the presence of an additional compartment. Our hypothesis is that the administered calcium, predicted by our model, that doesn’t appear plasma could be deposited in bones and/or soft tissues. It is then theoretically possible to estimate the total calcium deposition or accumulation from the difference between predicted and measured post-treatment values

PRELIMINARY RESULTS OF DIALYSIS STUDY: ACCURACY OF A SINGLE POOL VARIABLE-VOLUME CALCIUM KINETIC MODEL WITH DIFFERENT CALCIUM DIALYSATE CONCENTRATIONS

INTRODUCTION AND AIMS: The primary aim of the international DialysIS study (Dialysis therapy between Italy and Switzerland) is to imptove the personalization of hemodialysis treatments through a modeling approach. Within the DialysIS study, we compared the accuracy of a single-pool variable volume calcium kinetic model (SPVV-CaKM) using two different dialysate calcium concentrations (CaD). METHODS: Pre- and post-treatment relevant variables of 31 patients treated with nominal CaD of 1.5 mmol/l (Group 1) and 22 patients with nominal CaD of 1.75 mmol/l (Group 2) were analyzed. The accuracy of the model was evaluated by determining the difference between predicted (Ca2+pwtP) and measured (Ca2+pwt) plasma water ionized calcium concentrations at the end of the dialysis sessions. To account for the changes in blood pH during dialysis session, which is known to affect plasma water ionized calcium concentrations, Ca2+pwt values were normalized at pH of 7.40. RESULTS: In Group 1 we found: Ca2+D = 1.26 + 0.04 mmol/l; a rise in Ca2+pw from 1.18 + 0.07 at the start to 1.32 + 0.04 mmol/l at the end of the dialysis session with a mean difference between Ca2+pwtP (1.33 + 0.04 mmol/l) and Ca2+pwt of 0.01 + 0.04 mmol/l. In Group 2 we found : Ca2+D = 1.41 + 0.04 mmol/l; a similar rise in Ca2+pw (from 1.18 + 0.07 mmol/l to 1.36 + 0.06 mmol/l) but with a mean difference between Ca2+pwtP (1.48 + 0.04 mmol/l) and Ca2+pwt of 0.12 + 0.05 mmol/l.CONCLUSIONS: The SPVV-CaKM was highly accurate when using a dialysate calcium concentration of 1.5 mmol/l while it wildly overestimated the post-treatment plasma water concentration when using a higher dialysate calcium concentration; the measured post-treatment values in the two groups did not seem to account for the increased dialysate calcium concentration, suggesting the presence of an additional compartment. We hypothesize that the administered calcium that according to our model did not appear in the plasma could be deposited in bones and/or soft tissues. It is then theoretically possible to estimate the total calcium deposition or accumulation from the difference between predicted and measured post-treatment in Ca2+pw values

Environmental pollution and systemic sclerosis manifestations: a pilot study on benzene and particulate exposure

Many works have studied interactions between genetic and autoimmunity but only a few have studied the interactions between autoimmune diseases, such as systemic sclerosis (SSc), and exposure to environmental pollutants, reporting no conclusive. Results This study aims to analyze the relationships between outdoor concentration of benzene (B) and particulate matter 10 m (PM10) with clinical manifestations of SSc in a big Italian city. A pilot cohort study of 88 SSc patients filled a validate selfadministered questionnaire to investigate potential risk exposure before and after the onset of the disease. The demographic and clinical characteristics were recorded. The average mean concentrations of B (11 monitoring sites) and environmental PM10 (14 sites) were computed using data from monitors located throughout the Lazio region, in Italy, and they were correlated with demographic and clinical characteristics. Besides maps of the particle\u2019s diffusion have been developed through spatial data modelling techniques (FAI-K geostatistical analysis). The questionnaire validation has resulted in an agreement of the overall experts about of 94%, with a very good concordance (Inter-observer agreement K Cohen test = 0.8019; p < 0.01). SSc patients with diffuse skin disease were exposed 2 years before the onset of Raynaud\u2019s phenomenon to higher concentrations of benzene (8.5 1.5 mg/m3) in respect to patients with limited skin disease (4.97 2.7 mg/m3) [p=0.02]. The maps of the particle\u2019s diffusion expected values, obtained through FAI-K geostatistical analysis, show higher concentration of PM10 and B in the residence area of patients with diffuse skin disease (Indicative Goodness of Fit = 0.0667; K-order Rank = 1; Jacknife = 1.0016). This pilot study suggests a possible role of benzene in the developing a diffuse skin disease. Moreover geostatistical maps are of great importance because they allow to estimate PM10 and B concentration all over monitoring area and not only where the samples are performed, other than showing clearly the pollutants distribution in the environment

ENVIRONMENTAL POLLUTION AND SYSTEMIC SCLEROSIS: A PILOT STUDY ON BENZENE AND PARTICULATE EXPOSURE AS RISK FACTORS FOR THE SYSTEMIC MANIFESTATIONS

Background: The association of systemic sclerosis (SSc) with the exposure to environmental agents is supported by a number of case reports and some case-control studies. No conclusive results have been reported, but there are some evidences that exposure to vinyl-chloride-polymers (PVC), silica dust or organic solvents such as benzene (B) and xylene (X) may be implicated. Furthermore a higher prevalence of scleroderma in boroughs in close proximity to a major airport, has been reported, but few data on air pollution exposure and risk of systemic sclerosis are available. Recently, particulate air pollution has been consistently linked to increased risk of arterial cardiovascular disease. Objectives: We studied relationships between outdoor concentration of B and particulate with clinical manifestations of SSc based, for the exposure, on the urban residence of patients. Methods: Before patient administration, the questionnaire was validated by Delphi technique (4 rheumatologists, 4 statisticians and 2 common people). A cohort study of 88 SSc patients, filled the validated self administered questionnaire (analyzing drug, work and environmental exposure) to investigate potential risk exposure before and after the onset of the disease. The average mean concentrations of B (11 monitoring sites) and environmental particulate matter with aerodynamic diameter ≤ 10 μm(PM10) (14 sites) were computed using data from monitors located throughout the Lazio region, in Italy. In a sample of 33 patients we performed correlations between the concentrations of PM10 and B with the demographic and clinical characteristics, going back to a prior exposure of 2 years before the onset of Raynaud’s phenomenon (RP). Results: The questionnaire resulted in an agreement of the overall experts of about 94% (according to11/190 disagreement for comprehension, only few lexical modifications were done to improve the questionnaire after the consensus between the experts), with an Inter-observer agreement (measured throughout K Cohen test) of 0.8019(p <0.01) showing a very good concordance. The mean disease duration from the RP onset was 13.0±9.4 years and the mean age was 55.0±12.9 years. 92.5% of patients were female. No correlations were found between different clinical disease characteristics and drug assumption and work exposure. Considering patients that lived in Lazio, SSc patients with diffuse skin disease were exposed 2 years, before the onset of RP, to a higher concentrations of benzene (8.5±1.5µg/m3 ) with respect to patients with limited skin disease (4.97±2.7µg/m3 ), which was statistically significant of p=0.02. Furthermore the concentrations of benzene correlated directly with the skin score (R=0.3, p≤0.05) and inversely with DLCO (R=-0.36,p≤0.05). SSc patients with ulcers were exposed 2 years before the onset of RP to higher concentrations of B (6.4±3.2 µg/m3 ), than the patients without ulcers (4.9±2.3µg/m3 ), but the difference did not reach statistical significance. Conclusions: This study, on the role of environmental agents in the manifestations of SSc, suggests an increased exposure to benzene in the development of a diffuse skin disease and a possible predisposing effect on the occurrence of ulcers. Disclosure of Interest: None Declare

Investigating the Role of Physical Education in Physical Activity Promotion: An Italian Multicenter Study

Physical education (PE) can be considered an instrument for active lifestyle promotion, and PE teachers can motivate youths to continue their studies in the field of Movement Sciences (MS)

Attitudini e comportamenti nei confronti delle vaccinazioni contro N. meningitidis, S. pneumoniae e HPV: un’analisi multicentrica sulla popolazione generale

Introduzione: Conoscere attitudini e comportamenti della popolazione nei confronti delle vaccinazioni è indispensabile per poter intraprendere azioni mirate. Questo studio, di cui sono stati presentati parte dei risultati allo scorso congresso SItI, ha analizzato anche i fattori associati alla propensione alle vaccinazioni contro N. meningitidis, S. pneumoniae e HPV e le motivazioni alla vaccinazione/non vaccinazione. Metodi: E’ stato somministrato un questionario anonimo a un campione di 530 individui con età compresa tra 19 e 86 anni che hanno usufruito, nel 2013, dei servizi dei Dipartimenti di Prevenzione della ASL Roma A, ASL3 di Genova, ASL2 di Savona e ASL Viterbo. Risultati: Il 96,2%, il 94% e il 92,7% dei responders si è detto favorevole alla vaccinazione contro N. meningitidis, S. pneumoniae e HPV rispettivamente, e il 58,4% ha espresso parere positivo nei confronti del vaccino MenB. L’attitudine alla vaccinazione meningococcica è risultata significativamente maggiore nelle donne, quella contro HPV è risultata associata alla presenza di figli e alla conoscenza della malattia mentre quella contro lo pneumococco al proprio stato vaccinale e alla conoscenza della malattia stessa. Rispetto alla vaccinazione dei propri figli, il 68,8%, l’82,6% e l’84,5% dei responders ha dichiarato di averli vaccinati contro N. meningitidis, S. pneumoniae e HPV rispettivamente. Dal 45% a oltre il 50% ha riportato come principale motivazione la raccomandazione da parte del pediatra o di un altro medico. Anche la paura delle sequele di malattia ha rappresentato una motivazione comune. Le motivazioni alla non vaccinazione sono state invece scarsamente riferite. Conclusioni: Questi dati suggeriscono che azioni volte a incrementare il livello di conoscenza della popolazione e a promuovere un ruolo attivo dei professionisti sanitari nell’offerta vaccinale potrebbero influenzare positivamente attitudini e comportamenti nei confronti delle vaccinazioni prese in esam

ATXN2 is a modifier of phenotype in ALS patients of Sardinian ancestry

Abstract Intermediate-length CAG expansions (encoding 27-33 glutamines, polyQ) of the Ataxin2 (ATXN2) gene represent a risk factor for amyotrophic lateral sclerosis (ALS). Recently, it has been proposed that ≥31 CAG expansions may influence ALS phenotype. We assessed whether ATXN2 intermediate-length polyQ expansions influence ALS phenotype in a series of 375 patients of Sardinian ancestry. Controls were 247 neurologically healthy subjects, resident in the study area, age- and gender-matched to cases. The frequency of ≥31 polyQ ATNX2 repeats was significantly more common in ALS cases (4 patients vs. no control, p = 0.0001). All patients with ≥31 polyQ repeats had a spinal onset versus 73.3% of patients with &lt;31 polyQ repeats. Patients with an increased number of polyQ repeats have a shorter survival than those with &lt;31 repeats (1.2 vs. 4.2 years, p = 0.035). In this large series of ALS patients of Sardinian ancestry, we have found that ≥31 polyQ repeats of the ATXN2 gene influenced patients' phenotype, being associated to a spinal onset and a significantly shorter survival