Analysis of the rate of force development reveals high neuromuscular fatigability in elderly patients with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) induces muscle wasting and a reduction in the maximum voluntary force (MVF). Little is known about the neuromuscular fatigability in CKD patients, defined as the reduction of muscle force capacities during exercise. Neuromuscular fatigability is a crucial physical parameter of the daily living. The quantification of explosive force has been shown to be a sensitive means to assess neuromuscular fatigability. Thus, our study used explosive force estimates to assess neuromuscular fatigability in elderly CKD patients.

METHODS

Inclusion criteria for CKD patients were age ≥ 60 years old and glomerular filtration rate (GFR) < 45 mL/min/1.73 m2 not on dialysis, and those for controls were GFR > 60 mL/min/1.73 m2 , age and diabetes matched. The fatigability protocol focused on a handgrip task coupled with surface electromyography (sEMG). Scalars were extracted from the rate of force development (RFD): absolute and normalized time periods (50, 75, 100, 150 and 200 ms, RFD50 , RFD75 , RFD100 , RFD150 and RFD200 , respectively), peak RFD (RFDpeak in absolute; NRFDpeak normalized), time-to-peak RFD (t-RFDpeak ) and the relative force at RFDpeak (MVF-RFDpeak ). A statistical parametric mapping approach was performed on the force, impulse and RFD-time curves. The integrated sEMG with time at 0-30, 0-50, 0-100 and 0-200 ms time intervals relative to onset of sEMG activity was extracted and groups were compared separately for each sex.

RESULTS

The cohort of 159 individuals had a median age of 69 (9IQR ) years and body mass index was 27.6 (6.2IQR ) kg/m2 . Propensity-score-matched groups balanced CKD patients and controls by gender with 66 males and 34 females. In scalar analysis, CKD patients manifested a higher decrement than controls in the early phase of contraction, regarding the NRFDpeak (P = 0.009; η2 p  = 0.034) and RFD75 and RFD100 (for both P < 0.001; η2 p  = 0.068 and 0.064). The one-dimensional analysis confirmed that CKD males manifest higher and delayed neuromuscular fatigability, especially before 100 ms from onset of contraction. sEMG was lower in CKD patients than controls in the 0-100 ms (at rest: P = 0.049, Cohen's d = 0.458) and 0-200 ms (at rest: P = 0.016, Cohen's d = 0.496; during exercise: P = 0.006, Cohen's d = 0.421) time windows. Controls showed greater decrease of sEMG than CKD patients in the 0-30 ms (P = 0.020, Cohen's d = 0.533) and 0-50 ms (P = 0.010, Cohen's d = 0.640) time windows. As opposite to females, males showed almost the same differences between groups.

CONCLUSIONS

Our study is the first to show that CKD patients have higher fatigability than controls, which may be associated with an impaired motor-unit recruitment, highlighting a neural drive disturbance with CKD. Further studies are needed to confirm these findings.

The association between TMAO, CMPF, and clinical outcomes in advanced chronic kidney disease: results from the European QUALity (EQUAL) Study

BACKGROUND

Trimethylamine N-oxide (TMAO), a metabolite from red meat and fish consumption, plays a role in promoting cardiovascular events. However, data regarding TMAO and its impact on clinical outcomes are inconclusive, possibly due to its undetermined dietary source.

OBJECTIVES

We hypothesized that circulating TMAO derived from fish intake might cause less harm compared with red meat sources by examining the concomitant level of 3-carboxy-4-methyl-5-propyl-2-furanpropionate (CMPF), a known biomarker of fish intake, and investigated the association between TMAO, CMPF, and outcomes.

METHODS

Patients were recruited from the European QUALity (EQUAL) Study on treatment in advanced chronic kidney disease among individuals aged ≥65 y whose estimated glomerular filtration rate (eGFR) had dropped for the first time to ≤20 mL/min per 1.73 m2 during the last 6 mo. The association between TMAO, CMPF, and outcomes including all-cause mortality and kidney replacement therapy (KRT) was assessed among 737 patients. Patients were further stratified by median cutoffs of TMAO and CMPF, suggesting high/low red meat and fish intake.

RESULTS

During a median of 39 mo of follow-up, 232 patients died. Higher TMAO was independently associated with an increased risk of all-cause mortality (multivariable HR: 1.46; 95% CI: 1.17, 1.83). Higher CMPF was associated with a reduced risk of both all-cause mortality (HR: 0.79; 95% CI: 0.71, 0.89) and KRT (HR: 0.80; 95% CI: 0.71, 0.90), independently of TMAO and other clinically relevant confounders. In comparison to patients with low TMAO and CMPF, patients with low TMAO and high CMPF had reduced risk of all-cause mortality (adjusted HR: 0.49; 95% CI: 0.31, 0.73), whereas those with high TMAO and high CMPF showed no association across adjusted models.

CONCLUSIONS

High CMPF conferred an independent role in health benefits and might even counteract the unfavorable association between TMAO and outcomes. Whether higher circulating CMPF concentrations are due to fish consumption, and/or if CMPF is a protective factor, remains to be verified.

Associations between depressive symptoms and disease progression in older patients with chronic kidney disease: results of the EQUAL study

Background

Depressive symptoms are associated with adverse clinical outcomes in patients with end-stage kidney disease; however, few small studies have examined this association in patients with earlier phases of chronic kidney disease (CKD). We studied associations between baseline depressive symptoms and clinical outcomes in older patients with advanced CKD and examined whether these associations differed depending on sex.

Methods

CKD patients (≥65 years; estimated glomerular filtration rate ≤20 mL/min/1.73 m²) were included from a European multicentre prospective cohort between 2012 and 2019. Depressive symptoms were measured by the five-item Mental Health Inventory (cut-off ≤70; 0–100 scale). Cox proportional hazard analysis was used to study associations between depressive symptoms and time to dialysis initiation, all-cause mortality and these outcomes combined. A joint model was used to study the association between depressive symptoms and kidney function over time. Analyses were adjusted for potential baseline confounders.

Results

Overall kidney function decline in 1326 patients was –0.12 mL/min/1.73 m²/month. A total of 515 patients showed depressive symptoms. No significant association was found between depressive symptoms and kidney function over time (P = 0.08). Unlike women, men with depressive symptoms had an increased mortality rate compared with those without symptoms [adjusted hazard ratio 1.41 (95% confidence interval 1.03–1.93)]. Depressive symptoms were not significantly associated with a higher hazard of dialysis initiation, or with the combined outcome (i.e. dialysis initiation and all-cause mortality).

Conclusions

There was no significant association between depressive symptoms at baseline and decline in kidney function over time in older patients with advanced CKD. Depressive symptoms at baseline were associated with a higher mortality rate in men.

The relationship between uremic toxins and symptoms in older men and women with advanced chronic kidney disease

Background

Patients with stage 4/5 chronic kidney disease (CKD) suffer from various symptoms. The retention of uremic solutes is thought to be associated with those symptoms. However, there are relatively few rigorous studies on the potential links between uremic toxins and symptoms in patients with CKD.

Methods

The EQUAL study is an ongoing observational cohort study of non-dialyzed patients with stage 4/5 CKD. EQUAL patients from Germany, Poland, Sweden and the UK were included in the present study (n = 795). Data and symptom self-report questionnaires were collected between April 2012 and September 2020. Baseline uric acid and parathyroid hormone and 10 uremic toxins were quantified. We tested the association between uremic toxins and symptoms and adjusted P-values for multiple testing.

Results

Symptoms were more frequent in women than in men with stage 4/5 CKD, while levels of various uremic toxins were higher in men. Only trimethylamine N-oxide (TMAO; positive association with fatigue), p-cresyl sulfate (PCS) with constipation and 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid (negative association with shortness of breath) demonstrated moderately strong associations with symptoms in adjusted analyses. The association of phenylacetylglutamine with shortness of breath was consistent in both sexes, although it only reached statistical significance in the full population. In contrast, TMAO (fatigue) and PCS and phenylacetylglutamine (constipation) were only associated with symptoms in men, who presented higher serum levels than women.

Conclusion

Only a limited number of toxins were associated with symptoms in persons with stage 4/5 CKD. Other uremic toxins, uremia-related factors or psychosocial factors not yet explored might contribute to symptom burden.

MO259LYMPHOPENIA AT ANCA-GLOMERULONEPHRITIS DIAGNOSIS IS CORRELATED WITH SEVERITY AND RENAL PROGNOSIS

Background and Aims

Lymphopenia is commonly observed in various autoimmune diseases, such as systemic lupus erythematosus, where it has been associated with disease activity or prognosis. However, in ANCA-associated vasculitis (AAV) only few, small-scale studies have been targeted to this issue. Research has not yet focused on ANCA-glomerulonephritis (ANCA-GN) patients. Thus, the aim of this study was to analyze the association between lymphocyte counts and outcomes in a large cohort of ANCA-GN patients.

Method

We used the Maine-Anjou AAV registry that retrospectively gathers data on consecutive patients affected by AAV in four French Nephrology Centers, recorded since January 2000. We analyzed clinical, biological, and histological data at diagnosis of ANCA-GN. Biological data, including lymphocyte counts, were collected before the administration of any immunosuppressive treatment. Risk factors for end-stage kidney disease (ESKD) were analyzed. Event-free survival was also assessed.

Results

Among the 145 patients included in the study, 53 (37%) patients presented with lymphopenia at ANCA-GN diagnosis. Lymphopenic patients were older (72 [63–79] vs 66 [56–73] years old, p = 0.010), had a lower renal function at baseline (eGFR 13 mL/min vs 26 mL/min, p = 0.002), and a higher proteinuria (1.86 [1.21–3.52] g/g vs 1.30 [0.75–2.65] g/g, p = 0.042). There was a trend for a higher BVAS (18 [14–22] vs 15 [12–20], p = 0.076) in lymphopenic patients. Therapeutic management between the two groups was similar. There was no difference in relapse rate between the two groups but lymphopenic patients were more likely to require kidney replacement therapy (51% vs 25%, p = 0.003) and were more likely to die (34% vs 17%, p = 0.039). Lymphopenia was correlated with histological lesions and especially with the percentage of sclerotic glomeruli (p = 0.0027). ESKD-free survival and overall survival were lower in lymphopenic patients (p &lt; 0.0001 and 0.0051 respectively). In multivariate Cox analysis, lymphopenia, but not death, was an independent risk factor for ESKD (HR 4.47 (95% confidence interval: [2.06–9.72], p &lt; 0.001).

Conclusion

Lymphopenia correlates with severity of ANCA-GN at diagnosis and predicts poor renal outcome. In this view, lymphopenia could be used as a simple and cost-effective biomarker to assess renal prognosis at ANCA-GN diagnosis.

MO1052GREEN DIALYSIS: FROM MITH TO FUTURE

Background and Aims

Over 2 million persons of the 7.8 billion world population undergo hemodialysis (HD). The need is underestimated because dialysis is not available free of charge for more of half of the word population. HD is costly process and produces a large quantity of medical waste. Reducing the environmental burden should be addressed as part of implementation dialysis programs.

While collaboration between physicians and several different professionals is needed to design and develop projects in this direction, these are lingering and the literature is still scant. We overviewed literature to frame what is in progress and find clues for development.

Method

We conducted a systematic review of the literature from 2000 searching in PubMed, Scopus, Web of Science, and Google Scholar using search keywords including dialysis, green, recycling, ecology. We retrieved 41 publications in medical and technological fields. The results were summarized in a narrative review.

Results

Facilities: the points on which attention is focused are the design of new buildings, whose project should encompass green solutions, including solar power and water conservation, to reduce long-term expenses and ensure an eco-friendly development.

Water: water consumption remains high, and the essential targets to improve efficiency are the optimization of the reverse osmosis system, and of the dialysate flow rate, and the waste-water management. The current idea is to substitute standard reverse osmosis, which have a high percent of waste-water, with recirculating systems. Likewise, lowering of dialysate flow rate could spare water consumption with no significant difference in term of efficiency. Moreover, different solutions have been proposed to reuse reject water: local sanitation, laundry departments, sterilization units within health facilities using redirected water, landscaping and irrigation.

Power: electricity needed per dialysis session is twice the average daily consumption of a family of four people. Use of renewable energies, as solar or wind power, has been proposed, and are occasionally applied to home HD. To date just one attempt has been made to recycling energy by using hydroturbine.

Disposable materials: most of dialysis disposables is made of plastic, over half of which is labeled as “potentially hazardous”. Only a minimal part of the plastic used in dialysis disposables is recyclable, both because of its composition and its assembly which makes in fact impossible the segregation of the different components. Present research regards bioplastics, new assembling techniques, alternative technologies of incineration, microwave treatment, alkaline hydrolysis, biological treatment and the new steam sterilize-then-shred system.

Dialysis machines: at the best of our knowledge there are no studies available about dialysis machine recycling.

Personnel education: the role of dialysis staff is essential in recycling and reusing materials as well as in correctly dividing contaminated and non-contaminated waste.

Conclusion

The development of sustainable buildings, devices and procedures requires a multidisciplinary approach: medical, chemical, biological, engineering; in addition producers contribution and government regulation are needed. Talking about these issues, involving specialists, spreading the concepts of planet friendly treatments, gives the opportunity to share ideas, experiences and turn them into relevant innovations. A good starting point could be data collection to identify critical issues and outline pragmatic operational possibilities to reduce consumption, increase reuse and recycle, involve and instruct health care personnel, integrate dialysis facilities in the environment they are built in.

Lymphopenia at diagnosis of ANCA-vasculitis with renal involvement is correlated with severity and renal prognosis

BACKGROUND

Lymphopenia is commonly observed in autoimmune diseases, where it has been associated with disease activity or prognosis. However, in ANCA-associated vasculitis (AAV) only few, small-scale studies have been targeted to this issue. Research has not yet focused on AAV with renal involvement (AAV-RI) patients. Thus, the aim of this study was to analyze the association between lymphocyte counts and outcomes in a large cohort of AAV-RI patients.

METHODS

We used the Maine-Anjou AAV registry that retrospectively gathers data on consecutive patients affected by AAV in four French Nephrology Centers, recorded since January 2000. We analyzed clinical, biological, and histological data at diagnosis of AAV-RI. Risk factors for end-stage kidney disease (ESKD) were analyzed. Event-free survival was also assessed.

RESULTS

Among the 145 patients included in the study, those with lymphopenia at diagnosis had a lower renal function at baseline (eGFR 13 mL/min vs 26 mL/min, p = 0.002) and were more likely to require kidney replacement therapy (51% vs 25%, p = 0.003). Lymphopenia was correlated with histological lesions and especially with the percentage of sclerotic glomeruli (p = 0.0027). ESKD-free survival was lower in lymphopenic patients (p < 0.0001). In multivariate Cox analysis, lymphopenia was an independent risk factor for ESKD (HR 4.47 (95% confidence interval: [2.06-9.72], p < 0.001).

CONCLUSION

Lymphopenia correlates with the severity of AAV glomerulonephritis at diagnosis and predicts poor renal outcome. In this view, lymphopenia could be used as a simple and cost-effective biomarker to assess renal prognosis at AAV-RI diagnosis.

Multimodal MRI Longitudinal Assessment of White and Gray Matter in Different SPG Types of Hereditary Spastic Paraparesis

Hereditary spastic paraplegias (HSP) are a group of genetically and clinically heterogeneous neurologic disorders. Hereby we describe a relatively large group of patients (pts) affected by HSP studied at baseline (31 pts) and at follow-up (mean period 28.9 ± 8.4 months; 23 pts) with multimodal advanced MRI: high-resolution T1 images for voxel-based morphometry (VBM) analysis, magnetic resonance spectroscopy (MRS), and diffusion tensor imaging (DTI). An age-matched healthy control (HC) group underwent the same neuroimaging protocol in a time schedule matched with the HSP patients. At baseline, VBM showed gray matter (GM) reduction in HSP in the right pre-frontal cortex and bilaterally in the thalami. MRS at baseline depicted in HSP patients compared to the HC group reduction of NAA/Cr ratio in the right pre-frontal region, increase of Cho/Cr ratio in the right pre-central regions, and increase of mI/Cr ratio on the left pre-central area. At cross-sectional follow-up analysis and longitudinal evaluation, no VBM and MRS statistically significant results were obtained. Tract-based spatial statistics (TBSS) analysis showed widespread DTI brain white matter (WM) alterations in patients compared to HC at baseline, which are characterized by reduction of fractional anisotropy (FA) and increase of mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity, as confirmed on cross-analysis of the follow-up dataset. A longitudinal analysis with TBSS in HSP patients did not show significant variations, while upon applying region-based analysis we found increased FA and decreased MD and AD in specific brain WM fiber complex during follow-up. The changes were not correlated with the clinical presentation (pure vs complicated HSP), motor function, and motility indexes or history of specific treatments (botulinum toxin). In conclusion, the cross-sectional analysis of the multiparametric MRI data in our HSP patients confirmed the non-prominent involvement of the cortex in the primary motor regions but rather of other more associative areas. On the contrary, DTI demonstrated a widespread involvement of the brain WM, including the primary motor regions, which was confirmed at follow-up. The longitudinal analysis revealed an apparent inversion of tendency when considering the expected evolution of a neurodegenerative process: we detected an increase of FA and a decrease of MD and AD. These time-related modifications may suggest a repair attempt by the residual central WM fibers, which requires confirmation with a larger group of patients and with a longer time interval.

P0794A REAL-WORLD OBSERVATIONAL STUDY OF ETELCALCETIDE USE IN HEMODIALYSIS PATIENTS WITH SECONDARY HYPERPARATHYROIDISM IN EUROPE

Background and Aims

Intravenous etelcalcetide was approved in Europe in 2016 for treatment of secondary hyperparathyroidism (SHPT) in adult patients on hemodialysis (HD). Data on real-world use of etelcalcetide are needed to inform clinicians on routine clinical practice with this newly approved therapy.

Method

A multi-country observational medical chart review study was performed to describe clinical management of patients treated with etelcalcetide. Sites with at least 6 months of use of etelcalcetide were eligible for study participation. Chronic HD patients who had at least one record of etelcalcetide prescription were recruited. Abstracted data included demographics, clinical history, laboratory parameters and etelcalcetide use over time. Interim data are being reported.

Results

Medical charts for 238 HD patients who started etelcalcetide between December 24, 2016 and June 7, 2019 were reviewed. Data were obtained from 47 sites from 9 countries (Austria, Denmark, France, Germany, Greece, Netherlands, Russia, Slovenia, and Spain). Forty eight percent of patients (113/238) switched from cinacalcet to etelcalcetide (≤90 days from last cinacalcet prescription), whereas the remaining 125 patients were calcimimetic naive. Median (interquartile range, IQR) age was 62.5 (52-74) and dialysis vintage was 4.7 years (2.4-8.7). Twenty four percent of patients were diabetic and 17% of patients had a history of at least one cardiovascular event (heart failure, myocardial infarction, peripheral vascular disease, or stroke). Parathyroidectomy had been performed in 6% (13/238) of patients and 11% (26/238) had received a kidney transplant. Two-thirds of patients (63%) had a starting etelcalcetide dose of 5 mg and the median weekly dose was 7.5 mg (range: 2.5-15 mg). Table 1 summarizes the median and IQR for parathyroid hormone (PTH), calcium (Ca) and phosphate (P) levels at baseline, 3, 6 and 12 months following etelcalcetide initiation. At baseline, 85% (201/237) had normal Ca (≥2.1 mmol/L). Among patients who had a normal Ca at baseline, the cumulative incidence of hypocalcemia (&lt;2.1 mmol) at 3, 6, 9 and 12 months was, 31%, 45%, 57% and 63%, respectively. Median time to first hypocalcemia event (Kaplan-Meier estimation) was 6.9 months (95% CI: 5.4, 8.9). Etelcalcetide persistence at 3, 6, 9 and 12 months was 96%, 94%, 91% and 87%, respectively. Of the 40 patients who discontinued etelcalcetide by 12 months, 10 patients discontinued for side effects (hypocalcemia=6, nausea=3, and vomiting=1), 5 for parathyroidectomy, 9 for low PTH, 1 for high PTH, and 15 for other reasons. More than half of the patients achieved a &gt;30% reduction in PTH from baseline at 6-months (55.9%) and 73.5% at 12 months; and it was 63.2% and 80% for patients who were calcimimetic naive and 47.8% and 66.4% for patients who switched from cinacalcet to etelcalcetide, respectively.

Conclusion

To date, this is the largest study on real-world etelcalcetide use in Europe. Etelcalcetide switchers had higher PTH levels than calcimimetic naive patients at initiation. Persistence of etelcalcetide remained high at 12 months. As expected, we observed a substantial reduction in PTH, Ca, and P, and this was greater among patients who were calcimimetic naive than switchers (-43% vs. -32% at 12 months) for PTH. No new safety signals were observed.

P0263A NEPHROLOGIST'S LOOK AT HYPERTENSIVE DISORDERS OF PREGNANCY

Background and Aims

Preeclampsia (PE) is a pregnancy-related syndrome of variable severity that falls under the broad category of hypertensive disorders of pregnancy (HDP). The relationship between PE and chronic kidney disease (CKD) is not entirely understood. Once considered a self-limited disease healed by delivery, it is now acknowledged that PE is a marker of cardiovascular and kidney health in the long term. The aim of this study was to review the data of women with hypertensive disorders of pregnancy at our institution, to identify need and to organize a conjoint nephrology and obstetrical activity in our setting

Method

We retrospectively reviewed all the medical charts of the patients hospitalized in the last two years for hypertensive disorders of pregnancy and who delivered in our Hospital. The cohort was divided into two groups: gestational hypertension (GH) and PE. A descriptive analysis of the clinical-laboratoristic was performed (t-test for continuous data with normal distribution).

Results

We identified 93 cases of hypertensive disorders of pregnancy on a total of 3279 deliveries (2.8%), 47 GH and 46 PE [2 cases of HELLP syndrome and 1 of eclampsia included in the PE group]. These two groups showed similar mean age: 33.5±6 vs 34.9±6 years (p value= 0.25); serum creatinine (sCr) and uric acid at admission were statistically different, and higher in the PE group (sCr 0.57±0.15 and 0.66±0.2 – p=0.01 and uric acid 4.5±1.38 and 5.6±1.47 – p=0.01).

Comorbidities were frequent in the PE group: thyroid disfunction was found in 17% of cases (7 hypothyroidism and 1 hyperthyroidism, all under treatment), coagulation abnormalities were present in 15% of cases (4 MTHFR mutation, 1 protein S deficiency, 1 prothrombin-gene mutation, 1 patient was positive for LLAC); gestational diabetes was diagnosed in 13% of the cases. We identified 1 renal transplant recipient, 1 IgA-vasculitis patient, 1 patient with family medical history positive for PE (in her twin sister); none of these patients had been identified as at high risk for PE. At hospital admission, 54% of the patients were on antihypertensive treatment, 7 of them for chronic hypertension and 18 for gestational hypertension (12 of these patients underwent a previous hospitalization during the same pregnancy, diagnosed with gestational hypertension); at admission only 24% of PE patients were treated with anticoagulant or antiplatelet prophylaxis. Caesarean section was performed in 36 cases (78%). All but one children live-born, the exception being a child from a multiple pregnancy (quadruplets).

Conclusion

A multidisciplinary approach and a nephrological follow-up are increasingly indicated in PE. Our series underlines a high prevalence of comorbidity or risk factors, including thyroid disfunction, gestational diabetes and coagulation abnormalities. The high prevalence (7/46) of chronic hypertension and the fact that the two patients with kidney disease were not identified as at risk for PE underlines the potential role for developing a synergic approach between nephrologist and obstetricians.

Formulation and Clinical Evaluation of Sodium Benzoate Oral Solution for the Treatment of Urea Cycle Disorders in Pediatric Patients

BACKGROUND

Sodium benzoate, a common food preservative, is used in the treatment of patients with urea cycle disorders (UCDs) as it stimulates ammonia removal by a non-urea cycle-based pathway. Despite its use in the clinical routine, no commercially available oral formulations currently exist. Liquid formulation is normally well accepted in pediatric age and allows precise dosage according to the children's needs.

AIMS

(1) To prepare an oral sodium benzoate solution in different tastes and determine its stability, palatability, and tolerability and (2) to describe the long-term follow-up of two pediatric patients with UCDs treated with our formulation.

METHODS

We prepared five oral solutions of sodium benzoate (200 mg/ml) by adding different flavoring agents. We measured drug concentration in the samples by high-performance liquid chromatography (HPLC). We evaluated palatability and tolerability with adult volunteers. Long-term drug compliance and metabolic control were appraised in two pediatric patients.

RESULTS

All the oral solutions remained stable at room temperature along the 96-day test period, and they were well tolerated. The mint-flavored solution resulted the most palatable and preferred by adult volunteers. We report good drug compliance and good metabolic outcomes for both pediatric patients during the entire follow-up.

CONCLUSIONS

Our study highlighted the stability and tolerability of flavored sodium benzoate oral solutions. These solutions were well accepted during a long-term follow-up and guaranteed a good metabolic control. Since taste attributes are critical to ensure acceptable medication adherence in the pediatric age, flavored liquid formulations of sodium benzoate may be an efficient strategy to achieve therapeutic outcomes in UCD pediatric patients.

Lymphocyte Subsets Assayed by Numerical Tests in CAPD

Peripheral and peritoneal lumphocytes were assayed by numerical tests in adults on peritoneal dialysis. T lymphocytes were classified by monoclonal antibodies (OKT3, OKT4, OKT8) and B lymphocytes by the presence of surface immunoglobulins, using the immunofluorescence technique.

Peripheral T cells showed no significant change from the normal, except for T suppressor cells which increased in patients with 2 or more peritonitis episodes.

Examination of peritoneal lymphocytes showed a significant reduction in S-IgA lymphocytes (B cells bearing IgA receptors) and an increase in T-suppressor cells (OKT8+) in patients who developed peritonitis in the follow-up study. The implications of these results are discussed with particular reference to susceptibility to peritonitis.

The Immunological State in Chronic Renal Insufficiency

To evaluate the immunological state in chronic renal insufficiency, the Authors studied cellular and humoral immunity in 292 patients with chronic renal failure.

They were divided into 3 groups: 1) 37 with creatinine clearance between 50 and 20 ml/min; 2) 57 with creatinine clearance between 20 and 8 ml/min; 3) 178 treated by hemodialysis.

In vivo and in vitro tests, that is DNCB, PPD skin tests, spontaneous, active and EAC rosettes, surface membrane immunoglobulin test, complement (C3, C4) and serum immunoglobulins were taken as markers of the immune response.

Cell-mediated immunity was found to be significantly impaired in patients with terminal renal insufficiency or on hemodialysis and also markedly reduced in patients with non-terminal renal insufficiency.

Humoral immunity produced less significant results: the B lymphocyte count and serum immunoglobulins were normal; only C3 levels were found below normal range.

Thus it would seem that cell-mediated immunodeficiency appears in an early stage of chronic renal failure and that hemodialysis does not improve this deficiency.

The pathogenic LRRK2 R1441C mutation induces specific deficits modeling the prodromal phase of Parkinson's disease in the mouse

The aim of the present study was to further explore the in vivo function of the Leucine-rich repeat kinase 2 (LRRK2)-gene, which is mutated in certain familial forms of Parkinson's disease (PD). We generated a mouse model harboring the disease-associated point mutation R1441C in the GTPase domain of the endogenous murine LRRK2 gene (LRRK2 R1441C line) and performed a comprehensive analysis of these animals throughout lifespan in comparison with an existing knockdown line of LRRK2 (LRRK2 knockdown line). Animals of both lines do not exhibit severe motor dysfunction or pathological signs of neurodegeneration neither at young nor old age. However, at old age the homozygous LRRK2 R1441C animals exhibit clear phenotypes related to the prodromal phase of PD such as impairments in fine motor tasks, gait, and olfaction. These phenotypes are only marginally observable in the LRRK2 knockdown animals, possibly due to activation of compensatory mechanisms as suggested by in vitro studies of synaptic transmission. Thus, at the organismal level the LRRK2 R1441C mutation does not emerge as a loss of function of the protein, but induces mutation specific deficits. Furthermore, judged by the phenotypes presented, the LRRK2-R1441C knock-in line is a valid preclinical model for the prodromal phase of PD.

Adherence to ketoacids/essential amino acids-supplemented low protein diets and new indications for patients with chronic kidney disease

BACKGROUND

Low protein diets (LPD) have long been prescribed to chronic kidney disease patients with the goals of improving metabolic abnormalities and postpone the start of maintenance dialysis.

METHODS

We reviewed the recent literature addressing low protein diets supplemented with ketoacids/essential aminoacids prescribed during chronic kidney disease and their effects on metabolic, nutritional and renal parameters since 2013.

RESULTS

We show new information on how to improve adherence to these diets, on metabolic improvement and delay of the dialysis needs, and preliminary data in chronic kidney disease associated pregnancy. In addition, data on incremental dialysis have been reviewed, as well as potential strategies to reverse protein energy wasting in patients undergoing maintenance dialysis.

CONCLUSION

These recent data help to better identify the use of low protein diets supplemented with ketoacids/essential aminoacids during chronic kidney disease.

[Pregnancy, CKD and solitary kidney: kidney donation between clinical logic and taboos]

On the occasion of the Congress of the American Society of Nephrology, the yearly issue of the NEJM introduces a selection of articles of interest for Nephrology, drawing attention to the incidence of hypertensive disorders of pregnancy in kidney donors. The article reconsiders this issue five years after two studies that described an increase in risk for adverse pregnancy outcomes after kidney donation. It disproves a previous assumption of "non-interference" between kidney donation and pregnancy outcomes. Meanwhile,CKD has been recognized as a risk factor for pregnancy, regardless of the presence of reduced renal function, hypertension and proteinuria, although these factors modulate the risk. In the discussion, the authors help to dispel the taboos that donor women are substantially different from women born with a solitary kidney or were so as an effect of a disease. Beside the issue of transplantation,the study indicates that we have to pay attention to all patients with CKD in pregnancy, giving us a very interesting clue for counselling. The risk of complications is greater in the donor population compared to a "low risk" population, but it is roughly equal to that of the general population, if the latter is not subject to a careful clinical work-up. Control and follow-up offset the risk: in a time when economic cuts to health care are almost killing the prevention programs, this is probably the most important message.

[The communication of uncertainty: the lessons of Ebola and the tsunami]

An enlightening article, recently published in the New England Journal, mentions the natural disasters and the epidemic of Ebola to discuss the importance and the difficulty of the communication of uncertainty. History shows how difficult it is to make a prognostic (and being understood). The story of the tsunami is similar, it explains the fear and the difficulty to communicate forecasted events which by nature have a certain level of probability and are not a certainty. In this article, we take the opportunity to reflect on the changing of our paradigms."How can we trust you, if your opinions are always changing?" says the author, underlining how this aspect of science is not intuitive.In a time in which our work is changing, early dialysis is replaced by intent to delay, palliation intensifies along with the pride of being able to start renal replacement therapy at any age, pregnancy is made possible on dialysis, the so-called conservative therapy is rediscovered. This work can make us wonder about the fragility of dogmas and can make us reflect on the importance of communication, in a balance between answering to our patients and admitting that, often, we are the first ones not to have all the answers.

[Acute pielonephritis and renal abscesses in Piedmont and Aosta Valley]

The Piedmont Group of Clinical Nephrology compared the activity of 18 nephrology centers in Piedmont and Aosta Valley as regards acute pielonephritis (APN). Data from more than 500 cases per year of APN were examined. The microbial spectrum of APN consists mainly of Escherichia coli and Klebsiella pneumoniae. Diagnosis was based on both clinical and radiological criteria in most of the centers (computed tomography-CT o Magnetic Resonance Imaging-MRI). In four centers diagnosis was made with the radiological criteria and in one center only with the clinical features. CT and MRI were performed in about 47% and 44% of cases respectively. Urine culture was positive in 22 up to 100% of cases. The most commonly used antibiotics were fluoroquinolones (ciprofloxacin or levofloxacin) and ceftriaxone (50% of centers) or amoxicillin/clavulanic acid (25% of centers). In 75% of the centers, patients received a combination of two antibiotics (aminoglycoside in 22% of them ). In 72% of the centers, almost 50% of the patients were re-examined, while 38.8% of centers re-examined all the patients. Renal ultrasound was inappropriate to identify abscesses. The mean of patients in whom renal abscesses were detected by CT or MRI was 18.2%. The analysis shows a high variability in the way of diagnosing and treating APN in Piedmont and Aosta Valley regions. This suggests that even if APN is a frequent pathological condition, practical recommendations are required.