Use of Highly Individualized Complement Blockade Has Revolutionized Clinical Outcomes after Kidney Transplantation and Renal Epidemiology of Atypical Hemolytic Uremic Syndrome.

BACKGROUND: Atypical hemolytic uremic syndrome (HUS) is associated with high recurrence rates after kidney transplant, with devastating outcomes. In late 2011, experts in France recommended the use of highly individualized complement blockade-based prophylaxis with eculizumab to prevent post-transplant atypical HUS recurrence throughout the country. METHODS: To evaluate this strategy's effect on kidney transplant prognosis, we conducted a retrospective multicenter study from a large French nationwide registry, enrolling all adult patients with atypical HUS who had undergone complement analysis and a kidney transplant since January 1, 2007. To assess how atypical HUS epidemiology in France in the eculizumab era evolved, we undertook a population-based cohort study that included all adult patients with atypical HUS (n=397) between 2007 and 2016. RESULTS: The first study included 126 kidney transplants performed in 116 patients, 58.7% and 34.1% of which were considered to be at a high and moderate risk of atypical HUS recurrence, respectively. Eculizumab prophylaxis was used in 52 kidney transplants, including 39 at high risk of recurrence. Atypical HUS recurred after 43 (34.1%) of the transplants; in four cases, patients had received eculizumab prophylaxis and in 39 cases they did not. Use of prophylactic eculizumab was independently associated with a significantly reduced risk of recurrence and with significantly longer graft survival. In the second, population-based cohort study, the proportion of transplant recipients among patients with ESKD and atypical HUS sharply increased between 2012 and 2016, from 46.2% to 72.3%, and showed a close correlation with increasing eculizumab use among the transplant recipients. CONCLUSIONS: Results from this observational study are consistent with benefit from eculizumab prophylaxis based on pretransplant risk stratification and support the need for a rigorous randomized trial.

Survival and specific outcome of sickle cell disease patients after renal transplantation.

The prognosis of sickle cell disease (SCD) patients who need dialysis is poor, but experience with kidney transplantation is limited. This study assessed the characteristics of 36 SCD patients undergoing renal transplantation. Immediate post-surgical complications occurred in 25% of cases. Cytomegalovirus and bacterial infections were frequently observed. Twelve patients died after a median follow-up period of 17·4 months. Overall patient survival was significantly lower in SCD than in the control group without significant difference for overall death-censored graft survival. Our data suggest that renal transplantation should be systematically considered in SCD patients with end-stage renal disease.

Prevalence and incidence of kidney diseases leading to hospital admission in people living with HIV in France: an observational nationwide study.

OBJECTIVES: To describe hospitalisations for kidney disease (KD) among people living with HIV (PLHIV) in France and to identify the factors associated with such hospitalisations since data on the epidemiology of KD leading to hospitalisation are globally scarce. DESIGN: Observational nationwide study using the French Programme de Médicalisation des Systèmes d'Information database. SETTING: France 2008-2013. PARTICIPANTS: Around 10 862 PLHIV out of a mean of 5 210 856 patients hospitalised each year. All hospital admissions with a main diagnosis code indicating KD (International Classification of Diseases, 10th revision codes, N00 to -N39) were collected. MAIN OUTCOME MEASURES: The prevalence and incidence of KD leading to hospital admission in PLHIV and the associated risk factors. RESULTS: The prevalence of patients hospitalised for KD was 1.5 higher in PLHIV than in the general population, and increased significantly from 3.0% in 2008 to 3.7% in 2013 (p<0.01). The main cause of hospitalisation for KD was acute renal failure (ARF, 25.4%). Glomerular diseases remained stable (6.4%) throughout the study period, focal segmental glomerulosclerosis being the main diagnosis (37.6%). Only 41.3% of patients hospitalised for glomerular disease were biopsied. The other common motives for admission were nephrolithiasis (22.1%) and pyelonephritis (22.6%).The 5-year cumulative incidence of KD requiring hospitalisation was 5.9% in HIV patients newly diagnosed for HIV in 2009. Factors associated with a higher risk of incident KD requiring hospitalisation were cardiovascular disease (HR 3.30, 95% CI 1.46 to 7.49), and, for female patients, AIDS (HR 2.45, 95% CI 1.07 to 5.58). Two-thirds of hospitalisations for incident ARF occurred in the first 2 years of follow-up. CONCLUSIONS: Hospital admission for KD is more frequent in PLHIV than in the general population and increases over time. ARF remains the leading cause. Glomerular diseases are infrequently documented by renal biopsies. Older patients and those with cardiovascular disease are particularly concerned.

Guillain-Barré Syndrome and Chikungunya: Description of All Cases Diagnosed during the 2014 Outbreak in the French West Indies.

The Guillain-Barré syndrome (GBS) has been reported as a possible complication of acute chikungunya infection. The chikungunya epidemics, which occurred in Martinique and Guadeloupe in 2014, affected 308,000 people in these two islands. GBS occurred during or immediately after acute chikungunya infection in 13 patients (10 men, three women; mean age: 61 years). Median time from acute chikungunya to GBS onset was 9 days. Twelve patients were treated with intravenous polyvalent immunoglobulins, nine of whom improved within 7 days. Five of 13 patients required mechanical ventilation. Two patients with severe GBS died. At 6 months of follow-up, 7/13 achieved a good functional recovery with no or minor residual symptoms. A 2-fold increase in incidence was observed during the year of chikungunya outbreak. This study supports prior reports suggesting that GBS may be a complication of chikungunya.

Differences in motor imagery time when predicting task duration in alpine skiers and equestrian riders.

Athletes' ability to use motor imagery (MI) to predict the speed at which they could perform a motor sequence has received little attention. In this study, 21 alpine skiers and 16 equestrian riders performed MI based on a prediction of actual performance time (a) after the course inspection, (b) before the start, and (c) after the actual performance. MI and physical times were similar in expert skiers during each imagery session, while novice skiers and novice and expert riders underestimated the actual course duration. These findings provide evidence that the temporal accuracy of an imagery task prediction depends on the performer's expertise level and characteristics of the motor skill.

Role of TRPC1 channel in skeletal muscle function.

Skeletal muscle contraction is reputed not to depend on extracellular Ca2+. Indeed, stricto sensu, excitation-contraction coupling does not necessitate entry of Ca2+. However, we previously observed that, during sustained activity (repeated contractions), entry of Ca2+ is needed to maintain force production. In the present study, we evaluated the possible involvement of the canonical transient receptor potential (TRPC)1 ion channel in this entry of Ca2+ and investigated its possible role in muscle function. Patch-clamp experiments reveal the presence of a small-conductance channel (13 pS) that is completely lost in adult fibers from TRPC1(-/-) mice. The influx of Ca2+ through TRPC1 channels represents a minor part of the entry of Ca(2+) into muscle fibers at rest, and the activity of the channel is not store dependent. The lack of TRPC1 does not affect intracellular Ca2+ concentration ([Ca2+](i)) transients reached during a single isometric contraction. However, the involvement of TRPC1-related Ca2+ entry is clearly emphasized in muscle fatigue. Indeed, muscles from TRPC1(-/-) mice stimulated repeatedly progressively display lower [Ca2+](i) transients than those observed in TRPC1(+/+) fibers, and they also present an accentuated progressive loss of force. Interestingly, muscles from TRPC1(-/-) mice display a smaller fiber cross-sectional area, generate less force per cross-sectional area, and contain less myofibrillar proteins than their controls. They do not present other signs of myopathy. In agreement with in vitro experiments, TRPC1(-/-) mice present an important decrease of endurance of physical activity. We conclude that TRPC1 ion channels modulate the entry of Ca(2+) during repeated contractions and help muscles to maintain their force during sustained repeated contractions.

TRPC1 regulates skeletal myoblast migration and differentiation.

Myoblast migration is a key step in myogenesis and regeneration. It allows myoblast alignment and their fusion into myotubes. The process has been shown to involve m-calpain or mu-calpain, two Ca(2+)-dependent cysteine proteases. Here we measure calpain activity in cultured cells and show a peak of activity at the beginning of the differentiation process. We also observed a concomitant and transient increase of the influx of Ca(2+) and expression of TRPC1 protein. Calpains are specifically activated by a store-operated entry of Ca(2+) in adult skeletal muscle fibres. We therefore repressed the expression of TRPC1 in myoblasts and studied the effects on Ca(2+) fluxes and on differentiation. TRPC1-depleted myoblasts presented a largely reduced store-operated entry of Ca(2+) and a significantly diminished transient influx of Ca(2+) at the beginning of differentiation. The concomitant peak of calpain activity was abolished. TRPC1-knockdown myoblasts also accumulated myristoylated alanine-rich C-kinase substrate (MARCKS), an actin-binding protein and substrate of calpain. Their fusion into myotubes was significantly slowed down as a result of the reduced speed of cell migration. Accordingly, migration of control myoblasts was inhibited by 2-5 microM GsMTx4 toxin, an inhibitor of TRP channels or by 50 microM Z-Leu-Leu, an inhibitor of calpain. By contrast, stimulation of control myoblasts with IGF-1 increased the basal influx of Ca(2+), activated calpain and accelerated migration. These effects were not observed in TRPC1-knockdown cells. We therefore suggest that entry of Ca(2+) through TRPC1 channels induces a transient activation of calpain and subsequent proteolysis of MARCKS, which allows in turn, myoblast migration and fusion.

Tumor associated antigen PRAME is a marker of favorable prognosis in childhood acute myeloid leukemia patients and modifies the expression of S100A4, Hsp 27, p21, IL-8 and IGFBP-2 in vitro and in vivo.

Preferentially expressed antigen of melanoma (PRAME) is expressed in a wide variety of tumors, but in contrast with most other tumor associated antigens, it is also expressed in leukemias. In a previous study, we showed that overexpression of PRAME induced apoptosis, inhibited cell proliferation and reduced tumorigenicity of leukemic cells in vivo. We also demonstrated that PRAME overexpression induced the repression of three genes (Hsp27, S100A4 and p21) associated with an unfavorable prognosis in leukemia. Here, we further investigated the mechanisms of PRAME-induced tumor suppression in vitro and in vivo. We performed a gene profiling study by analysing PRAME shRNA-silenced leukemic cells on high-density micro-arrays (Affymetrix) and found that PRAME altered the expression of two additional genes potentially involved in cancerogenesis and cancer progression: IL-8 and IGFBP-2. In a series of 28 acute myeloid leukemia pediatric patients, we observed that PRAME expression was associated with an increased leukemia-free survival. Importantly, the correlation between PRAME expression in leukemic cell lines and the decreased expression of Hsp27, S100A4, p21, IL-8 and the increased expression of IGFBP-2 was also observed in vivo, in leukemic patients. Our results suggest that the favorable prognosis of PRAME could be mediated, at least in part, by the modified expression of those genes.

Effect of imagined movement speed on subsequent motor performance.

Researchers realize that motor imagery (MI) duration is closely linked to actual motor action duration. In 2 experiments, the authors investigated the effect of changing MI speed on actual movement duration over a 3-week training period. Experiment 1 involved 2 series of body movements that 24 participants mentally performed faster or slower than their actual execution speeds. The fast MI group's actual times decreased on subsequent performance. Participants in Experiment 2 were 21 skilled athletes who increased (decreased) their well-rehearsed actual movement times after MI training at a slow (fast) speed. The effect was task-related, however: MI affected only self-initiated movement. The effect of MI on actual speed execution supports the ideomotor theory because anticipation of sensory consequences of actions is mentally represented.

Tumor-associated antigen preferentially expressed antigen of melanoma (PRAME) induces caspase-independent cell death in vitro and reduces tumorigenicity in vivo.

Preferentially expressed antigen of melanoma (PRAME) is expressed in a wide variety of tumors, but in contrast with most other tumor associated antigens, it is also expressed in leukemias. The physiologic role of PRAME remains elusive. Interestingly, PRAME expression is correlated with a favorable prognosis in childhood acute leukemias. Moreover, a high expression of PRAME seems to be predominantly found in acute leukemias carrying a favorable prognosis. On these clinical observations, we assumed that PRAME could be involved in the regulation of cell death or cell cycle. In this study, we show that transient overexpression of PRAME induces a caspase-independent cell death in cultured cell lines (CHO-K1 and HeLa). Cells stably transfected with PRAME also exhibit a decreased proliferation rate due, at least partially, to an elevated basal rate of cell death. Immunocytochemistry of a FLAG-tagged PRAME, in vivo imaging of an enhanced green fluorescent protein-tagged PRAME, and Western blotting after cell fractionation reveal a nuclear localization of the protein. Using a microarray-based approach, we show that KG-1 leukemic cells stably transfected with PRAME present a significant decrease of expression of the heat-shock protein Hsp27, the cyclin-dependent kinase inhibitor p21, and the calcium-binding protein S100A4. The expression of these three proteins is known to inhibit apoptosis and has been associated with an unfavorable prognosis in a series of cancers. Finally, repression of PRAME expression by a short interfering RNA strategy increases tumorigenicity of K562 leukemic cells in nude mice. We suggest that all these observations might explain the favorable prognosis of the leukemias expressing high levels of PRAME.

Increased IGF mRNA in human skeletal muscle after creatine supplementation.

PURPOSE: We hypothesized that creatine supplementation would facilitate muscle anabolism by increasing the expression of growth factors and the phosphorylation of anabolic signaling molecules; we therefore tested the responses of mRNA for IGF-I and IGF-II and the phosphorylation state of components of anabolic signaling pathways p70(s6k) and 4E-BP1 to a bout of high-intensity resistance exercise after 5 d of creatine supplementation. METHODS: In a double-blind cross-over design, muscle biopsies were taken from the m. vastus lateralis at rest and 3 and 24 h postexercise in subjects who had taken creatine or placebo for 5 d (21 g x d(-1)). For the first 3 h postexercise, the subjects were fed with a drink containing maltodextrin (0.3 g x kg(-1) body weight x h(-1)) and protein (0.08 g x kg(-1) body weight x h(-1)). RESULTS: After creatine supplementation, resting muscle expressed more mRNA for IGF-I (+30%, P < 0.05) and IGF-II (+40%, P = 0.054). Exercise caused an increase by 3 h postexercise in IGF-I (+24%, P < 0.05) and IGF-II (+48%, P < 0.05) and by 24 h postexercise in IGF-I (+29%, P < 0.05), but this effect was not potentiated by creatine supplementation. The phosphorylation states of p70(s6k) and 4E-BP1 were not affected by creatine at rest; phosphorylation of both increased (150-400%, P < 0.05) to similar levels under placebo and creatine conditions at 3 h postexercise plus feeding. However, the phosphorylation state of 4E-BP1 was higher in the creatine versus placebo condition at 24 h postexercise. CONCLUSION: The increase in lean body mass often reported after creatine supplementation could be mediated by signaling pathway(s) involving IGF and 4E-BP1.

Rapid combined genotyping of factor V, prothrombin and methylenetetrahydrofolate reductase single nucleotide polymorphisms using minor groove binding DNA oligonucleotides (MGB probes) and real-time polymerase chain reaction.

Risk factors for cardiovascular diseases and venous thromboembolism involve both acquired and hereditary conditions. Among the latter, mutations in genes coding for coagulation factors (factor V Leiden [Arg506Gly], G20210A in the 3'-untranslated region of factor II ) and variant C677T of the methylenetetrahydrofolate reductase (MTHFR ) are often involved and co-inherited. These three factors were genotyped simultaneously in the same 96-well plate, using a real-time polymerase chain reaction (PCR) Taqman assay and minor groove binding DNA oligonucleotides (MGB probes). While primers and MGB probes matched their corresponding single nucleotide polymorphism (SNP), the real-time MGB program was identical for each target gene. Homozygous wild-type (WT; -/-), heterozygous (+/-) or homozygous (+/+) variants (n = 362) were selected for factor V (n = 115, with -/-, 40; +/-, 40; +/+, 35), factor II (n = 122, with -/-, 60; +/-, 60; +/+, 2), and MTHFR (n = 120, with -/-, 40; +/-, 40; +/+, 40), according to the results of conventional PCR-restriction fragment length polymorphism (PCR-RFLP), but the allelic discrimination was performed blind. Results of the real-time MGB and PCR-RFLP assays were identical. This new assay was easy and fast with high throughput, without risk of molecular carryover, and cost-effective for laboratories utilizing the Taqman or related fluorescence reading methods. These advantages make it particularly suitable for large-scale combined genotyping of several polymorphisms in the routine setting.

Power spectral analysis of heart rate in relation to sleep position.

We used spectral analysis of heart rate variability, as a measure of autonomic tone, to determine spectral power differences in infants sleeping supine and prone. We studied 29 infants with a birth weight of 1,915 +/- 939 g, at the postconceptional age of 36 +/- 2 weeks. We then calculated total power (TP), low-frequency power (LF, 0.03-0.15 Hz), and high-frequency power (HF, 0.5-1.0 Hz). TP corresponds to overall heart rate variability, LF to both sympathetic and parasympathetic activity, and HF to parasympathetic activity only. Median (25th, 75th percentile) TP (beats/min2) in the supine position was 32.60 (23.12, 59.90), which was significantly higher than the prone position of 25.87 (14.94, 35.57). Similarly, LF (beats/min2) in the supine position of 13.82 (8.63, 23.31) was significantly higher than the prone position of 9.79 (5.46, 14.33). No significant difference was seen in the HF. We conclude that the prone position is associated with decreased heart rate variability and probably decreased sympathetic tone, which imply decreased autonomic stability in this position.

Effect of creatine supplementation on skeletal muscle of mdx mice.

Dystrophic mice (mdx) and their controls (C57/Bl10) were fed for 1 month with a diet with or without creatine (Cr) enrichment. Cr supplementation reduced mass (by 19%, P < 0.01) and mean fiber surface (by 25%, P < 0.05) of fast-twitch mdx muscles. In both strains, tetanic tension increased slightly (9.2%) without reaching statistical significance (P = 0.08), and relaxation time increased by 16% (P < 0.001). However, Cr had no protective effect on the other hallmarks of dystrophy such as susceptibility to eccentric contractions; large numbers of centrally nucleated fibers in tibialis anterior; and elevated total calcium content, which increased by 85% (P = 0.008) in gastrocnemius mdx muscles. In conclusion, Cr may be a positive intervention for improving function of dystrophic muscle.

Creatine increases IGF-I and myogenic regulatory factor mRNA in C(2)C(12) cells.

Addition of creatine to the differentiation medium of C(2)C(12) cells leads to hypertrophy of the myotubes. To investigate the implication of insulin-like growth factor I (IGF-I) and myogenic regulatory factors (MRFs) in this hypertrophy, their mRNA levels were assessed during the first 72 h of differentiation. Creatine significantly increased the IGF-I mRNA level over the whole investigated period of time, whereas the MRF mRNA levels were only augmented at precise moments, suggesting a general activation mechanism for IGF-I and a specifically regulated mechanism for MRF transcription. Our results suggest therefore that creatine-induced hypertrophy of C(2)C(12) cells is at least partially mediated by overexpression of IGF-I and MRFs.

No effect of creatine supplementation on human myofibrillar and sarcoplasmic protein synthesis after resistance exercise.

Muscle hypertrophy during resistance training is reportedly increased by creatine supplementation. Having previously failed to find an anabolic effect on muscle protein turnover at rest, either fed or fasted, we have now examined the possibility of a stimulatory effect of creatine in conjunction with acute resistance exercise. Seven healthy men (body mass index, 23 +/- 2 kg/m2, 21 +/- 1 yr, means +/- SE) performed 20 x 10 repetitions of leg extension-flexion at 75% one-repetition maximum in one leg, on two occasions, 4 wk apart, before and after ingesting 21 g/day creatine for 5 days. The subjects ate approximately 21 g maltodextrin + 6 g protein/h for 3 h postexercise. We measured incorporation of [1-13C]leucine into quadriceps muscle proteins in the rested and exercised legs. Leg protein breakdown (as dilution of [2H5]phenylalanine) was also assessed in the exercised and rested leg postexercise. Creatine supplementation increased muscle total creatine by approximately 21% (P < 0.01). Exercise increased the synthetic rates of myofibrillar and sarcoplasmic proteins by two- to threefold (P < 0.05), and leg phenylalanine balance became more positive, but creatine was without any anabolic effect.

Beneficial effects of creatine supplementation in dystrophic patients.

The effect of creatine (Cr) supplementation on muscle function and body composition of 12 boys with Duchenne muscular dystrophy and three with Becker dystrophy was evaluated by a randomized double-blind cross-over study (3 g Cr or maltodextrin daily for 3 months, with wash-out period of 2 months). After placebo, no change was observed in maximal voluntary contraction (MVC) and resistance to fatigue, whereas total joint stiffness (TJS) was increased by approximately 25% (P < 0.05). The patients receiving Cr did not show any change in TJS, improved MVC by 15% (P = 0.02), and almost doubled their resistance to fatigue (P < 0.001). In patients still independent of a wheelchair (n = 5), bone mineral density increased by 3% (P < 0.05), and urinary excretion of collagen type I cross-linking N-telopeptide declined to about one third (P < 0.001) after Cr. No adverse effect was observed. Thus, Cr may provide some symptomatic benefit in these patients.

Creatine supplementation has no effect on human muscle protein turnover at rest in the postabsorptive or fed states.

Dietary creatine supplementation is associated with increases in muscle mass, but the mechanism is unknown. We tested the hypothesis that creatine supplementation enhanced myofibrillar protein synthesis (MPS) and diminished muscle protein breakdown (MPB) in the fed state. Six healthy men (26 +/- 7 yr, body mass index 22 +/- 4 kg/m(2)) were studied twice, 2-4 wk apart, before and after ingestion of creatine (21 g/day, 5 days). We carried out two sets of measurements within 5.5 h of both MPS (by incorporation of [1-(13)C]leucine in quadriceps muscle) and MPB (as dilution of [1-(13)C]leucine or [(2)H(5)]phenylalanine across the forearm); for the first 3 h, the subjects were postabsorptive but thereafter were fed orally (0.3 g maltodextrin and 0.083 g protein. kg body wt(-1) x h(-1)). Creatine supplementation increased muscle total creatine by approximately 30% (P < 0.01). Feeding had significant effects, doubling MPS (P < 0.001) and depressing MPB by approximately 40% (P < 0.026), but creatine had no effect on turnover in the postabsorptive or fed states. Thus any increase in muscle mass accompanying creatine supplementation must be associated with increased physical activity.