Pharmacological and non-pharmacological treatments for neuropathic pain: Systematic review and French recommendations

Neuropathic pain remains a significant unmet medical need. Several recommendations have recently been proposed concerning pharmacotherapy, neurostimulation techniques and interventional management, but no comprehensive guideline encompassing all these treatments has yet been issued. We performed a systematic review of pharmacotherapy, neurostimulation, surgery, psychotherapies and other types of therapy for peripheral or central neuropathic pain, based on studies published in peer-reviewed journals before January 2018. The main inclusion criteria were chronic neuropathic pain for at least three months, a randomized controlled methodology, at least three weeks of follow-up, at least 10 patients per group, and a double-blind design for drug therapy. Based on the GRADE system, we provide weak-to-strong recommendations for use and proposal as a first-line treatment for SNRIs (duloxetine and venlafaxine), gabapentin and tricyclic antidepressants and, for topical lidocaine and transcutaneous electrical nerve stimulation specifically for peripheral neuropathic pain; a weak recommendation for use and proposal as a second-line treatment for pregabalin, tramadol, combination therapy (antidepressant combined with gabapentinoids), and for high-concentration capsaicin patches and botulinum toxin A specifically for peripheral neuropathic pain; a weak recommendation for use and proposal as a third-line treatment for high-frequency rTMS of the motor cortex, spinal cord stimulation (failed back surgery syndrome and painful diabetic polyneuropathy) and strong opioids (in the absence of an alternative). Psychotherapy (cognitive behavioral therapy and mindfulness) is recommended as a second-line therapy, as an add-on to other therapies. An algorithm encompassing all the recommended treatments is proposed.

Pharmacological and non-pharmacological treatments for neuropathic pain: Systematic review and French recommendations.

Neuropathic pain remains a significant unmet medical need. Several recommendations have recently been proposed concerning pharmacotherapy, neurostimulation techniques and interventional management, but no comprehensive guideline encompassing all these treatments has yet been issued. We performed a systematic review of pharmacotherapy, neurostimulation, surgery, psychotherapies and other types of therapy for peripheral or central neuropathic pain, based on studies published in peer-reviewed journals before January 2018. The main inclusion criteria were chronic neuropathic pain for at least three months, a randomized controlled methodology, at least three weeks of follow-up, at least 10 patients per group, and a double-blind design for drug therapy. Based on the GRADE system, we provide weak-to-strong recommendations for use and proposal as a first-line treatment for SNRIs (duloxetine and venlafaxine), gabapentin and tricyclic antidepressants and, for topical lidocaine and transcutaneous electrical nerve stimulation specifically for peripheral neuropathic pain; a weak recommendation for use and proposal as a second-line treatment for pregabalin, tramadol, combination therapy (antidepressant combined with gabapentinoids), and for high-concentration capsaicin patches and botulinum toxin A specifically for peripheral neuropathic pain; a weak recommendation for use and proposal as a third-line treatment for high-frequency rTMS of the motor cortex, spinal cord stimulation (failed back surgery syndrome and painful diabetic polyneuropathy) and strong opioids (in the absence of an alternative). Psychotherapy (cognitive behavioral therapy and mindfulness) is recommended as a second-line therapy, as an add-on to other therapies. An algorithm encompassing all the recommended treatments is proposed.

A scoping review of the role of primary care providers and primary care-based interventions in the treatment of pediatric eating disorders.

Youth with eating disorders are often cared for by specialized interdisciplinary teams in pediatric tertiary care centers. Enhanced involvement of primary care providers may provide added benefits to patients because it offers improved access, better continuity of care, and possibly less financial burden. This paper aims to synthesize and assess the literature on the role of the primary care provider in treating pediatric eating disorders in order to identify an optimal model of shared care. Sources were identified by entering search terms in 10 databases. Eligible sources were English publications focusing on primary care-based interventions for eating disorders in youth (=<24 years). The search yielded 5,516 unique citations. Of these, 61 were ultimately included. Sources fell into two categories: (1) primary research (n = 3) and (2) reviews with recommendations for primary care providers (n = 58). The primary studies considered the primary care provider conducting behavioral therapy and guided self-help. Review articles suggested providing education, assessing for hospitalization, aiding in weight restoration, managing complications, referring, and coordinating care. Limited evidence exists that can guide effective primary care-based interventions for the treatment of pediatric eating disorders. Further research is needed to develop and evaluate interventions for the treatment of pediatric eating disorders in primary care settings so that best practices can be identified.

Asymptomatic carriage of extensively drug-resistant bacteria (eXDR), a simple way to assess spontaneous clearance.

The duration of eXDR carriage depends on several factors that might be difficult to recover. We aim to assess the duration of eXDR carriage by using a simple to recover parameter: the number of consecutive negative screening. 131 eXDR carriers (51 VRE and 80 CPE) were included. The number of consecutive negative screenings was strongly associated with eXDR clearance. All patients displaying at least three negative screenings over a seven-month period were never screened positive thereafter. Taking into account the number of negative screenings as a part of a case-by-case risk assessment would be helpful for the decision to maintain or lift eXDR-focused precautions.

Toxigenic Clostridium difficile carriage in general practice: results of a laboratory-based cohort study.

OBJECTIVES: Reported rates of community-acquired Clostridium difficile infections (CDIs) have been increasing. However, the true burden of the disease in general practice is unknown in France. Our objective was to determine the incidence of toxigenic C. difficile carriage and the percentage of stool samples prescribed by general practitioners (GPs) which contained free C. difficile toxins. METHODS: During an 11-month period, all stool samples submitted for any enteric pathogen detection to 15 different private laboratories in Paris and the surrounding areas were tested for C. difficile, irrespective of the GPs' request. A clinical questionnaire was completed for each patient. Stool samples were screened using a rapid simultaneous glutamate dehydrogenase and toxins A/B detection test: any positive result (glutamate dehydrogenase or toxin) was further confirmed by the stool cytotoxicity assay (CTA) on MRC-5 cells and by toxigenic culture (TC) at a central laboratory. The C. difficile isolates were characterized by PCR ribotyping. RESULTS: A total of 2541 patients (1295 female, 1246 male) were included. The incidences of patients with a positive toxigenic culture and a positive CTA were 3.27% (95% CI 2.61%-4.03%) and 1.81% (95% CI 1.33%-2.41%), respectively. GPs requested C. difficile testing in only 12.93% of the stool samples, detecting 52.30% of all TC-positive patients. The 83 toxigenic C. difficile strains belonged to 36 different PCR ribotypes. CONCLUSIONS: Toxigenic C. difficile carriage is frequent in general practice but remains under-recognized. It may affect young patients without previous antimicrobial therapy or hospitalization.

Environmental contamination by bacteria in hospital washrooms according to hand-drying method: a multi-centre study.

BACKGROUND: Hand hygiene is a fundamental component of infection prevention, but few studies have examined whether hand-drying method affects the risk of dissemination of potential pathogens. AIM: To perform a multi-centre, internal-crossover study comparing bacterial contamination levels in washrooms with hand-drying by either paper towels (PT) or jet air dryer (JAD; Dyson). METHODS: A total of 120 sampling sessions occurred over 12 weeks in each of three hospitals (UK, France, Italy). Bacteria were cultured from air, multiple surfaces, and dust. Washroom footfall (patients/visitors/staff) was monitored externally. FINDINGS: Footfall was nine times higher in UK washrooms. Bacterial contamination was lower in PT versus JAD washrooms; contamination was similar in France and the UK, but markedly lower in Italian washrooms. Total bacterial recovery was significantly greater from JAD versus PT dispenser surfaces at all sites (median: 100-300 vs 0-10 cfu; all P < 0.0001). In the UK and France, significantly more bacteria were recovered from JAD washroom floors (median: 24 vs 191 cfu, P < 0.00001). UK meticillin-susceptible Staphylococcus aureus recovery was three times more frequent and six-fold higher for JAD vs PT surfaces (both P < 0.0001). UK meticillin-resistant S. aureus recovery was three times more frequent (21 vs 7 cfu) from JAD versus PT surfaces or floors. Significantly more enterococci and extended-spectrum ß-lactamase (ESBL)-producing bacteria were recovered from UK JAD versus PT washroom floors (P < 0.0001). In France, ESBL-producing bacteria were recovered from dust twice as often during JAD versus PT use. CONCLUSION: Multiple examples of significant differences in surface bacterial contamination, including by faecal and antibiotic-resistant bacteria, were observed, with higher levels in JAD versus PT washrooms. Hand-drying method affects the risk of (airborne) dissemination of bacteria in real-world settings.

How to: diagnose infection caused by Clostridium difficile.

BACKGROUND: Clostridium difficile is recognized as the major agent responsible for nosocomial diarrhoea. In the context of recent increase in the incidence and severity of C. difficile infections (CDI), an accurate diagnosis is essential for optimal treatment and prevention, but continues to be challenging. AIMS: The present article reviews each key step of CDI diagnosis including stool selection, methods and strategies used, and interpretation of the results. SOURCES: The most recent guidelines for CDI diagnosis published by scientific societies were reviewed. CONTENT: CDI diagnosis is based on clinical presentation and laboratory tests confirming the presence of toxigenic strain or toxins in stools. Stool selection is crucial and can be improved by implementing rejection criteria and a strict policy for appropriate testing. Multiple laboratory tests detecting different targets (free toxin or presence of a potentially toxigenic strain) are commercially available. However, none of these tests combine high sensitivity and specificity to diagnose CDI, low hands-on time and low cost. An optimized diagnosis can be achieved by implementing a two- or three-step algorithm. Algorithms currently recommended by the ESCMID comprise a screening test with high sensitivity followed by a more specific test to detect free toxins. Presence of free toxins in stools has been shown to better correlate with severe outcome whereas nucleic acid amplification tests may lead to an over-diagnosis by detecting asymptomatic carriers of a toxigenic strain. IMPLICATION: To date, no single test can accurately diagnose CDI. Guidelines from the ESCMID recommend a two- or three-step algorithm for optimal CDI detection.

[Pain in children with neurological impairment: A review from the French Pediatric Neurology Society]. / La douleur chez l'enfant en situation de handicap neurologique : mise au point de la Commission « déficience intellectuelle et handicap ¼ de la Société française de neurologie pédiatrique.

Management of pain is one of the major expectations of children with neurological impairment and their families. The medical literature is poor on this topic accounting for approximately 0.15 % of the publications on pain in general. The objective of the French Pediatric Neurology Society was to review the current knowledge on this topic. Bibliographic research was conducted with PubMed and RefDoc for publications between 1994 and 2014 in French or English. A total of 925 articles were retrieved and 92 were selected for review. Pain is common in this population: a 2-week survey indicated that pain occurs in 50-75 % of children. Pain negatively impacts the quality of life of children and their parents. Children with neurological impairment express their pain with pain expression patterns and specific patterns common to children (change of tone, abnormal movements, spasticity, paradoxical reactions, such as laughter, self-injury or vasomotor dysfunction). Some children with neurological impairment are able to use self-report pain scales. If not, observational measures should be used. Behavioral rating scales specifically designed for this population are more sensitive than others. Scales must be selected according to children's communication skills, type of pain, and the context. Sometimes behavioral changes are the only expression of pain: any change in sleep, tone, feeding, or mood must suggest pain in this population. Management of pain remains difficult. There are no specific guidelines. Procedural pain management guidelines and the usual analgesic drugs can be used in children with neurological impairment with specific concerns regarding tolerance and side effects. These children are particularly at risk for neuropathic pain. A multidisciplinary approach is helpful, involving physicians, nurses, physiotherapists, psychologists and parents.

The research gap in chronic paediatric pain: A systematic review of randomised controlled trials.

BACKGROUND AND OBJECTIVE: Chronic pain is associated with significant functional and social impairment. The objective of this review was to assess the characteristics and quality of randomized controlled trials (RCTs) evaluating pain management interventions in children and adolescents with chronic pain. METHODS: We performed a systematic search of PubMed, Embase and the Cochrane Library up to July 2017. We included RCTs that involved children and adolescents (3 months-18 years) and evaluated the use of pharmacological or non-pharmacological intervention(s) in the context of pain persisting or re-occurring for more than 3 months. Methodological quality was evaluated using the Cochrane Risk of Bias (ROB) Tool. RESULTS: A total of 58 RCTs were identified and numbers steadily increased over time. The majority were conducted in single hospital institutions, with no information on study funding. Median sample size was 47.5 participants (Q1,Q3: 32, 70). Forty-five percent of RCTs included both adults and children and the median of the mean ages at inclusion was 12.9 years (Q1,Q3: 11, 15). Testing of non-pharmacological interventions was predominant and only 5 RCTs evaluated analgesics or co-analgesics. Abdominal pain, headache/migraine and musculoskeletal pain were the most common types of chronic pain among participants. Methodological quality was poor with 90% of RCTs presenting a high or unclear ROB. CONCLUSIONS: Evaluation of analgesics targeting chronic pain relief in children and adolescents through RCTs is marginal. Infants and children with long-lasting painful conditions are insufficiently represented in RCTs. We discuss possible research constraints and challenges as well as methodologies to circumvent them. SIGNIFICANCE: There is a substantial research gap regarding analgesic interventions for children and adolescents with chronic pain. Most clinical trials in the field focus on the evaluation of non-pharmacological interventions and are of low methodological quality. There is also a specific lack of trials involving infants and children and adolescents with long-lasting diseases.

Long-term Use of Proton Pump Inhibitors Is Associated With Increased Microbial Product Translocation, Innate Immune Activation, and Reduced Immunologic Recovery in Patients With Chronic Human Immunodeficiency Virus-1 Infection.

BACKGROUND: Translocation of microbial products from the damaged gut causes increased immune activation in human immunodeficiency virus (HIV). Proton pump inhibitors (PPIs) predispose to bacterial overgrowth in the gut. We hypothesized that long-term use of PPIs is associated with greater microbial translocation and immune activation in HIV. METHODS: HIV-infected persons on suppressive antiretroviral therapy (ART), including those receiving long-term PPIs (PPI+ group) or not (PPI- group), were enrolled. We determined CD38+HLA-DR+CD8+ (activated) T-cell frequency, and plasma levels of lipopolysaccharide (LPS), LPS binding protein (LBP), soluble CD14 (sCD14), and intestinal fatty acid binding protein (I-FABP). RESULTS: We recruited 77 HIV-infected participants (37 PPI+ and 40 PPI-) and 20 HIV-uninfected volunteers. PPI+ subjects were older and more likely to have hypertension and receive statins than PPI-. Nadir and enrollment CD4 counts, activated T-cells, and time on ART were similar in both groups. PPI+ group had higher sCD14 (2.15 vs. 1.50 mcg/mL, P < .01), and LBP (21.78 vs. 18.28 mcg/mL, P = .02) but lower I-FABP levels (608.5 vs. 2281.7 pg/mL, P = .05) than PPI-. In multivariate analysis, sCD14 levels remained associated with PPIs. In the year prior to enrollment, PPI+ group lost more CD4 cells than PPI- (-18 vs. 54 cells/mm3, P = .03). HIV-infected subjects had higher immune activation and microbial translocation biomarkers than uninfected volunteers. CONCLUSION: In HIV, long-term use of PPIs was associated with increased microbial translocation, innate immune activation, and reduced immune reconstitution. Further studies are needed to evaluate the clinical implications of our findings. In the meantime, cautious use of PPIs is advised.

Themes arising in clinical consultation for therapists implementing family-based treatment for adolescents with anorexia nervosa: a qualitative study.

BACKGROUND: Our study aims to explore and describe themes arising in sessions of clinical consultation with therapists implementing Family-Based Treatment (FBT) for adolescents with Anorexia Nervosa (AN). There is currently no literature describing the content of clinical consultation for FBT. Thus, this knowledge will add to the evidence-base on what therapists need from consultants in ongoing clinical consultation. METHODS: Eight therapists at four sites participated in this study, which spanned a two-year period. Following a two-day training workshop, each therapist treated at least one adolescent patient presenting with a restrictive eating disorder with FBT, focusing on adherence to the treatment manual. Clinical consultation sessions occurred monthly and were led by an external FBT expert. Thirty-five (average per site = 9) audio recorded group clinical consultation sessions were transcribed verbatim and coded for themes. Twenty percent of the transcripts were double-coded to ensure consistency. Fundamental qualitative description guided the sampling and data collection. RESULTS: Thematic content analysis revealed ten common themes relating to the provision of clinical consultation to therapists implementing FBT in clinical practice: encouraging parental meal time supervision,discussing the role of mothers, how to align parents, ensuring parental buy-in, when to transition to Phase 2, weighing the patient and the patients' knowledge of their weight, the role of siblings in FBT sessions, how best to manage patient co-morbidities, the role of the father in FBT and how best to manage the family meal. CONCLUSIONS: In conclusion, clinical consultation themes aligned with many of the central tenets of FBT, including how to help parents align their supportive approach during the refeeding process, and how to help parents assume control of eating disordered behaviours. This knowledge helps to guide consultants to anticipate common issues brought forward by therapists attempting to implement FBT.

[Multidisciplinary management of children with disabling chronic pain in a French pediatric rehabilitation center: Current management and perspectives]. / Prise en charge multidisciplinaire des enfants souffrant de douleurs chroniques invalidantes dans un centre de rééducation fonctionnelle pédiatrique français : analyse rétrospective d'une série et perspectives.

INTRODUCTION: Chronic pain in children and adolescents has a major impact on their life in terms of school, sleep as well as family and social life. Teenagers aged 13-15 and girls are at the highest risk. Zeltzer et al. established a bio-psychosocial model of chronic pain in 1998 to account for all its dimensions and advocated a multidisciplinary management plan. Programs based on their principles target specific symptoms such as anxiety and loss of function, while treating underlying factors and teaching coping skills to patients and their families. They aim for patients to regain autonomy rather than focusing on pain resolution. Such programs, with varied protocols, have existed outside of France for approximately 15 years. The efficacy of these multidisciplinary programs has been shown in studies in Germany, the United Kingdom, the United States, Canada, and Australia. To our knowledge, there are no French studies on this topic; therefore, our aim was to describe a French program. We hypothesized that the program would be effective in reducing chronic pain and its impact. METHODS: The aim of this study was to describe the multidisciplinary management of chronic pain in a French pediatric functional rehabilitation center. It is a public health establishment located in the suburbs of Lille, offering care for children aged 0-18 with various conditions. It has 52 hospital beds, can accommodate up to 22 day-hospital visits per day and has comprehensive technical facilities. This prospective study consisted in a chart review of all consecutive patients who were hospitalized in the functional rehabilitation center for chronic pain with significant disability since 2010. We reviewed the treatment protocol for each patient as well as the treatment results for the composite primary endpoint, comprising pain characteristics and the impact of pain on function and schooling after discharge. RESULTS: Twenty-nine patients, aged 9.4-17.8 years, 62.1% of whom were girls, were hospitalized for chronic pain with a significant impact on their daily life between 2010 and August 2014. The most common diagnosis was complex regional pain syndrome type 1 (CRPS1) (37.9%). Pain had major consequences, with total disability in 69% of cases and 100% of children taking pain medications. In 65.5% of cases, patients were hospitalized in an inpatient setting, and 34.5% attended an outpatient program. Treatment lasted from 1 to 68 weeks (mean, 24.3; standard deviation [SD], 21.6). Patients received a combination of medical care, physical therapy (100%), occupational therapy (37.9%), psychological counseling (100%), pain medications (96.6%), and schooling (96.6%). Pain improved significantly in 89.7% of patients (95% confidence interval [95% CI] [0.73-0.98]) and pain medication consumption decreased significantly in 72.4% of children (95% CI [0.53-0.87]). Patients who had stopped walking could ambulate again in 91.7% of cases (95% CI [0.73-0.99]) and 86.4% of patients who had been missing school were back at school full time (95% CI [0.65-0.97]). There were no significant differences for these results between inpatient and outpatient management programs. Improvements were maintained at 3-6 months after discharge in 83.3% of cases. CONCLUSION: The multidisciplinary pain management program in this French pediatric functional rehabilitation center shows results comparable to the programs described in other countries. Chronic pain should be evaluated with standardized and validated tools, such as the measurement of the pain-related disability with the Functional Disability Index.

Prospective study of surveillance testing for metastasis in 100 high-risk uveal melanoma patients.

Despite advances in the local treatment of UM, half of patients develop metastases typically to the liver with poor survival. Microscopic complete surgical resection (R0) of liver metastases improves survival in high selected patients. Early identification of high-risk patients might allow detection of asymptomatic metastases, and increase R0 liver surgery rate. From October 2006 to December 2009, we conducted a prospective study to detect early minimal lesions with 6-monthly liver function tests (LFTs) and liver MRI in 100 high-risk patients. High risk was defined by primary tumor clinical or genomic criteria: thickness>8mm or diameter>15 mm, or extra-scleral extension, or monosomy 3 by FISH or aCGH. With a median follow-up of 49 months, the 5-year metastasis-free survival and overall survival were 47 and 33%, respectively. Of the 60 patients who became metastatic, 50 (83%) had exclusive liver metastasis. LFTs screening had no sufficient accurary, but biannual MRI showed high predictive value to detect metastasis and select patients eligible for curative surgery: 25/50 underwent laparotomy and among them, 8/25 (32%) had a R0 surgery. Median survival after metastasis was 14 months, mean survival reached 40 months in the R0 resected population. Six-monthly liver MRI screening is recommended in patients with large tumors or genomic high risk in order to detect early patient candidates to complete resection of liver metastases.

Influence of segmental chromosome abnormalities on survival in children over the age of 12 months with unresectable localised peripheral neuroblastic tumours without MYCN amplification.

BACKGROUND: The prognostic impact of segmental chromosome alterations (SCAs) in children older than 1 year, diagnosed with localised unresectable neuroblastoma (NB) without MYCN amplification enrolled in the European Unresectable Neuroblastoma (EUNB) protocol is still to be clarified, while, for other group of patients, the presence of SCAs is associated with poor prognosis. METHODS: To understand the role of SCAs we performed multilocus/pangenomic analysis of 98 tumour samples from patients enrolled in the EUNB protocol. RESULTS: Age at diagnosis was categorised into two groups using 18 months as the age cutoff. Significant difference in the presence of SCAs was seen in tumours of patients between 12 and 18 months and over 18 months of age at diagnosis, respectively (P=0.04). A significant correlation (P=0.03) was observed between number of SCAs per tumour and age. Event-free (EFS) and overall survival (OS) were calculated in both age groups, according to both the presence and number of SCAs. In older patients, a poorer survival was associated with the presence of SCAs (EFS=46% vs 75%, P=0.023; OS=66.8% vs 100%, P=0.003). Moreover, OS of older patients inversely correlated with number of SCAs (P=0.002). Finally, SCAs provided additional prognostic information beyond histoprognosis, as their presence was associated with poorer OS in patients over 18 months with unfavourable International Neuroblastoma Pathology Classification (INPC) histopathology (P=0.018). CONCLUSIONS: The presence of SCAs is a negative prognostic marker that impairs outcome of patients over the age of 18 months with localised unresectable NB without MYCN amplification, especially when more than one SCA is present. Moreover, in older patients with unfavourable INPC tumour histoprognosis, the presence of SCAs significantly affects OS.

Diagnosis of Xp11 translocation renal cell carcinomas in adult patients under 50 years: interest and pitfalls of automated immunohistochemical detection of TFE3 protein.

Renal cell carcinomas associated with Xp11.2 translocations form a new and little known entity of the WHO 2004 classification. An immunohistochemical (IHC) test aiming at demonstrating the nuclear expression of the protein TFE3, product of a gene frequently involved in translocation, has been proposed as a diagnostic tool. The aims of this work were to define our evaluation criteria of the immunohistochemical test with the antibody anti-TFE3 and to describe new cases of renal cell carcinomas with TFE3 translocations. Using immunohistochemistry with antibody anti-TFE3, we retrospectively studied 83 renal cell carcinomas diagnosed at Edouard Herriot Hospital and Biomnis Laboratory, Lyon, between 2003 and 2009. The patients were 50 years old or younger. We detail our experience of the IHC test using the anti-body anti-TFE3 and the interpretation criteria. This work has enabled two new cases of renal cell carcinomas associated with TFE3 translocations to be detailed, confirmed by molecular biology. The TFE3 immunohistochemical test is a useful tool that demands strict interpretation criteria. In our experience, more than 80% of nuclei stained with an intensity of ++ to +++ is necessary to suspect the diagnosis of Xp11 translocation renal cell carcinoma.

Glutaredoxin s12: unique properties for redox signaling.

AIMS: Cysteines (Cys) made acidic by the protein environment are generally sensitive to pro-oxidant molecules. Glutathionylation is a post-translational modification that can occur by spontaneous reaction of reduced glutathione (GSH) with oxidized Cys as sulfenic acids (-SOH). The reverse reaction (deglutathionylation) is strongly stimulated by glutaredoxins (Grx) and requires a reductant, often GSH. RESULTS: Here, we show that chloroplast GrxS12 from poplar efficiently reacts with glutathionylated substrates in a GSH-dependent ping pong mechanism. The pK(a) of GrxS12 catalytic Cys is very low (3.9) and makes GrxS12 itself sensitive to oxidation by H(2)O(2) and to direct glutathionylation by nitrosoglutathione. Glutathionylated-GrxS12 (GrxS12-SSG) is temporarily inactive until it is deglutathionylated by GSH. The equilibrium between GrxS12 and glutathione (E(m(GrxS12-SSG))= -315 mV, pH 7.0) is characterized by K(ox) values of 310 at pH 7.0, as in darkened chloroplasts, and 69 at pH 7.9, as in illuminated chloroplasts. INNOVATION: Based on thermodynamic data, GrxS12-SSG is predicted to accumulate in vivo under conditions of mild oxidation of the GSH pool that may occur under stress. Moreover, GrxS12-SSG is predicted to be more stable in chloroplasts in the dark than in the light. CONCLUSION: These peculiar catalytic and thermodynamic properties could allow GrxS12 to act as a stress-related redox sensor, thus allowing glutathione to play a signaling role through glutathionylation of GrxS12 target proteins.

Segmental chromosomal alterations lead to a higher risk of relapse in infants with MYCN-non-amplified localised unresectable/disseminated neuroblastoma (a SIOPEN collaborative study).

BACKGROUND: In neuroblastoma (NB), the presence of segmental chromosome alterations (SCAs) is associated with a higher risk of relapse. METHODS: In order to analyse the role of SCAs in infants with localised unresectable/disseminated NB without MYCN amplification, we have performed an array CGH analysis of tumours from infants enrolled in the prospective European INES trials. RESULTS: Tumour samples from 218 out of 300 enroled patients could be analysed. Segmental chromosome alterations were observed in 11%, 20% and 59% of infants enroled in trials INES99.1 (localised unresectable NB), INES99.2 (stage 4s) and INES99.3 (stage 4) (P<0.0001). Progression-free survival was poorer in patients whose tumours harboured SCA, in the whole population and in trials INES99.1 and INES99.2, in the absence of clinical symptoms (log-rank test, P=0.0001, P=0.04 and P=0.0003, respectively). In multivariate analysis, a SCA genomic profile was the strongest predictor of poorer progression-free survival. CONCLUSION: In infants with stage 4s MYCN-non-amplified NB, a SCA genomic profile identifies patients who will require upfront treatment even in the absence of other clinical indication for therapy, whereas in infants with localised unresectable NB, a genomic profile characterised by the absence of SCA identifies patients in whom treatment reduction might be possible. These findings will be implemented in a future international trial.