Critical appraisal of evidence for anti-Xa monitoring and dosing of low-molecular-weight heparin in renal insufficiency.

INTRODUCTION: Several guidelines advise to monitor therapeutic LMWH therapy with peak anti-Xa concentrations in renal insufficiency with subsequent dose adjustments. A better understanding of the clinical association between peak anti-Xa concentrations and clinical outcomes is mandatory, because misunderstanding this association could lead to erroneous, and potentially even harmful, LMWH dose adjustments. AREAS COVERED: We reviewed the evidence of the widely applied therapeutic window for anti-Xa peak concentrations and report on the evidence for pharmacokinetic dose reduction in renal insufficiency, limitations of peak and trough anti-Xa concentration monitoring. EXPERT OPINION: The added value of peak anti-Xa monitoring in patients with renal insufficiency, receiving a dose reduced for pharmacokinetic changes, is not supported by data. Enoxaparin and nadroparin should be adjusted to 50-65% and 75-85% of the original dose for patients with a creatinine clearance (CrCL) of <30 ml/min and 30-60 ml/min, respectively. Tinzaparin should be adjusted to around 50% of the original dose for patients with a CrCL of <30 ml/min. In case anti-Xa monitoring is applied, trough concentration anti-Xa monitoring is preferred over peak monitoring, aiming at a maximum concentration of 0.4 IU/mL for once-daily dosed tinzaparin and 0.5 IU/mL for twice-daily dosed enoxaparin and nadroparin.

Multifactorial inhibition of lactobacilli against the respiratory tract pathogen Moraxella catarrhalis.

Probiotics, mainly lactic acid bacteria (LAB), are widely focused on gastrointestinal applications. However, recent microbiome studies indicate that LAB can be endogenous members of other human body sites such as the upper respiratory tract (URT). Interestingly, DNA-based microbiome research suggests an inverse correlation between the presence of LAB and the occurrence of potential pathogens, such as Moraxella catarrhalis, an important URT pathogen linked to otitis media, sinusitis and chronic obstructive pulmonary disease. However, a direct interaction between these microbes has not been explored in detail. This study investigated the direct antipathogenic effects of Lactobacillus species, including several well-documented probiotic strains, on M. catarrhalis using agar-based assays, time course analysis, biofilm assays and minimal inhibitory concentration (MIC) testing. These assays were performed using spent culture supernatans (SCS) at two pHs (4.3 and 7) and D- and/or L-lactic acid at three pHs (2, 4 and 7). In addition, cell line assays for adhesion competition and immunomodulation were used to substantiate the inhibitory effect of lactobacilli against M. catarrhalis. A proportion of Lactobacillus strains, including the model probiotic Lactobacillus rhamnosus GG, showed a strong and direct activity against M. catarrhalis. Screening of the activity of the SCS after different treatments demonstrated that lactic acid has an important antimicrobial activity against this pathogen - at least in vitro - with mean MIC values for D- and L-lactic acid varying between 0.5 and 27 g/l depending on the pH. Furthermore, L. rhamnosus GG also decreased the adhesion of M. catarrhalis to human airway epithelial Calu-3 cells with more than 50%, and the expression of mucin MUC5AC, pro-inflammatory cytokines interleukin (IL)-8, IL-1ß, and tumor necrosis factor-α at least 1.2 fold. This study suggests that several lactobacilli and their key metabolite lactic acid are possible candidates for probiotic therapeutic interventions against URT infections.

Reverse shoulder arthroplasty in young patient with achondroplasia - Ten year follow up: Case report.

Skeletal dysplasia in achondroplasia can affect all body joints - including the glenohumeral joint - and is prone to develop to degenerative osteoarthritis (OA). This may cause pain and mobility problems at young age. Surgical treatment is challenging due to the dysplastic anatomy of the shoulder joint - with a dysplastic deformed short humerus, a small, hypoplastic medialized glenoid and lateralized acromion - and the long life expectancy of these patients. The indications for reverse shoulder arthroplasty (RSA) evolved during years with rotator cuff tears and rotator cuff arthropathy in combination with or without glenohumeral OA as the main indicator, with good short to mid-term results. Long term results of RSA are rarely found in literature, especially in young patients. The use of a RSA in glenohumeral OA with an intact rotator cuff has rarely been reported. In this case report we present the ten-year clinical and radiographic results of a RSA for the treatment of degenerative OA with glenohumeral dysplasia in a young patient with achondroplasia.

Efficacy and safety of collagenase treatment for Dupuytren's disease: 2-year follow-up results.

Dupuytren's contracture is a common hand problem that affects the palmar fascia. Several treatment options exist, but none are curative and recurrence is common. Bacterial collagenase has recently been proven beneficial for treating Dupuytren's disease, cleaving the collagen fibers at different sites, with weakening and eventually rupture of the fibrous cords after manipulation. An independent prospective follow-up study was organized on 87 patients, treated with one or more collagenase injections. Inclusion criteria were a contracture of at least 20° at the metacarpophalangeal (MCP) or the proximal interphalangeal (PIP) joint. The most diseased joint was taken into consideration for follow-up evaluation. The resulting extension deficit was measured at 1 month, 1 year and 2 years and was graded as "clinical success", "clinical improvement" or "clinical failure". The mean contracture improved from 45° (39° for MCP and 54° for PIP joints) before treatment to 5° (2° for MCP and 9° for PIP joints) 4 weeks after treatment. No serious complications occurred. After 2 years, 68 joints were evaluated; 61.5% of the MCP joints and 34.5% of the PIP joints had a contracture of ≤20°. When compared with the 4-week evaluation, 28.2% of MCP joints and 62.1% of PIP joints had a recurrence (20° or greater worsening) or had received additional treatment. Collagenase injection is a safe and effective treatment option for Dupuytren disease, but recurrence is common especially for the PIP joint.

Predicting therapy response to mycophenolic acid using UGT1A9 genotyping: towards personalized medicine in atopic dermatitis.

Atopic dermatitis (AD) is a very common chronic inflammatory skin disease requiring long-term treatment. Mycophenolic acid (MPA) is used off-label in treatment of patients with severe AD failing Cyclosporin A (CsA) treatment, however clinical efficacy is observed in only half of the AD patients. In blood, MPA levels are known to have a large interindividual variability. Low MPA exposure and increased enzyme activity correlates with the presence of UGT1A9 polymorphisms. In this retrospective study, 65 adult AD patients treated with MPA were classified as responder or non-responder to MPA treatment. UGT1A9 polymorphisms were determined using PCR. A significantly higher number of UGT1A9 polymorphisms was found in the group that did not respond to MPA treatment. Of the patients that carried a UGT1A9 polymorphism, 85.7% were non-responsive to MPA treatment. This implies that non-responsiveness in AD patients is more likely to occur in carriers of a UGT1A9 polymorphism. In a binary logistic regression analysis the odds ratio (OR) was 8.65 (95% confidence interval: 0.93-80.17). Our results show that UGT1A9 polymorphisms can be used to identify patients with non-responsiveness to MPA. Patients with UGT1A9 polymorphisms might benefit from higher MPA dosage.

Sinusoidal obstruction syndrome (SOS): A light and electron microscopy study in human liver.

AIMS: Oxaliplatin is an important chemotherapeutic agent, used in the treatment of hepatic colorectal metastases, and known to induce the sinusoidal obstruction syndrome (SOS). Pathophysiological knowledge concerning SOS is based on a rat model. Therefore, the aim was to perform a comprehensive study of the features of human SOS, using both light microscopy (LM) and electron microscopy (EM). METHODS AND RESULTS: Included were all patients of whom wedge liver biopsies were collected during a partial hepatectomy for colorectal liver metastases, in a 4-year period. The wedge biopsy were perfusion fixated and processed for LM and EM. The SOS lesions were selected by LM and details were studied using EM. Material was available of 30 patients, of whom 28 patients received neo-adjuvant oxaliplatin. Eighteen (64%) of the 28 patients showed SOS lesions, based on microscopy. The lesions consisted of sinusoidal endothelial cell detachment from the space of Disse on EM. In the enlarged space of Disse a variable amount of erythrocytes were located. CONCLUSION: Sinusoidal endothelial cell detachment was present in human SOS, accompanied by enlargement of the space of Disse and erythrocytes in this area. These findings, originally described in a rat model, were now for the first time confirmed in human livers under clinically relevant settings.

Adipose tissue-derived stromal cells acquire endothelial-like features upon reprogramming with SOX18.

Adipose tissue-derived stromal cells (ASC) form a rich source of autologous cells for use in regenerative medicine. In vitro induction of an endothelial phenotype may improve performance of ASCs in cardiovascular repair. Here, we report on an in vitro strategy using direct reprogramming of ASCs by means of ectopic expression of the endothelial-specific transcription factor SRY (sex determining region Y)-box18 (SOX18). SOX18 induces ASCs to express a set of genes involved in vascular patterning: MMP7, KDR, EFNB2, SEMA3G and CXCR4. Accordingly, SOX18 transduced ASCs reorganize under conditions of shear stress, display VEGF-induced chemotaxis and form tubular structures in 3D matrices in an MMP7-dependent manner. These in vitro findings provide insight into molecular and cellular processes downstream of SOX18 and show that reprogramming using SOX18 is sufficient to induce several endothelial-like features in ASCs.

Rapid target allopurinol concentrations in the hypoxic fetus after maternal administration during labour.

OBJECTIVE: Perinatal hypoxia-induced free radical formation is an important cause of hypoxic-ischaemic encephalopathy and subsequent neurodevelopmental disabilities. Allopurinol reduces the formation of free radicals, which potentially limits hypoxia-induced brain damage. We investigated placental transfer and safety of allopurinol after maternal allopurinol treatment during labour to evaluate its potential role as a neuroprotective agent in suspected fetal hypoxia. DESIGN: We used data from a randomised, double-blind multicentre trial comparing maternal allopurinol versus placebo in case of imminent fetal hypoxia (NCT00189007). PATIENTS: We studied 58 women in labour at term, with suspected fetal hypoxia prompting immediate delivery, in the intervention arm of the study. SETTING: Delivery rooms of 11 Dutch hospitals. INTERVENTION: 500 mg allopurinol, intravenously to the mother, immediately prior to delivery. MAIN OUTCOME MEASURES: Drug disposition (maternal plasma concentrations, cord blood concentrations) and drug safety (maternal and fetal adverse events). RESULTS: Within 5 min after the end of maternal allopurinol infusion, target plasma concentrations of allopurinol of ≥2 mg/L were present in cord blood. Of all analysed cord blood samples, 95% (52/55) had a target allopurinol plasma concentration at the moment of delivery. No adverse events were observed in the neonates. Two mothers had a red and/or painful arm during infusion. CONCLUSIONS: A dose of 500 mg intravenous allopurinol rapidly crosses the placenta and provides target concentrations in 95% of the fetuses at the moment of delivery, which makes it potentially useful as a neuroprotective agent in perinatology with very little side effects. TRIAL REGISTRATION: The study is registered in the Dutch Trial Register (NTR1383) and the Clinical Trials protocol registration system (NCT00189007).

Association of high body mass index with decreased treatment response to combination therapy in recent-onset rheumatoid arthritis patients.

OBJECTIVE: To assess the association between high body mass index (BMI) and treatment response in recent-onset rheumatoid arthritis. METHODS: In the Behandelstrategieën voor Reumatoide Artritis (Treatment Strategies for Rheumatoid Arthritis) study, 508 patients were randomized to initial monotherapy or combination therapy with prednisone or infliximab (IFX). The response to Disease Activity Score (DAS) ≤2.4-steered treatment (first dose and after 1 year) was compared between patients with a BMI <25 kg/m(2) and ≥25 kg/m(2) , using relative risk (RR) regression analyses. DAS, components of DAS, and functional ability during the first year were compared using linear mixed models. RESULTS: High BMI was independently associated with failure to achieve a DAS ≤2.4 on initial therapy (RR 1.20 [95% confidence interval (95% CI) 1.05, 1.37]). The effect for combination therapy with prednisone was RR 1.55 (95% CI 1.06, 2.28) and for combination therapy with IFX 1.42 (95% CI 0.98, 2.06). The RRs for failure after 1 year were 1.46 (95% CI 0.75, 2.83) and 2.20 (95% CI 0.99, 4.92), respectively. High BMI was also associated with failure on delayed combination therapy with IFX, after adjustment for selection bias related to previous failure on disease-modifying antirheumatic drugs. No significant association was observed in the initial monotherapy groups. In the first year, patients with a high BMI had higher DAS and worse functional ability, with more tender joints and a higher visual analog scale global health, but not more swollen joints and similar systemic inflammation. CONCLUSION: High BMI was independently associated with failure to achieve low DAS on initial combination therapy with prednisone and on initial and delayed treatment with IFX. Patients with a high BMI experienced more pain, but not more swelling or systemic inflammation.

Glutathione S-transferase M1-null genotype as risk factor for SOS in oxaliplatin-treated patients with metastatic colorectal cancer.

BACKGROUND: Oxaliplatin is used as a neo-adjuvant therapy in hepatic colorectal carcinoma metastasis. This treatment has significant side effects, as oxaliplatin is toxic to the sinusoidal endothelial cells and can induce sinusoidal obstruction syndrome (SOS), which is related to decreased overall survival. Glutathione has an important role in the defence system, catalysed by glutathione S-transferase (GST), including two non-enzyme producing polymorphisms (GSTM1-null and GSTT1-null). We hypothesise that patients with a non-enzyme producing polymorphism have a higher risk of developing toxic injury owing to oxaliplatin. METHODS: In the nontumour-bearing liver, the presence of SOS was studied histopathologically. The genotype was determined by a semi-nested PCR. RESULTS: Thirty-two of the 55 (58%) patients showed SOS lesions, consisting of 27% mild, 22% moderate and 9% severe lesions. The GSTM1-null genotype was present in 25 of the 55 (46%). Multivariate analysis showed that the GSTM1-null genotype significantly correlated with the presence of (moderate-severe) SOS (P=0.026). CONCLUSION: The GSTM1-null genotype is an independent risk factor for SOS. This finding allows us, in association with other risk factors, to conceive a potential risk profile predicting whether the patient is at risk of developing SOS, before starting oxaliplatin, and subsequently might result in adjustment of treatment.

Risk of alanine transferase (ALT) elevation in patients with rheumatoid arthritis treated with methotrexate in a DAS-steered strategy.

OBJECTIVE: To determine incidence of increased levels of alanine transferase (ALT) >2× upper limit of normal (ULN) in patients receiving methotrexate (MTX), treated according to a dynamic strategy, and to identify predictors of ALT of >2× ULN. METHODS: Data of 508 recent-onset rheumatoid arthritis (RA) patients from the BeSt study, randomized to initial monotherapy or combination therapy, were used. Treatment was dynamic, aiming at a disease activity score = ≤ 2.4. ALT was measured every three months. With logistic regression analyses, baseline variables predictive of first ALT of >2× ULN were identified and the association between use of concomitant antirheumatic drugs, the actual and cumulative dose of MTX and ALT of >2× ULN was determined. RESULTS: In total, 498 patients ever initiated MTX, with a total duration on MTX of 1,416 patient-years. In 89 patients, a first incidence of ALT of >2× ULN occurred. Incidence rate was 6.3 per 100 patient-years and cumulative incidence 18 %. ACPA positivity and baseline ALT of >1× ULN were independent predictors of later ALT of >2× ULN (OR 1.8 (95 % CI, 1.1-3.1) and OR 3.1 (95 % CI, 1.6-6.2), respectively). Smoking showed a trend (OR 1.6 (95 % CI, 0.98-2.7)). Mean MTX dosage over time was higher in patients with an ALT of >2× ULN. Patients who did not have an ALT of >2× ULN used more concomitant disease-modifying antirheumatic drugs and longer. CONCLUSIONS: In RA patients treated with MTX according to a dynamic strategy resembling daily clinical practice, incidence of increased ALT of >2× ULN was lower than previously reported, and also without treatment adjustments, persistence was rare. The recommendations for ALT monitoring may be reevaluated.

Development of a composite endpoint for randomized controlled trials in liver surgery.

BACKGROUND: The feasibility of randomized controlled trials (RCTs) in liver surgery using a single-component clinical endpoint is low as such endpoints require large sample sizes owing to their low incidence. A liver surgery-specific composite endpoint (CEP) could solve this problem. The aim of this study was to develop a liver surgery-specific CEP with well-defined components. METHODS: Components of a liver surgery-specific CEP were selected based on a systematic literature search and consensus among 28 international hepatopancreatobiliary (HPB) surgeons. As an example, two prospective cohorts of patients who had undergone liver surgery in high-volume HPB centres were used to assess the event rate and effect of implementing a liver surgery-specific CEP. RESULTS: Components selected for the liver surgery-specific CEP were ascites, postresectional liver failure, bile leakage, intra-abdominal haemorrhage, intra-abdominal abscess and operative mortality, all with a Clavien-Dindo grade of at least 3 and occurring within 90 days after initial surgery. The incidence of this liver surgery-specific CEP was 19.2 per cent in one cohort and 10.7 per cent in the other. These rates led to an approximately twofold reduction in the theoretical sample size required for an adequately powered RCT in liver surgery using the CEP as primary endpoint. CONCLUSION: The proposed liver surgery-specific CEP consists of ascites, postresectional liver failure, bile leakage, intra-abdominal haemorrhage, intra-abdominal abscess and operative mortality. It has a considerably higher event rate than any of its components. Its use as the primary endpoint will increase the feasibility and comparability of RCTs in liver surgery.

Discontinuation of infliximab and potential predictors of persistent low disease activity in patients with early rheumatoid arthritis and disease activity score-steered therapy: subanalysis of the BeSt study.

OBJECTIVE: To describe the disease course after the cessation of infliximab in early rheumatoid arthritis patients with disease activity score (DAS)-steered treatment and to identify predictors of persistent low disease activity. METHODS: In a post-hoc analysis of the BeSt study, disease activity and joint damage progression were observed in patients treated with methotrexate plus infliximab, who discontinued infliximab after achieving low disease activity (DAS ≤2.4) for 6 months. Predictors were identified using Cox regression analysis. RESULTS: 104 patients discontinued infliximab, of whom 77 had received infliximab plus methotrexate as initial treatment. Mean DAS at the time of infliximab cessation was 1.3, median symptom duration was 23 months and median Sharp/van derHeijde score was 5.5. The median follow-up was 7.2 years. Infliximab was re-introduced after loss of low disease activity in 48%, after a median of 17 months. The joint damage progression rate did not increase in the year after cessation, regardless of flare. After re-introduction of infliximab, 84% of these patients again achieved a DAS ≤2.4. In the multivariable model, smoking, infliximab treatment duration ≥18 months and shared epitope (SE) were independently associated with the re-introduction of infliximab: 6% of the non-smoking, SE-negative patients treated <18 months needed infliximab re-introduction. CONCLUSION: Cessation of infliximab was successful in 52%, with numerically higher success rates in patients initially treated with infliximab. Of the 48% who flared, 84% regained low disease activity. The joint damage progression rate did not increase in the year after cessation. Smoking, long infliximab treatment duration and SE were independently associated with re-introduction of infliximab.

Feasibility of randomized controlled trials in liver surgery using surgery-related mortality or morbidity as endpoint.

BACKGROUND: There is a shortage of randomized controlled trials (RCTs) on which to base guidelines in liver surgery. The feasibility of conducting an adequately powered RCT in liver surgery using the dichotomous endpoints surgery-related mortality or morbidity was examined. METHODS: Articles published between January 2002 and November 2007 with mortality or morbidity after liver surgery as primary endpoint were retrieved. Sample size calculations for a RCT aiming to show a relative reduction of these endpoints by 33, 50 or 66 per cent were performed. RESULTS: The mean operative mortality rate was 1.0 per cent and the total morbidity rate 28.9 per cent; mean rates of bile leakage and postresectional liver failure were 4.4 and 2.6 per cent respectively. The smallest numbers of patients needed in each arm of a RCT aiming to show a 33 per cent relative reduction were 15 614 for operative mortality, 412 for total morbidity, 3446 for bile leakage and 5924 for postresectional liver failure. CONCLUSION: The feasibility of conducting an adequately powered RCT in liver surgery using outcomes such as mortality or specific complications seems low. Conclusions of underpowered RCTs should be interpreted with caution. A liver surgery-specific composite endpoint may be a useful and clinically relevant solution to pursue.

The impact of regulatory T cells on carcinogen-induced sarcogenesis.

Burnet proposed in the 1950's that the immune system is engaged in identifying and destroying abnormal cancerous cells. This process, termed immune surveillance, has been at the centre of intense debate for decades. Results using immunodeficient mice lend support to the immune surveillance hypothesis. We surmised that immune surveillance would be hampered by the inhibitory effect of naturally occurring FoxP3(+) regulatory T cells, a population of T cells shown to be present at an increased frequency in a variety of human tumours. The carcinogen, methylcholanthrene was injected subcutaneously into mice and the steady development of fibrosarcomas was observed over approximately 200 days. These fibrosarcomas were strikingly infiltrated with FoxP3(+) regulatory T cells implying that these cells impinge upon immune-mediated rejection of the tumour. This was confirmed by partial ablation of FoxP3(+) regulatory T-cell activity, which resulted in a marked reduction in tumour incidence. The reduction of tumour incidence was ablated in mice that lacked interferon gamma. These data offer strong support for the concept of immune surveillance and indicate that this process is limited by the inhibitory effect of FoxP3(+) regulatory T cells.

[Reversible posterior leucoencephalopathy due to hypercalcaemia]. / Reversibele posterieure leuko-encefalopathie bij hypercalciëmie.

A 60-year-old woman presented with changes in behaviour, cognition, cortical blindness and headache. These symptoms were caused by a reversible posterior leucoencephalopathy syndrome due to hypercalcaemia caused by a multiple myeloma, type IgD wavelength. She was treated with isotonic saline and pamidronate; the serum calcium levels normalised and the radiological brain abnormalities disappeared as did the clinical neurological abnormalities. Hypercalcaemia probably affects cerebral perfusion and has direct neurotoxic effects which can lead to cerebral oedema. This case history illustrates a rare cause of a syndrome that can be easily treated and is completely reversible.