Multiparametric MRI and 18F-PSMA-1007 PET/CT for the Detection of Clinically Significant Prostate Cancer

Background Multiparametric MRI (mpMRI) is effective for detecting prostate cancer (PCa); however, there is a high rate of equivocal Prostate Imaging Reporting and Data System (PI-RADS) 3 lesions and false-positive findings. Purpose To investigate whether fluorine 18 (18F) prostate-specific membrane antigen (PSMA) 1007 PET/CT after mpMRI can help detect localized clinically significant PCa (csPCa), particularly for equivocal PI-RADS 3 lesions. Materials and Methods This prospective study included participants with elevated prostate-specific antigen (PSA) levels referred for prostate mpMRI between September 2020 and February 2022. 18F-PSMA-1007 PET/CT was performed within 30 days of mpMRI and before biopsy. PI-RADS category and level of suspicion (LOS) were assessed. PI-RADS 3 or higher lesions at mpMRI and/or LOS 3 or higher lesions at 18F-PSMA-1007 PET/CT underwent targeted biopsies. PI-RADS 2 or lower and LOS 2 or lower lesions were considered nonsuspicious and were monitored during a 1-year follow-up by means of PSA testing. Diagnostic accuracy was assessed, with histologic examination serving as the reference standard. International Society of Urological Pathology (ISUP) grade 2 or higher was considered csPCa. Results Seventy-five participants (median age, 67 years [range, 52-77 years]) were assessed, with PI-RADS 1 or 2, PI-RADS 3, and PI-RADS 4 or 5 groups each including 25 participants. A total of 102 lesions were identified, of which 80 were PI-RADS 3 or higher and/or LOS 3 or higher and therefore underwent targeted biopsy. The per-participant sensitivity for the detection of csPCa was 95% and 91% for mpMRI and 18F-PSMA-1007 PET/CT, respectively, with respective specificities of 45% and 62%. 18F-PSMA-1007 PET/CT was used to correctly differentiate 17 of 26 PI-RADS 3 lesions (65%), with a negative and positive predictive value of 93% and 27%, respectively, for ruling out or detecting csPCa. One additional significant and one insignificant PCa lesion (PI-RADS 1 or 2) were found at 18F-PSMA-1007 PET/CT that otherwise would have remained undetected. Two participants had ISUP 2 tumors without PSMA uptake that were missed at PET/CT. Conclusion 18F-PSMA-1007 PET/CT showed good sensitivity and moderate specificity for the detection of csPCa and ruled this out in 93% of participants with PI-RADS 3 lesions. Clinical trial registration no. NCT04487847 © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Turkbey in this issue.

[Decision-making concerning involuntary oral care in older individuals with dementia]

Many older individuals with dementia show care-resistant behavior for oral care. Providing care despite resistance is considered to be involuntary care. The Dutch law, 'Wet zorg en dwang' (care and coercion), states that care must be ceased in the presence of resistance, unless there is (a risk of) serious harm. This study was conducted to gain insight into the attitudes of healthcare providers with regard to involuntary oral care in older individuals with dementia. An online questionnaire consisting of general questions, case specific questions and knowledge questions about the Dutch law was filled out by 392 care providers. In all cases, a discrepancy was seen between the assessment of oral health problems as potentially harmful and the willingness to provide involuntary oral care. Hence, many healthcare providers are aware of the subsequent potential health risks related to not providing care, but are still reluctant to provide involuntary oral care. A large part of the healthcare providers also has a low level of knowledge with regard to the Dutch law 'Wet zorg en Dwang'.

Plasmodium falciparum gametocyte carriage in longitudinally monitored incident infections is associated with duration of infection and human host factors

Malaria transmission depends on the presence of Plasmodium gametocytes that are the only parasite life stage that can infect mosquitoes. Gametocyte production varies between infections and over the course of infections. Infection duration is highly important for gametocyte production but poorly quantified. Between 2017 and 2019 an all-age cohort of individuals from Tororo, eastern Uganda was followed by continuous passive and routine assessments. We longitudinally monitored 104 incident infections from 98 individuals who were sampled once every 28 days and on any day of symptoms. Among infections that lasted ≥ 3 months, gametocyte appearance was near-universal with 96% of infections having detectable gametocytes prior to clearance. However, most infections were of much shorter duration; 55.7% of asymptomatic infections were detected only once. When considering all asymptomatic infections, regardless of their duration, only 36.3% had detectable gametocytes on at least one time-point prior to parasite clearance. Infections in individuals with sickle-cell trait (HbAS) were more likely to have gametocytes detected (Hazard Rate (HR) = 2.68, 95% CI 1.12, 6.38; p = 0.0231) and had gametocytes detected at higher densities (Density Ratio (DR) = 9.19, 95% CI 2.79, 30.23; p = 0.0002) compared to infections in wildtype (HbAA) individuals. Our findings suggest that a large proportion of incident infections is too short in duration and of too low density to contribute to onward transmission.

A phase II study on the efficacy and toxicity of cabozantinib in recurrent/metastatic salivary gland cancer patients

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A phase II study on the efficacy and toxicity of cabozantinib in recurrent/metastatic salivary gland cancer patients. Background: Because c-MET and VEGFR are often overexpressed in salivary gland cancer (SGC), this study evaluated the efficacy and safety of cabozantinib in recurrent/metastatic (R/M) SGC pts. Methods: A single center, single arm, phase II study was conducted. Immunohistochemical c-MET positive (H-score ≥10) R/M SGC pts were included in 3 cohorts: adenoid cystic carcinoma (ACC), salivary duct carcinoma (SDC), and other SGCs. Objective growth or complaints due to the disease were required before inclusion in the ACC and other SGC cohort. No prior systemic treatments were required. Pts started 60 mg cabozantinib tablets OD. Primary endpoint was the objective response rate (ORR). A Simon two-stage design was used. In case of ≥1 objective response in the first 9 pts/cohort, 8 additional pts would be included in the cohort. Results: In total 25 pts were included from Sep. 2018 until premature closure due to severe toxicity in Nov. 2019. Median age was 56 years (range 49-72), prior treatments included: primary tumor resection ( n=19), radiotherapy ≥50Gy ( n=24), systemic therapy ( n=10; adjuvant in 2 pts, palliative in 8 pts). Six pts had grade 3 ( n=4), grade 4 ( n=1), or grade 5 ( n=1) wound/fistula complications, occurring at a median of 7.2 mths on cabozantinib (range 2.1-12.8). This resulted in a severe wound complication rate of 32% in 19 pts on treatment for ≥2 mths. Remarkably, 4 out of 6 pts developed this complication in the area exposed to high-dose Rx; 2/4 had a pre-existing fistula in this area. Median interval between Rx and start of cabozantinib was 71.3 mths (range 10.6-94.7). Other grade ≥3 adverse events in >1 pt were: hypertension (5 pts), diarrhoea (2 pts) and dehydration (2 pts). Current median follow-up is 6.8 mths. The ORR was 6% (1/17 pts) in the ACC cohort, 20% (1/5 pts) in the SDC cohort, and 0% (0/3 pts) in other SGC pts; median PFS is 12.6 mths (95% CI 6.8 – 18.4 mths), 9.0 mths (insufficient events for 95% CI), and 6.9 mths (95% CI 0 – 15.2 mths), respectively. Median OS is not reached in any cohort. Conclusions: This phase II study on cabozantinib in R/M SGC pts demonstrated severe wound and fistula complications in 32% of pts on treatment for ≥2 mths, mostly (4/6 pts) within the radiotherapy field. Because of this toxicity the study was closed prematurely. Furthermore, cabozantinib showed minimal clinical activity in SGC pts. Research funding: Ipsen Pharmaceuticals Clinical trial information: NCT03729297 .

Reliability and Responsiveness of the Observable Movement Quality Scale for Children with Mild to Moderate Motor Impairments

AIM

The Observable Movement Quality (OMQ) scale measures generic movement quality and is used alongside standardized age-adequate motor performance tests. The scale consists of 15 items, each focusing on a different aspect; together, the entire construct of movement quality is assessed. This study aimed to determine interrater and intrarater reliability, and responsiveness of the OMQ scale.

METHODS

A prospective intervention study with pre-post design in pediatric physical therapy practices. For interrater reliability, 3 physical therapists observed video-recorded motor assessments of 30 children with mild to moderate motor impairments -aged 4 to 12 years-using the OMQ scale. One therapist scored baseline assessment a second time for intrarater reliability, and to calculate smallest detectable change (SDC). Responsiveness (n = 28) was tested by comparing outcomes before and after intervention.

RESULTS

Interrater reliability was moderate to good (ICC_2,1: 0.79); intrarater reliability was high (ICC_2,1: 0.97). Responsiveness results revealed an SDC of 2.4 and a minimal important change of 2.5; indicating sufficient validity in differentiating groups of children showing improved versus unchanged movement quality.

CONCLUSION

The OMQ scale is reliable and responsive to change when used to assess movement quality in clinical practice for children with mild to moderate motor impairments, aged 4-12 year.

The Psychometric Evaluation of a Speech Production Test Battery for Children: The Reliability and Validity of the Computer Articulation Instrument

Purpose The aims of this study were to assess the reliability and validity of the Computer Articulation Instrument (CAI), a speech production test battery assessing phonological and speech motor skills in 4 tasks: (1) picture naming, (2) nonword imitation, (3) word and nonword repetition, and (4) maximum repetition rate (MRR). Method Normative data were collected in 1,524 typically developing Dutch-speaking children (aged between 2;0 and 7;0 [years;months]). Parameters were extracted on segmental and syllabic accuracy (Tasks 1 and 2), consistency (Task 3), and syllables per second (Task 4). Interrater reliability and test-retest reliability were analyzed using subgroups of the normative sample and studied by estimating intraclass correlation coefficients (ICCs). Construct validity was investigated by determining age-related changes of test results and factor analyses of the extracted speech measures. Results ICCs for interrater reliability ranged from sufficient to good, except for percentage of vowels correct of picture naming and nonword imitation and for the MRRs for bisyllabic and trisyllabic items. The ICCs for test-retest reliability were sufficient (picture naming, nonword imitation) to insufficient (word and nonword repetition, MRR) due to larger-than-expected normal development and learning effects. Continuous norms showed developmental patterns for all CAI parameters. The factor analyses revealed 5 meaningful factors: all picture-naming parameters, the segmental parameters of nonword imitation, the syllabic structure parameters of nonword imitation, (non)word repetition consistency, and all MRR parameters. Conclusion Its overall sufficient to good psychometric properties indicate that the CAI is a reliable and valid instrument for the assessment of typical and delayed speech development in Dutch children in the ages of 2-7 years.

Make a Move: A Comprehensive Effect Evaluation of a Sexual Harassment Prevention Program in Dutch Residential Youth Care

Sexual harassment-unwanted sexual comments, advances, or behaviors-and sexual violence are still prevalent worldwide, leading to a variety of physical, cognitive, and emotional problems among those being harassed. In particular, youth in care are at risk of becoming perpetrators (and victims) of sexual harassment. However, in general, there are very few interventions targeting this at-risk group, and no such programs exist in the Netherlands. To this end, a group intervention program-Make a Move-targeting determinants of sexual harassment was developed. This program was implemented and evaluated among boys ( N = 177) in Dutch residential youth care (20 institutions). A pre-test, post-test, and 6-month follow-up design including an intervention and a waiting list control group with randomized assignment of institutions (cluster randomized trial) was used to measure the effects of the intervention on determinants of sexual harassment. Multilevel (mixed) regression analysis with Bonferroni correction for multiple testing (α = .005) showed no significant effects of Make a Move on determinants of sexual harassment ( ps > .03, Cohen's ds < .44). Results are discussed in light of a three-way explanatory model focusing on intervention content, evaluation, and implementation as potential explanations for not finding any measurable intervention effects.

Bachelor completion and dropout rates of selected, rejected and lottery-admitted medical students in the Netherlands

BACKGROUND

Evidence for the effectiveness of the selection of medical students is weak. This study aimed to examine the added value of a two-step selection procedure (first step non-academic, second step academic tests) to a pre-university GPA-based lottery procedure. Because previous research has suggested that participation in selection (regardless of the outcome) is a predictor of study success, this study is the first to include students who initially applied for selection, then refrained from (actively) participating in selection and were eventually admitted through lottery.

METHODS

Bachelor completion and dropout rates of selected (n = 416) and lottery-admitted students from four cohorts (2006-2009) were compared using logistic regression analysis. Four groups of lottery-admitted students were distinguished: students who were rejected after step 2 (n = 57), were rejected after step 1 (n = 169), withdrew during selection step 1 (n = 42) and students who only applied for lottery (n = 366). Covariates included gender, age, pre-university GPA and cohort.

RESULTS

There was a significant association between admission group and obtaining a bachelor degree in three years. Selected students were more likely to obtain a bachelor degree within three years (64.2% versus 51.6%; OR = 1.7) or four years (81.5% versus 74.3%; OR = 1.6) than students who only applied to a lottery (p <  0.05); selected students also seemed more likely to obtain all Year-1 course credits than students who withdrew during step 1 (40.4% versus 21.4%; OR = 2.3; p <  0.05). We found no significant association between dropout and admission groups. Students rejected at step 1 or 2 did not perform significantly different from selected students on any of the outcome measures.

CONCLUSIONS

The findings indicated that students at risk for study delay in the preclinical phase in our context were more likely to refrain from applying to a demanding selection procedure when a less demanding alternative was available. We found no significant associations between the non-academic and academic selection steps and bachelor completion and dropout rates. These findings suggest that the presence of the selection was more important than these specific selection components. In follow-up research, we plan to investigate the associations between the admission groups and outcome measures in the clinical phase.

A family-based study into penetrance in facioscapulohumeral muscular dystrophy type 1

OBJECTIVE

An observational cross-sectional study was conducted in a national facioscapulohumeral muscular dystrophy (FSHD) expertise center to estimate the penetrance of FSHD1 and to evaluate phenotype-genotype correlations.

METHODS

Ten FSHD1 probands carrying 4-9 D4Z4 unit alleles and 140 relatives were examined. All 150 participants were genetically characterized, including D4Z4 methylation levels in the mutation carriers. Mutation carriers were classified as (1) symptomatic: with symptoms of muscle weakness on history and muscle FSHD signs on examination; (2) asymptomatic: without symptoms of muscle weakness but with muscle FSHD signs on examination; and (3) nonpenetrant: without symptoms of muscle weakness on history and without muscle FSHD signs on examination. We assessed the relationship between age-corrected clinical severity score and repeat size, sex, and D4Z4 methylation levels.

RESULTS

The maximum likelihood estimates of symptomatic and those of symptomatic plus asymptomatic FSHD showed that penetrance depends on repeat size and increases until late adulthood. We observed many asymptomatic carriers with subtle facial weakness with or without mild shoulder girdle weakness (25% [17/69]). Nonpenetrance was observed less frequently than in recent population studies (17% [12/69]), and most asymptomatic patients reported some shoulder pain. D4Z4 methylation tended to be lower in moderately to severely affected mutation carriers with 7 or 9 repeats.

DISCUSSION

This family-based study detected a lower overall nonpenetrance than previously observed, probably due to many asymptomatic mutation carriers identified by careful examination of facial and shoulder muscles. The recognition of asymptomatic mutation carriers is essential for selection of participants for future trials, and the likelihood estimates are helpful in counseling.

Interrater Reliability of the Observable Movement Quality Scale for Children

Purpose: The authors investigated the interrater reliability, the standard deviation of the random measurement error, and the limits of agreement (LoA) of the Observable Movement Quality (OMQ) scale in children. Movement quality is important in the recognition of motor problems, and the OMQ scale, a questionnaire used by paediatric physical therapists, has been developed for use with an age-specific motor test to observe movement quality and score relative to what is expected for a child's age. Method: Paediatric physical therapists (n=28; 2 men, 26 women) observed video-recorded assessments of age-related motor tests in children (n=9) aged 6 months to 6 years and filled in the OMQ scale (possible score range 15-75 points). For our analyses, we used linear mixed models without fixed effects. Results: The interrater reliability was moderate (intra-class correlation coefficient [ICC2,1]: 0.67, 95% CI: 0.47, 0.88); neither work setting nor work experience exerted any influence on it. The standard deviation of the random measurement error was 5.7, and the LoA was 31.5. Item agreement was good (proportion of observed agreement [Po] total 0.82-0.99). Conclusion: The OMQ scale showed moderate interrater reliability when being used by therapists who were unfamiliar with the questionnaire and who had received only 2 hours of training. Feedback from the participants suggested a need for more comprehensive training in using the OMQ scale in clinical practice.

Voluntary premarital screening to prevent sickle cell disease in Jamaica: does it work?

To determine whether identifying haemoglobin genotype, and providing education and counselling to senior school students will influence their choice of partner and reduce the frequency of births with sickle cell disease. The Manchester Project provided free voluntary blood tests to determine haemoglobin genotype to the fifth and sixth forms (grades 11-13), median age of 16.7 years, of all 15 secondary schools in the parish of Manchester in south central Jamaica. A total of 16,636 students complied, and counselling was offered to carriers of abnormal genes over 6 years (2008-2013). The genotypes of their offspring were determined by newborn screening of 66,892 deliveries in 12 regional hospitals over 8 years (2008-2015). The study focused on the genotypes of live deliveries to female students with the four most common haemoglobin genotypes: 7905 with an AA genotype, 898 with the sickle cell trait, 326 with the HbC trait and 78 with the beta thalassaemia trait. A total of 2442 live deliveries were identified by the end of 2015 in mothers screened at school. Eleven babies had clinically significant genotypes, and the prevalence of SS and SC disease did not differ from that predicted by random mating. First pregnancy was not delayed in AS or AC mothers. There was no evidence that knowledge of maternal haemoglobin genotype influenced choice of partner. On an interview, mothers of affected babies correctly recalled their genotype, but either did not discuss this with their partners or the latter refused to be tested. Subjects delaying child bearing for tertiary education would be largely excluded from the present study of first pregnancies and may make greater use of this information. Future options are a greater role for prenatal diagnosis.

Analysis of components of variance determining probability of setup errors in CBCT-guided stereotactic radiotherapy of lung tumors

PURPOSE

Online tumor matching for SABR lung setup requires margins for inaccuracies due to intra-fraction variability of breathing-averaged tumor position (BATP) and CBCT image guidance. We studied intra-fraction variability during SABR delivery using VMAT, corrected these for measurement inaccuracies, and quantified the CBCT image-guidance uncertainties.

MATERIALS AND METHODS

For 193 fractions in 38 patients positioned without immobilization devices, CBCT scans were acquired before and after 2 arcs of a RapidArc treatment. A hidden marker test was performed to determine the accuracy of the CBCT system and an inter-observer test was performed to measure registration accuracy. Intra-fraction variability was calculated after correction for these components of variance, and the prediction interval for setup inaccuracies was determined.

RESULTS

Correction for measurement inaccuracies reduced the intra-fraction variability of the BATP from 1.9 to 1.6 mm in AP, from 1.7 to 1.4 mm in SI and from 1.5 to 1.1 mm in LR direction (1 SD). Intra-fraction variability in bony anatomy after correction was ≤ 1 mm (1 SD). The 95% prediction interval to account for CBCT image-guidance uncertainties and intra-fraction variability was determined, and was found to be within our institutional PTV margins of 5 mm.

CONCLUSIONS

Our findings show that it is essential to account for measurement and system inaccuracies when obtaining data for validating PTV margins from online CBCT image guidance.

Grey Matter Atrophy in Multiple Sclerosis: Clinical Interpretation Depends on Choice of Analysis Method

Background

Studies disagree on the location of grey matter (GM) atrophy in the multiple sclerosis (MS) brain.

Aim

To examine the consistency between FSL, FreeSurfer, SPM for GM atrophy measurement (for volumes, patient/control discrimination, and correlations with cognition).

Materials and Methods

127 MS patients and 50 controls were included and cortical and deep grey matter (DGM) volumetrics were performed. Consistency of volumes was assessed with Intraclass Correlation Coefficient/ICC. Consistency of patients/controls discrimination was assessed with Cohen’s d, t-tests, MANOVA and a penalized double-loop logistic classifier. Consistency of association with cognition was assessed with Pearson correlation coefficient and ANOVA. Voxel-based morphometry (SPM-VBM and FSL-VBM) and vertex-wise FreeSurfer were used for group-level comparisons.

Results

The highest volumetry ICC were between SPM and FreeSurfer for cortical regions, and the lowest between SPM and FreeSurfer for DGM. The caudate nucleus and temporal lobes had high consistency between all software, while amygdala had lowest volumetric consistency. Consistency of patients/controls discrimination was largest in the DGM for all software, especially for thalamus and pallidum. The penalized double-loop logistic classifier most often selected the thalamus, pallidum and amygdala for all software. FSL yielded the largest number of significant correlations. DGM yielded stronger correlations with cognition than cortical volumes. Bilateral putamen and left insula volumes correlated with cognition using all methods.

Conclusion

GM volumes from FreeSurfer, FSL and SPM are different, especially for cortical regions. While group-level separation between MS and controls is comparable, correlations between regional GM volumes and clinical/cognitive variables in MS should be cautiously interpreted.

The association between time to antibiotics and relevant clinical outcomes in emergency department patients with various stages of sepsis: a prospective multi-center study

Introduction

In early sepsis stages, optimal treatment could contribute to prevention of progression to severe sepsis. Therefore, we investigated if there was an association between time to antibiotics and relevant clinical outcomes in hospitalized emergency department (ED) patients with mild to severe sepsis stages.

Methods

This is a prospective multicenter study in three Dutch EDs. Patients were stratified into three categories of illness severity, as assessed by the predisposition, infection, response, and organ failure (PIRO) score: PIRO score 1 to 7, 8 to 14 and >14 points, reflected low, intermediate, and high illness severity, respectively. Consecutive hospitalized ED patients with a suspected infection who were treated with intravenous antibiotics were eligible to participate in the study. The primary outcome measure was the number of surviving days outside the hospital at day 28 which was used as an inverse measure of hospital length of stay (LOS). The secondary outcome measure was 28-day mortality, taking into account the time to mortality.

Multivariable Cox regression analysis was used to estimate the association between time to antibiotics and the primary and secondary outcome measures corrected for confounders, including appropriateness of antibiotics and initial ED resuscitation, in three categories of illness severity.

Results

Of the 1,168 included patients, 112 died (10%), while 85% and 95% received antibiotics within three and six hours, respectively. No association between time to antibiotics and surviving days outside the hospital or mortality was found. Only in PIRO group 1 to 7 was delayed administration of antibiotics (>3 hours) associated with an increase in surviving days outside the hospital at day 28 (hazard ratio: 1.46, 95% confidence interval: 1.05 to 2.02 after correction for potential confounders).

Conclusions

In ED patients with mild to severe sepsis who received antibiotics within six hours after ED presentation, a reduction in time to antibiotics was not found to be associated with an improvement in relevant clinical outcomes.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-015-0936-3) contains supplementary material, which is available to authorized users.

On the correction of the asymptotic distribution of the likelihood ratio statistic if nuisance parameters are estimated based on an external source

In practice, nuisance parameters in statistical models are often replaced by estimates based on an external source, for instance if estimates were published before or a second dataset is available. Next these estimates are assumed to be known when the parameter of interest is estimated, a hypothesis is tested or confidence intervals are constructed. By this assumption, the level of the test is, in general, higher than supposed and the coverage of the confidence interval is too low. In this article, we derive the asymptotic distribution of the likelihood ratio statistic if the nuisance parameters are estimated based on a dataset that is independent of the data used for estimating the parameter of interest. This distribution can be used for correctly testing hypotheses and constructing confidence intervals. Four theoretical and practical examples are given as illustration.

Accurate prediction of a minimal region around a genetic association signal that contains the causal variant

In recent years, genome-wide association studies have been very successful in identifying loci for complex traits. However, typically these findings involve noncoding and/or intergenic SNPs without a clear functional effect that do not directly point to a gene. Hence, the challenge is to identify the causal variant responsible for the association signal. Typically, the first step is to identify all genetic variation in the locus region, usually by resequencing a large number of case chromosomes. Among all variants, the causal one needs to be identified in further functional studies. Because the experimental follow up can be very laborious, restricting the number of variants to be scrutinized can yield a great advantage. An objective method for choosing the size of the region to be followed up would be highly valuable. Here, we propose a simple method to call the minimal region around a significant association peak that is very likely to contain the causal variant. We model linkage disequilibrium (LD) in cases from the observed single SNP association signals, and predict the location of the causal variant by quantifying how well this relationship fits the data. Simulations showed that our approach identifies genomic regions of on average ∼50 kb with up to 90% probability to contain the causal variant. We apply our method to two genome-wide association data sets and localize both the functional variant REP1 in the α-synuclein gene that conveys susceptibility to Parkinson's disease and the APOE gene responsible for the association signal in the Alzheimer's disease data set.

Developments in mycotoxin analysis: an update for 2010-2011

This review highlights developments in mycotoxin analysis and sampling over a period between mid-2010 and mid-2011. It covers the major mycotoxins: aflatoxins, Alternaria toxins, ergot alkaloids, fumonisins, ochratoxin, patulin, trichothecenes, and zearalenone. Analytical methods for mycotoxins continue to be developed and published. Despite much interest in immunochemical methods and in the rapid development of LC-MS methodology, more conventional methods, sometimes linked to novel clean-up protocols, have also been the subject of research publications over the above period. Occurrence of mycotoxins falls outside the main focus of this review; however, where relevant to analytical method development, this has been mentioned.

Developments in mycotoxin analysis: an update for 2009-2010

This review highlights developments in mycotoxin analysis and sampling over a period between mid-2009 and mid-2010. It covers the major mycotoxins aflatoxins, Alternaria toxins, ergot alkaloids, fumonisins, ochratoxin, patulin, trichothecenes, and zearalenone. New and improved methods for mycotoxins continue to be published. Immunological-based method developments continue to be of wide interest in a broad range of formats. Multimycotoxin determination by LC-MS/MS is now being targeted at the specific ranges of mycotoxins and matrices of interest or concern to the individual laboratory. Although falling outside the main emphasis of the review, some aspects of natural occurrence have been mentioned, especially if linked to novel method developments.

Blocking T cell co-stimulation using a CD80 blocking small molecule reduces delayed type hypersensitivity responses in rhesus monkeys

Blockade of co-stimulation signals between T cells and antigen-presenting cells could be an important approach for treatment of autoimmune diseases and transplant rejection. Recently a series of small compound inhibitors which bind human CD80 (B7-1) and inhibit T cell co-stimulation has been described. To investigate their potency for clinical use, one of these compounds, RhuDex, was evaluated for reactivity with rhesus monkey CD80. The in vitro biological effect on rhesus monkey lymphocytes, the potency for suppression of an inflammatory recall response and the protein-induced delayed type hypersensitivity (DTH) response in the skin were studied. In a rhesus monkey T cell co-stimulation assay RhuDex inhibited proinflammatory cytokine release and cellular proliferation with micromolar potency. Systemic administration of RhuDex to rhesus monkeys inhibited the DTH response significantly, indicating that this compound may inhibit autoimmune mediated inflammatory processes where the target, CD80, is up-regulated.

Expression patterns of regulatory T-cell markers in accepted and rejected nonhuman primate kidney allografts

The identification of FOXP3 expressing cells in recipients of an allograft, in particular inside the graft itself, may help to define criteria for immunosuppressive drug withdrawal. We therefore examined expression patterns of several regulatory T-cell (Treg) markers in kidney biopsies and kidney tissues taken at the time of graft rejection from monkeys treated with alpha CD40, alpha CD86, CsA, a combination of these or after drug withdrawal. In advanced stages of rejection, organized multifocal nodular infiltrates, with mature dendritic cells, T cells and B cells could be found. In contrast, interstitial infiltrates contain more macrophages, less T cells and few B cells. Cells expressing FOXP3, CD25 and CTLA-4 were mainly found in nodular infiltrates of rejected tissue samples. A significant correlation was found between the percentage FOXP3(+) cells and markers for rejection, i.e. creatinine levels and Banff interstitial and tubular infiltrate scores. The type of immunosuppression did not influence the percentage of cells expressing Treg markers. Three animals with prolonged drug-free survival showed low numbers of FOXP3(+) cells. We conclude that the presence of intragraft FOXP3(+) cells is not confined to tolerated grafts, but should be considered as part of the normal immune response during rejection.

Multi-centre first-trimester screening for Down syndrome in the Netherlands in routine clinical practice

OBJECTIVES

This is the first report on the results of a first-trimester combined-test screening programme in the Netherlands in a multi-centre routine clinical setting.

METHODS

Between July 2002 and May 2004, blood samples were taken from subjects in 44 centres in the Netherlands and sent to our laboratory to assay for maternal serum concentrations of fbeta-hCG and PAPP-A. Fetal nuchal translucency (NT) was measured in the participating centres at a gestational age (GA) of 10-14 weeks. Results of those pregnancies for which a combined biochemical and NT risk was calculated were included in the epidemiological analysis of this study.

RESULTS

A total of 4033 singleton pregnancies were included in the analysis. The median maternal age of the analysed group was 36.5 years. The distribution of GA was biphasic, with median GA of 10.3 and 12.1 weeks, respectively. The detection rate using the combined ultrasound and serum screening at a cut-off level of 1 in 250 was 71% (15/21), with a screen-positive rate of 4.7%.

CONCLUSION

The results of this study show that the first-trimester combined test is suitable as a prenatal screening test in a multi-centre routine clinical setting in the Netherlands. Strict performance evaluation should identify weaknesses in the organisation that impair the performance of the test. Here, the performance of NT was especially identified as a candidate for improvement.

Inhibition of costimulation allows for repeated systemic administration of adenoviral vector in rhesus monkeys

Immunogenicity of recombinant adenoviral (Ad) vectors severely hampers the clinical development of gene therapy protocols using repeated vector administrations. Inhibition of costimulation by APCs was explored as a strategy to circumvent the immune response against Ad particles. This strategy was tested in rhesus monkeys, treated transiently with chimeric anti-human CD40 and anti-human CD86 antagonist monoclonal antibodies (MAbs) at the time of systemic administration of a recombinant Ad vector. After Ad vector administration in the absence of immunosuppressive treatment, transgene expression in the serum lasted about 3-4 weeks. All control animals developed a strong neutralizing antibody (NAb) response to the Ad particles, which totally prevented efficient administration of a second vector, as shown by the lack of transgene expression. Treatment with anti-CD40 and anti-CD86 chimeric MAbs delayed or blocked the development of a humoral response against Ad and the infiltration of CD8(+) lymphocytes into the liver. This resulted in (i) increased persistence of Ad-transduced cells after injection of a first vector encoding a nonimmunogenic transgene, and (ii) the possibility of readministering a second Ad vector with significant efficacy. In both respects, the combined blockade of CD40 and CD86 was more efficient than treatment with anti-CD40 alone. This study shows for the first time in non-human primates that blocking CD40 and CD86 costimulatory molecules represents a promising strategy to inhibit immune responses against an Ad vector injected systemically.

Lymphoproliferative disorders developing after transplantation and their relation to simian T-cell leukemia virus infection

In this report the role of the HTLV-1-like simian T-cell leukemia virus (STLV) during the development of posttransplantation lymphoproliferative disorders (PTLPD) is described. To prevent rejection of an allogeneic transplant in 12 rhesus monkeys cyclosporin A (CyA), prednisone, and/or lymphocyte-specific monoclonal antibodies were used for immunosuppression. Seven monkeys died during the experiment between 22 and 179 days postoperatively. At autopsy in 4 monkeys PTLPD were found. In each case, STLV provirus was acquired during the experiment, either from the blood transfusions or allograft donors. Seroconversion of anti-STLV titers occurred in 3 monkeys. However, Southern blot analysis showed the presence of STLV provirus at the DNA level in all PTLP tissues. PTLPD morphology and phenotype varied significantly. In conclusion, for the first time the oncogenic potential of STLV is identified in a rhesus monkey transplantation model. Moreover, the importance of screening blood and organ donors for HTLV-1 must be emphasized.

Contrast in the efficacy of hDAF mouse hearts between ex vivo perfusion and transplantation into primates

In recent experiments, in which we compared hDAF transgenic rat hearts perfused with 15% human serum in the Langendorff device and hDAF rat hearts transplanted into cynomolgus monkeys, we demonstrated that in the ex vivo heart perfusion model both homozygous and heterozygous hDAF hearts survived longer as nontransgenic controls. Surprisingly, we found that only homozygous hDAF hearts were protected against hyperacute rejection in vivo. The first aim of this study was to determine whether perfusion of mouse hearts with higher human serum concentrations or human blood might explain some of the differences found in survival time of the recently performed experiments with rat heart xenografts. Secondly, we investigated whether the observed differences in survival times of rat xenografts between in vivo and ex vivo transplantation would also hold for mouse hearts transgenic for hDAF. An ex vivo model was used to perfuse hDAF mouse hearts and controls with human serum or blood, and hDAF transgenic hearts and controls were transplanted into cynomolgus monkeys. hDAF transgenic mouse hearts survived significantly longer than their controls when perfused with 15% human serum, but no difference was found when 30% human serum was used, or when these hearts were transplanted into cynomolgus monkeys. However, in both the in vivo and ex vivo models the amount of PMNs adhering to the vascular endothelium was significantly lower in hDAF transgenes as compared with their controls. In conclusion, in the ex vivo situation, the efficacy of hDAF transgenesis in preventing HAR is limited by serum complement concentration.

Immunomodulation by intrathymic injection of donor leukocytes in rhesus monkeys

BACKGROUND

Several studies have demonstrated that intrathymic injection of donor cells into adult rodents can result in long-term allograft survival. The rationale for using the intrathymic route of donor cell administration is that in the thymic environment immature T cells are educated to discriminate between self and non-self antigens. The validity of this approach was tested in non-human primates.

METHODS

The effect of the intrathymic injection of allogeneic donor cells was investigated in rhesus monkeys and compared with IV and intracutaneous administration of donor cells. Intrathymic injections were carried out without and with antithymocyte globulin. All animals received subsequently an allogeneic skin graft of the same donor and no immunosuppression post transplantation.

RESULTS

Skin graft survival was slightly shorter in animals treated with IC donor cell injections (mean survival time [MST]=8.9+/-0.52) than untreated control animals (MST=10.0+/-0.44), indicating that this route caused sensitisation. Intravenous donor cell injection showed prolongation of graft survival times (MST=11.6+/-1.69). Intrathymic donor cell injection resulted in a graft survival of 9.2+/-1.44 days although addition of antithymocyte globulin slightly prolonged graft survival to 10.3+/-2.84 (not significant). Whereas the cellular responses after intrathymic and intravenous donor cell injections increased, antithymocyte globulin treated animals did not show an increased cellular response. Recipients of intrathymic donor cells showed a significantly decreased humoral anti-donor response as compared to other groups.

CONCLUSIONS

Donor cell pretreatment alters the subsequent response to an allogeneic skin graft in monkeys and is dependent on the route of donor cell administration. This is also reflected in the alloantibody response and the in vitro cellular reactivity. Intrathymic administration of donor cells does not lead to prolonged skin graft acceptance.

6-Methylprednisolone does not impair anti-thymocyte globulin (ATG) immunosuppressive activity in non-human primates

BACKGROUND

Induction treatments with anti-thymocyte globulin (ATG) in solid organ transplantation may enhance the efficacy of maintenance immunosuppressive therapy. Since ATG can trigger Fas (CD95) mediated T cell apoptosis, a process antagonized in vitro by corticosteroids, an important issue is whether corticosteroids could interfere with T cell depleting and immunosuppressive activities of ATG.

METHODS

MHC mismatched skin allografts were performed on cynomolgus and rhesus monkeys treated with ATG (20 mg/kg) associated or not with 6-methylprednisolone (10 mg/kg).

RESULTS

There was no difference between the two immunosuppressive regimens as regards the intensity and duration of peripheral T lymphocyte depletion and the appearance of anti-ATG antibodies. Skin graft survival was increased in monkeys treated with 6-methylprednisolone as compared with ATG alone.

CONCLUSIONS

In vivo, corticosteroids do not interfere with ATG ability to induce massive T cell depletion and to delay skin allograft rejection in non-human primates.

Non-human primate models of multiple sclerosis

The phylogenetic proximity between non-human primate species and humans is reflected by a high degree of immunological similarity. Non-human primates therefore provide important experimental models for disorders in the human population that are caused by the immune system, such as autoimmune diseases. In this paper we describe non-human primate models of multiple sclerosis, a chronic inflammatory and demyelinating disease of the human central nervous system. While reviewing data from the literature and our own research we will discuss the unique role of such models in the research of basic disease mechanisms and the development of new therapies.

Pharmacokinetics of cyclosporine in monkeys after oral and intramuscular administration: relation to efficacy in kidney allografting

In cynomolgus and rhesus monkeys, the dose-normalized exposure of cyclosporine administered orally as microemulsion preconcentrate (Neoral) was lower than that upon intramuscular administration. For oral administration, mean values ( +/- SD) of Cmax, 24-h area-under-the curve (AUC) and 24-h trough level, all normalized for a 1 mg/kg dose, were 20 +/- 9 ng x kg/mg x ml, 210 +/- 70 ng x h x kg/mg x ml and 2.6 +/- 0.9 ng x kg/mg x ml, respectively. For intramuscular administration, levels were about 5.5-fold, 9-fold and 22-fold higher. Based on pharmacokinetic data, the efficacy of oral cyclosporine treatment (without any other immunosuppressant) was evaluated in life-supporting cynomolgus monkey kidney allotransplantation. Rejection-free kidney allograft survival could be achieved using oral cyclosporine monotherapy with average 24-h trough concentrations above 100 ng/ml during maintenance treatment. Typically, daily oral doses of 100 mg/kg-150 mg/kg during the first two weeks post-transplantation, followed by daily 30 mg/kg-100 mg/kg dose levels during subsequent maintenance can result in long-term allograft survival, with 24-h average trough levels in individual animals during maintenance between 110 ng/ml and 700 ng/ml.

Successful suppression of the early rejection of pig islets in monkeys

Primary nonfunction (PNF) is seen very frequently after xenogeneic transplantation of islets of Langerhans. In a pig-to-rat model we recently observed that no PNF occurs when the islets are kept in culture at 37 degrees C for 1-2 weeks prior to transplantation. In order to investigate the rejection mechanisms in a preclinical model, we transplanted cultured porcine islets under the capsule of both kidneys in four cynomolgous monkeys. Islets were isolated from adult sows by means of digestion with Liberase in University of Wisconsin solution (UWS). The digest was purified by a density gradient of OptiPrep in UWS. Highly purified (>95%) islets were cultured 1-2 weeks in RPMI. All monkeys showed significant titers of preformed anti-pig antibodies. The immunosuppression of the monkeys consisted of cyclophosphamide (Cy) (2 days), cyclosporin A (CsA), and prednisolone. Anticipating a fast rejection we carried out nephrectomies at different time points within 2 weeks after transplantation. Following unilateral nephrectomy, well-preserved islets with no signs of rejection were observed between 3 and 7 days posttransplant. Later, between days 11 and 15 posttransplant, histology in the first three animals demonstrated no islets. In the fourth monkey histology on day 11 showed islets with excellent morphology and some small focal infiltrates. The highest CsA blood levels (around 1000 ng/ml) were found in animals with the best graft survival. We conclude that cultured porcine islets can be grafted without hyperacute rejection in monkeys with preformed anti-pig antibodies. In the presence of high levels of CsA only marginal signs of a cellular immune response were observed 11 days after transplantation.

Oral efficacy of the macrolide immunosuppressant SDZ RAD and of cyclosporine microemulsion in cynomolgus monkey kidney allotransplantation

BACKGROUND

40-O-(2-Hydroxyethyl)-rapamycin (SDZ RAD) is a novel, potent, macrolide immunosuppressant. Its efficacy in rodent transplantation models provided the rationale for us to evaluate the compound in a more relevant, large animal transplantation model.

METHODS

Life-supporting kidney allotransplantation was performed in cynomolgus monkeys: rejection was inferred from a rise in serum creatinine or urea and was subsequently confirmed by histopathology. This model was validated with the microemulsion formulation of cyclosporine (i.e., Neoral). Two studies with a microemulsion formulation of SDZ RAD were performed. First, in a dose-finding study, the SDZ RAD dose was reduced in a stepwise fashion until rejection occurred, either with SDZ RAD as monotherapy, or in combination with a fixed, suboptimal dose of cyclosporine. Second, an efficacy study was performed in which two fixed SDZ RAD doses (0.75 and 1.50 mg/kg/ day) were evaluated in monotherapy and compared with the same doses of rapamycin (sirolimus). All immunosuppressants were administered once daily by gastric gavage.

RESULTS

Untreated control animals rejected their grafts between 4 and 8 days after transplantation. Cyclosporine (initially at 150 mg/kg/day, reduced to 100 mg/kg/day 2 weeks after transplantation) yielded long-term (>100 days) rejection-free allograft survival in four of five animals. A 10 mg/kg/day dose of cyclosporine led to rejection between 10 and 27 days after transplantation and was considered suboptimal. In the dose-finding study with SDZ RAD monotherapy, rejection occurred in most of the cases (four of six animals) when a dose level of 0.63 mg/kg/day had been reached. Combined with suboptimal cyclosporine, this threshold SDZ RAD dose was about 2-fold lower. In the efficacy study, median graft survival with histologically proven rejection was 32 days (range 8-91 days, n=6) for 0.75 mg(kg/day SDZ RAD and 59 days (range 28-85 days, n=6) for 1.50 mg/kg/day SDZ RAD. For sirolimus, median graft survival was 43 days (range 5-103 days, n=7) for the 0.75 mg/kg/day dose and 56 days (range 8-103 days, n=8) for the 1.50 mg/kg/day dose. There was no statistically significant difference in efficacy between SDZ RAD and sirolimus.

CONCLUSION

SDZ RAD, in the absence of any other immunosuppressant and at doses that do not show any overt toxicity, considerably prolongs rejection-free survival of cynomolgus monkeys after life-supporting kidney allotransplantation.

Prevention of renal allograft rejection in primates by blocking the B7/CD28 pathway

BACKGROUND

There is accumulating evidence that blockade of the costimulatory pathways offers a valid approach for immune suppression after solid organ transplantation. In this study, the efficacy of anti-CD80 and anti-CD86 monoclonal antibodies (mAbs) in combination with cyclosporine (CsA) to prevent renal allograft rejection was tested in non-human primates.

METHODS

Rhesus monkeys were transplanted with a partly major histocompatibility complex-matched kidney on day 0. Anti-CD80 and anti-CD86 mAbs were administered intravenously daily for 14 days starting at day - 1. CsA was given intramuscularly for 35 days starting just after transplantation. The kidney function was monitored by determining serum creatinine levels.

RESULTS

The combination of anti-CD80 and anti-CD86 mAbs completely abrogated the mixed lymphocyte reaction. Untreated rhesus monkeys rejected the kidney allograft in 5-7 days. Treatment with anti-CD80 plus anti-CD86 mAbs resulted in a significantly prolonged graft survival of 28+ 7 days (P=0.025). There were no clinical signs of side effects or rejection during treatment. Kidney graft rejection started after the antibody therapy was stopped. The anti-mouse antibody response was delayed from day 10 to 30 after the first injection. No difference in graft survival was observed between animals treated with CsA alone or in combination with anti-CD80 and anti-CD86 mAbs. However, treatment with anti-CD80 and anti-CD86 mAbs reduced development of vascular rejection.

CONCLUSIONS

In combination, anti-CD80 and antiCD86 mAbs abrogate T-cell proliferation in vitro, delay the anti-mouse antibody response in vivo, and prevent graft rejection and development of graft vascular disease in a preclinical vascularized transplant model in non-human primates.

Prolonged skin graft survival by administration of anti-CD80 monoclonal antibody with cyclosporin A

Costimulation via the B7/CD28 pathway is an important signal for the activation of T cells. Maximal inhibition of T-cell activation and the induction of alloantigen-specific nonresponsiveness in vitro was achieved using anti-CD80 monoclonal antibody (mAb) in combination with cyclosporin A (CsA). Based on this knowledge, the efficacy of the prophylactic treatment of anti-CD80 mAb and CsA on allogeneic skin graft survival was tested in a preclinical rhesus monkey model. No side effects have been observed. Administration of anti-CD80 mAb resulted in high mAb serum levels that decreased to undetectable values around day 7. At the same time, the anti-mouse antibody response started to develop. The anti-CD80 mAb bound to peripheral blood mononuclear cells and was detectable in lymph node and grafted skin during the treatment period. The skin graft survival time of untreated or suboptimally CsA-treated rhesus monkeys was 10 days. Treatment with CsA (blood levels of 100-160 ng/ml) in combination with anti-CD80 mAb (0.5 mg/kg) resulted in a significantly increased skin graft survival time to 14 days. Eventually, skin grafts in all rhesus monkeys were rejected, which coincided with an increase in helper and cytotoxic T-cell frequency and induction of an antibody response directed against the donor antigens. Therefore, treatment of anti-CD80 mAb in combination with CsA has significant immunosuppressive potency, but was unable to induce donor-specific nonresponsiveness in skin graft recipients.

The effects of interferon beta treatment on arthritis

OBJECTIVE

To determine whether interferon beta (IFN-beta) therapy might have a beneficial effect on arthritis, we evaluated the effect of IFN-beta on collagen type II-induced arthritis (CIA) in rhesus monkeys and conducted a pilot study in patients with rheumatoid arthritis (RA).

METHODS

Four rhesus monkeys with CIA were treated with 10 x 10(6) U (MIU)/kg mammalian cell-derived recombinant IFN-beta (Rebif; Ares-Serono) s.c. daily for 1 week. Subsequently, 12 patients with active RA were treated for 12 weeks with purified natural fibroblast IFN-beta (Frone, Ares-Serono) s.c. 3 times weekly at the following dosages: 6 MIU (n = 4), 12 MIU (n = 4) and 18 MIU (n = 4).

RESULTS

Rapid clinical improvement during IFN-beta therapy was observed in three of the four rhesus monkeys with CIA. There was also a marked decrease in serum C-reactive protein (CRP) levels with a subsequent increase after discontinuation of the treatment in all monkeys. The 10 RA patients who completed the study exhibited on average gradual improvement of tender and swollen joint counts, patient's assessment of pain, and patient's and doctor's global assessment (all P < 0.05). The health assessment questionnaire and serum CRP levels also tended to decrease, but this was not statistically significant; 40% of the patients fulfilled the ACR criteria for 20%, improvement, whereas none fulfilled the ACR criteria for 50% improvement 12 weeks after initiation of treatment. There was no clear dose response relationship.

CONCLUSION

The data suggest that IFN-beta treatment has a beneficial effect on arthritis.