Acute grade IV toxic hepatitis due to the e-cigarette

A 46-year-old woman presented at the emergency department because of acute hepatitis with jaundice. After hepatological work-up including liver biopsy, drug induced liver disease (DILI) was suspected. Patient recovered completely within a few months. One year later she presented again with jaundice due to acute hepatitis. Vaping was the only agent that could be identified as causative agent for DILI. After VAPING cessation, the hepatitis resolved completely. Calculated RUCAM score was 10, making the diagnosis of toxic hepatitis very likely. During follow-up liver tests remained normal. This is the first report of severe DILI secondary to the use of e-cigarettes. In future vaping can be included in the differential diagnosis of DILI.

Clinical Outcomes and Immunotoxicity in People with HIV (PWH) after Definitive Chemoradiation (CRT) for Anal Squamous Cell Carcinoma

PURPOSE/OBJECTIVE(S)

Anal cancer disproportionately affects PWH despite antiretroviral therapy. Data on CRT outcomes are limited. Modern IMRT CRT decreases acute toxicity but may exacerbate immune dysregulation from chronic HIV. Although historical CRT has been associated with prolonged CD4 count suppression, little is known about late immunotoxicity in PWH after contemporary CRT. We report clinical outcomes and long term immunotoxicity.

MATERIALS/METHODS

Single-center retrospective review of all PWH confirmed on chart review with anal squamous cell carcinoma without prior pelvic irradiation treated with definitive IMRT CRT. Patient and CRT factors including HIV suppression (<200 copies/mL), mean CD4 count (cells/µL), and receipt of capecitabine (C) or 5-fluorouracil (F) +/- mitomycin (M) were summarized with n (%) or median (interquartile range). Progression-free and overall survival (PFS; OS) were estimated per Kaplan-Meier with 95% confidence intervals and compared with log-rank tests. Mean CD4 count and CD4:CD8 were compared by HIV suppression status (Welch's t-test); longitudinal changes in median CD4 count and CD4:CD8 were compared between baseline vs. nadir (within 6 months of CRT start) and 1-year follow-up for patients with complete data (Wilcoxon signed-rank test).

RESULTS

A total of 23 PWH were treated between 2010-2022, median age 52, median 16 (13 - 19) years after HIV diagnosis; 4 had unsuppressed HIV; AJCC 8th stage I/II/III/IV 5/5/12/1. Radiation dose was median 54 Gy in 30 fractions over 42 (40 - 44) days. Most had C+M (57%); only 43% had 2×M with either C or F. One had neoadjuvant carboplatin/paclitaxel/pembrolizumab. With 2.9 (1.03 - 3.3) years follow-up, median OS was 6.6 (6.2 - unreached [UR]) years. With 2.2 (0.67 - 2.7) years follow-up, median PFS was UR. OS and PFS were similar regardless of HIV suppression status (both P ≥ 0.09). Overall baseline CD4 count was 458 (226 - 484), and CD4:CD8 was 0.54 (0.2 - 0.7). Nadir CD4 was 100 (59 - 126) and CD4:CD8 was 0.3 (0.2 - 0.4). Baseline and nadir CD4 count and CD4:CD8 were lower if HIV-unsuppressed (each P ≤ 0.04). One year after CRT, CD4 count was 252 (102 - 276), while CD4:CD8 was 0.5 (0.2 - 0.7). For 7 patients with repeated values the change in median from baseline to nadir, 6-, and 12-months post-CRT was -282, -549 (both P = 0.02), -480 (P = 0.9) for CD4 counts, and -0.7, -0.5, -0.4 (each P > 0.5) for CD4:CD8 ratios; none had unsuppressed HIV.

CONCLUSION

Definitive IMRT CRT with guideline-concordant doublet chemotherapy for anal cancer in PWH is effective despite unsuppressed HIV. Treatment leads to prolonged immunological changes that may increase the risk of HIV-related morbidity and mortality. Modifiable treatment-related causes of hematoimmunologic toxicity should be investigated further, and immune surveillance after CRT should be considered to better understand impact on quality of life.

Characteristics of mpox positive, versus mpox negative, and mpox unsuspected clients from the Centre of Sexual Health, Public Health Service of Amsterdam, 20 May to 15 September 2022

BACKGROUND

In May 2022, an outbreak of mpox (monkeypox) in men-who-have-sex-with-men (MSM) emerged and quickly affected over 100 countries. In the early stages of the outbreak, overlap in symptoms with sexually transmitted infections (STI) made triage for mpox testing challenging. More information was needed on whom to screen and the main route of transmission.

OBJECTIVES

We aimed to identify characteristics of mpox cases to further strengthen case definitions. We also compared Cycle threshold (Ct) values of the DNA positive mpox samples as a proxy for viral load by body location.

METHODS

From 20 May 2022 to 15 September 2022, we tested all MSM who presented with malaise, and/or ulcerative lesions, and/or proctitis and/or a papular-vesicular-pustular eruption attending the Centre of Sexual Health in Amsterdam, the Netherlands, for mpox, with a PCR test. In the same period, 6932 MSM mpox unsuspected clients were not tested. We compared those tested positive for mpox with those tested negative and those unsuspected for mpox.

RESULTS

Of the 374 MSM tested, 135 (36%) were positive for mpox. The mpox-positive MSM were older (median age, respectively, 36, 34 and 34 years, p = 0.019) and more often lived with HIV (30% vs. 16% and 7%, p < 0.001). Furthermore, mpox-positive patients more often reported receptive anal sex without a condom, sexualized drug use, more sex partners, and were more often diagnosed with bacterial STI (p < 0.001). Systemic symptoms and anogenital lesions were associated with mpox infection. For mpox-positive patients, anal samples (p = 0.009) and lesional samples (p = 0.006) showed significantly lower median mpox Ct values compared to throat samples.

CONCLUSIONS

Mpox-positive patients more often reported receptive anal sex without a condom, had more sex partners and more often lived with HIV. Our results suggest that in the current mpox outbreak among MSM, sexual transmission is the main route.

Safety, effectiveness, and cost-effectiveness of immediate versus delayed sequential bilateral cataract surgery in the Netherlands (BICAT-NL study): a multicentre, non-inferiority, randomised controlled trial

BACKGROUND

In an ageing population, efficiency improvements are required to assure future accessibility of cataract care. We aim to address remaining knowledge gaps by evaluating the safety, effectiveness, and cost-effectiveness of immediate sequential bilateral cataract surgery (ISBCS) versus delayed sequential bilateral cataract surgery (DSBCS). We hypothesised that ISBCS is non-inferior to DSBCS, regarding safety and effectiveness, and being superior in cost-effectiveness.

METHODS

We did a multicentre, non-inferiority, randomised controlled trial, which included participants from ten Dutch hospitals. Eligible participants were 18 years or older, underwent expected uncomplicated surgery, and had no increased risk of endophthalmitis or refractive surprise. Participants were randomly assigned (1:1) to either the ISBCS (intervention) group or DSBCS (conventional procedure) group, using a web-based system stratified by centre and axial length. Participants and outcome assessors were not masked to the treatment groups because of the nature of the intervention. The primary outcome was the proportion of second eyes with a target refractive outcome of 1·0 dioptre (D) or less 4 weeks postoperatively, with a non-inferiority margin of -5% for ISBCS versus DSBCS. For the trial-based economic evaluation, the primary endpoint was the incremental societal costs per quality-adjusted life-year. All analyses were done by a modified intention-to-treat principle. Costs were calculated by multiplying volumes of resource use with unit cost prices and converted to 2020 Euros (€) and US$. This study was registered with ClinicalTrials.gov, number NCT03400124, and is now closed for recruitment.

FINDINGS

Between Sept 4, 2018, and July 10, 2020, a total of 865 patients were randomly assigned to either the ISBCS group (427 [49%] patients; 854 eyes) or DSBCS group (438 [51%] patients; 876 eyes). In the modified intention-to-treat analysis, the proportion of second eyes with a target refraction of 1·0 D or less was 97% (404 of 417 patients) in the ISBCS group versus 98% (407 of 417) in the DSBCS group. The percentage difference was -1% (90% CI -3 to 1; p=0·526), thereby establishing non-inferiority for ISBCS compared with DSBCS. Endophthalmitis was not observed or reported in either group. Adverse events were comparable between groups, with only a significant difference in disturbing anisometropia (p=0·0001). Societal costs were €403 (US$507) lower with ISBCS than with DSBCS. The cost-effectiveness probability of ISBCS versus DSBCS was 100% across the willingness-to-pay range of €2500-80 000 (US$3145-100 629) per quality-adjusted life-year.

INTERPRETATION

Our results showed non-inferiority of ISBCS versus DSBCS regarding effectiveness outcomes, comparable safety, and superior cost-effectiveness of ISBCS. National cost savings could amount to €27·4 million (US$34·5 million) annually, advocating for ISBCS if strict inclusion criteria are applied.

FUNDING

Research grant from The Netherlands Organization for Health Research and Development (ZonMw) and Dutch Ophthalmological Society.

Preclinical profile of BYON3521 predicts an effective and safe c-MET-antibody-drug conjugate

c-MET, the cell-surface receptor for the hepatocyte growth factor/scatter factor (HGF/SF), which is widely overexpressed in various solid cancer types, is an attractive target for the development of antibody-based therapeutics. BYON3521 is a novel site-specifically conjugated duocarmycin-based ADC, comprising a humanized cysteine-engineered IgG1 monoclonal antibody with low pM binding affinity towards both human and cynomolgus c-MET. In vitro studies showed that BYON3521 internalizes efficiently upon c-MET binding and induces both target- and bystander-mediated cell killing. BYON3521 showed good potency and full efficacy in MET-amplified and high c-MET-expressing cancer cell lines; in moderate and low c-MET-expressing cancer cell lines good potencies and partial efficacy were observed. In mouse xenograft models, BYON3521 showed significant anti-tumor activity upon single dose administration in multiple non-MET-amplified tumor types with low, moderate and high c-Met expression, including complete tumor remissions in models with moderate c-MET expression. In the repeat-dose GLP safety assessment in cynomolgus monkeys, BYON3521 was well tolerated and based on the observed toxicities and their reversibility, the highest non-severely toxic dose (HNSTD) was set at 15 mg/kg. A human pharmacokinetics (PK) model was derived from the PK data from the cynomolgus safety assessments, and the minimal efficacious dose in humans is estimated to be in the range of 3-4 mg/kg. In all, our nonclinical data suggests that BYON3521 is a safe ADC with potential for clinical benefit in patients. A first-in-human dose escalation study is currently ongoing to determine the maximum tolerated dose and recommended dose for expansion (NCT05323045).

Hyperferritinemia and non-HFE hemochromatosis: differential diagnosis and workup

Hyperferritinemia is a common reason for referral to a hepatogastroenterologist. The most frequent causes are not associated with iron overload (e.g. inflammatory diseases, alcohol abuse, metabolic syndrome, etc.). However, hyperferritinemia can also be caused by a genetic variant in one of the iron regulatory genes, called hereditary hemochromatosis, often but not always associated with iron overload. A variation in the human Hemostatic Iron Regulator protein (HFE) gene is the most common genotype, but many other variants have been described. In this paper we discuss two cases of rare hyperferritinemia associated disorders, ferroportin disease and hyperferritinemia-cataract syndrome. We also propose an algorithm for evaluating hyperferritinemia, facilitating a correct diagnosis and preventing potentially unnecessary examinations and therapeutic actions.

BYON4228 is a pan-allelic antagonistic SIRPα antibody that potentiates destruction of antibody-opsonized tumor cells and lacks binding to SIRPγ on T cells

BACKGROUND

Preclinical studies have firmly established the CD47-signal-regulatory protein (SIRP)α axis as a myeloid immune checkpoint in cancer, and this is corroborated by available evidence from the first clinical studies with CD47 blockers. However, CD47 is ubiquitously expressed and mediates functional interactions with other ligands as well, and therefore targeting of the primarily myeloid cell-restricted inhibitory immunoreceptor SIRPα may represent a better strategy.

METHOD

We generated BYON4228, a novel SIRPα-directed antibody. An extensive preclinical characterization was performed, including direct comparisons to previously reported anti-SIRPα antibodies.

RESULTS

BYON4228 is an antibody directed against SIRPα that recognizes both allelic variants of SIRPα in the human population, thereby maximizing its potential clinical applicability. Notably, BYON4228 does not recognize the closely related T-cell expressed SIRPγ that mediates interactions with CD47 as well, which are known to be instrumental in T-cell extravasation and activation. BYON4228 binds to the N-terminal Ig-like domain of SIRPα and its epitope largely overlaps with the CD47-binding site. BYON4228 blocks binding of CD47 to SIRPα and inhibits signaling through the CD47-SIRPα axis. Functional studies show that BYON4228 potentiates macrophage-mediated and neutrophil-mediated killing of hematologic and solid cancer cells in vitro in the presence of a variety of tumor-targeting antibodies, including trastuzumab, rituximab, daratumumab and cetuximab. The silenced Fc region of BYON4228 precludes immune cell-mediated elimination of SIRPα-positive myeloid cells, implying anticipated preservation of myeloid immune effector cells in patients. The unique profile of BYON4228 clearly distinguishes it from previously reported antibodies representative of agents in clinical development, which either lack recognition of one of the two SIRPα polymorphic variants (HEFLB), or cross-react with SIRPγ and inhibit CD47-SIRPγ interactions (SIRPAB-11-K322A, 1H9), and/or have functional Fc regions thereby displaying myeloid cell depletion activity (SIRPAB-11-K322A). In vivo, BYON4228 increases the antitumor activity of rituximab in a B-cell Raji xenograft model in human SIRPα_BIT transgenic mice. Finally, BYON4228 shows a favorable safety profile in cynomolgus monkeys.

CONCLUSIONS

Collectively, this defines BYON4228 as a preclinically highly differentiating pan-allelic SIRPα antibody without T-cell SIRPγ recognition that promotes the destruction of antibody-opsonized cancer cells. Clinical studies are planned to start in 2023.

Current clinical practice in antibiotic treatment of Staphylococcus aureus bacteraemia: results from a survey in five European countries

OBJECTIVES

To determine clinical practice variation and identify knowledge gaps in antibiotic treatment of Staphylococcus aureus bacteraemia (SAB).

METHODS

A web-based survey with questions addressing antibiotic treatment of SAB was distributed through the ESGAP network among infectious disease specialists, clinical microbiologists and internists in Croatia, France, Greece, the Netherlands and the UK between July 2021 and November 2021.

RESULTS

A total number of 1687 respondents opened the survey link, of whom 677 (40%) answered at least one question. For MSSA and MRSA bacteraemia, 98% and 94% preferred initial monotherapy, respectively. In patients with SAB and non-removable infected prosthetic material, between 80% and 90% would use rifampicin as part of the treatment. For bone and joint infections, 65%-77% of respondents would consider oral step-down therapy, but for endovascular infections only 12%-32% would. Respondents recommended widely varying treatment durations for SAB with different foci of infection. Overall, 48% stated they used 18F-fluorodeoxyglucose positron emission tomography/CT (18F-FDG-PET/CT) to guide antibiotic treatment duration. Persistent bacteraemia was the only risk factor for complicated SAB that would prompt a majority to extend treatment from 2 to 4-6 weeks.

CONCLUSIONS

This survey in five European countries shows considerable clinical practice variation between and within countries in the antibiotic management of SAB, in particular regarding oral step-down therapy, choice of oral antibiotic agents, treatment duration and use of 18F-FDG-PET/CT. Physicians use varying criteria for treatment decisions, as evidence from clinical trials is often lacking. These areas of practice variation could be used to prioritize future studies for further improvement of SAB care.

Severity of oEsophageal Anastomotic Leak in patients after oesophagectomy: the SEAL score

Background

Anastomotic leak (AL) is a common but severe complication after oesophagectomy. It is unknown how to determine the severity of AL objectively at diagnosis. Determining leak severity may guide treatment decisions and improve future research. This study aimed to identify leak-related prognostic factors for mortality, and to develop a Severity of oEsophageal Anastomotic Leak (SEAL) score.

Methods

This international, retrospective cohort study in 71 centres worldwide included patients with AL after oesophagectomy between 2011 and 2019. The primary endpoint was 90-day mortality. Leak-related prognostic factors were identified after adjusting for confounders and were included in multivariable logistic regression to develop the SEAL score. Four classes of leak severity (mild, moderate, severe, and critical) were defined based on the risk of 90-day mortality, and the score was validated internally.

Results

Some 1509 patients with AL were included and the 90-day mortality rate was 11.7 per cent. Twelve leak-related prognostic factors were included in the SEAL score. The score showed good calibration and discrimination (c-index 0.77, 95 per cent c.i. 0.73 to 0.81). Higher classes of leak severity graded by the SEAL score were associated with a significant increase in duration of ICU stay, healing time, Comprehensive Complication Index score, and Esophagectomy Complications Consensus Group classification.

Conclusion

The SEAL score grades leak severity into four classes by combining 12 leak-related predictors and can be used to the assess severity of AL after oesophagectomy.

[Confusion and abdominal pain after COVID-19 vaccination]

BACKGROUND

Vaccine-induced immune thrombotic trombocytopenia (VITT) is a rare phenomenon, that may present with diffuse and atypical symptoms.

CASE DESCRIPTION

We present a case of 63 years old female patient with abdominal pain, confusion and tromboctytopenia. CT scan shows sinustrombosis and trombosis of the vena renalis. The diagnosis VITT was confirmed by a positive HIT test. After initiating treatment with immunoglobulines and a non-heparinoid anticoagulans, symptoms improved and platelet count increased.

CONCLUSION

This case illustrates that awareness in case of atypical symptoms and a history of vaccination is important to recognize this phenomenon.

Proxy indicators to estimate the appropriateness of medications prescribed by paediatricians in infectious diseases: a cross-sectional observational study based on reimbursement data

Background

We previously developed proxy indicators (PIs) that can be used to estimate the appropriateness of medications used for infectious diseases (in particular antibiotics) in primary care, based on routine reimbursement data that do not include clinical indications.

Objectives

To: (i) select the PIs that are relevant for children and estimate current appropriateness of medications used for infectious diseases by French paediatricians and its variability while using these PIs; (ii) assess the clinimetric properties of these PIs using a large regional reimbursement database; and (iii) compare performance scores for each PI between paediatricians and GPs in the paediatric population.

Methods

For all individuals living in north-eastern France, a cross-sectional observational study was performed analysing National Health Insurance data (available at prescriber and patient levels) regarding antibiotics prescribed by their paediatricians in 2017. We measured performance scores of the PIs, and we tested their clinimetric properties, i.e. measurability, applicability and room for improvement.

Results

We included 116 paediatricians who prescribed a total of 44 146 antibiotic treatments in 2017. For all four selected PIs (seasonal variation of total antibiotic use, amoxicillin/second-line antibiotics ratio, co-prescription of anti-inflammatory drugs and antibiotics), we found large variations between paediatricians. Regarding clinimetric properties, all PIs were measurable and applicable, and showed high improvement potential. Performance scores did not differ between these 116 paediatricians and 3087 GPs.

Conclusions

This set of four proxy indicators might be used to estimate appropriateness of prescribing in children in an automated way within antibiotic stewardship programmes.

A Platform for the Generation of Site-Specific Antibody-Drug Conjugates That Allows for Selective Reduction of Engineered Cysteines

Engineering cysteines at specific sites in antibodies to create well-defined ADCs for the treatment of cancer is a promising approach to increase the therapeutic index and helps to streamline the manufacturing process. Here, we report the development of an in silico screening procedure to select for optimal sites in an antibody to which a hydrophobic linker-drug can be conjugated. Sites were identified inside the cavity that is naturally present in the Fab part of the antibody. Conjugating a linker-drug to these sites demonstrated the ability of the antibody to shield the hydrophobic character of the linker-drug while resulting ADCs maintained their cytotoxic potency in vitro. Comparison of site-specific ADCs versus randomly conjugated ADCs in an in vivo xenograft model revealed improved efficacy and exposure. We also report a selective reducing agent that is able to reduce the engineered cysteines while leaving the interchain disulfides in the oxidized state. This enables us to manufacture site-specific ADCs without introducing impurities associated with the conventional reduction/oxidation procedure for site-specific conjugation.

EBV : not your Everyday Benign Virus

BACKGROUND

Epstein-Barr virus infection is common, with seroprevalence of 90% in adults. Clinical presentation of primary EBV infection can be variable and atypical. It is often subclinical or can result in infectious mononucleosis. Clinical course is mostly benign, but in rare cases serious short- and long-term complications may occur.

CASE PRESENTATION

We present a case of a 19-year-old woman who was admitted to the hospital with general malaise, fever, dyspnea, icterus, vomiting and diarrhea, with acute left upper quadrant pain. She was diagnosed with acute EBV-infection with hepatitis, splenomegaly and spontaneous splenic rupture.

CONCLUSIONS

Spontaneous splenic rupture is an uncommon, but potentially fatal complication of infectious mononucleosis. In a patient with suspicion of EBV infection and abdominal pain, we should always be aware of the possibility of spontaneous splenic rupture and emphasis should be put on appropriate counseling.

Atypical and fulminant presentations of pneumococcal infections: A case series in a tertiary intensive care unit

With the introduction of conjugate pneumococcal vaccines, changes in causative serotypes and clinical presentations of Streptococcus pneumoniae infections are occurring. During the 2017-2018 winter, an unusual number of patients with a severe manifestation of pneumococcal disease was admitted to a tertiary care intensive care unit (ICU) in the Netherlands. We describe some of the cases in depth. Given our observed change in infecting serotypes and extreme clinical manifestations of pneumococcal disease, a systematic clinical registry of pneumococcal infections in the ICU may be a valuable addition to pneumococcal disease surveillance.

Intragenic and structural variation in the SMN locus and clinical variability in spinal muscular atrophy

Clinical severity and treatment response vary significantly between patients with spinal muscular atrophy. The approval of therapies and the emergence of neonatal screening programmes urgently require a more detailed understanding of the genetic variants that underlie this clinical heterogeneity. We systematically investigated genetic variation other than SMN2 copy number in the SMN locus. Data were collected through our single-centre, population-based study on spinal muscular atrophy in the Netherlands, including 286 children and adults with spinal muscular atrophy Types 1–4, including 56 patients from 25 families with multiple siblings with spinal muscular atrophy. We combined multiplex ligation-dependent probe amplification, Sanger sequencing, multiplexed targeted resequencing and digital droplet polymerase chain reaction to determine sequence and expression variation in the SMN locus. SMN1, SMN2 and NAIP gene copy number were determined by multiplex ligation-dependent probe amplification. SMN2 gene variant analysis was performed using Sanger sequencing and RNA expression analysis of SMN by droplet digital polymerase chain reaction. We identified SMN1–SMN2 hybrid genes in 10% of spinal muscular atrophy patients, including partial gene deletions, duplications or conversions within SMN1 and SMN2 genes. This indicates that SMN2 copies can vary structurally between patients, implicating an important novel level of genetic variability in spinal muscular atrophy. Sequence analysis revealed six exonic and four intronic SMN2 variants, which were associated with disease severity in individual cases. There are no indications that NAIP1 gene copy number or sequence variants add value in addition to SMN2 copies in predicting the clinical phenotype in individual patients with spinal muscular atrophy. Importantly, 95% of spinal muscular atrophy siblings in our study had equal SMN2 copy numbers and structural changes (e.g. hybrid genes), but 60% presented with a different spinal muscular atrophy type, indicating the likely presence of further inter- and intragenic variabilities inside as well as outside the SMN locus. SMN2 gene copies can be structurally different, resulting in inter- and intra-individual differences in the composition of SMN1 and SMN2 gene copies. This adds another layer of complexity to the genetics that underlie spinal muscular atrophy and should be considered in current genetic diagnosis and counselling practices.

The frequency of SMN gene variants lacking exon 7 and 8 is highly population dependent

Spinal Muscular Atrophy (SMA) is a disorder characterized by the degeneration of motor neurons in the spinal cord, leading to muscular atrophy. In the majority of cases, SMA is caused by the homozygous absence of the SMN1 gene. The disease severity of SMA is strongly influenced by the copy number of the closely related SMN2 gene. In addition, an SMN variant lacking exons 7 and 8 has been reported in 8% and 23% of healthy Swedish and Spanish individuals respectively. We tested 1255 samples from the 1000 Genomes Project using a new version of the multiplex ligation-dependent probe amplification (MLPA) P021 probemix that covers each SMN exon. The SMN variant lacking exons 7 and 8 was present in up to 20% of individuals in several Caucasian populations, while being almost completely absent in various Asian and African populations. This SMN1/2Δ7-8 variant appears to be derived from an ancient deletion event as the deletion size is identical in 99% of samples tested. The average total copy number of SMN1, SMN2 and the SMN1/2Δ7-8 variant combined was remarkably comparable in all populations tested, ranging from 3.64 in Asian to 3.75 in African samples.

Validation of a Fast, Robust, Inexpensive, Two-Tiered Neonatal Screening Test algorithm on Dried Blood Spots for Spinal Muscular Atrophy

Spinal muscular atrophy (SMA) is one of the leading genetic causes of infant mortality with an incidence of 1:10,000. The recently-introduced antisense oligonucleotide treatment improves the outcome of this disease, in particular when applied at an early stage of progression. The genetic cause of SMA is, in >95% of cases, a homozygous deletion of the survival motor neuron 1 (SMN1) gene, which makes the low-cost detection of SMA cases as part of newborn screening programs feasible. We developed and validated a new SALSA MC002 melting curve assay that detects the absence of the SMN1 exon 7 DNA sequence without detecting asymptomatic carriers and reliably discriminates SMN1 from its genetic homolog SMN2 using crude extracts from newborn screening cards. Melting curve analysis shows peaks specific for both the SMN1 gene and the disease modifying SMN2 homolog. The detection of the SMN2 homolog, of which the only clinically relevant difference from the SMN1 gene is a single nucleotide in exon 7, was only used to confirm a correct reaction in samples that lacked the SMN1 gene, and not for SMN2 quantification. We retrieved 47 DBS samples from children with genetically-confirmed SMA, after informed consent from parents, and 375 controls from the national archive of the Dutch National Institute for Public Health and the Environment (RIVM). The assay correctly identified all anonymized and randomized SMA and control samples (i.e., sensitivity and specificity of 100%), without the detection of carriers, on the three most commonly-used PCR platforms with melting curve analysis. This test's concordance with the second-tier 'golden standard' P021 SMA MLPA test was 100%. Using the new P021-B1 version, crude extracts from DBS cards could also be used to determine the SMN2 copy number of SMA patients with a high level of accuracy. The MC002 test showed the feasibility and accuracy of SMA screening in a neonatal screening program.

Reconnection of Interrupted Curvilinear Structures via Cortically Inspired Completion for Ophthalmologic Images

OBJECTIVE

In this paper, we propose a robust, efficient, and automatic reconnection algorithm for bridging interrupted curvilinear skeletons in ophthalmologic images.

METHODS

This method employs the contour completion process, i.e., mathematical modeling of the direction process in the roto-translation group to achieve line propagation/completion. The completion process can be used to reconstruct interrupted curves by considering their local consistency. An explicit scheme with finite-difference approximation is used to construct the three-dimensional (3-D) completion kernel, where we choose the Gamma distribution for time integration. To process structures in , the orientation score framework is exploited to lift the 2-D curvilinear segments into the 3-D space. The propagation and reconnection of interrupted segments are achieved by convolving the completion kernel with orientation scores via iterative group convolutions. To overcome the problem of incorrect skeletonization of 2-D structures at junctions, a 3-D segment-wise thinning technique is proposed to process each segment separately in orientation scores.

RESULTS

Validations on 4 datasets with different image modalities show that our method achieves an average success rate of in reconnecting gaps of sizes from to , including challenging junction structures.

CONCLUSION

The reconnection approach can be a useful and reliable technique for bridging complex curvilinear interruptions.

SIGNIFICANCE

The presented method is a critical work to obtain more complete curvilinear structures in ophthalmologic images. It provides better topological and geometric connectivities for further analysis.

Multiplex Ligation-Dependent Probe Amplification (MLPA) for Prenatal Diagnosis of Common Aneuploidies

Multiplex Ligation-dependent Probe Amplification (MLPA) is a method to determine the copy number of up to 60 genomic DNA sequences in a single multiplex PCR based reaction.MLPA probes consist of two oligonucleotides that can hybridize next to each other on a certain DNA sequence of interest, where they are ligated. All ligated probes are subsequently amplified by PCR using a single set of primers. Each amplified MLPA probe has a unique length and can be visualized and quantified by capillary electrophoresis. As the primers are almost 100% consumed in the PCR reaction, the quantity of each PCR amplicon is proportional to the number of copies of each probe target sequence in the DNA sample. A trisomy 21 can therefore be detected by an approximately 50% increased signal of each chromosome 21 specific probe relative to reference samples.MLPA with the P095 Aneuploidy probemix for chromosomes 13, 18, 21, X and Y has been used as a rapid detection method on large numbers of samples from uncultured amniotic fluid or from chorionic villi. As compared to FISH and karyotyping, MLPA is more rapid, has a higher throughput, and is less expensive. MLPA however cannot detect low grade mosaicism, female triploidies, and copy number neutral chromosome abnormalities such as inversions and translocations.

Human resources required for antimicrobial stewardship teams: a Dutch consensus report

SCOPE

Antimicrobial stewardship teams are responsible for implementing antimicrobial stewardship programmes (ASP). However, in many countries, lack of funding challenges this obligation. A consensus procedure was performed to investigate which structural activities need to be performed by Dutch stewardship teams and how much time (and thus full-time equivalent (FTE) labor) is needed to perform these activities.

METHODS

In 2015, an electronic survey, based on a nonsystematic literature search and interviews with seven experienced stewardship teams, was sent to 21 stewardship teams that performed an ASP. This was followed by a semistructured face-to-face consensus meeting. Fourteen stewardship teams completed the survey (18% of Dutch acute-care hospitals), and 13 participated in the consensus meeting.

RECOMMENDATIONS

The hours needed each year are dependent on hospital size and number of stewardship objectives monitored. If all activities are performed at a minimal base (one stewardship objective; minimal staffing standard), time investment was estimated to be 1393 to 2680 hours annually in the early phase, corresponding with 0.87 (300 beds) to 1.68 FTE (1200 beds), with a further increase to minimally 1.25 to 3.18 FTE in the following years with three stewardship objectives monitored (optimal staffing standards during the first few years of implementing an ASP). This consensus on required human resources provides a directive for structural financial support of stewardship teams in the Dutch context. Some stewardship activities (and related time investments) might be specific to the Dutch context and hospital setting. To develop standards for other settings, our methodology could be applied.

What is antimicrobial stewardship?

BACKGROUND

The use of the term 'antimicrobial stewardship' has grown exponentially in recent years, typically referring to programmes and interventions that aim to optimize antimicrobial use. Although antimicrobial stewardship originated within human healthcare, it is increasingly applied in broader contexts including animal health and One Health. As the use of the term 'antimicrobial stewardship' becomes more common, it is important to consider what antimicrobial stewardship is, as well as what it is not.

AIMS

To review the emergence and evolution of the term 'antimicrobial stewardship'.

SOURCES

We searched and reviewed existing literature and official documents, which mostly focused on antibiotics. We contacted the authors of the first publications that mentioned antimicrobial stewardship.

CONTENT

We describe the historical background behind how antimicrobial stewardship came into use in clinical settings. We discuss challenges emerging from the varied descriptions of antimicrobial stewardship in the literature, including an over-emphasis on individual prescriptions, an under-emphasis on the societal implications of antimicrobial use, and language translation problems.

IMPLICATIONS

To help address these challenges, we suggest viewing antimicrobial stewardship as a strategy, a coherent set of actions which promote using antimicrobials responsibly. We stress the continuous need for 'responsible use' to be defined and translated into context-specific and time-specific actions. Furthermore, we present examples of actions that can be undertaken within antimicrobial stewardship across human and animal health.

Characterization of low affinity Fcγ receptor biotinylation under controlled reaction conditions by mass spectrometry and ligand binding analysis

Chemical protein biotinylation and streptavidin or anti-biotin-based capture is regularly used for proteins as a more controlled alternative to direct coupling of the protein on a biosensor surface. On biotinylation an interaction site of interest may be blocked by the biotin groups, diminishing apparent activity of the protein. Minimal biotinylation can circumvent the loss of apparent activity, but still a binding site of interest can be blocked when labeling an amino acid involved in the binding. Here, we describe reaction condition optimization studies for minimal labeling. We have chosen low affinity Fcγ receptors as model compounds as these proteins contain many lysines in their active binding site and as such provide an interesting system for a minimal labeling approach. We were able to identify the most critical parameters (protein:biotin ratio and incubation pH) for a minimal labeling approach in which the proteins of choice remain most active toward analyte binding. Localization of biotinylation by mass spectrometric peptide mapping on minimally labeled material was correlated to protein activity in binding assays. We show that only aiming at minimal labeling is not sufficient to maintain an active protein. Careful fine-tuning of critical parameters is important to reduce biotinylation in a protein binding site.

A comparison of anti-HER2 IgA and IgG1 in vivo efficacy is facilitated by high N-glycan sialylation of the IgA

Monomeric IgA has been proposed as an alternative antibody format for cancer therapy. Here, we present our studies on the production, purification and functional evaluation of anti-HER2 IgA antibodies as anti-cancer agents in comparison to the anti-HER2 IgG1 trastuzumab. MALDI-TOF MS analysis showed profound differences in glycosylation traits across the IgA isotypes and cell lines used for production, including sialylation and linkage thereof, fucosylation (both core and antennary) and the abundance of high-mannose type species. Increases in sialylation proved to positively correlate with in vivo plasma half-lives. The polymerization propensity of anti-HER2 IgA2m2 could be suppressed by an 18-aa deletion of the heavy chain tailpiece - coinciding with the loss of high-mannose type N-glycan species - as well as by 2 cysteine to serine mutations at positions 320 and 480. The HER2 F(ab')2-mediated anti-proliferative effect of the IgA2m1 and IgA2m2 subtypes was similar to IgG1, whereas the IgA1 isotype displayed considerably lower potency and efficacy. The Fc-mediated induction of antibody-dependent cell-mediated cytotoxicity (ADCC) using human whole blood ADCC assays did not demonstrate such clear differences between the IgA isotypes. However, the potency of the anti-HER2 IgA antibodies in these ADCC assays was found to be significantly lower than that of trastuzumab. In vivo anti-tumor activity of the anti-HER2 IgA antibodies was compared to that of trastuzumab in a BT-474 breast cancer xenograft model. Multiple dosing and sialylation of the IgA antibodies compensated for the short in vivo half-life of native IgA antibodies in mice compared to a single dose of IgG1. In the case of the IgA2m2 antibody, the resulting high plasma exposure levels were sufficient to cause clear tumor stasis comparable to that observed for trastuzumab at much lower plasma exposure levels.

232 ADDITION OF VERY LOW AMOUNTS OF SERUM (ESTRUS COW SERUM) IMPROVES IN VITRO EMBRYO PRODUCTION IN DAIRY CATTLE

Improving the efficiency of the in vitro production (IVP) process is very important because it results in more embryos to be used in breeding programs or as commercial service. At CRV, a culture medium consisting of SOF with amino acids and BSA is used. In the past, richer culture media were used with 10% fetal calf serum combined with BRL cell co-culture. Although the efficiency of the IVP process of these media was good, these rather high serum concentrations were quite often related to large offspring syndrome (LOS). The switch to a culture system without serum resulted in a significant reduction in LOS but also in a reduction of embryo yield. The aim of the present study was to investigate the effect of adding low amounts of serum to the culture medium on efficiency of embryo production. Immature cumulus-oocyte complexes (COC) were recovered from ovaries 6 to 8 h upon slaughter. The COC were matured in vitro in TCM199/FCS/LH/FSH supplemented with cysteamine (0.1 mM). Subsequently, matured oocytes were fertilised with frozen-thawed gradient-separated semen and further cultured for 7 days in SOFaaBSA. The SOF medium contained either 0 (control), 0.1, 0.5, or 1.0% oestrus cow serum (ECS). Embryos development was scored at Day 7. Three replicates were performed and results were analysed by chi-square analyses. The results clearly show that adding ECS significantly improved embryo production (Table 1). Interestingly, already very low amounts (0.1%) of serum gave a significant increase in embryo percentage. In conclusion, addition of very low amounts of ECS (0.1%) is beneficial for embryo production, resulting in significantly higher embryo production (from 19 to 27%). In a subsequent field trial with OPU-derived embryos, the effect of addition of 0.1% ECS on birth weight (LOS) of the calves has to be investigated. Table 1.Percentage of blastocysts at Day 7 after culture in SOF medium with different amounts of serum

240 OVUM-PICK UP IN HOLSTEIN-FRIESIAN COWS AT 9 TO 10 MONTHS OF AGE

Rate of genetic gain can be improved by increasing selection intensity, increasing selection accuracy, creating a higher amount of variation, or shortening the generation interval. A reduction in the generation interval can be realised by collecting embryos from animals at a young age. At CRV it is currently routine practice to start embryo collection (by flushing) at 12 to 15 months of age. The aim of this study was to investigate if the collection of embryos at a younger age by means of ovum pickup (OPU) is beneficial for our breeding program. Healthy 9- to 10-month-old Holstein-Friesian animals were selected at young age based on their maturity, (i.e. OPU could be performed by normal standard procedure/equipment). Animals were not stimulated with hormones. Oocytes were collected by OPU once every week during a period of ~8 weeks. Collected oocytes were matured, fertilized, and cultured for 7 days in SOF culture medium according to standard procedures (Merton et al. 2002). Embryo development was scored at Day 7. Results were analysed by Student's t-test. On average 11.7 oocytes were collected from animals as young as 9 months of age. However, embryo development of the oocytes from young animals was only 0.4 embryo per session at Day 7 (3% embryo development). When only the results of the first OPU session were taken into account, 18.2 oocytes and 0.8 embryo could be collected per animal per session. Whether an animal was observed in oestrus before the first OPU session affected results. Animals that had shown clear signs of oestrus before the first OPU session produced significantly more embryos than animals that did not (Table 1). It is concluded that OPU is possible on animals at 9 to 10 months of age but only when animals have been in oestrus before the first OPU session. Best results were obtained for the first OPU session. Table 1.Effect of first oestrus before OPU on embryo production

Screening of congenital heart disease patients using multiplex ligation-dependent probe amplification: early diagnosis of syndromic patients

Recurrent copy number variants (CNVs) are found in a significant proportion of patients with congenital heart disease (CHD) and some of these CNVs are associated with other developmental defects. In some syndromic patients, CHD may be the first presenting symptom, thus screening of patients with CHD for CNVs in specific genomic regions may lead to early diagnosis and awareness of extracardiac symptoms. We designed a multiplex ligation-dependent probe amplification (MLPA) assay specifically for screening of CHD patients. The MLPA assay allows for simultaneous analysis of CNVs in 25 genomic regions previously associated with CHD. We screened blood samples from 402 CHD patients and identified 14 rare CNVs in 13 (3.2%) patients. Five CNVs were de novo and six where inherited from a healthy parent. The MLPA screen led to early syndrome diagnosis in two of these patients. We conclude that the MLPA assay detects clinically relevant CNVs and suggest that it could be used within pediatric cardiology as a first tier screen to detect clinically relevant CNVs and identify syndromic patients at an early stage.

The role of the expected value of individualized care in cost-effectiveness analyses and decision making

OBJECTIVE

To explore the feasibility and potential role of the expected value of individualized care (EVIC) framework.

METHODS

The EVIC quantifies how much benefits are forgone when a treatment decision is based on the best-expected outcomes in the population rather than in the individual patient. We have reviewed which types of patient-level attributes contribute to the EVIC and how they affect the interpretation of the outcomes. In addition, we have applied the EVIC framework to the outcomes of a microsimulation-based cost-effectiveness analysis for glaucoma treatment.

RESULTS

For EVIC outcomes to inform decisions about clinical practice, we need to calculate the parameter-specific EVIC of known or knowable patient-level attributes and compare it with the real costs of implementing individualized care. In the case study, the total EVIC was €580 per patient, but patient-level attributes known at treatment decision had minimal impact. A subgroup policy based on individual disease progression could be worthwhile if a predictive test for glaucoma progression could be developed and implemented for less than €130 per patient.

CONCLUSIONS

The EVIC framework is feasible in cost-effectiveness analyses and can be informative for decision making. The EVIC outcomes are particularly informative when they are (close to) zero. When the EVIC has a high value, implications depend on the type of patient-level attribute. EVIC can be a useful tool to identify opportunities to improve efficiency in health care by individualization of care and to quantify the maximal investment opportunities for implementing subgroup policy.

The impact of HIV/HCV co-infection on health care utilization and disability: results of the ACTG Longitudinal Linked Randomized Trials (ALLRT) Cohort

HIV/hepatitis C virus (HCV) co-infection places a growing burden on the HIV/AIDS care delivery system. Evidence-based estimates of health services utilization among HIV/HCV co-infected patients can inform efficient planning. We analyzed data from the ACTG Longitudinal Linked Randomized Trials (ALLRT) cohort to estimate resource utilization and disability among HIV/HCV co-infected patients and compare them to rates seen in HIV mono-infected patients. The analysis included HIV-infected subjects enrolled in the ALLRT cohort between 2000 and 2007 who had at least one CD4 count measured and completed at least one resource utilization data collection form (N = 3143). Primary outcomes included the relative risk of hospital nights, emergency department (ED) visits, and disability days for HIV/HCV co-infected vs HIV mono-infected subjects. When controlling for age, sex, race, history of AIDS-defining events, current CD4 count and current HIV RNA, the relative risk of hospitalization, ED visits, and disability days for subjects with HIV/HCV co-infection compared to those with HIV mono-infection were 1.8 (95% CI: 1.3-2.5), 1.7 (95% CI: 1.4-2.1), and 1.6 (95% CI: 1.3-1.9) respectively. Programs serving HIV/HCV co-infected patients can expect approximately 70% higher rates of utilization than expected from a similar cohort of HIV mono-infected patients.

Germline CDH1 deletions in hereditary diffuse gastric cancer families

Germline CDH1 point or small frameshift mutations can be identified in 30-50% of hereditary diffuse gastric cancer (HDGC) families. We hypothesized that CDH1 genomic rearrangements would be found in HDGC and identified 160 families with either two gastric cancers in first-degree relatives and with at least one diffuse gastric cancer (DGC) diagnosed before age 50, or three or more DGC in close relatives diagnosed at any age. Sixty-seven carried germline CDH1 point or small frameshift mutations. We screened germline DNA from the 93 mutation negative probands for large genomic rearrangements by Multiplex Ligation-Dependent Probe Amplification. Potential deletions were validated by RT-PCR and breakpoints cloned using a combination of oligo-CGH-arrays and long-range-PCR. In-silico analysis of the CDH1 locus was used to determine a potential mechanism for these rearrangements. Six of 93 (6.5%) previously described mutation negative HDGC probands, from low GC incidence populations (UK and North America), carried genomic deletions (UK and North America). Two families carried an identical deletion spanning 193 593 bp, encompassing the full CDH3 sequence and CDH1 exons 1 and 2. Other deletions affecting exons 1, 2, 15 and/or 16 were identified. The statistically significant over-representation of Alus around breakpoints indicates it as a likely mechanism for these deletions. When all mutations and deletions are considered, the overall frequency of CDH1 alterations in HDGC is approximately 46% (73/160). CDH1 large deletions occur in 4% of HDGC families by mechanisms involving mainly non-allelic homologous recombination in Alu repeat sequences. As the finding of pathogenic CDH1 mutations is useful for management of HDGC families, screening for deletions should be offered to at-risk families.

MLPAnalyzer: data analysis tool for reliable automated normalization of MLPA fragment data

Background: Multiplex Ligation dependent Probe Amplification (MLPA) is a rapid, simple, reliable and customized method for detection of copy number changes of individual genes at a high resolution and allows for high throughput analysis. This technique is typically applied for studying specific genes in large sample series. The large amount of data, dissimilarities in PCR efficiency among the different probe amplification products, and sample-to-sample variation pose a challenge to data analysis and interpretation. We therefore set out to develop an MLPA data analysis strategy and tool that is simple to use, while still taking into account the above-mentioned sources of variation.

Materials and Methods: MLPAnalyzer was developed in Visual Basic for Applications, and can accept a large number of file formats directly from capillary sequence systems. Sizes of all MLPA probe signals are determined and filtered, quality control steps are performed, and variation in peak intensity related to size is corrected for. DNA copy number ratios of test samples are computed, displayed in a table view and a set of comprehensive figures is generated. To validate this approach, MLPA reactions were performed using a dedicated MLPA mix on 6 different colorectal cancer cell lines. The generated data were normalized using our program and results were compared to previously performed array-CGH results using both statistical methods and visual examination.

Results and Discussion: Visual examination of bar graphs and direct ratios for both techniques showed very similar results, while the average Pearson moment correlation over all MLPA probes was found to be 0.42. Our results thus show that automated MLPA data processing following our suggested strategy may be of significant use, especially when handling large MLPA data sets, when samples are of different quality, or interpretation of MLPA electropherograms is too complex. It remains, however, important to recognize that automated MLPA data processing may only be successful when a dedicated experimental setup is also considered.

MLPA for prenatal diagnosis of commonly occurring aneuploidies

Multiplex ligation-dependent probe amplification (MLPA) is a new method to determine the copy number of up to 45 genomic DNA sequences in a single multiplex polymerase chain reaction (PCR)-based reaction. In contrast to standard multiplex PCR, only one pair of PCR primers is used. MLPA reactions with currently commercial available kits result in very reproducible gel patterns with fragments of 130 to 480 bp that can be analyzed by sequence type electrophoresis. Comparison of this gel pattern to that obtained from a control sample indicates which sequences show an aberrant copy number.

Serotonin transporter polymorphisms and the occurrence of adverse events during treatment with selective serotonin reuptake inhibitors

During treatment with selective serotonin reuptake inhibitors, some patients experience adverse events whereas others do not. Assessment of predictors for selective serotonin reuptake inhibitors-induced adverse events would be useful for the identification of patients likely to develop these events. This study evaluates the association between adverse events during selective serotonin reuptake inhibitor treatment and two polymorphisms in the serotonin transporter (5-HTTLPR and STin2) gene. We included 214 patients meeting Diagnostic and statistical manual of mental disorder-IV criteria for major depression and using an selective serotonin reuptake inhibitor for at least 6 weeks. Blood samples or buccal swabs were taken to determine 5-HTTLPR and STin2 genotype. Information on adverse events was gathered through interviews and general practitioners' files. The association between serotonin transporter genotype and adverse events was assessed by use of logistic regression. Patients with the 5-HTTLPR s/s or s/l genotype appeared to have an increased risk of adverse events, especially general adverse events (dermatologic reactions, weight change and fatigue); odds ratio 1.77 (95% confidence interval 0.80-3.92) for the s/s genotype, odds ratio 2.37 (95% confidence interval 1.13-4.96) for the s/l genotype. For STin2, results were inconsistent and observed associations were weak and statistically nonsignificant. Our findings indicate that patients with the 5-HTTLPR s/s or s/l genotype have an increased risk of developing adverse events during selective serotonin reuptake inhibitor treatment.

Treatment of cirrhotic ascites

Cirrhosis is the most common cause of ascites and accounts for almost 85% of all cases. It is the most common complication of cirrhosis, after development of ascites only 50% of patients will survive for 2 to 5 years. Successful treatment is dependent on accurate diagnosis of the cause of ascites. Because sodium and water retention is the basic abnormality leading to ascites formation, restriction of sodium intake and enhancing sodium excretion is the mainstay of the treatment of ascites. Patients with cirrhosis and ascites must limit sodium intake to 2 gram per day. Enhancement of sodium excretion can be accomplished by usage of oral diuretics. The recommended initial dose is spironolactone 100-200 mg/d and furosemide 20-40 mg/d. usual maximum doses are 400 mg/d of spironolactone and 160 mg/d of furosemide. The recommended weight loss in patients without peripheral edema is 300 to 500 g/d. There is no limit to the daily weight loss of patients who have edema. About 90% of patients respond well to medical therapy for ascites. Refractory ascites is defined as fluid overload that is unresponsive to sodium restricted diet and high dose diuretic treatment (diuretic resistant) or when there is an inability to reach maximal dose of diuretics because of adverse effects (diuretic-intractable). It has a poor prognosis. Treatment options for patients with refractory ascites are serial therapeutic paracentesis, transjugular intrahepatic stent-shunt (TIPS) or peritoneovenous shunt and liver transplantation. TIPS should be considered in patients who repeatedly fail large-volume paracentesis and have relatively preserved liver functions. Liver transplantation is the only modality that is associated with improved survival.

Clinical indicators: development and applications

Clinical indicators give an indication of the quality of the patient care delivered. They must comply with highquality standards and should be constructed in a careful and transparent manner. Indicators must be relevant to the important aspects of quality of care. There should be adequate research evidence that the recommendations from which they are derived are related to clinical effectiveness, safety and efficiency. They should measure the quality in a valid and reliable manner with little inter- and intra-observer variability so that they are suitable for comparisons between professionals, practices, and institutions. Indicators are selected from research data with consideration for optimal patient care (preferably an evidence-based guideline), supplemented by expert opinion. In the selection procedure, the feasibility, such as their measurability and improvability, is important beside validity and reliability. A clinical indicator should be defined exactly and expressed as a quotient. After a try-out, the measurements and reporting should follow. The report contains an in-depth analysis of causal and contributing factors associated with the measured results. A description of the clinical circumstances and a correction for case mix should be included to allow for a justified interpretation. The indicators must be part of an improvement strategy, for which comparison feedback is often used. We give examples of indicator development and applications in oncology, diabetes care, and the use of antibiotics for treating pneumonia. We explain how comparison with reference data can be used to construct improvement programmes.

Determinants of poor adherence in hypertensive patients: development and validation of the "Maastricht Utrecht Adherence in Hypertension (MUAH)-questionnaire"

OBJECTIVES

(1) To help identify patients with poor adherence and (2) to identify potential reasons that impede or facilitate adherence.

METHODS

Seventeen patients who used antihypertensive drugs participated in semi-standardized interviews. Interviews were recorded and reviewed by two investigators. Forty-four items were selected. An exploratory factor analysis was performed. Convergent validity was assessed by evaluating the association between sum scores on the identified subscales and three other adherence measures: (1) the Brief Medication Questionnaire (BMQ), (2) pharmacy refill records and (3) electronic monitoring. Regression analysis was used to evaluate the magnitude of associations.

RESULTS

Two hundred and fifty-five (90%) patients completed the questionnaire. Factor analysis resulted in a four-factor solution, explaining 30% of cumulative variance among respondents. The factors (scales) were labeled: positive attitude towards health care and medication (I), lack of discipline (II), aversion towards medication (III) and active coping with health problems (IV). Chronbach's alpha coefficient was 0.75, 0.80, 0.63 and 0.76 for scales I, II, III and IV, respectively. Convergent validity was partly supported by statistically significant associations that were found between sum scores of subscales 1 and II and the BMQ and electronic monitoring, respectively.

CONCLUSION

The MUAH-questionnaire has excellent psychometric properties and may be useful to identify factors that impede or facilitate adherence. However, it is not clear to what extent the questionnaire measures actual adherence.

PRACTICE IMPLICATIONS

Validation of the MUAH-questionnaire in other studies is needed.

A new molecular mechanism for severe myoclonic epilepsy of infancy: Exonic deletions in SCN1A

We examined cases of severe myoclonic epilepsy of infancy (SMEI) for exon deletions or duplications within the sodium channel SCN1A gene by multiplex ligation-dependent probe amplification. Two of 13 patients (15%) who fulfilled the strict clinical definition of SMEI but without SCN1A coding or splicing mutations had exonic deletions of SCN1A.