Synthetic surfactants with SP-B and SP-C analogues to enable worldwide treatment of neonatal respiratory distress syndrome and other lung diseases

Treatment of neonatal respiratory distress syndrome (RDS) using animal-derived lung surfactant preparations has reduced the mortality of handling premature infants with RDS to a 50th of that in the 1960s. The supply of animal-derived lung surfactants is limited and only a part of the preterm babies is treated. Thus, there is a need to develop well-defined synthetic replicas based on key components of natural surfactant. A synthetic product that equals natural-derived surfactants would enable cost-efficient production and could also facilitate the development of the treatments of other lung diseases than neonatal RDS. Recently the first synthetic surfactant that contains analogues of the two hydrophobic surfactant proteins B (SP-B) and SP-C entered clinical trials for the treatment of neonatal RDS. The development of functional synthetic analogues of SP-B and SP-C, however, is considerably more challenging than anticipated 30 years ago when the first structural information of the native proteins became available. For SP-B, a complex three-dimensional dimeric structure stabilized by several disulphides has necessitated the design of miniaturized analogues. The main challenge for SP-C has been the pronounced amyloid aggregation propensity of its transmembrane region. The development of a functional non-aggregating SP-C analogue that can be produced synthetically was achieved by designing the amyloidogenic native sequence so that it spontaneously forms a stable transmembrane α-helix.

Brain β-Amyloid and Atrophy in Individuals at Increased Risk of Cognitive Decline

BACKGROUND AND PURPOSE

The relationship between brain β-amyloid and regional atrophy is still incompletely understood in elderly individuals at risk of dementia. Here, we studied the associations between brain β-amyloid load and regional GM and WM volumes in older adults who were clinically evaluated as being at increased risk of cognitive decline based on cardiovascular risk factors.

MATERIALS AND METHODS

Forty subjects (63-81 years of age) were recruited as part of a larger study, the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability. Neuroimaging consisted of PET using ¹¹C Pittsburgh compound-B and T1-weighted 3D MR imaging for the measurement of brain β-amyloid and GM and WM volumes, respectively. All subjects underwent clinical, genetic, and neuropsychological evaluations for the assessment of cognitive function and the identification of cardiovascular risk factors.

RESULTS

Sixteen subjects were visually evaluated as showing cortical β-amyloid (positive for β-amyloid). In the voxel-by-voxel analyses, no significant differences were found in GM and WM volumes between the samples positive and negative for β-amyloid. However, in the sample positive for β-amyloid, increases in ¹¹C Pittsburgh compound-B uptake were associated with reductions in GM volume in the left prefrontal (P = .02) and right temporal lobes (P = .04).

CONCLUSIONS

Our results show a significant association between increases in brain β-amyloid and reductions in regional GM volume in individuals at increased risk of cognitive decline. This evidence is consistent with a model in which increases in β-amyloid incite neurodegeneration in memory systems before cognitive impairment manifests.

Automation Expectation Mismatch: Incorrect Prediction Despite Eyes on Threat and Hands on Wheel

OBJECTIVE

The aim of this study was to understand how to secure driver supervision engagement and conflict intervention performance while using highly reliable (but not perfect) automation.

BACKGROUND

Securing driver engagement-by mitigating irony of automation (i.e., the better the automation, the less attention drivers will pay to traffic and the system, and the less capable they will be to resume control) and by communicating system limitations to avoid mental model misconceptions-is a major challenge in the human factors literature.

METHOD

One hundred six drivers participated in three test-track experiments in which we studied driver intervention response to conflicts after driving highly reliable but supervised automation. After 30 min, a conflict occurred wherein the lead vehicle cut out of lane to reveal a conflict object in the form of either a stationary car or a garbage bag.

RESULTS

Supervision reminders effectively maintained drivers' eyes on path and hands on wheel. However, neither these reminders nor explicit instructions on system limitations and supervision responsibilities prevented 28% (21/76) of drivers from crashing with their eyes on the conflict object (car or bag).

CONCLUSION

The results uncover the important role of expectation mismatches, showing that a key component of driver engagement is cognitive (understanding the need for action), rather than purely visual (looking at the threat), or having hands on wheel.

APPLICATION

Automation needs to be designed either so that it does not rely on the driver or so that the driver unmistakably understands that it is an assistance system that needs an active driver to lead and share control.

CXADR-Mediated Formation of an AKT Inhibitory Signalosome at Tight Junctions Controls Epithelial-Mesenchymal Plasticity in Breast Cancer

Tight junctions (TJ) act as hubs for intracellular signaling pathways controlling epithelial cell fate and function. Deregulation of TJ is a hallmark of epithelial-mesenchymal transition (EMT), which contributes to carcinoma progression and metastasis. However, the signaling mechanisms linking TJ to the induction of EMT are not understood. Here, we identify a TJ-based signalosome, which controls AKT signaling and EMT in breast cancer. The coxsackie and adenovirus receptor (CXADR), a TJ protein with an essential yet uncharacterized role in organogenesis and tissue homeostasis, was identified as a key component of the signalosome. CXADR regulated the stability and function of the phosphatases and AKT inhibitors PTEN and PHLPP2. Loss of CXADR led to hyperactivation of AKT and sensitized cells to TGFβ1-induced EMT. Conversely, restoration of CXADR stabilized PHLPP2 and PTEN, inhibited AKT, and promoted epithelial differentiation. Loss of CXADR in luminal A breast cancer correlated with loss of PHLPP2 and PTEN and poor prognosis. These results show that CXADR promotes the formation of an AKT-inhibitory signalosome at TJ and regulates epithelial-mesenchymal plasticity in breast cancer cells. Moreover, loss of CXADR might be used as a prognostic marker in luminal breast cancer. SIGNIFICANCE: The tight junction protein CXADR controls epithelial-mesenchymal plasticity in breast cancer by stabilizing the AKT regulators PTEN and PHLPP2.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/1/47/F1.large.jpg.

International benchmarking in oesophageal and gastric cancer surgery

Background

Benchmarking on an international level might lead to improved outcomes at a national level. The aim of this study was to compare treatment and surgical outcome data from the Swedish National Register for Oesophageal and Gastric Cancer (NREV) and the Dutch Upper Gastrointestinal Cancer Audit (DUCA).

Methods

All patients with primary oesophageal or gastric cancer who underwent a resection and were registered in NREV or DUCA between 2012 and 2014 were included. Differences in 30‐day mortality were analysed using case mix‐adjusted multivariable logistic regression.

Results

In total, 4439 patients underwent oesophagectomy (2509 patients) or gastrectomy (1930 patients). Estimated resection rates were comparable. Swedish patients were older but had less advanced disease and less co‐morbidity than Dutch patients. Neoadjuvant treatment rates were lower in Sweden than in the Netherlands, both for patients who underwent oesophagectomy (68·6 versus 90·0 per cent respectively; P < 0·001) and for those having gastrectomy (38·3 versus 56·6 per cent; P < 0·001). In Sweden, transthoracic oesophagectomy was performed in 94·7 per cent of patients, whereas in the Netherlands, a transhiatal approach was undertaken in 35·8 per cent. Higher annual procedural volumes per hospital were observed in the Netherlands. Adjusted 30‐day and/or in‐hospital mortality after gastrectomy was statistically significantly lower in Sweden than in the Netherlands (odds ratio 0·53, 95 per cent c.i. 0·29 to 0·95).

Conclusion

For oesophageal and gastric cancer, there are differences in patient, tumour and treatment characteristics between Sweden and the Netherlands. Postoperative mortality in patients with gastric cancer was lower in Sweden.

North European comparison of treatment strategy and survival in older patients with resectable gastric cancer: A EURECCA upper gastrointestinal group analysis

BACKGROUND

As older gastric cancer patients are often excluded from randomized clinical trials, the most appropriate treatment strategy for these patients remains unclear. The current study aimed to gain more insight in treatment strategies and relative survival of older patients with resectable gastric cancer across Europe.

METHODS

Population-based cohorts from Belgium, Denmark, The Netherlands, Norway, and Sweden were combined. Patients ≥70 years with resectable gastric cancer (cT1-4a, cN0-2, cM0), diagnosed between 2004 and 2014 were included. Resection rates, administration of chemotherapy (irrespective of surgery), and relative survival within a country according to stage were determined.

RESULTS

Overall, 6698 patients were included. The percentage of operated patients was highest in Belgium and lowest in Sweden for both stage II (74% versus 56%) and stage III disease (57% versus 25%). For stage III, chemotherapy administration was highest in Belgium (44%) and lowest in Sweden (2%). Three year relative survival for stage I, II, and III disease in Belgium was 67.8% (95% CI:62.8-72.6), 41.2% (95% CI:37.3-45.2), 17.8% (95% CI:12.5-24.0), compared with 56.7% (95% CI:51.5-61.7), 31.3% (95% CI:27.6-35.2), 8.2% (95% CI:4.4-13.4) in Sweden. There were no significant differences in treatment strategies of patients with stage I disease.

CONCLUSION

Substantial treatment differences are observed across North European countries for patients with stages II and III resectable gastric cancer aged 70 years or older. In the present comparison, treatment strategies with a higher proportion of patients undergoing surgery seemed to be associated with higher survival rates for patients with stages II or III disease.

Heparin-binding protein in ventilator-induced lung injury

Background

Although mechanical ventilation is often lifesaving, it can also cause injury to the lungs. The lung injury is caused by not only high pressure and mechanical forces but also by inflammatory processes that are not fully understood. Heparin-binding protein (HBP), released by activated granulocytes, has been indicated as a possible mediator of increased vascular permeability in the lung injury associated with trauma and sepsis. We investigated if HBP levels were increased in the bronchoalveolar lavage fluid (BALF) or plasma in a pig model of ventilator-induced lung injury (VILI). We also investigated if HBP was present in BALF from healthy volunteers and in intubated patients in the intensive care unit (ICU).

Methods

Anaesthetized pigs were randomized to receive ventilation with either tidal volumes of 8 ml/kg (controls, n = 6) or 20 ml/kg (VILI group, n = 6). Plasma and BALF samples were taken at 0, 1, 2, 4, and 6 h. In humans, HBP levels in BALF were sampled from 16 healthy volunteers and from 10 intubated patients being cared for in the ICU.

Results

Plasma levels of HBP did not differ between pigs in the control and VILI groups. The median HBP levels in BALF were higher in the VILI group after 6 h of ventilation compared to those in the controls (1144 ng/ml (IQR 359–1636 ng/ml) versus 89 ng/ml (IQR 33–191 ng/ml) ng/ml, respectively, p = 0.02).

The median HBP level in BALF from healthy volunteers was 0.90 ng/ml (IQR 0.79–1.01 ng/ml) as compared to 1959 ng/ml (IQR 612–3306 ng/ml) from intubated ICU patients (p < 0.001).

Conclusions

In a model of VILI in pigs, levels of HBP in BALF increased over time compared to controls, while plasma levels did not differ between the two groups.

HBP in BALF was high in intubated ICU patients in spite of the seemingly non-harmful ventilation, suggesting that inflammation from other causes might increase HBP levels.

Electronic supplementary material

The online version of this article (10.1186/s40635-018-0198-x) contains supplementary material, which is available to authorized users.

Targeting Alzheimer's disease with gene and cell therapies

Alzheimer's disease (AD) causes dementia in both young and old people affecting more than 40 million people worldwide. The two neuropathological hallmarks of the disease, amyloid beta (Aβ) plaques and neurofibrillary tangles consisting of protein tau are considered the major contributors to the disease. However, a more complete picture reveals significant neurodegeneration and decreased cell survival, neuroinflammation, changes in protein and energy homeostasis and alterations in lipid and cholesterol metabolism. In addition, gene and cell therapies for severe neurodegenerative disorders have recently improved technically in terms of safety and efficiency and have translated to the clinic showing encouraging results. Here, we review broadly current data within the field for potential targets that could modify AD through gene and cell therapy strategies. We envision that not only Aβ will be targeted in a disease-modifying treatment strategy but rather that a combination of treatments, possibly at different intervention times may prove beneficial in curing this devastating disease. These include decreased tau pathology, neuronal growth factors to support neurons and modulation of neuroinflammation for an appropriate immune response. Furthermore, cell based therapies may represent potential strategies in the future.

Comparative effects of dexmedetomidine, propofol, sevoflurane, and S-ketamine on regional cerebral glucose metabolism in humans: a positron emission tomography study

INTRODUCTION

The highly selective α₂-agonist dexmedetomidine has become a popular sedative for neurointensive care patients. However, earlier studies have raised concern that dexmedetomidine might reduce cerebral blood flow without a concomitant decrease in metabolism. Here, we compared the effects of dexmedetomidine on the regional cerebral metabolic rate of glucose (CMR_glu) with three commonly used anaesthetic drugs at equi-sedative doses.

METHODS

One hundred and sixty healthy male subjects were randomised to EC₅₀ for verbal command of dexmedetomidine (1.5 ng ml^-1; n=40), propofol (1.7 μg ml^-1; n=40), sevoflurane (0.9% end-tidal; n=40) or S-ketamine (0.75 μg ml^-1; n=20) or placebo (n=20). Anaesthetics were administered using target-controlled infusion or vapouriser with end-tidal monitoring. ¹⁸F-labelled fluorodeoxyglucose was administered 20 min after commencement of anaesthetic administration, and high-resolution positron emission tomography with arterial blood activity samples was used to quantify absolute CMR_glu for whole brain and 15 brain regions.

RESULTS

At the time of [F¹⁸]fluorodeoxyglucose injection, 55% of dexmedetomidine, 45% of propofol, 85% of sevoflurane, 45% of S-ketamine, and 0% of placebo subjects were unresponsive. Whole brain CMR_glu was 63%, 71%, 71%, and 96% of placebo in the dexmedetomidine, propofol, sevoflurane, and S-ketamine groups, respectively (P<0.001 between the groups). The lowest CMR_glu was observed in nearly all brain regions with dexmedetomidine (P<0.05 compared with all other groups). With S-ketamine, CMR_glu did not differ from placebo.

CONCLUSIONS

At equi-sedative doses in humans, potency in reducing CMR_glu was dexmedetomidine>propofol>ketamine=placebo. These findings alleviate concerns for dexmedetomidine-induced vasoconstriction and cerebral ischaemia.

CLINICAL TRIAL REGISTRATION

NCT02624401.

Ventral striatal dopaminergic defect is associated with hallucinations in Parkinson's disease

BACKGROUND AND PURPOSE

Visual hallucinations (VHs) are a common complication of Parkinson's disease (PD). The pathogenesis of VHs in PD is still largely unclear. The aim of this study was to investigate the dopaminergic mechanisms of VHs and specifically whether the degree of striatal dopamine transporter (DAT) function or extrastriatal serotonin transporter (SERT) function can predict the appearance of VHs in patients with PD.

METHODS

Twenty-two PD patients scanned with [¹²³ I]FP-CIT single photon emission computed tomography at an early stage of their disease who later developed VHs were identified and compared with 48 non-hallucinating PD patients. The groups were matched for age, medication, disease duration and motor symptom severity. Clinical follow-up after the scan was a median (range) of 6.9 (3.8-9.6) years. Imaging analyses were performed with both regions-of-interest-based and voxel-based (Statistical Parametric Mapping) methods for the striatal and extrastriatal regions.

RESULTS

The median interval between the scan and the emergence of VHs was 4.8 years. Patients who developed VHs had 18.4% lower DAT binding in the right ventral striatum (P = 0.009), 16.7% lower binding in the left ventral striatum (P = 0.02) and 18.8% lower binding in the right putamen (P = 0.03) compared to patients who did not develop VHs.

CONCLUSIONS

Low striatal DAT function may predispose PD patients to VHs, and the regional distribution of the findings suggests a particular role of the ventral striatum. This is in line with non-PD research that has implicated ventral striatal dysfunction in psychosis.

Heparin-binding protein as a biomarker of acute kidney injury in critical illness

BACKGROUND

There is no biomarker with high sensitivity and specificity for the development of acute kidney injury (AKI) in a mixed intensive care unit (ICU) population. Heparin-binding protein (HBP) is released from granulocytes and causes increased vascular permeability which plays a role in the development of AKI in sepsis and ischemia. The aim of this study was to investigate whether plasma levels of HBP on admission can predict the development of AKI in a mixed ICU population and in the subgroup with sepsis.

METHODS

Longitudinal observational study with plasma HBP levels from 245 patients taken on admission to ICU. Presence and severity of AKI was scored daily for 1 week.

RESULTS

Mean (95% CI) plasma concentrations of log HBP (ng/ml) in the groups developing different stages of AKI were: stage 0 (n = 175), 3.5 (3.4-3.7); stage 1 (n = 33), 3.7 (3.5-4.0), stage 2 (n = 20), 4.4 (3.5-4.8); and stage 3 (n = 17), 4.6 (3.8-5.2). HBP levels were significantly higher in patients developing AKI stage 3 (P < 0.01) compared to AKI stage 0 and 1. The area under the curve (AUC) for HBP to discriminate the group developing AKI stage 2-3 was 0.70 (CI: 0.58-0.82) and in the subgroup with severe sepsis 0.88 (CI: 0.77-0.99).

CONCLUSION

Heparin-binding protein levels on admission to ICU are associated with the development of severe kidney injury. The relationship between HBP and AKI needs to be further validated in larger studies.

iPTF16geu: A multiply imaged, gravitationally lensed type Ia supernova

We report the discovery of a multiply imaged, gravitationally lensed type Ia supernova, iPTF16geu (SN 2016geu), at redshift z = 0.409. This phenomenon was identified because the light from the stellar explosion was magnified more than 50 times by the curvature of space around matter in an intervening galaxy. We used high-spatial-resolution observations to resolve four images of the lensed supernova, approximately 0.3 arc seconds from the center of the foreground galaxy. The observations probe a physical scale of ~1 kiloparsec, smaller than is typical in other studies of extragalactic gravitational lensing. The large magnification and symmetric image configuration imply close alignment between the lines of sight to the supernova and to the lens. The relative magnifications of the four images provide evidence for substructures in the lensing galaxy.

Outcome of neoadjuvant therapies for cancer of the oesophagus or gastro-oesophageal junction based on a national data registry

BACKGROUND

Randomized trials have shown that neoadjuvant treatment improves survival in the curative treatment of oesophageal and gastro-oesophageal junction cancer. Results from population-based observational studies are, however, sparse and ambiguous.

METHODS

This prospective population-based cohort study included all patients who had oesophagectomy for cancer in Sweden, excluding clinical T1 N0, recorded in the National Register for Oesophageal and Gastric Cancer, 2006-2014. Patients were stratified into three groups: surgery alone, neoadjuvant chemotherapy and neoadjuvant chemoradiotherapy.

RESULTS

Neoadjuvant treatment was given to 521 patients (51·1 per cent) and 499 (48·9 per cent) received surgery alone. Neoadjuvant chemotherapy increased the risk of postoperative surgical complications compared with surgery alone (adjusted odds ratio 2·01, 95 per cent c.i. 1·24 to 3·25; P = 0·005). Postoperative mortality was significantly increased after neoadjuvant chemoradiotherapy compared with surgery alone (odds ratio 2·37, 1·06 to 5·29; P = 0·035). Survival improved in patients with squamous cell carcinoma after neoadjuvant chemotherapy, whereas after neoadjuvant chemoradiotherapy survival was significantly improved only in the subgroup with the highest performance status and without known co-morbidity. In adenocarcinoma there was a trend towards improved overall survival after neoadjuvant chemotherapy, but neoadjuvant chemoradiotherapy did not offer a survival benefit. Stratified analysis including only patients with adenocarcinoma in the highest performance category without known co-morbidity showed a strong trend towards improved survival after neoadjuvant chemotherapy compared with surgery alone (adjusted hazard ratio 0·47, 0·21 to 1·04; P = 0·061).

CONCLUSION

For patients with squamous cell carcinoma of the oesophagus or gastro-oesophageal junction, neoadjuvant treatments seemed to increase long-term survival, but also the risk of postoperative morbidity and mortality, compared with surgery alone. Neither neoadjuvant treatment option seemed to improve survival significantly among patients with adenocarcinoma, compared with surgery alone.

Lessons Learnt from the Fukushima Accident-A Swedish Medical Preparedness Perspective

The triple disaster in March 2011 tragically and severely affected the Japanese society, in spite of its well-developed infrastructure and good access to resources. A multitude of Japanese and international reports have since described the chain of events and actions taken in connection with the earthquake, the tsunami and the power plant failure in Fukushima. In order to further evaluate Japanese experiences of the disaster, and to bring home 'lessons-learnt' of relevance for continued emergency preparedness planning, a group from the National Board of Health and Welfare and other Swedish agencies performed an observer visit to Japan in 2012. A report from the group was recently published. Its main conclusions, and implications focusing on a strengthened national medical preparedness for radionuclear events in Sweden (and possibly elsewhere), are presented here.

Optimization of ecg gating in quantitative femoral angiography

Purpose: To determine which phase of the heart cycle would yield the highest reproducibility in measuring atherosclerosis-related variables such as arterial lumen volume and edge roughness.

Material and Methods: 35 patients with hypercholesterolemia underwent select‐ ive femoral angiography, repeated four times at 10-min intervals. The angiographies were performed with ECG-gated exposures. In angiographies 1 and 2 the delay from R-wave maximum to each exposure was 0.1 s, in angiographies 3 and 4 the delay was 0.1, 0.3, 0.5 or 0.7 s or the exposures were performed 1/s without ECG gating. Arterial lumen volume and edge roughness were measured in a 20-cm segment of the superficial femoral artery using a computer-based densitometric method. Measurement reproducibility was determined by comparing angiographies 1–2 and angiographies 3–4.

Results: When measuring arterial lumen volume and edge roughness of a 20-cm segment of the femoral artery, reproducibility was not dependent on ECG gating. In measuring single arterial diameters and cross-sectional areas, the reproducibility was better when exposures were made 0.1 s after the R-wave maximum than when using other settings of the ECG gating device or without ECG gating.

Conclusion: The influence of pulsatile flow upon quantitative measurement in femoral angiograms seems to be the smallest possible in early systole, as can be demonstrated when measuring single diameters and cross-sectional areas. In variables based on integration over longer segments, measurement reproducibility seems to be independent of phase.

Reproducibility of Quantitative Arteriographic Assessment of Atherosclerosis in the Femoral Artery

Results from computer-analysed angiograms in the Probucol Quantitative Regression Swedish Trial (PQRST) were analysed to determine the reproducibility of the method and any drift in the analysing system. The precision index (P(μ)) for 2 angiography series, made at 10 min intervals, of the femoral artery in 276 patients was 10.5 for lumen volume and 21.9 for roughness (edge irregularity). No difference in reproducibility was found between patients with and without symptoms of peripheral atherosclerosis or when looking at the reproducibility over years. A drift of 0.67% per year in the radiographic equipment (but not in the analysis system) was found, confirmed by use of phantoms. Computer-based analysis of femoral atherosclerosis is a reliable method for follow-up trials, giving high reproducibility even if the trial spans over several years and involves different centres. The use of phantoms is essential for checking the method over time.

Arterial Segmental Vasoconstriction in Hypercholesterolaemic Patients

Regular, wave-like constriction in medium-sized arteries, arterial segmental vasoconstriction (ASV), has been observed at arteriography and described by many authors. We found ASV in arteriograms of the superficial femoral artery in 13 of 107 hypercholesterolaemic patients, enrolled in the Probucol Quantitative Regression Swedish Trial (PQRST). The arteriograms were digitized and studied with a quantitative computer-assisted technique. The frequency of ASV was higher than has been reported earlier in clinical materials, possibly because of an increased vasoreactivity in hypercholesterolaemia, as recently observed experimentally. The ASV patients were, on average, younger, had lower blood pressure and less atherosclerosis, than the non-ASV patients. ASV was not found in any of the 19 patients in the material who either had symptoms of peripheral vascular disease or arteriographically verified arterial occlusions. No significant correlations with smoking habits or serum cholesterol levels were found. A computer-based index of ASV and measurement of ASV wavelength are discussed.

S, Walldius G. Allergic reactions at repeat femoral angiography with ioxaglate

Purpose: To study the occurrence of allergy-like reactions at angiography, repeated several times, and, secondly, to evaluate the effect of prophylactic treatment in individuals who had earlier experienced such reactions.

Material and Methods: One hundred and fifty-seven patients with hypercholesterolaemia, participating in the Probucol Quantitative Regression Swedish Trial (PQRST), underwent aortofemoral angiography with ioxaglate (Hexabrix) repeated annually for 3 years. Allergic reactions to the contrast medium were recorded. At the following angiographies, all patients who had earlier experienced such reactions were treated prophylactically with steroids and antihistamine.

Results: Allergic reactions were observed in 35 patients. Twelve reacted only year 0, 3 only year 1, 5 only year 2 and 6 only year 3. Eight patients had at least one reaction also when treated prophylactically. It was significantly ( p&lt;0.05) more common to react at year 0 but not at year 1 than to react at year 1 but not at year 0. At years 1, 2 and 3 the frequency of reactions was significantly greater in the group given prophylactic treatment than in the group without any earlier reaction at all: 8/20 versus 3/137, 4/23 versus 6/134, and 6/29 versus 6/128, respectively.

Conclusion: Some individuals had an increased risk of an allergy-like reaction to the contrast agent. Prophylactic treatment reduced the risk of renewed reactions, but not to the same level as for those without earlier reaction. Nevertheless, individuals who have had earlier reactions can be investigated in the future, with prophylactic treatment.