Analysis of a large cohort of African/Afro-Caribbean patients by cardiac magnetic resonance

Funding Acknowledgements

Type of funding sources: None.

Background

Limited data is available in the literature on Cardiac Magnetic Resonance (CMR) features of African/Afro-Caribbeans, in particular exploring differences between hypertensive heart disease (HHD) and hypertrophic cardiomyopathy (HCM). 

Purpose

To describe the cardiac morphology and pattern of late gadolinium enhancement (LGE) in patients of African/Afro-Caribbean origin. 

Methods

We retrospectively analysed African/Afro-Caribbean patients who underwent clinical CMR at a tertiary centre. Three groups were specifically investigated: HHD, HCM and combination of HHD and HCM or ambiguous (HHD&HCM). 

Results

Overall, 166 consecutive patients (58% male, mean age 55 ± 14yo) were analysed. One-hundred fifty-four (93%) had history of arterial hypertension (HTN), including 17 with uncontrolled/malignant HTN. Overall, 28(17%) had normal scans, 70(42%) HHD, 15(9%) apical HCM, 10(6%) classical septal HCM, 19(11%) dilated cardiomyopathy, 6(4%) cardiac amyloidosis, 3(2%) ischemic heart disease, 4(2%) myocarditis, 2 sarcoidosis and 1 valvular disease. In 7(4%) the diagnosis was ambiguous between HHD and HCM and 1 uncertain. Forty-four (27%) had dual pathology, most frequently HHD, bystander myocardial infarction (MI) and embolic MI. LGE was detected in 95(57%), 26 with ischemic pattern, 13 diffuse mid-wall, 29 focal non-ischemic and 28 diffuse/multifocal non-ischemic. CMR features and correlations between subgroups are reported in the Table. Patients with HHD had significantly higher left ventricular (LV) end-diastolic (ED) volume indexed (Vi) and LV end-systolic (ES) Vi, but lower LV ejection fraction (EF) and LV maximum wall thickness (MWT) compared to HCM patients. HHD&HCM had higher LVEF and MWT compared to HHD and higher LVEDVi compared to HCM. LGE was more frequently seen in HCM and HHD&HCM as focal non-ischemic (6vs5vs10,p = 0.049) and diffuse multifocal(5vs6vs9,p = 0.009). A history of uncontrolled/malignant HTN was more frequent in HHD and HHD&HCM (11vs1vs5,p = 0.025) and was associated with diffuse LGE with lateral wall involvement (p < 0.0001) (Figure). Conclusions: CMR findings in African/Afro-Caribbeans may overlap between aetiologies. A specific pattern of diffuse non-ischaemic LGE involving the lateral wall appears though to be more often associated with severe uncontrolled HTN.

Table HHD(n = 70) HCM(n = 19) HHD&HCM or ambiguous (n = 13) p LVEDVi, ml/m2 88 ± 33 62 ± 11 77 ± 6 0.003 LVESVi, ml/m2 36 ± 26 16 ± 10 26 ± 19 0.002 LVEF, % 62 ± 16 79 ± 6 74 ± 12 0.567 LVMWT, mm 13 ± 2 15 ± 4 14 ± 3 <0.0001 CMR features and correlations between subgroups Abstract Figure

Short- and Long-term Outcome After Interventional VSD Closure: A Single-Center Experience in Pediatric and Adult Patients

Interventional closure of congenital ventricular septal defects (VSD) is recording a continuous rise in acceptance. Complete atrioventricular block (cAVB) and residual shunting are major concerns during follow-up, but long-term data for both are still limited. We retrospectively evaluated the outcome of patients with interventional VSD closure and focused on long-term results (> 1 year follow-up). Transcatheter VSD closures were performed between 1993 and 2015, in 149 patients requiring 155 procedures (104 perimembranous, 29 muscular, 19 residual post-surgical VSDs, and 3 with multiple defects). The following devices were used: 65 × Amplatzer™ Membranous VSD Occluder, 33 × Duct Occluder II, 27 × Muscular VSD Occluder, 3 × Duct Occluder I, 24 × PFM-Nit-Occlud®, and 3 × Rashkind-Occluder. The median age at time of implantation was 6.2 (0.01-66.1) years, median height 117 (49-188) cm, and median weight 20.9 (3.2-117) kg. Median follow-up time was 6.2 (1.1-21.3) years and closure rate was 86.2% at last follow-up. Complications resulting in device explantation include one case of cAVB with a Membranous VSD occluder 7 days after implantation and four cases due to residual shunt/malposition. Six (4%) deaths occurred during follow-up with only one procedural related death from a hybrid VSD closure. Overall, our reported results of interventional VSD closure show favorable outcomes with only one (0.7%) episode of cAVB. Interventional closure offers a good alternative to surgical closure and shows improved performance by using softer devices. However, prospective long-term data in the current era with different devices are still mandatory to assess the effectiveness and safety of this procedure.

Is mapping the BCG vaccine-induced immune responses the key to improving the efficacy against tuberculosis?

In recent years, the century-old Mycobacterium bovis Bacillus Calmette-Guérin (BCG) vaccine against tuberculosis (TB) has been re-evaluated for its capacity to stem the global tide of TB. There is increasing evidence that the efficacy of BCG can be improved by the modified administration methods and schedules. Here, we first discuss recent approaches of vaccine administration, revaccination or boosting that have been used to try to improve the efficacy of BCG against TB. We then dive deeper into studies investigating the immune correlates of protection and describe studies that have investigated BCG-specific T-cell responses and the influence of environmental exposures. These studies all highlight that there is still a lot to learn about the immune response induced by BCG, both in terms of phenotype and specificity, which has been surprisingly understudied. We argue that several critical gaps in knowledge exist and must be addressed by future research to rationally improve the efficacy of BCG, including comprehensive, proteome-wide understanding of the epitopes derived from BCG recognized by BCG-vaccinated individuals, the phenotype of responding antigen-specific T cells and how previous exposure to environmental mycobacteria affect these parameters and thus influence vaccine efficacy. The development of modern techniques allows us to answer some of these questions to better understand how BCG works in terms of both protection against TB and the immune response that it triggers.

[A boy with white sponge naevus of the buccal mucosa]

White sponge naevus (WSN) is a rare, autosomal dominant disorder that causes various complaints WSN is most commonly found on the buccal mucosa. Clinically, the white, slightly elevated lesions of WSN may be confused with other disorders on oral mucosa. We report a case of WSN in a 14-year-old boy who had complaints for a considerable period of time. WSN is caused by mutations in KRT4 and KRT13.

Female patients are less satisfied with biological treatment for psoriasis and experience more side-effects than male patients: results from the prospective BioCAPTURE registry

BACKGROUND

Female sex has been reported as a predictor for treatment discontinuation with biological therapies for psoriasis, although reasons remain unclear. It can be hypothesized that lower satisfaction with biological treatment in women might add to the lower drug survival rates.

OBJECTIVES

To identify possible differences in satisfaction with biological treatment between female and male patients using the Treatment Satisfaction Questionnaire for Medication (TSQM).

METHODS

Data of psoriasis patients treated with biologics were obtained from the prospective, multicentre, daily-practice BioCAPTURE registry. Longitudinal TSQM data were analysed by linear mixed models. Relevant patient characteristics were incorporated as possible confounding factors. Post hoc analysis of adverse events was performed in order to investigate differences between sexes.

RESULTS

We included 315 patients with 396 corresponding treatment episodes (137 adalimumab, 90 etanercept, 137 ustekinumab, 24 secukinumab and 8 infliximab). Almost forty per cent of the patients were female. Women had significantly lower baseline PASI scores (P = 0.01). Longitudinal analyses demonstrated lower TSQM scores for 'side-effects' (P = 0.05) and 'global satisfaction' (P = 0.01) in female patients compared with male patients over 1 year of treatment. Women reported more relevant adverse events in the context of biologic treatment compared to men (rate ratio 1.79; P < 0.001), with more fungal (rate ratio 2.20; P = 0.001) and herpes simplex infections (rate ratio 3.25; P = 0.005).

CONCLUSIONS

This study provides a prospective, longitudinal analysis of treatment satisfaction with biologics in female and male patients with psoriasis. Women were slightly less satisfied with treatment regarding side-effects and global satisfaction. Differences in treatment satisfaction and side-effects might add to the fact that women discontinue biological treatments more often.

HIV: ageing, cognition and neuroimaging at 4-year follow-up

OBJECTIVES

The aim of the study was to investigate the hypothesis of accelerated cognitive ageing in HIV-positive individuals using longitudinal assessment of cognitive performance and quantitative magnetic resonance imaging (MRI).

METHODS

We assessed a broad cognitive battery and quantitative MRI metrics [voxel-based morphometry (VBM) and diffusion tensor imaging (DTI)] in asymptomatic HIV-positive men who have sex with men (15 aged 20-40 years and 15 aged ≥ 50 years), and HIV-seronegative matched controls (nine aged 20-40 years and 16 aged ≥ 50 years).

RESULTS

Being HIV positive was associated with greater decreases in executive function and global cognition. Additionally, using DTI, we found that the HIV-positive group had a greater increase in mean diffusivity, but we did not find group differences in volume change using VBM. With respect to the HIV status by age group interaction, this was statistically significant for change in global cognition, with older HIV-positive individuals showing greater global cognitive decline, but there were no significant interaction effects on other measures. Lastly, change in cognitive performance was correlated with change in the DTI measures, and this effect was stronger for the HIV-positive participants.

CONCLUSIONS

In the present study, we found some evidence for accelerated ageing in HIV-positive individuals, with a statistically significant HIV status by age group interaction in global cognition, although this interaction could not be explained by the imaging findings. Moreover, we also found that change in cognitive performance was correlated with change in the DTI measures, and this effect was stronger for the HIV-positive participants. This will need replication in larger studies using a similarly lengthy follow-up period.

Lack of allergy to timothy grass pollen is not a passive phenomenon but associated with the allergen-specific modulation of immune reactivity

BACKGROUND

Timothy grass (TG) pollen is a common seasonal airborne allergen associated with symptoms ranging from mild rhinitis to severe asthma.

OBJECTIVE

The aim of this study was to characterize changes in TG-specific T cell responses as a function of seasonality.

METHODS

Peripheral blood mononuclear cells (PBMCs) obtained from allergic individuals and non-allergic controls, either during the pollen season or out of season, were stimulated with either TG extract or a pool of previously identified immunodominant antigenic regions.

RESULTS

PBMCs from allergic subjects exhibit higher IL-5 and IL-10 responses in season than when collected out of season. In the case of non-allergic subjects, as expected we observed lower IL-5 responses and robust production of IFN-γ compared to allergic individuals. Strikingly, non-allergic donors exhibited an opposing pattern, with decreased immune reactivity in season. The broad down-regulation in non-allergic donors indicates that healthy individuals are not oblivious to allergen exposure, but rather react with an active modulation of responses following the antigenic stimulus provided during the pollen season. Transcriptomic analysis of allergen-specific T cells defined genes modulated in concomitance with the allergen exposure and inhibition of responses in non-allergic donors.

CONCLUSION AND CLINICAL RELEVANCE

Magnitude and functionality of T helper cell responses differ substantially in season vs. out of season in allergic and non-allergic subjects. The results indicate the specific and opposing modulation of immune responses following the antigenic stimulation during the pollen season. This seasonal modulation reflects the enactment of specific molecular programmes associated with health and allergic disease.

A flagellum-specific chaperone facilitates assembly of the core type III export apparatus of the bacterial flagellum

Many bacteria move using a complex, self-assembling nanomachine, the bacterial flagellum. Biosynthesis of the flagellum depends on a flagellar-specific type III secretion system (T3SS), a protein export machine homologous to the export machinery of the virulence-associated injectisome. Six cytoplasmic (FliH/I/J/G/M/N) and seven integral-membrane proteins (FlhA/B FliF/O/P/Q/R) form the flagellar basal body and are involved in the transport of flagellar building blocks across the inner membrane in a proton motive force-dependent manner. However, how the large, multi-component transmembrane export gate complex assembles in a coordinated manner remains enigmatic. Specific for most flagellar T3SSs is the presence of FliO, a small bitopic membrane protein with a large cytoplasmic domain. The function of FliO is unknown, but homologs of FliO are found in >80% of all flagellated bacteria. Here, we demonstrate that FliO protects FliP from proteolytic degradation and promotes the formation of a stable FliP–FliR complex required for the assembly of a functional core export apparatus. We further reveal the subcellular localization of FliO by super-resolution microscopy and show that FliO is not part of the assembled flagellar basal body. In summary, our results suggest that FliO functions as a novel, flagellar T3SS-specific chaperone, which facilitates quality control and productive assembly of the core T3SS export machinery.

Many bacteria use the bacterial flagellum for directed movement in various environments. The assembly and function of the bacterial flagellum and the related virulence-associated injectisome relies on protein export via a conserved type III secretion system (T3SS). The multicomponent transmembrane core export apparatus of the flagellar T3SS consists of FlhA/B and FliP/Q/R and must assemble in a highly coordinated manner. In the present study, we determined the role of the transmembrane protein FliO in the maturation of the flagellar core protein export apparatus. We show that FliO functions as a flagellum-specific chaperone during the initial step of export apparatus assembly. FliO facilitates the efficient formation of a stable FliP–FliR core complex and is thus required for quality management and productive assembly of the flagellar export apparatus. Our results suggest a coordinated assembly process of the flagellar core export apparatus that nucleates with the FliO-dependent formation of a FliP–FliR complex. Subsequent incorporation of FliQ, FlhB, and FlhA leads to the assembly of a secretion-competent flagellar T3SS.

Autonomic cardiac regulation, blood pressure and cardiorespiratory fitness responses to different training doses over a 12 week group program in the elderly

AIM

The study assessed the effects of different weekly training frequencies performed over a 12 week exercise programme (strength, endurance, balance) on autonomic cardiac activity, blood pressure and cardiorespiratory fitness (CRF) in elderly individuals.

METHODS

Fifty-eight individuals participated in the study: 2TG (N=24, 71.1±6.4 yrs; 19 females, 5 males) performing two, 60min sessions/week; and 3TG (N=34, 72.3±7.9 yrs; 25 females, 9 males) performing three, 60min sessions/week. Time domain and spectral analysis of heart rate variability (HRV) quantified autonomic cardiac regulation.

RESULTS

Natural logarithm (Ln) transformation was applied to all HRV parameters. There were significant reductions in total power (Ln TP) (p=0.006), low frequency (Ln LF) (p=0.013), high frequency (Ln HF) (p=0.013) and root mean square of successive differences (Ln rMSSD) (p=0.014) post training in 3TG after intervention. Diastolic BP (DBP) decreased significantly in both groups (2TG: P<0.001; 3TG: P<0.001). Both groups showed significant improvements in six-minute walk distance (2TG: P=0.003, 3TG: P=0.001). However, there were significant HRV differences between 2TG and 3TG for Ln TP (P=0.018), Ln LF (P=0.049), Ln HF (P=0.039) and Ln rMSSD (P=0.049).

CONCLUSIONS

A combined exercise programme resulted in improved DBP and CRF irrespective of training two or three 60min sessions/week. However, training three, sessions/week induced negative health-related changes in autonomic cardiac activity through reducing HRV parasympathetic function, while HRV was maintained in the group training twice a week.

Distinct modulation of allergic T cell responses by subcutaneous vs. sublingual allergen-specific immunotherapy

BACKGROUND

Allergen-specific immunotherapy is the only curative treatment for type I allergy. It can be administered subcutaneously (SCIT) or sublingually (SLIT). The clinical efficacy of these two treatment modalities appears to be similar, but potential differences in the immunological mechanisms involved have not been fully explored.

OBJECTIVE

To compare changes in the allergen-specific T cell response induced by subcutaneous vs. sublingual administration of allergen-specific immunotherapy (AIT).

METHODS

Grass pollen-allergic patients were randomized into groups receiving either SCIT injections or SLIT tablets or neither. PBMCs were tested for Timothy grass (TG)-specific cytokine production by ELISPOT after in vitro expansion with TG-peptide pools. Phenotypic characterization of cytokine-producing cells was performed by FACS.

RESULTS

In the SCIT group, decreased IL-5 production was observed starting 10 months after treatment commenced. At 24 months, T cell responses showed IL-5 levels significantly below the before-treatment baseline. No significant reduction of IL-5 was observed in the SLIT or untreated group. However, a significant transient increase in IL-10 production after 10 months of treatment compared to baseline was detected in both treatment groups. FACS analysis revealed that IL-10 production was associated with CD4(+) T cells that also produced IFNγ and therefore may be associated with an IL-10-secreting type 1 cell phenotype.

CONCLUSION AND CLINICAL RELEVANCE

The most dominant immunological changes on a cellular level were a decrease in IL-5 in the SCIT group and a significant, transient increase of IL-10 observed after 10 months of treatment in both treated groups. The distinct routes of AIT administration may induce different immunomodulatory mechanisms at the cellular level.

Investigation of hydrogen induced fluorescence in C60 and its potential use in luminescence down shifting applications

Herein the photophysical properties of hydrogenated fullerenes (fulleranes) synthesized by direct hydrogenation utilizing hydrogen pressure (100 bar) and elevated temperatures (350 °C) are compared to the fulleranes C₆₀H₁₈ and C₆₀H₃₆ synthesized by amine reduction and the Birch reduction, respectively. Through spectroscopic measurements and density functional theory (DFT) calculations of the HOMO-LUMO gaps of C₆₀H_x (0 ≤ x ≤ 60), we show that hydrogenation significantly affects the electronic structure of C₆₀ by decreasing conjugation and increasing sp³ hybridization. This results in a blue shift of the emission maximum as the number of hydrogen atoms attached to C₆₀ increases. Correlations in the emission spectra of C₆₀H_x produced by direct hydrogenation and by chemical methods also support the hypothesis of the formation of C₆₀H₁₈ and C₆₀H₃₆ during direct hydrogenation with emission maxima of 435 and 550 nm respectively. We also demonstrate that photophysical tunability, stability, and solubility of C₆₀H_x in a variety of organic solvents make them easily adaptable for application as luminescent down-shifters in heads-up displays, light-emitting diodes, and luminescent solar concentrators. The utilizization of carbon based materials in these applications can potentially offer advantages over commonly utilized transition metal based quantum dot chromophores. We therefore propose that the controlled modification of C₆₀ provides an excellent platform for evaluating how individual chemical and structural changes affect the photophysical properties of a well-defined carbon nanostructure.

Large-scale monitoring of effects of clothianidin-dressed oilseed rape seeds on pollinating insects in Northern Germany: effects on red mason bees (Osmia bicornis)

The aim of this study was to investigate the effects of Elado® (10 g clothianidin & 2 g beta-cyfluthrin/kg seed)-dressed oilseed rape on the development and reproduction of mason bees (Osmia bicornis) as part of a large-scale monitoring field study in Northern Germany, where oilseed rape is usually cultivated at 25-33 % of the arable land. Both reference and test sites comprised 65 km2 in which no other crops attractive to pollinating insects were present. Six study locations were selected per site and three nesting shelters were placed at each location. Of these locations, three locations were directly adjacent to oilseed rape fields, while the other three locations were situated 100 m distant from the nearest oilseed rape field. At each location, 1500 cocoons of O. bicornis were placed into the central nesting shelter. During the exposure phase, nest building activities and foraging behaviour were assessed repeatedly. Cocoons were harvested in autumn to assess parasitization and reproduction including larval development. The following spring, the emergence of the next generation of adults from cocoons was monitored. High reproductive output and low parasitization rates indicated that Elado®-dressed oilseed rape did not cause any detrimental effects on the development or reproduction of mason bees.

Large-scale monitoring of effects of clothianidin-dressed OSR seeds on pollinating insects in Northern Germany: effects on large earth bumble bees (Bombus terrestris)

The aim of this study was to investigate the effects of Elado®-dressed winter oilseed rape (OSR, 10 g clothianidin & 2 g beta-cyfluthrin/kg seed) on the development, reproduction and behaviour of large earth bumble bees (Bombus terrestris) as part of a large-scale monitoring field study in Northern Germany, where OSR is usually cultivated at 25-33 % of the arable land. Both reference and test sites comprised 65 km2 in which no other crops attractive to pollinating insects were present. Six study locations were selected per site and 10 bumble bee hives were placed at each location. At each site, three locations were directly adjacent to OSR fields and three locations were situated 400 m distant from the nearest OSR field. The development of colonies was monitored from the beginning of OSR flowering in April until June 2014. Pollen from returning foragers was analysed for its composition. An average of 44 % of OSR pollen was found in pollen loads of bumble bees indicating that OSR was a major resource for the colonies. At the end of OSR flowering, hives were transferred to a nature reserve until the end of the study. Colony development in terms of hive weight and the number of workers showed a typical course with no statistically significant differences between the sites. Reproductive output was comparatively high and not negatively affected by the exposure to treated OSR. In summary, Elado®-dressed OSR did not cause any detrimental effects on the development or reproduction of bumble bee colonies.

Large-scale monitoring of effects of clothianidin-dressed oilseed rape seeds on pollinating insects in northern Germany: residues of clothianidin in pollen, nectar and honey

This study was part of a large-scale monitoring project to assess the possible effects of Elado^® (10 g clothianidin & 2 g β-cyfluthrin/kg seed)-dressed oilseed rape seeds on different pollinators in Northern Germany. Firstly, residues of clothianidin and its active metabolites thiazolylnitroguanidine and thiazolylmethylurea were measured in nectar and pollen from Elado^®-dressed (test site, T) and undressed (reference site, R) oilseed rape collected by honey bees confined within tunnel tents. Clothianidin and its metabolites could not be detected or quantified in samples from R fields. Clothianidin concentrations in samples from T fields were 1.3 ± 0.9 μg/kg and 1.7 ± 0.9 μg/kg in nectar and pollen, respectively. Secondly, pollen and nectar for residue analyses were sampled from free flying honey bees, bumble bees and mason bees, placed at six study locations each in the R and T sites at the start of oilseed rape flowering. Honey samples were analysed from all honey bee colonies at the end of oilseed rape flowering. Neither clothianidin nor its metabolites were detectable or quantifiable in R site samples. Clothianidin concentrations in samples from the T site were below the limit of quantification (LOQ, 1.0 µg/kg) in most pollen and nectar samples collected by bees and 1.4 ± 0.5 µg/kg in honey taken from honey bee colonies. In summary, the study provides reliable semi-field and field data of clothianidin residues in nectar and pollen collected by different bee species in oilseed rape fields under common agricultural conditions.

Sequence conservation predicts T cell reactivity against ragweed allergens

BACKGROUND

Ragweed is a major cause of seasonal allergy, affecting millions of people worldwide. Several allergens have been defined based on IgE reactivity, but their relative immunogenicity in terms of T cell responses has not been studied.

OBJECTIVE

We comprehensively characterized T cell responses from atopic, ragweed-allergic subjects to Amb a 1, Amb a 3, Amb a 4, Amb a 5, Amb a 6, Amb a 8, Amb a 9, Amb a 10, Amb a 11, and Amb p 5 and examined their correlation with serological reactivity and sequence conservation in other allergens.

METHODS

Peripheral blood mononuclear cells (PBMCs) from donors positive for IgE towards ragweed extracts after in vitro expansion for secretion of IL-5 (a representative Th2 cytokine) and IFN-γ (Th1) in response to a panel of overlapping peptides spanning the above-listed allergens were assessed.

RESULTS

Three previously identified dominant T cell epitopes (Amb a 1 176-191, 200-215, and 344-359) were confirmed, and three novel dominant epitopes (Amb a 1 280-295, 304-319, and 320-335) were identified. Amb a 1, the dominant IgE allergen, was also the dominant T cell allergen, but dominance patterns for T cell and IgE responses for the other ragweed allergens did not correlate. Dominance for T cell responses correlated with conservation of ragweed epitopes with sequences of other well-known allergens.

CONCLUSIONS AND CLINICAL RELEVANCE

These results provide the first assessment of the hierarchy of T cell reactivity in ragweed allergens, which is distinct from that observed for IgE reactivity and influenced by T cell epitope sequence conservation. The results suggest that ragweed allergens associated with lesser IgE reactivity and significant T cell reactivity may be targeted for T cell immunotherapy, and further support the development of immunotherapies against epitopes conserved across species to generate broad reactivity against many common allergens.

Definition of a pool of epitopes that recapitulates the T cell reactivity against major house dust mite allergens

BACKGROUND

Allergens from house dust mites (HDM) are a common cause of asthma. Der p and Der f from Dermatophagoides sp. are strong immunogens in humans. Allergen extracts are used to study T helper (Th2) cell responses to HDM, which are implicated in the development and regulation of allergic disease.

OBJECTIVE

To define an epitope mixture that recapitulates, and might substitute for, HDM extract in terms of detecting and characterizing Th2 cell responses.

METHODS

Peripheral blood mononuclear cells (PBMC) from 52 HDM allergic and 10 non-allergic individuals were stimulated with HDM extracts and assayed with a set of 178 peptides spanning mite allergens group Der p 1, 2, 23 and Der f group 1 and 2 allergens. A pool of the most dominant T cell epitopes identified in the present study and from published literature was assembled and tested for ex vivo T cell responses. Correlation with HDM-specific IgE titres was examined.

RESULTS

Patterns of T cell reactivity to Der p and Der f - derived peptides revealed a large number of epitopes. Clear patterns of immunodominance were apparent, with HDM allergen group 1 and 2 dominant over group 23. Furthermore, within a given antigen, 6-11 epitopes accounted for the vast majority of responses. Based on these results and published data, a comprehensive dust mite pool (DMP) of epitopes was designed and found to allow detection of ex vivo T cell responses. DMP ex vivo reactivity correlated with HDM-specific IgE titres and was similar to that detected with commonly used HDM extracts. Ex vivo DMP stimulation was associated with a predominant Th2 response in allergic donors, and minor reactivity of T cells producing IFNγ, IL17 and IL10.

CONCLUSIONS & CLINICAL RELEVANCE

A detailed map of Der p and Der f antigens defined a pool of epitopes that can be used to detect ex vivo HDM responses.

[Amoxicillin and paracetamol dosing in children: playing safe]

Amoxicillin and paracetamol are the two most widely prescribed and recommended medicines in children. Due to lack of scientific evidence of the most effective dosage, dosing instructions of both medicines are often unclear. In this article we challenge general practitioners, paediatricians, child-health clinic physicians, ENT specialists, pharmacists and guideline committees to critically evaluate the current dosing instructions of these two medicines. The Netherlands paediatric formulary, the Kinderformularium, should become the primary formulary for children in the Netherlands, but it has to be more in line with daily practice, and basic dosing instructions should be less ambiguous: (a) dosing instructions based on body weight instead of age; b) in case of pain, paracetamol should be given 60 mg/kg/day in four divided doses; (c) in case of common uncomplicated infections, amoxicillin should be given orally 60 mg/kg/day in two divided doses; (d) the following should be mentioned on the antibiotic prescription: the daily dose, the number of divided doses, the duration of therapy, the indication for the prescription, and the child's weight. This will result in safe prescription of medicines for children, with fewer unnecessary disruptive consultations between prescriber and pharmacist.

Evaluation of contraceptive methods in women with congenital heart disease in Germany, Hungary and Japan

AIMS

For women with congenital heart defects (CHD), pregnancy may pose a health risk. Sexually active women with CHD without the desire for own children or for whom pregnancy would imply considerable health risks require adequate counselling regarding appropriate contraception. This study gathers data on the contraceptive behaviour of women with CHD from three different cultural regions.

METHODS AND RESULTS

634 women with CHD from Germany, Hungary and Japan were surveyed regarding contraception and contraceptive methods (CM) used. The patients were divided into groups according to different criteria such as pregnancy associated cardiovascular risk or "safety" of the contraceptive methods used. 59% of the study participants had already gained experience with CM. The average age at the first time of use was 18.4 years; the German patients were significantly younger at the first time of using a CM than those from Hungary and Japan. Overall the condom was the method used the most (38%), followed by oral contraceptives (30%) and coitus interruptus (11%). The range of CM used in Japan was much smaller than that in Germany or Hungary. Unsafe contraceptives were currently, or had previously been used, by 29% of the surveyed patients (Germany: 25%, Hungary: 37%, Japan: 32%).

CONCLUSION

Most women with CHD use CM. There are differences between the participating countries. Adequate contraceptive counselling of women with CHD requires considering the individual characteristics of each patient, including potential contraindications. For choosing an appropriate CM, both the methods' "safety", as well as the maternal cardiovascular risk, are important.

Different Bla-g T cell antigens dominate responses in asthma versus rhinitis subjects

BACKGROUND AND OBJECTIVE

The allergenicity of several German cockroach (Bla-g) antigens at the level of IgE responses is well established. However, less is known about the specificity of CD4+ TH responses, and whether differences exist in associated magnitude or cytokine profiles as a function of disease severity.

METHODS

Proteomic and transcriptomic techniques were used to identify novel antigens recognized by allergen-specific T cells. To characterize different TH functionalities of allergen-specific T cells, ELISPOT assays with sets of overlapping peptides covering the sequences of known allergens and novel antigens were employed to measure release of IL-5, IFNγ, IL-10, IL-17 and IL-21.

RESULTS

Using these techniques, we characterized TH responses in a cohort of adult Bla-g-sensitized subjects, either with (n = 55) or without (n = 17) asthma, and nonsensitized controls (n = 20). T cell responses were detected for ten known Bla-g allergens and an additional ten novel Bla-g antigens, representing in total a 5-fold increase in the number of antigens demonstrated to be targeted by allergen-specific T cells. Responses of sensitized individuals regardless of asthma status were predominantly TH 2, but higher in patients with diagnosed asthma. In asthmatic subjects, Bla-g 5, 9 and 11 were immunodominant, while, in contrast, nonasthmatic-sensitized subjects responded mostly to Bla-g 5 and 4 and the novel antigen NBGA5.

CONCLUSIONS

Asthmatic and nonasthmatic cockroach-sensitized individuals exhibit similar TH 2-polarized responses. Compared with nonasthmatics, however, asthmatic individuals have responses of higher magnitude and different allergen specificity.

High phylogenetic diversity of the cat flea (Ctenocephalides felis) at two mitochondrial DNA markers

The cat flea, Ctenocephalides felis (Siphonaptera: Pulicidae) (Bouché), is the most common flea species found on cats and dogs worldwide. We investigated the genetic identity of the cosmopolitan subspecies C. felis felis and evaluated diversity of cat fleas from Australia, Fiji, Thailand and Seychelles using mtDNA sequences from cytochrome c oxidase subunit I (cox1) and II (cox2) genes. Both cox1 and cox2 confirmed the high phylogenetic diversity and paraphyletic origin of C. felis felis. The African subspecies C. felis strongylus (Jordan) is nested within the paraphyletic C. felis felis. The south East Asian subspecies C. felis orientis (Jordan) is monophyletic and is supported by morphology. We confirm that Australian cat fleas belong to C. felis felis and show that in Australia they form two distinct phylogenetic clades, one common with fleas from Fiji. Using a barcoding approach, we recognize two putative species within C. felis (C. felis and C. orientis). Nucleotide diversity was higher in cox1 but COX2 outperformed COX1 in amino acid diversity. COX2 amino acid sequences resolve all phylogenetic clades and provide an additional phylogenetic signal. Both cox1 and cox2 resolved identical phylogeny and are suitable for population structure studies of Ctenocephalides species.