Clinical characteristics and myocardial function assessed by traditional and novel echocardiographic methods in competitive triathletes with and without myocardial fibrosis

Background

The aim of the present study was to compare clinical characteristics and cardiac structure and function in competitive triathletes with and without myocardial fibrosis.

Methods

Cardiac fibrosis in 61 healthy male competitive triathletes (>10 hrs of training per week, age 45±10 yrs) was quantified using LGE-sequences in CMR (1.5 tesla scanner).

Transthoracic echocardiography, physical examination, past medical history and routine lab diagnosis for exclusion of other conditions were performed.

Baseline characteristics like blood pressure at rest (BP), bodymass-index (BMI), and systolic and diastolic echocardiographic parameters (left atrial volume index (LAVI), e', E, A, right ventricular pressure gradient) as well as global longitudinal strain, were analysed by two independent observers blinded to the CMR measurements. Triathletes were sub-divided into LGE-positives (LGE+) vs. LGE-negatives (LGE-).

Results

All individuals appeared healthy with no drug history. Focal non-ischaemic LGE was detected in 19 triathletes. Compared to LGE-negative triathletes, LGE-positives showed significantly higher systolic BP (142 vs. 128 mmHg, p=0.004). Logistic regression showed, that per 10 mmHg enhanced blood pressure the chance for LGE rises by 89%. Triathletes with and without LGE demonstrated no difference in conventional echocardiographic measurements such as left ventricular ejection fraction and volumes and no difference in diastolic parameters. But the presence of MF did mediate global longitudinal strain (GLS).

Global longitudinal strain was significantly reduced in LGE positive athletes (LGE+: −19.8±3.4; LGE-: −21.7±2.4, p=0.04)

Conclusions

Reduced global longitudinal strain mediated as an early echocardiographic marker for subclinical changes in asymptomatic competitive triathletes with myocardial fibrosis compared to triathletes without LGE. Novel echocardiographic parameter such as longitudinal strain might serve as an easy tool to identify high endurance athletes at higher risk for cardiovascular events and that individuals with enhanced blood pressure should undergo cardiac consultation before starting endurance-training in competitive disciplines.

Funding Acknowledgement

Type of funding source: None

P1692Cardiac fibrosis in competitive triathletes is associated with arterial hypertension

Background

Myocardial fibrosis is an occasional finding in asymptomatic athletes.

Purpose

Evaluation of clinical conditions with possible impact on cardiac fibrosis in competitive triathletes.

Methods

Cardiac fibrosis in 61 male competitive triathletes (>10 hrs of training per week, mean 45 yrs) and 19 controls (mean 38 yrs), was quantified using late gadolinium enhancement (LGE) in cardiac magnet-resonance imaging (CMR). Physical examination, past medical history, and routine lab diagnosis were performed and baseline characteristics like blood pressure at rest (BP), body mass index (BMI), and echocardiographic parameters were measured. Triathletes were sub-divided into LGE positives vs. negatives.

Results

All individuals appeared healthy with no drug history of note and a normal cardiac function according to echocardiography. Focal non-ischaemic LGE was detected in 18 triathletes (5.2±4.5 g; 3.5±2.8 g/m2) and none of the controls. Compared to LGE negative triathletes, LGE positives showed significantly higher systolic BP and BMI (see Table). 67% of the LGE positives and only 14% of the LGE negative athletes showed first degree arterial hypertension and 56% of the LGE positives vs. 21% of the LGE negatives were formally overweight (BMI≥25 kg/m2). Controls had smaller left atrial volume indices than the triathletes, in line with characteristics of the athlete's heart. The triathletes were older than the controls (see Table below), but had a normal diastolic function. 38% of the controls and 31% of all triathletes were overweight. Equally to the LGE negatives, 14% of the controls were hypertensive.

Clinical parameters Athletes LGE+ LGE− Controls p-value (athletes vs. controls) p-value (LGE+ vs. LGE−) p-value (LGE− vs. controls) n 61 18 43 19 Age (yrs) 44.6±9.80 48.2±9.04 42.2±9.96 38.4±11.12 0.0371* 0.1222 0.0016* BMI (kg/m2) 24.1±2.57 25.3±2.75 23.8±2.4 24.5±2.74 0.2564 0.0315* 0.1228 Sys. BP (mmHg) 132±15.80 144±17.52 128±12.99 124±15.93 0.0145* 0.0020* 0.2426 LAVI (ml/m2) 29.13±6.79 31.45±8.02 26.68±6.26 24.25±5.48 0.0014* 0.4389 0.0053* All values shown as mean values with standard deviation, if not otherwise indicated, BMI = body mass index, LAVI = left atrial volume index, athletes = all triathletes; LGE+ = triathletes with cardiac LGE visualised by CMR, LGE− = triathletes without LGE in CMR. *Significant p-value, vs. = versus, Sys. BP = systolic blood pressure.

Conclusion

In competitive triathletes, there is a significant correlation between cardiac fibrosis and arterial hypertension at rest as well as overweight. We therefore recommend, that individuals with these characteristics should undergo cardiac consultation before starting endurance-training in competitive disciplines.

Strong and frequent T-cell responses to the minor allergen Phl p 12 in Spanish patients IgE-sensitized to Profilins

BACKGROUND

Profilins are dominant pan-allergens known to cause cross-sensitization, leading to clinical symptoms such as pollen-food syndrome. This study aimed to determine the T-cell response to Phl p 12 in profilin-sensitized patients, by measuring the prevalence, strength and cross-reactivity to clinically relevant profilins.

METHODS

The release of Phl p allergens from pollen was determined by mass spectrometry and immunochemistry. T-cell responses, epitope mapping and cross-reactivity to profilins (Phl p 12, Ole e 2, Bet v 2 and Mal d 4) were measured in vitro using PBMCs from 26 Spanish grass-allergic donors IgE-sensitized to profilin. Cross-reactivity was addressed in vivo using 2 different mouse strains (BALB/c and C3H).

RESULTS

Phl p 12 and Phl p 1 are released from pollen simultaneously and in similar amounts. Both T-cell response frequency (17/26 donors) and strength were comparable between Phl p 12 and Phl p 1. T-cell cross-reactivity to other profilins correlated with overall sequence homology, and 2 immunodominant epitope regions of Phl p 12 were identified. Data from mice immunized with Phl p 12 showed that cross-reactivity to Bet v 2 was mediated by conserved epitopes and further influenced by additional genetic factors, likely to be MHC II.

CONCLUSION

The strength, prevalence and cross-reactivity of T-cell responses towards Phl p 12 are comparable to the major allergen Phl p 1, which supports the hypothesis that T cells to Phl p 12 can play an important role in development of allergic symptoms, such as those associated with pollen-food syndrome.

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.

Accuracy of Coronary Plaque Detection and Assessment of Interobserver Agreement for Plaque Quantification Using Automatic Coronary Plaque Analysis Software on Coronary CT Angiography

PURPOSE

To evaluate the accuracy of automatic plaque detection and the interobserver agreement of automatic versus manually adjusted quantification of coronary plaques on coronary CT angiography (cCTA) using commercially available software.

MATERIALS AND METHODS

10 cCTA datasets were evaluated using plaque software. First, the automatically detected plaques were verified. Second, two observers independently performed plaque quantification without revising the automatically constructed plaque contours (automatic approach). Then, each observer adjusted the plaque contours according to plaque delineation (adjusted approach). The interobserver agreement of both approaches was analyzed.

RESULTS

32 of 114 automatically identified findings were true-positive plaques, while 82 (72 %) were false-positive. 20 of 52 plaques (38 %) were missed by the software (false-negative). The automatic approach provided good interobserver agreement with relative differences of 0.9 ± 16.0 % for plaque area and -3.3 ± 33.8 % for plaque volume. Both observers independently adjusted all contours because they did not represent the plaque delineation. Interobserver agreement decreased for the adjusted approach with relative differences of 25.0 ± 24.8 % for plaque area and 20.0 ± 40.4 % for plaque volume.

CONCLUSION

The automatic plaque analysis software is of limited value due to high numbers of false-positive and false-negative plaque findings. The automatic approach was reproducible but it necessitated adjustment of all constructed plaque contours resulting in deterioration of the interobserver agreement.

KEY POINTS

• Automatic plaque detection is limited due to high false-positive and false-negative findings.• Automatic plaque quantification was reproducible in the few accurately detected plaques.• The automatically constructed contours did not represent the plaque delineation.• Both observers independently adjusted the plaque contours.• Manual adjustment of plaque contours reduced the interobserver agreement. Citation Format: • Laqmani A, Klink T, Quitzke M et al. Accuracy of Coronary Plaque Detection and Assessment of Interobserver Agreement for Plaque Quantification Using Automatic Coronary Plaque Analysis Software on Coronary CT Angiography. Fortschr Röntgenstr 2016; 188: 933 - 939.

Prevention of hepatitis C virus infection using a broad cross-neutralizing monoclonal antibody (AR4A) and epigallocatechin gallate

The anti-hepatitis C virus (HCV) activity of a novel monoclonal antibody (mAb; AR4A) and epigallocatechin gallate (EGCG) were studied in vitro using a HCV cell culture system and in vivo using a humanized liver mouse model capable of supporting HCV replication. Alone, both exhibit reliable cross-genotype HCV inhibition in vitro, and combination therapy completely prevented HCV infection. In vitro AR4A mAb (alone and combined with EGCG) robustly protects against the establishment of HCV genotype 1a infection. EGCG alone fails to reliably protect against an HCV challenge. In conclusion, AR4A mAb represents a safe and efficacious broadly neutralizing antibody against HCV applicable to strategies to safely prevent HCV reinfection following liver transplantation, and it lends further support to the concept of HCV vaccine development. The poor bioavailability of EGCG limits HCV antiviral activity in vitro.

Adjuvant effects of aluminium hydroxide-adsorbed allergens and allergoids - differences in vivo and in vitro

Allergen-specific immunotherapy (SIT) is a clinically effective therapy for immunoglobulin (Ig)E-mediated allergic diseases. To reduce the risk of IgE-mediated side effects, chemically modified allergoids have been introduced. Furthermore, adsorbance of allergens to aluminium hydroxide (alum) is widely used to enhance the immune response. The mechanisms behind the adjuvant effect of alum are still not completely understood. In the present study we analysed the effects of alum-adsorbed allergens and allergoids on their immunogenicity in vitro and in vivo and their ability to activate basophils of allergic donors. Human monocyte derived dendritic cells (DC) were incubated with native Phleum pratense or Betula verrucosa allergen extract or formaldehyde- or glutaraldehyde-modified allergoids, adsorbed or unadsorbed to alum. After maturation, DC were co-cultivated with autologous CD4(+) T cells. Allergenicity was tested by leukotriene and histamine release of human basophils. Finally, in-vivo immunogenicity was analysed by IgG production of immunized mice. T cell proliferation as well as interleukin (IL)-4, IL-13, IL-10 and interferon (IFN)-γ production were strongly decreased using glutaraldehyde-modified allergoids, but did not differ between alum-adsorbed allergens or allergoids and the corresponding unadsorbed preparations. Glutaraldehyde modification also led to a decreased leukotriene and histamine release compared to native allergens, being further decreased by adsorption to alum. In vivo, immunogenicity was reduced for allergoids which could be partly restored by adsorption to alum. Our results suggest that adsorption of native allergens or modified allergoids to alum had no consistent adjuvant effect but led to a reduced allergenicity in vitro, while we observed an adjuvant effect regarding IgG production in vivo.

Cultured mast cells from patients with asthma and controls respond with similar sensitivity to recombinant Der p2-induced, IgE-mediated activation

The function of cultured mast cells may depend on genetic or environmental influence on the stem cell donor. This study investigates whether asthma or atopy in the donor influenced the growth and sensitivity of mast cells cultured from patients with asthma and healthy controls under identical conditions. Mast cells were cultured from peripheral blood from twelve patients with an objectively confirmed asthma diagnosis and eight healthy subjects. During the last 2 weeks of culture, mast cells were incubated with IL-4 and 80 kU/l recombinant human IgE containing two clones (7% + 7%) specific for mite allergen Der p2. The sensitivity of IgE-mediated activation of mast cells was investigated as FcεRI-mediated upregulation of CD63. Ten subjects were atopic, defined as a positive skin prick test (>3 mm) to at least one of ten common allergens. After activation with recombinant Der p2, the maximum CD63 median fluorescence intensity was 20 456 ± 1640 (SE) for patients with asthma and 22,275 ± 1971 (SE) for controls (ns). The fraction of CD63 positive cells was 54.4% in patients with asthma and 48.4% in controls (ns). The allergen concentration inducing 50% of the maximal CD63 response was similar in patients with asthma [-0.4795 log ng/ml ± 0.092 (SE)] and controls (-0.6351 log ng/ml ± 0.083, ns) and in atopic and non-atopic subjects. When cultured, sensitized and activated under identical conditions, mast cells from allergic asthmatics and healthy controls respond similar. Activation of cultured mast cells appears to depend on culture conditions (IL-4, IgE) rather than on donor status as atopy and asthma.

Quantification of mechanical ventricular dyssynchrony: direct comparison of velocity-encoded and cine magnetic resonance imaging

PURPOSE

The preoperative assessment of mechanical dyssynchrony can help to improve patient selection in candidates for cardiac resynchronization therapy (CRT). The present study compared the performance of velocity-encoded (VENC) MRI to cine-magnetic resonance imaging (MRI) for quantifying mechanical ventricular dyssynchrony.

MATERIALS AND METHODS

VENC-MRI and cine-MRI were performed in 20 patients with heart failure NYHA class III and reduced ejection fraction (median: 24 %, interquartile range: 18 - 28 %) before CRT device implantation. The interventricular mechanical delay (IVMD) was assessed by VENC-MRI as the temporal difference between the onset of aortic and pulmonary flow. Intraventricular dyssynchrony was quantified by cine-MRI, using the standard deviation of time to maximal wall thickening in sixteen left ventricular segments (SDt-16). The response to CRT was assessed in a six-month follow-up.

RESULTS

14 patients (70 %) clinically responded to CRT. A similar accuracy was found to predict the response to CRT by measurements of the IVMD and SDt-16 (75 vs. 70 %; p = ns). The time needed for data analysis was significantly shorter for the IVMD at 1.69 min (interquartile range: 1.66 - 1.88 min) compared to 9.63 min (interquartile range: 8.92 - 11.63 min) for the SDt-16 (p < 0.0001).

CONCLUSION

Measurements of the IVMD by VENC-MRI and the SDt-16 by cine-MRI provide a similar accuracy to identify clinical responders to CRT. However, data analysis of the IVMD is significantly less time-consuming compared to data analysis of the SDt-16.

Comparison between surgery and physiotherapy in the treatment of small and medium-sized tears of the rotator cuff: A randomised controlled study of 103 patients with one-year follow-up

In order to compare the outcome from surgical repair and physiotherapy, 103 patients with symptomatic small and medium-sized tears of the rotator cuff were randomly allocated to one of the two approaches. The primary outcome measure was the Constant score, and secondary outcome measures included the self-report section of the American Shoulder and Elbow Surgeons score, the Short Form 36 Health Survey and subscores for shoulder movement, pain, strength and patient satisfaction. Scores were taken at baseline and after six and 12 months by a blinded assessor. Nine patients (18%) with insufficient benefit from physiotherapy after at least 15 treatment sessions underwent secondary surgical treatment. Analysis of between-group differences showed better results for the surgery group on the Constant scale (difference 13.0 points, p - 0.002), on the American Shoulder and Elbow surgeons scale (difference 16.1 points, p < 0.0005), for pain-free abduction (difference 28.8 degrees , p = 0.003) and for reduction in pain (difference on a visual analogue scale -1.7 cm, p < 0.0005).

Allergenicity, immunogenicity and dose-relationship of three intact allergen vaccines and four allergoid vaccines for subcutaneous grass pollen immunotherapy

Different vaccines containing intact allergens or chemically modified allergoids as active ingredients are commercially available for specific immunotherapy. Allergoids are claimed to have decreased allergenicity without loss of immunogenicity and this is stated to allow administration of high allergoid doses. We compared the allergenicity and immunogenicity of four commercially available chemically modified grass pollen allergoid products with three commercially available intact grass pollen allergen vaccines. The allergenicity was investigated with immunoglobulin (Ig)E-inhibition and basophil activation assays. Human T cell proliferation and specific IgG-titres following mouse immunizations were used to address immunogenicity. Furthermore, intact allergen vaccines with different contents of active ingredients were selected to study the influence of the allergen dose. In general, a lower allergenicity for allergen vaccines was clearly linked to a reduced immunogenicity. Compared with the vaccine with the highest amount of intact allergen, the allergoids caused reduced basophil activation as well as diminished immunogenicity demonstrated by reduced T cell activation and/or reduced induction of murine grass-specific IgG antibodies. Interestingly, intact allergen vaccines with lower content of active ingredient exhibited similarly reduced allergenicity, while immunogenicity was still higher or equal to that of allergoids. The low allergenicity observed for some allergoids was inherently linked to a significantly lower immunogenic response questioning the rationale behind the chemical modification into allergoids. In addition, the linkage between allergenicity, immunogenicity and dose found for intact allergen vaccines and the immunogen as well as allergenic immune responses observed for allergoids suggest that the modified allergen vaccines do not contain high doses of immunologically active ingredients.

A double-blind placebo-controlled birch allergy vaccination study II: correlation between inhibition of IgE binding, histamine release and facilitated allergen presentation

BACKGROUND

The pathogenesis of IgE-mediated allergic disease is closely related to the production of T-helper type 2 (Th2) cytokines, which lead to IgE production pivotal for activation of mast cells and basophils. Proliferating T cells along with eosinophils expanded and attracted by Th2 cytokines are major contributors to the late-phase reaction. The activation of these Th2 cells is strongly enhanced by CD23-mediated IgE facilitated allergen presentation (FAP).

OBJECTIVE

The present study aims to investigate the effect of specific immunotherapy (SIT)-induced allergen-specific non-IgE antibodies (blocking antibodies) on IgE binding to allergen, histamine release (HR) and CD23-mediated allergen uptake in antigen-presenting cells.

METHODS

Competition between IgE and non-IgE for allergen binding was studied by Advia Centaur antibody measurements, passively sensitized basophils were used to study HR and IgE-facilitated binding of allergen to B cells (FAP) was studied by flow cytometry. FAP measurements were performed both with and without the addition of a reference IgE serum, which was included to obtain optimal complex formation. The serum samples were obtained from birch pollen immunotherapy (n=21) or placebo control patients (n=21) before and after 1 and 2 years of treatment.

RESULTS

Statistically significant reduction of all parameters investigated was observed after 1 year of treatment and the effect was maintained during the second year of treatment. There was a clear correlation between the two FAP measurements and between each of them and the level of T cell activation reported upon previously. Moreover, strong correlations were found between changes in FAP, IgE binding and HR.

CONCLUSION

The present study clearly demonstrates that SIT induces changes in the composition of serum antibodies that inhibit IgE binding, HR and FAP to a similar extent. This suggests that these measurements, individually or in combination, may be used to monitor the immunological effect of SIT, even though direct correlations to changes in clinical parameters could not be demonstrated.

Comparison of allergenicity and immunogenicity of an intact allergen vaccine and commercially available allergoid products for birch pollen immunotherapy

BACKGROUND

Specific immunotherapy with intact allergen vaccine is a well-documented treatment for allergic diseases. Different vaccine formulations are currently commercially available, the active ingredient either being intact allergens or chemically modified allergoids. The rationale behind allergoids is to decrease allergenicity while maintaining immunogenicity. However, data from the German health authorities based on reporting of adverse events over a 10-year period did not indicate increased safety of allergoids over intact allergens.

OBJECTIVE

The objective of this study was to investigate the effect of chemical modification on allergenicity and immunogenicity comparing four commercial allergoid products for birch pollen immunotherapy with an intact allergen vaccine.

METHODS

Solid-phase IgE inhibition and histamine release assays were selected as model systems for allergenicity, and a combination of human T cell proliferation and IgG titres following mouse immunizations were used to address the immunogenicity of the intact allergen vaccine and the four allergoids. In all assays, the products were normalized with respect to the manufacturer's recommended maintenance dose.

RESULTS

IgE inhibition experiments showed a change in epitope composition comparing intact allergen vaccine with allergoid. One allergoid product induced enhanced histamine release compared to the intact allergens, while the other three allergoids showed reduced release. Standard T cell stimulation assays using lines from allergic patients showed a reduced response for all allergoids compared with the intact allergen vaccine regardless of the cell type used for antigen presentation. All allergoids showed reduced capacity to induce allergen-specific IgG responses in mice.

CONCLUSION

While some allergoids were associated with reduced allergenicity, a clear reduction in immunogenicity was observed for all allergoid products compared with the intact allergen vaccine, and the commercial allergoids tested therefore do not fulfil the allergoid concept.

Inhibition of rBet v 1-induced basophil histamine release with specific immunotherapy -induced serum immunoglobulin G: no evidence that FcgammaRIIB signalling is important

BACKGROUND

Human basophils and mast cells express the low-affinity immunoglobulin (Ig)G receptor FcgammaRIIB. It has previously been shown in artificial model systems that cross-linking of the high-affinity IgE receptor FcepsilonRI and FcgammaRIIB leads to inhibition of FcepsilonRI signalling.

OBJECTIVE

The aim of the present study was to investigate whether cross-linking of FcepsilonRI and FcgammaRIIB contributes to IgG-mediated inhibition of histamine release in human basophils in a system using the sera from specific immunotherapy (SIT) patients and the major allergen from birch pollen, Bet v 1. As IgG4 furthermore has been proposed to have special blocking properties, we investigated the significance of IgG subclass specificity for this inhibition.

METHODS

Binding of recombinant Bet v 1-IgG complexes to FcgammaRII and IgG-binding activities in the sera from 25 birch pollen-allergic patients treated with SIT were measured using (125)I-rBet v 1. Inhibition of basophil histamine release was assessed by incubating washed leucocytes with complexes of rBet v 1-IgG with or without blocking of FcgammaRII.

RESULTS

We observed low binding of rBet v 1-IgG complexes to FcgammaRII, which was negatively correlated with the relative IgG4-binding activities. Blocking of FcgammaRII did not reverse the SIT-IgG-induced inhibition of basophil histamine release. However, IgG-binding activities correlated significantly with the ability of the SIT sera to inhibit basophil histamine release.

CONCLUSION

We suggest that at least in birch pollen SIT, the contribution of FcgammaRIIB-mediated inhibitory signalling to SIT-IgG-induced inhibition of human basophil histamine release is of minor importance. The main contributor to the inhibitory effect of SIT-induced IgG seems to be blocking of the allergen-IgE interaction.