Evaluation of 'implications for research' statements in systematic reviews of interventions in advanced cancer patients - a meta-research study

BACKGROUND

Implications for research (IfR) sections are an important part of systematic reviews (SRs) to inform health care researchers and policy makers. PRISMA 2020 recommends reporting IfR, while Cochrane Reviews require a separate chapter on IfR. However, it is unclear to what extent SRs discuss IfR. We aimed i) to assess whether SRs include an IfR statement and ii) to evaluate which elements informed IfR statements.

METHODS

We conducted a meta-research study based on SRs of interventions in advanced cancer patients from a previous project (CRD42019134904). As suggested in the Cochrane Handbook, we assessed if the following predefined variables were referred to in IfR statements: patient, intervention, control, outcome (PICO) and study design; concepts underlying Grading of Recommendations, Assessment, Development and Evaluation (GRADE) domains: risk of bias, inconsistency, indirectness, imprecision, publication bias. Data were independently extracted by three reviewers after piloting the data extraction form. Discrepancies were resolved in weekly in-depth discussions.

RESULTS

We included 261 SRs. The majority evaluated a pharmacological intervention (n = 244, 93.5%); twenty-nine were Cochrane Reviews (11.1%). Four out of five SRs included an IfR statement (n = 210, 80.5%). IfR statements commonly addressed 'intervention' (n = 121, 57.6%), 'patient ' (n = 113, 53.8%), and 'study design' (n = 107, 51.0%). The most frequent PICO and study design combinations were 'patient and intervention ' (n = 71, 33.8%) and 'patient, intervention and study design ' (n = 34, 16.2%). Concepts underlying GRADE domains were rarely used for informing IfR recommendations: 'risk of bias ' (n = 2, 1.0%), and 'imprecision ' (n = 1, 0.5%), 'inconsistency ' (n = 1, 0.5%). Additional elements informing IfR were considerations on cost effectiveness (n = 9, 4.3%), reporting standards (n = 4, 1.9%), and individual patient data meta-analysis (n = 4, 1.9%).

CONCLUSION

Although about 80% of SRs included an IfR statement, the reporting of PICO elements varied across SRs. Concepts underlying GRADE domains were rarely used to derive IfR. Further work needs to assess the generalizability beyond SRs in advanced cancer patients. We suggest that more specific guidance on which and how IfR elements to report in SRs of interventions needs to be developed. Utilizing PICO elements and concepts underlying GRADE according to the Cochrane Handbook to state IfR seems to be a reasonable approach in the interim.

REGISTRATION

CRD42019134904.

Verification of the prognostic precision of the new 2023 FIGO staging system in endometrial cancer patients - An international pooled analysis of three ESGO accredited centres

BACKGROUND

Recently, the new 2023 International Federation of Gynecology and Obstetrics (FIGO) staging system for endometrial cancer (EC) critically integrating new pathological and molecular features was published. The present study evaluated the clinical impact of the new 2023 FIGO staging system by comparing it to the previous 2009 system.

METHODS

This is an international, pooled retrospective study of 519 EC patients who underwent primary treatment (and molecular characterisation) at three European Society of Gynaecological Oncology (ESGO) accredited centres in Austria/Italy. Patients were categorised according to the 2009 and the 2023 FIGO staging systems. Stage shifts were analysed and (sub)stage specific 5-year progression-free (PFS) and overall survival (OS) rates were calculated and compared. Different statistical tests were applied to evaluate the prognostic precision of the two FIGO staging systems and to compare them to each other.

RESULTS

(Sub)stage shifts occurred in 143/519 (27.6%) patients: 123 upshifts (23.7%) and 20 (3.9%) downshifts. 2023 FIGO staging system identified a stage I cohort with a notably higher 5-year PFS rate compared to 2009 (93.0% versus 87.4%, respectively). For stage II disease, the 5-year PFS rate was similar in the 2023 and the 2009 FIGO staging systems (70.2% versus 71.2%, respectively). The two new molecularly defined 2023 FIGO substages IAmPOLEmut and IICmp53abn displayed distinct, particularly favourable and adverse oncologic outcomes within early stage disease, respectively. A remarkably lower 5-year PFS rate for stage III patients was revealed in the 2023 FIGO staging system compared to 2009 (44.4% versus 54.1%, respectively). All applied statistical tests confirmed a more accurate prediction of PFS and OS by the 2023 FIGO staging system compared to 2009.

CONCLUSION

The new 2023 FIGO stating system led to a substantial stage shift in about one quarter of patients leading to a higher prognostic precision. In early stage disease, the new substages added further prognostic granularity and identified treatment relevant subgroups.

Off-Axis Layered Displays: Hybrid Direct-View/Near-Eye Mixed Reality with Focus Cues

This work introduces off-axis layered displays, the first approach to stereoscopic direct-view displays with support for focus cues. Off-axis layered displays combine a head-mounted display with a traditional direct-view display for encoding a focal stack and thus, for providing focus cues. To explore the novel display architecture, we present a complete processing pipeline for the real-time computation and post-render warping of off-axis display patterns. In addition, we build two prototypes using a head-mounted display in combination with a stereoscopic direct-view display, and a more widely available monoscopic direct-view display. In addition we show how extending off-axis layered displays with an attenuation layer and with eye-tracking can improve image quality. We thoroughly analyze each component in a technical evaluation and present examples captured through our prototypes.

Diagnostic accuracy of amyloid scintigraphy for the histopathological diagnosis of cardiac transthyretin amyloidosis – a retrospective Austrian multicenter study

Background

Previous studies indicated that amyloid scintigraphy in combination with free light chain (FLC) assessment yields an excellent diagnostic accuracy for cardiac transthyretin (ATTR) amyloidosis (1). As a consequence, the diagnosis of ATTR amyloidosis is increasingly made without the actual gold-standard method endomyocardial biopsy (EMB). Whether this leads to misdiagnosis in real-world practice is currently underinvestigated. We aimed to describe the diagnostic accuracy of amyloid scintigraphy in a real world setting.

Methods

Seven tertiary care centers throughout Austria agreed to participate in the study and performed a systematic retrospective medical records search from 2017 to 2020. Patients were included in case of available results of amyloid scintigraphy, FLC assessment and EMB, respectively. Amyloid scintigraphy was performed using a 99m-technetium-labelled tracer. Histological analysis was performed using immunohistochemistry. The number of submitted subjects with complete data per center ranged from 2 to 46. The patient number increased with years, with 15 patients investigated in 2017 and 32 in 2020.

Results

We enrolled 101 patients (21% women) with a mean age of 73±9 years and median NT-proBNP (IQR) of 2694 (1601–5239) pg/ml (Table 1). An abnormal Perugini Score (ie. grade II or III) was present in 57 patients (56%) and FLC assessment was overall indicative of monoclonal protein in 60 patients (59%). Among patients with abnormal Perugini Score, 29 had FLC assessment indicative of monoclonal protein. The most common histopathological diagnoses were ATTR in 60 patients (59%) and cardiac light chain (AL) amyloidosis in 20 patients (20%). One further patient was diagnosed with concomitant AL and ATTR amyloidosis. Further diagnoses included ApoA4 (n=2) and AA amyloidosis (n=1), while cardiac amyloidosis was ruled out in 17 patients (17%).

ATTR was diagnosed in 54 patients with Perugini Score II or III compared with 6 patients with Perugini < II, yielding a sensitivity of abnormal Perugini score for ATTR amyloidosis of 90%. Among patients with abnormal Perugini Score (n=57), ATTR was diagnosed in 55 patients, and AL amyloidosis in 3 (one had concomitant ATTR and AL), yielding a positive predictive value (PPV) of abnormal Perugini Score of 97% (Table 2). Two AL patients had Perugini Score of II and one had Perugini Score of III. When excluding patients with monoclonal gammopathy, the PPV of abnormal Perugini Score was 100%.

Conclusion

Our data confirm a PPV of abnormal amyloid scintigraphy of 100% for cardiac ATTR amyloidosis when monoclonal gammopathy was excluded. mong patients with monoclonal gammopathy, one of ten patients with abnormal scintigraphy had AL amyloidosis as the underlying condition. Our data underscore that tissue biopsy and histopathological analysis should be performed in every patient with suspected amyloidosis and monoclonal gammopathy even in case of Perugini Score II or III.

Funding Acknowledgement

Type of funding sources: None.

Prevention of early sudden cardiac death after myocardial infarction using the wearable cardioverter defibrillator - results from a real-life cohort

Funding Acknowledgements

Type of funding sources: None.

Background

Patients are at elevated risk of sudden cardiac death (SCD) after acute myocardial infarction (MI). The VEST trial failed to show a significant reduction in arrhythmic mortality in patients prescribed with a wearable converter-defibrillator (WCD), having a lower than expected wearing compliance. We aimed to investigate the incidence of WCD treatments and outcomes of all patients with acute MI and LVEF ≤35% in a real life and well-compliant cohort in Austria.

Methods

We performed a retrospective analysis of all patients meeting the in- and exclusion criteria of the original VEST trial within the Austrian WCD registry between 2010 and 2021.

Results

105/896 patients (12%) with an average age of 64±11 years (12% female; LVEF 28±6%) registered in the Austrian WCD registry met the VEST in- and exclusion criteria. 104/105 patients were revascularized and prescribed with a WCD prescription for 69 (1;277) days, the median wearing duration was 23.5 (0;24) hours/day. 4/105 (3.8%) patients received 9 appropriate WCD shocks, the per patient shock rate was 2 (1;5). No inappropriate shock was delivered. During follow-up, 46/105 patients (44%) received an ICD after the WCD period, 4/105 (3.8%) patients died during follow-up. Arrhythmic mortality (1.9% Austria vs. 1.6% VEST, p=ns), as well as all-cause mortality (3.8% vs. 3.1%, p=ns) in the Austrian cohort were comparable to the VEST cohort.

Conclusion

The WCD is a safe treatment option in a highly selected cohort of patients with a LVEF ≤35% after acute myocardial infarction. However, despite excellent WCD compliance as opposed to the VEST study, only 3.8% of patients receive appropriate WCD shocks and the arrhythmic mortality rate was not significantly improved.

Video See-Through Mixed Reality with Focus Cues

This work introduces the first approach to video see-through mixed reality with full support for focus cues. By combining the flexibility to adjust the focus distance found in varifocal designs with the robustness to eye-tracking error found in multifocal designs, our novel display architecture reliably delivers focus cues over a large workspace. In particular, we introduce gaze-contingent layered displays and mixed reality focal stacks, an efficient representation of mixed reality content that lends itself to fast processing for driving layered displays in real time. We thoroughly evaluate this approach by building a complete end-to-end pipeline for capture, render, and display of focus cues in video see-through displays that uses only off-the-shelf hardware and compute components.

Peanut-induced anaphylaxis in children and adolescents: Data from the European Anaphylaxis Registry

BACKGROUND

Peanut allergy has a rising prevalence in high-income countries, affecting 0.5%-1.4% of children. This study aimed to better understand peanut anaphylaxis in comparison to anaphylaxis to other food triggers in European children and adolescents.

METHODS

Data was sourced from the European Anaphylaxis Registry via an online questionnaire, after in-depth review of food-induced anaphylaxis cases in a tertiary paediatric allergy centre.

RESULTS

3514 cases of food anaphylaxis were reported between July 2007 - March 2018, 56% in patients younger than 18 years. Peanut anaphylaxis was recorded in 459 children and adolescents (85% of all peanut anaphylaxis cases). Previous reactions (42% vs. 38%; p = .001), asthma comorbidity (47% vs. 35%; p < .001), relevant cofactors (29% vs. 22%; p = .004) and biphasic reactions (10% vs. 4%; p = .001) were more commonly reported in peanut anaphylaxis. Most cases were labelled as severe anaphylaxis (Ring&Messmer grade III 65% vs. 56% and grade IV 1.1% vs. 0.9%; p = .001). Self-administration of intramuscular adrenaline was low (17% vs. 15%), professional adrenaline administration was higher in non-peanut food anaphylaxis (34% vs. 26%; p = .003). Hospitalization was higher for peanut anaphylaxis (67% vs. 54%; p = .004).

CONCLUSIONS

The European Anaphylaxis Registry data confirmed peanut as one of the major causes of severe, potentially life-threatening allergic reactions in European children, with some characteristic features e.g., presence of asthma comorbidity and increased rate of biphasic reactions. Usage of intramuscular adrenaline as first-line treatment is low and needs to be improved. The Registry, designed as the largest database on anaphylaxis, allows continuous assessment of this condition.

Do increases in deep grey matter volumes after electroconvulsive therapy persist in patients with major depression? A longitudinal MRI-study

BACKGROUND

Previous MRI studies reported deep grey matter volume increases after electroconvulsive therapy (ECT) in patients with major depressive disorder (MDD). However, the clinical correlates of these changes are still unclear. It remains debated whether such volume changes are transient, and if they correlate with affective changes over time. We here investigated if ECT induces deep grey matter volume increases in MDD-patients; and, if so, whether volume changes persist over more than 9 months and whether they are related to the clinical outcome.

METHODS

We examined 16 MDD-patients with 3Tesla MRI before (baseline) and after an ECT-series and followed 12 of them up for 10-36 months. Patients' data were compared to 16 healthy controls. Affective scales were used to investigate the relationship between therapy-outcome and MRI changes.

RESULTS

At baseline, MDD-patients had lower values in global brain volume, white matter and peripheral grey matter compared to healthy controls, but we observed no significant differences in deep grey matter volumes. After ECT, the differences in peripheral grey matter disappeared, and patients demonstrated significant volume increases in the right hippocampus and both thalami, followed by subsequent decreases after 10-36 months, especially in ECT-responders. Controls did not show significant changes over time.

LIMITATIONS

Beside the relatively small, yet carefully characterized cohort, we address the variability in time between the third scanning session and the baseline.

CONCLUSIONS

ECT-induced deep grey matter volume increases are transient. Our results suggest that the thalamus might be a key region for the understanding of the mechanisms of ECT action.

Decrease in gynecological cancer diagnoses during the COVID-19 pandemic: an Austrian perspective

Background

On March 16, 2020, the federal government of Austria declared a nationwide lockdown due to the COVID-19 pandemic. Since the lockdown, screening examinations and routine checkups have been restricted to prevent the spread of the virus and to increase the hospitals’ bed capacity across the country. This resulted in a severe decline of patient referrals to the hospitals.

Objective

To assess the impact of the COVID-19 pandemic on the rate of newly diagnosed gynecological and breast cancers in Austria.

Methods

Data of 2077 patients from 18 centers in Austria with newly diagnosed gynecological or breast cancer between January and May 2019 and January and May 2020 were collected. Clinical parameters, including symptoms, performance status, co-morbidities, and referral status, were compared between the time before and after the COVID-19 outbreak.

Results

Our results showed a slight increase of newly diagnosed cancers in January and February 2020 as compared with 2019 (+2 and +35%, respectively) and a strong decline in newly diagnosed tumors since the lockdown: −24% in March 2020 versus March 2019, −49% in April 2020 versus April 2019, −49% in May 2020 versus May 2019. Two-thirds of patients diagnosed during the pandemic presented with tumor-specific symptoms compared with less than 50% before the pandemic (p<0.001). Moreover, almost 50% of patients in 2020 had no co-morbidities compared with 35% in 2019 (p<0.001). Patients, who already had a malignant disease, were rarely diagnosed with a new cancer in 2020 as compared with 2019 (11% vs 6%; p<0.001).

Conclusions

The lockdown led to a decreased number of newly diagnosed gynecological and breast cancers. The decreased accessibility of the medical services and postponed diagnosis of potentially curable cancers during the COVID-19 pandemic may be a step backwards in our healthcare system and might impair cancer treatment outcomes. Therefore, new strategies to manage early cancer detection are needed to optimize cancer care in a time of pandemic in the future.

Abstract PO-038: Strong decline of newly diagnosed gynecologic and breast cancers during the COVID-19 pandemic: A retrospective analysis from Innsbruck, Austria

A nationwide lockdown was declared on March 16 in Austria due to coronavirus disease 2019 (COVID-19) outbreak, requiring citizens to remain in their homes except for necessary reasons. The lockdown resulted not only in social distancing and reduction of commercial activity, but also in severe restrictions in the health care system. Regular medical services and outpatient care were nearly shut down to prevent the spread of the virus and to increase the total hospital capacities. Thus, patients faced barriers to attend preventive checkups, such as mammography, screening for cervical cancer, or to consult the general practitioner. As a gynecologic department with a large oncologic subunit, we noticed significantly fewer tumor diagnoses presenting at our department since the lockdown. This phenomenon forced us to perform this retrospective study on newly diagnosed gynecologic and breast cancers before and during the COVID-19 pandemic. A retrospective analysis of newly diagnosed gynecologic and breast cancers presented at the University Hospital Innsbruck from January to May 2019 and from January to May 2020 was performed. Descriptive statistics and analysis of the clinical data stratified by the year of diagnosis were performed using SPSS software and Mann-Whitney U test. Our results showed a slight increase of newly diagnosed cancers in January and February 2020 as compared to 2019 (+13%) and a strong decline in newly diagnosed tumors since the lockdown: -45% in March 2020 vs. March 2019, -63% in April 2020 vs. April 2019, and -44% in May 2020 vs. May 2019. Around two third of patients diagnosed during the pandemic consulted the specialist due to tumor symptoms, while before the pandemic less than 50% of patients presented with symptoms. The ratio of breast and vulvar cancer was significantly higher during the pandemic (71 vs. 61% and 3 vs. 1.9%, respectively; p=0.043), but significantly fewer cervical cancers were diagnosed (4.4 vs. 8.9%; p=0.043). Patients with other malignant, rheumatic, or metabolic disease were rarely diagnosed with a new cancer in 2020 as compared to 2019 (7.5 vs. 12%; 0.7 vs. 3.7% and 6.7 vs. 12%, respectively; p=0.014). A better performance status was observed in patients presented in 2020 as compared to 2019 (p=0.011). In a country with maximum intensive care bed occupancy of 26% during the COVID-19 pandemic, the accessibility of the health care services was severely impaired and preventive care and early cancer detection was restricted, leading to an increase in undetected or postponed tumor diagnoses. The aim of our work is to raise awareness of this issue. It is not clear whether these undetected cases will lead to potential months of life lost; however, decreased accessibility of the medical services and postponed diagnosis of potentially curable cancers are clearly a step backwards in our health care system and will probably impair cancer treatment outcomes. Thus, new strategies to manage early cancer detection are needed to optimize cancer care in a time of pandemic in the future.

Citation Format: Irina Tsibulak, Elisabeth Reiser, Christoph Ebner, Katharina Knoll, Katharina Leitner, Verena Wieser, Justina Angerer, Christian Marth. Strong decline of newly diagnosed gynecologic and breast cancers during the COVID-19 pandemic: A retrospective analysis from Innsbruck, Austria [abstract]. In: Proceedings of the AACR Virtual Meeting: COVID-19 and Cancer; 2020 Jul 20-22. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(18_Suppl):Abstract nr PO-038.

917Appropriate shocks in WCD patients - Results from the Austrian WCD registry

Background

The wearable cardioverter-defibrillator (WCD) is a temporary treatment option for patients at high risk for sudden cardiac death (SCD) and/or for patients in whom implantation of a cardioverter defibrillator (ICD) is temporarily not possible.

Purpose

To investigate incidence and predictors of appropriate WCD shocks.

Methods

We performed a retrospective analysis of all patients with appropriate shocks delivered by a WCD in the cohort of the Austrian WCD registry between 2010 and 2018. Within this dataset, we identified predictors within the baseline characteristics, the indication for the WCD and preceding alarms automatically recorded by the WCD.

Results: Baseline

Within 879 registered in the Austrian WCD registry, 31 patients (3,5%) received appropriate WCD shocks due to ventricular tachycardia (VT) or ventricular fibrillation (VF). Compared to the total cohort, shocked patients were elder (mean age 67 ± 14 vs. 60 ± 14 years, p = 0,001) and the percentage of female patients was lower (11% vs. 21%, p = 0,262). The mean baseline LVEF at prescription was 33 ± 15% in the population with appropriate shocks compared to 32 ± 14% in the all-over cohort (p = ns).

In the Austrian WCD population, 378/879 patients had a WCD due to secondary prevention. Within this cohort 5,6% (21/378) had shocks for VT/VF again, compared to 10/501 (2%) shocked patients in the primary prevention cohort. 31/879 (3.5%) patients received 57 appropriate shocks, the per patient shock rate was 2 [1;5]. These shocks were induced by 25 ventricular tachycardia and 26 times ventricular fibrillation.

The octagenarians with 11% (7/34) shocked patients, showed a significant higher likelihood to receive shocks (p = 0,008) as well as the cohort of secondary preventive prescribed WCD-patients (p = 0,007). There were more shocks in patients, when prescribed with a WCD due to ICD associated infections (p = 0,001), when used as a bridge to ICD (p = 0,042) and in patients with ongoing risk stratification (p = 0,009).

Looking through the automatically recorded alarms preceding a WCD shock, shocked patients experienced significantly more often non sustained VTs (p &lt; 0,0005) and sustained VTs that were haemodynamically tolerated and did not require a treatment (p &lt; 0,0005).

Conclusion

The WCD is effective in preventing SCD and an important risk stratification tool. We identified advanced age, patients with either already confirmed indication for ICD implantation (either temporary contraindication for implantation or temporary explantation) or risk stratification of an unclear cardiomyopathy, the cohort of secondary prevention and preceding nsVTs and stable VTs as predictors for appropriate WCD therapies.

P2280Incidence and predictors of alarms in patients with wearable cardioverter defibrillator (WCD) - results of the Austrian WCD Registry

Background

The wearable cardioverter-defibrillator (WCD) is a treatment option for patients at high risk for ventricular arrhythmia, either if the risk is potentially reversible or if an implantable cardioverter defibrillator (ICD) implantation is currently not possible.

Methods

We performed a retrospective analysis of all alarms in the cohort of the Austrian WCD registry between 2010 and 2018. Type of arrhythmias was assessed by independent review of two cardiologists.

Results

25.540 automatically recorded ECGs in 605 patients (68%) were analyzed. 1125 ECGs showed sustained ventricular arrhythmias in 117 patients, 65 ECGs showed non sustained VTs.

24.415 ECGs in 488 patients showed inadequate alarms Reasons for inadequate alarms were artefacts (97%), pacemaker or t-wave oversensing (0,3%) and in 2,3% atrial fibrillation or SVTs.

5860 manually recorded ECGs in 608 patients (68%) were analyzed. 298 (5%) of these ECGs showed following arrhythmias: atrial fibrillation (34,7%), SVTs (28%), sinustachycardia (10,7%), non sustained VTs (12%) and sustained VTs or sustained slow VTs (6,7%), premature ventricular beats or bradycardia was identified in 8%. The remaining 5562 ECGs (95%) showed normal sinus rhythm.

Of the 895 patients (60±14 years, 20% female), 34 (3,8%) received a total of 65 automatically triggered shocks (median 2; range 1–5). 31/895 (3.5%) patients received 57 appropriate shocks (median 1, range 1–5) for 49 arrhythmic events, whereas 7/895 (0.8%) patients received 8 inappropriate shocks (median 1, range 1–2).

44 events were successfully terminated with the first shock (85,7%) and 4 events were terminated with the second shock. In one patient, a shock treatment for VF was not successful. The time from event onset to shock was median 60 [40; 1187] sec.

The median time from WCD prescription to a shock event was 8 days [1–151]. 23/ 34 patients (68%) received their first WCD shock within 30 days.

Seven patients (0.8%) received a total of nine inappropriate shocks due to different reasons: artefacts (2 inappropriate shocks), non-shockable rhythms (asystole, weak action, 3 shocks) and atrial fibrillation with a bundle branch block in two cases. In one patient VF terminated spontaneously before the WCD treatment was delivered.

Conclusion

The WCD is an effective treatment option in patients with a high SCD risk but it also triggers a significant amount of alarms. Although many inadequate alarms occurred, adequate alarms led to arrhythmia detection such as in VT/VF events which were successfully terminated by the WCD in 3,4% of patients.

[Remission of a complex periodic catatonic syndrome under electroconvulsive therapy]

This article is reporting about a spontaneous occurred catatonic syndrome in a 52 years old female patients with no prior psychiatric illness record. The catatonia followed a severe depressive episode with psychotic symptoms. At the beginning additionally to the catatonic-symptoms severe disorientation and memory disturbances were prominent in a way it can be seen in neurodegenerative diseases like Lewy-Body-Dementia and Creutzfeldt-Jacob-Disease. The patient didn't respond on any medication or showed severe side-effects which led to discontinue the medication. After applying widespread somatic diagnostics, which has excluded a neurodegenerative disease a electroconvulsive therapy was applied. During this treatment the patient showed a recurrence of her catatonic symptoms but they remitted if there was a too long period between the convulsive treatments. After establishing a sufficient period between the convulsive treatments the symptoms remitted totally.

Distinct epitope structures of defensin-like proteins linked to proline-rich regions give rise to differences in their allergenic activity

Background

Art v 1, Amb a 4, and Par h 1 are allergenic defensin‐polyproline–linked proteins present in mugwort, ragweed, and feverfew pollen, respectively. We aimed to investigate the physicochemical and immunological features underlying the different allergenic capacities of those allergens.

Methods

Recombinant defensin‐polyproline–linked proteins were expressed in E. coli and physicochemically characterized in detail regarding identity, secondary structure, and aggregation status. Allergenic activity was assessed by mediator releases assay, serum IgE reactivity, and IgE inhibition ELISA using sera of patients from Austria, Canada, and Korea. Endolysosomal protein degradation and T‐cell cross‐reactivity were studied in vitro.

Results

Despite variations in the proline‐rich region, similar secondary structure elements were observed in the defensin‐like domains. Seventy‐four percent and 52% of the Austrian and Canadian patients reacted to all three allergens, while Korean patients were almost exclusively sensitized to Art v 1. This was reflected by IgE inhibition assays demonstrating high cross‐reactivity for Austrian, medium for Canadian, and low for Korean sera. In a subgroup of patients, IgE reactivity toward structurally altered Amb a 4 and Par h 1 was not changed suggesting involvement of linear epitopes. Immunologically relevant endolysosomal stability of the defensin‐like domain was limited to Art v 1 and no T‐cell cross‐reactivity with Art v 1_25‐36 was observed.

Conclusions

Despite structural similarity, different IgE‐binding profiles and proteolytic processing impacted the allergenic capacity of defensin‐polyproline–linked molecules. Based on the fact that Amb a 4 demonstrated distinct IgE‐binding epitopes, we suggest inclusion in molecule‐based allergy diagnosis.

Amb a 1 isoforms: Unequal siblings with distinct immunological features

Background

Ragweed pollen represents a major allergy risk factor. Ragweed extracts contain five different isoforms of the major allergen Amb a 1. However, the immunological characteristics of Amb a 1 isoforms are not fully investigated. Here, we compared the physicochemical and immunological properties of three most important Amb a 1 isoforms.

Methods

After purification, the isoforms were physicochemically characterized, tested for antibody binding and induction of human T‐cell proliferative responses. Their immunological properties were further evaluated in vitro and in vivo in a mouse model.

Results

Amb a 1 isoforms exhibited distinct patterns of IgE binding and immunogenicity. Compared to Amb a 1.02 or 03 isoforms, Amb a 1.01 showed higher IgE‐binding activity. Isoforms 01 and 03 were the most potent stimulators of patients’ T cells. In a mouse model of immunization, Amb a 1.01 induced higher levels of IgG and IgE antibodies when compared to isoforms 02 and 03. Interestingly, ragweed‐sensitized patients also displayed an IgG response to Amb a 1 isoforms. However, unlike therapy‐induced antibodies, sensitization‐induced IgG did not show IgE‐blocking activity.

Conclusion

The present study showed that naturally occurring isoforms of Amb a 1 possess different immunogenic and sensitizing properties. These findings should be considered when selecting sequences for molecule‐based diagnosis and therapy for ragweed allergy. Due to its high IgE‐binding activity, isoform Amb a 1.01 should be included in diagnostic tests. In contrast, due to their limited B‐ and T‐cell cross‐reactivity patterns, a combination of different isoforms might be a more attractive strategy for ragweed immunotherapy.

Influence of the Ag concentration on the medium-range order in a CuZrAlAg bulk metallic glass

Fluctuation electron microscopy of bulk metallic glasses of CuZrAl(Ag) demonstrates that medium-range order is sensitive to minor compositional changes. By analyzing nanodiffraction patterns medium-range order is detected with crystal-like motifs based on the B2 CuZr structure and its distorted structures resembling the martensitic ones. This result demonstrates some structural homology between the metallic glass and its high temperature crystalline phase. The amount of medium-range order seems slightly affected with increasing Ag concentration (0, 2, 5 at.%) but the structural motifs of the medium-range ordered clusters become more diverse at the highest Ag concentration. The decrease of dominant clusters is consistent with the destabilization of the B2 structure measured by calorimetry and accounts for the increased glass-forming ability.

The quantity and quality of α-gal-specific antibodies differ in individuals with and without delayed red meat allergy

Background

IgG to galactose‐α‐1,3‐galactose (α‐gal) are highly abundant natural antibodies (Ab) in humans. α‐Gal‐specific IgE Ab cause a special form of meat allergy characterized by severe systemic reactions 3–7 h after consumption of red meat. We investigated 20 patients who experienced such reactions and characterized their α‐gal‐specific IgE and IgG responses in more detail.

Methods

α‐Gal‐specific IgE was determined by ImmunoCAP. IgE reactivity to meat extract and bovine gamma globulin (BGG) was assessed by immunoblotting and ELISA, respectively. In some experiments, sera were pre‐incubated with α‐gal or protein G to deplete IgG Ab. α‐Gal‐specific IgG_1–4 Ab in individuals with and without meat allergy were assessed by ELISA.

Results

In immunoblots, BGG was the most frequently recognized meat protein. Binding of IgE and IgG to BGG was confirmed by ELISA and completely abolished after pre‐incubation with α‐gal. Neither the depletion of autologous α‐gal‐specific IgG Ab nor the addition of α‐gal‐specific IgG Ab from nonallergic individuals changed the IgE recognition of BGG of meat‐allergic patients. Meat‐allergic patients showed significantly higher α‐gal‐specific IgG1 and IgG3 Ab than nonallergic individuals, whereas the latter showed significantly higher levels of α‐gal‐specific IgG4 Ab.

Conclusion

Patients with delayed meat allergy display IgE and IgG Ab that selectively recognize the α‐gal epitope on BGG. Their enhanced α‐gal‐specific IgE levels are accompanied by high levels of α‐gal‐specific IgG1 devoid of IgE‐blocking activity. This subclass distribution is atypical for food allergies and distinct from natural α‐gal IgG responses in nonallergic individuals.

Bet v 1--a Trojan horse for small ligands boosting allergic sensitization?

BACKGROUND

Birch pollen allergy represents the main cause of winter and spring pollinosis in the temperate climate zone of the northern hemisphere and sensitization towards Bet v 1, the major birch pollen allergen, affects over 100 million allergic patients. The major birch pollen allergen Bet v 1 has been described as promiscuous acceptor for a wide variety of hydrophobic ligands.

OBJECTIVE

In search of intrinsic properties of Bet v 1, which account responsible for the high allergenic potential of the protein, we thought to investigate the effects of ligand-binding on immunogenic as well as allergenic properties.

METHODS

As surrogate ligand of Bet v 1 sodium deoxycholate (DOC) was selected. Recombinant and natural Bet v 1 were characterised physico-chemically as well as immunologically in the presence or absence of DOC, and an animal model of allergic sensitization was established. Moreover, human IgE binding to Bet v 1 was analysed by nuclear magnetic resonance (NMR) spectroscopy.

RESULTS

Ligand-binding had an overall stabilizing effect on Bet v 1. This translated in a Th2 skewing of the immune response in a mouse model. Analyses of human IgE binding on Bet v 1 in mediator release assays revealed that ligand-bound allergen-induced degranulation at lower concentrations; however, in basophil activation tests with human basophils ligand-binding did not show this effect. For the first time, human IgE epitopes on Bet v 1 were determined using antibodies isolated from patients' sera. The IgE epitope mapping of Bet v 1 demonstrated the presence of multiple binding regions.

CONCLUSIONS AND CLINICAL RELEVANCE

Deoxycholate binding stabilizes conformational IgE epitopes on Bet v 1; however, the epitopes themselves remain unaltered. Therefore, we speculate that humans are exposed to both ligand-bound and free Bet v 1 during sensitization, disclosing the ligand-binding cavity of the allergen as key structural element.

HLA class II peptide tetramers vs allergen-induced proliferation for identification of allergen-specific CD4 T cells

BACKGROUND

Fluorescence-labeled MHC class II/peptide tetramer complexes are considered as optimal tools to characterize allergen-specific CD4(+) T cells, but this technique is restricted to frequently expressed HLA class II molecules and knowledge of immunodominant epitopes. In contrast, allergen-stimulated proliferation assessed by CFSE dilution is less sophisticated and widely applicable. The major mugwort allergen, Art v 1, contains only one single, immunodominant, HLA-DR1-restricted epitope (Art v 125-36 ). Thus, essentially all Art v 1-reactive cells should be identified by a HLA-DRB1*01:01/Art v 119-36 tetramer.

METHODS

We compared specificity and sensitivity of tetramer(+) and allergen-induced proliferating (CFSE(lo) ) CD4(+) T cells by flow cytometry.

RESULTS

The frequency of tetramer(+) CD4(+) T cells determined ex vivo in PBMC of mugwort-allergic individuals ranged from 0 to 0.029%. After 2-3 weeks of in vitro expansion, sufficient tetramer(+) T cells for phenotyping were detected in 83% of Art v 125-36 -reactive T-cell lines (TCL) from mugwort-allergic individuals, but not in TCL from healthy individuals. The tetramers defined bona fide Th2 cells. Notably, Art v 125-36 -reactive TCL depleted of tetramer(+) T cells still reacted to the peptide, and only 44% of Art v 125-36 -specific T-cell clones were detected by the tetramer. CFSE(lo) CD4(+) T cells contained only 0.3-10.7% of tetramer(+) T cells and very low proportions of Th2 cells.

CONCLUSION

Allergen-specific T cells can be identified by HLA class II tetramers with high specificity, but unexpected low sensitivity. In contrast, allergen-stimulated CFSE(lo) CD4(+) T cells contain extremely high fractions of bystander cells. Therefore, for T-cell monitoring, either method should be interpreted with caution.

IgE, IgG4 and IgA specific to Bet v 1-related food allergens do not predict oral allergy syndrome

BACKGROUND

Birch pollen-associated plant food allergy is caused by Bet v 1-specific IgE, but presence of cross-reactive IgE to related allergens does not predict food allergy. The role of other immunoglobulin isotypes in the birch pollen-plant food syndrome has not been investigated in detail.

METHODS

Bet v 1-sensitized birch pollen-allergic patients (n = 35) were diagnosed for food allergy by standardized interviews, skin prick tests, prick-to-prick tests and ImmunoCAP. Concentrations of allergen-specific IgE, IgG1, IgG4 and IgA to seven Bet v 1-related food allergens were determined by ELISA.

RESULTS

Bet v 1, Cor a 1, Mal d 1 and Pru p 1 bound IgE from all and IgG4 and IgA from the majority of sera. Immunoglobulins to Gly m 4, Vig r 1 and Api g 1.01 were detected in <65% of the sera. No significant correlation was observed between plant food allergy and increased or reduced levels of IgE, IgG1, IgG4 or IgA specific to most Bet v 1-related allergens. Api g 1-specific IgE was significantly (P = 0.01) elevated in celeriac-allergic compared with celeriac-tolerant patients. Likewise, frequencies of IgE (71% vs 15%; P = 0.01) and IgA (86% vs 38%; P = 0.04) binding to Api g 1.01 were increased.

CONCLUSION

Measurements of allergen-specific immunoglobulins are not suitable for diagnosing Bet v 1-mediated plant food allergy to hazelnut and Rosaceae fruits. In contrast, IgE and IgA to the distantly related allergen Api g 1 correlate with allergy to celeriac.

Allergen hybrids - next generation vaccines for Fagales pollen immunotherapy

Background

Trees belonging to the order of Fagales show a distinct geographical distribution. While alder and birch are endemic in the temperate zones of the Northern Hemisphere, hazel, hornbeam and oak prefer a warmer climate. However, specific immunotherapy of Fagales pollen-allergic patients is mainly performed using birch pollen extracts, thus limiting the success of this intervention in birch-free areas.

Objectives

T cells are considered key players in the modification of an allergic immune response during specific immunotherapy (SIT), therefore we thought to combine linear T cell epitope-containing stretches of the five most important Fagales allergens from birch, hazel, alder, oak and hornbeam resulting in a Fagales pollen hybrid (FPH) molecule applicable for SIT.

Methods

A Fagales pollen hybrid was generated by PCR-based recombination of low IgE-binding allergen epitopes. Moreover, a structural-variant FPH4 was calculated by in silico mutagenesis, rendering the protein unable to adopt the Bet v 1-like fold. Both molecules were produced in Escherichia coli, characterized physico-chemically as well as immunologically, and tested in mouse models of allergic sensitization as well as allergy prophylaxis.

Results

Using spectroscopic analyses, both proteins were monomeric, and the secondary structure elements of FPH resemble the ones typical for Bet v 1-like proteins, whereas FPH4 showed increased amounts of unordered structure. Both molecules displayed reduced binding capacities of Bet v 1-specific IgE antibodies. However, in a mouse model, the proteins were able to induce high IgG titres cross-reactive with all parental allergens. Moreover, prophylactic treatment with the hybrid proteins prevented pollen extract-induced allergic lung inflammation in vivo.

Conclusion

The hybrid molecules showed a more efficient uptake and processing by dendritic cells resulting in a modified T cell response. The proteins had a lower IgE-binding capacity compared with the parental allergens, thus the high safety profile and increased efficacy emphasize clinical application for the treatment of Fagales multi-sensitization.

The high molecular weight glutenin subunit Bx7 allergen from wheat contains repetitive IgE epitopes

BACKGROUND

Wheat is one of the most common food allergen sources for children and adults. The aim of this study was to characterize new wheat allergens using an IgE discovery approach and to investigate their IgE epitopes.

METHODS

A cDNA expression library representing the wheat transcriptome was constructed in phage lambda gt11 and screened with IgE antibodies from wheat food allergic patients. IgE-reactive cDNA clones coding for portions of high molecular weight (HMW) glutenin subunits were identified by sequence analysis of positive clones. IgE epitopes were characterized using recombinant fragments from the HMW Bx7 and synthetic peptides thereof for testing of allergic patients' sera and in basophil degranulation assays.

RESULTS

We found that the major IgE-reactive areas of HMW glutenins are located in the repetitive regions of the protein and could show that two independent IgE-reactive fragments from HMW Bx7 contained repetitive IgE epitopes.

CONCLUSIONS

Our results demonstrate that IgE antibodies from wheat food allergic patients can recognize repetitive epitopes in one of the important wheat food allergens. Recombinant HMW Bx7 may be included into the panel of allergens for component-resolved diagnosis of wheat food allergy.

Differences in the intrinsic immunogenicity and allergenicity of Bet v 1 and related food allergens revealed by site-directed mutagenesis

Background

Birch pollen allergies are frequently associated with adverse reactions to various fruits, nuts, or vegetables, described as pollen–food syndrome (PFS) and caused by cross-reactive IgE antibodies primarily directed against Bet v 1. Specific immunotherapy (SIT) represents an effective treatment for inhalant allergies; however, successful birch pollen SIT does not correlate well with the amelioration of concomitant food allergies.

Methods

As vaccine candidates, apple Mal d 1 as well as hazelnut Cor a 1 derivatives were designed by in silico backbone analyses of the respective allergens. The proteins were produced by site-directed mutagenesis as fold variants of their parental allergens. Because Mal d 1 and Cor a 1 form cysteine-mediated aggregates, nonaggregative cysteine to serine mutants were also generated. The proteins were characterized physicochemically, immunologically, and in in vivo models with or without adjuvant.

Results

The structurally modified proteins showed significantly decreased IgE binding capacity. Notably, both in vivo models revealed reduced immunogenicity of the hypoallergenic fold variants. When formulated with alum, the monomeric cysteine mutants induced a similar immune response as the aggregated parental allergens, which is in contrast with data published on Bet v 1.

Conclusion

These findings lead to the suggestion that the Bet v 1 structure has unique intrinsic properties, which could account for its high allergenicity. Obviously, these characteristics are not entirely shared with its food homologues from apple and hazelnut. Thus, it is important to tackle pollen-related food allergies from different angles for the generation of effective vaccine candidates to treat birch PFS.

Kinetics, cross-reactivity, and specificity of Bet v 1-specific IgG4 antibodies induced by immunotherapy with birch pollen

BACKGROUND

IgE antibodies specific for the major birch pollen allergen frequently cross-react with Bet v 1 homologous food proteins, for example Cor a 1 in hazelnut and Mal d 1 in apple. Specific immunotherapy with birch pollen (BP-SIT) induces IgG4 antibodies that inhibit IgE binding to Bet v 1. However, information on cross-reactivity of BP-SIT-induced Bet v 1-specific IgG4 antibodies with food allergens is limited. In this study, we investigated the kinetics of production, cross-reactivity, and IgE-blocking activity of Bet v 1-specific IgG4 antibodies emerging during conventional BP-SIT and whether IgG4-epitopes overlapped with IgE epitopes.

METHODS

IgE and IgG4 levels specific for Bet v 1, Mal d 1, and Cor a 1 were determined in 42 birch pollen-allergic patients before and during BP-SIT. Inhibition of IgE binding was studied by IgE-facilitated antigen-binding assays and basophil activation tests. Furthermore, inhibition of IgE-mediated activation of food allergen-reactive Bet v 1-specific T-cell lines was assessed. Competitive immunoscreening of phage-displayed peptides was applied to select mimotopes recognized by IgE and IgG4 antibodies, respectively. The resulting mimotopes were mapped on the surface of the 3D structure of the allergens using a computer-based algorithm.

RESULTS

BP-SIT significantly increased Bet v 1- and food allergen-reactive IgG4 antibodies. In parallel, allergen-specific IgE levels decreased significantly. Sera containing food allergen-reactive IgG4 antibodies inhibited IgE binding, basophil activation, and IgE-mediated food allergen-induced T-cell proliferation. Predicted IgE and IgG4 epitopes on all allergens showed high overlap.

CONCLUSION

Our results indicate that BP-SIT may induce Bet v 1-specific IgG4 antibodies that cross-react with related food allergens and inhibit IgE binding by epitope competition.

Clinical effects of electroconvulsive therapy in severe depression and concomitant changes in cerebral glucose metabolism--an exploratory study

OBJECTIVE

Electroconvulsive therapy (ECT) is an effective mode of treatment--especially for severe depression and for depression refractory to pharmacotherapy, nevertheless the mode of action of ECT is far from being fully understood. This study assessed the effects of a series of ECT in depressive subjects on cerebral glucose metabolism measured by FDG-PET scans pre- and post-therapy in thus far the largest group of 12 patients.

METHODS

Our analysis included careful repeated evaluation of clinical changes in mood and behaviour by standardised questionnaires, which allowed testing for a potential correlation between clinical and cerebral metabolic changes. PET scanning was done within a predefined time window and we used predefined ROIs with counts normalized to the pons activity.

RESULTS

We observed few changes in cerebral glucose metabolism over time. There was a marginal increase in the left temporal and a trend for a decrease in left frontobasal areas subsequent to treatment in our sample. FDG uptake patterns remained remarkably stable in all the other predefined ROIs pre- and post-treatment. There were no significant correlations between changes in relative metabolic rates and changes in depression scores and parameters derived from neurocognitive testing.

CONCLUSIONS

Our study thus cannot support the view that FDG-PET can assess the functional brain changes that are likely to occur subsequent to ECT in such a scenario, but this may be related to limited sensitivity given the sample size. Future studies thus might wish to challenge this notion in larger patient samples to clarify this issue.

Carrier-bound Alt a 1 peptides without allergenic activity for vaccination against Alternaria alternata allergy

BACKGROUND

The mould Alternaria alternata is a major elicitor of allergic asthma. Diagnosis and specific immunotherapy (SIT) of Alternaria allergy are often limited by the insufficient quality of natural mould extracts.

OBJECTIVE

To investigate whether recombinant Alt a 1 can be used for reliable diagnosis of Alternaria alternata allergy and to develop a safe, non-allergenic vaccine for SIT of Alternaria allergy.

METHODS

The qualitative sensitization profile of 80 Alternaria-allergic patients from Austria and Italy was investigated using an allergen micro-array and the amount of Alternaria-specific IgE directed to rAlt a 1 was quantified by ImmunoCAP measurements. Peptides spanning regions of predicted high surface accessibility of Alt a 1 were synthesized and tested for IgE reactivity and allergenic activity, using sera and basophils from allergic patients. Carrier-bound peptides were studied for their ability to induce IgG antibodies in rabbits which recognize Alt a 1 and inhibit allergic patients' IgE reactivity to Alt a 1.

RESULTS

rAlt a 1 allowed diagnosis of Alternaria allergy in all tested patients, bound the vast majority (i.e. >95%) of Alternaria-specific IgE and elicited basophil activation already at a concentration of 0.1 ng/mL. Four non-allergenic peptides were synthesized which, after coupling to the carrier protein keyhole limpet hemocyanin, induced Alt a 1-specific IgG and inhibited allergic patients' IgE binding to Alt a 1.

CONCLUSIONS AND CLINICAL RELEVANCE

rAlt a 1 is a highly allergenic molecule allowing sensitive diagnosis of Alternaria allergy. Carrier-bound non-allergenic Alt a 1 peptides are candidates for safe SIT of Alternaria allergy.

Molecular characterization of wheat allergens specifically recognized by patients suffering from wheat-induced respiratory allergy

BACKGROUND

Wheat (Triticum aestivum) is an important allergen source responsible for various clinical manifestations of allergy (i.e. food allergy, pollen allergy, respiratory allergy to flour-Baker's asthma).

OBJECTIVE

The objective of this study was the molecular and immunological characterization of new recombinant wheat allergens and to evaluate their usefulness for the diagnosis of allergy to wheat.

METHODS

A T. aestivum cDNA library was constructed and screened with serum IgE from patients suffering from wheat allergy to identify cDNAs coding for new wheat allergens. The allergen-encoding cDNAs were expressed in Escherichia coli and purified to homogeneity. IgE reactivity of recombinant proteins was analysed in RAST-based, non-denaturing dot blot experiments and by ELISA with sera from wheat allergic patients and their allergenic activity was assessed in basophil degranulation experiments.

RESULTS

We report the molecular characterization, recombinant expression and purification of five wheat allergens, a thioredoxin h isoform, glutathione transferase, 1-Cys-peroxiredoxin, profilin and dehydrin. Homologous proteins were identified by sequence comparisons in various plants. 1-Cys-peroxiredoxin appeared to be the most relevant of the newly identified wheat allergens according to prevalence of IgE recognition and results from basophil degranulation experiments. It showed IgE cross-reactivity with seed proteins from barley, rye, rice, maize, soy, oat and spelt. 1-Cys-peroxiredoxin, glutathione transferase and dehydrin were mainly recognized by patients with baker's asthma but not wheat-induced food allergy.

CONCLUSION AND CLINICAL RELEVANCE

The characterized recombinant wheat allergens may be useful for the development of serological tests which allow the discrimination of different clinical manifestations of wheat allergy.

Patients suffering from non-IgE-mediated cow's milk protein intolerance cannot be diagnosed based on IgG subclass or IgA responses to milk allergens

BACKGROUND

Cow's milk is one of the most common causes of food allergy. In two-thirds of patients, adverse symptoms following milk ingestion are caused by IgE-mediated allergic reactions, whereas for one-third, the mechanisms are unknown. Aim of this study was to investigate whether patients suffering from non-IgE-mediated cow's milk protein intolerance can be distinguished from persons without cow's milk protein intolerance based on serological measurement of IgG and IgA specific for purified cow's milk antigens.

METHODS

We determined IgG(1-4) subclass and IgA antibody levels to purified recombinant αS1-casein, αS2-casein, β-casein, κ-casein, α-lactalbumin, and β-lactoglobulin in four patient groups by ELISA: Patients with IgE-mediated cow's milk allergy (CMA, n=25), patients with non-IgE-mediated cow's milk protein intolerance (CMPI, n=19), patients with gastrointestinal symptoms not associated with cow's milk ingestion (GI, n=15) and control persons without gastrointestinal problems (C, n=26). Cow's milk-specific IgE levels were determined by ImmunoCAP.

RESULTS

Only CMA patients had IgE antibodies to cow's milk. Cow's milk allergic patients mounted the highest IgG(1) and IgG(4) antibody levels to αS1-casein, αS2-casein, β-casein, κ-casein, and α-lactalbumin. No elevated levels of IgG(4) , IgA, and complement-binding IgG subclasses (IgG(1) , IgG(2) , IgG(3) ) to purified cow's milk allergens were found within the CMPI patients compared to persons without cow's milk protein intolerance (GI and C groups).

CONCLUSION

Cow's milk protein intolerant patients cannot be distinguished from persons without cow's milk protein intolerance on the basis of IgG subclass or IgA reactivity to cow's milk allergens.

Microarray and allergenic activity assessment of milk allergens

BACKGROUND

Cow's milk is one of the most common causes of food allergy affecting approximately 2.5% of infants in the first years of their life. However, only limited information regarding the allergenic activity of individual cow's milk allergens is available.

OBJECTIVE

To analyse the frequency of IgE reactivity and to determine the allergenic activity of individual cow's milk allergens.

METHODS

A nitrocellulose-based microarray, based on purified natural and recombinant cow's milk allergens was used to determine IgE reactivity profiles using sera from 78 cow's milk-sensitized individuals of varying ages. The allergenic activity of the individual allergens was tested using patients' sera for loading rat basophil leukaemia cells (RBL) expressing the α-chain of the human receptor FcεRI.

RESULTS

Using the microarray and the RBL assay, cow's milk allergens were assessed for frequency of IgE recognition and allergenic activity. Moreover, the RBL assay allowed distinguishing individuals without or with mild clinical reactions from those with severe systemic or gastrointestinal symptoms as well as persons who grew out cow's milk allergy from those who did not.

CONCLUSIONS

Component-resolved testing using milk allergen microarrays and RBL assays seems to provide useful additional diagnostic information and may represent a basis for future forms of prophylactic and therapeutic strategies for cow's milk allergy.

Innovative telemonitoring system for cardiology: from science to routine operation

OBJECTIVE

Results of the Austrian MOBITEL (MOBIle phone based TELemonitoring for heart failure patients) trial indicate that home-based telemonitoring improves outcome of chronic heart failure (CHF) patients and reduces both frequency and duration of hospitalizations. Based on lessons learned, we assessed the weak points to clear the way for routine operations.

METHODS

We analyzed the system with respect to recommendations of the ESC Guidelines and experiences gained throughout the trial to identify potential improvements. The following components have been identified: a patient terminal with highest usability, integrated way to document drug-intake and well-being, and automated event detection for worsening of CHF. As a consequence the system was extended by Near Field Communication (NFC) technology and by an event management tool.

RESULTS

Usability evaluation with 30 adults (14f, median 51y. IQR[45-65]) showed that 21 (8f) were able to immediately operate the system after reading a step-by-step manual. Eight (6f) needed one time demonstration and one man (80y) failed to operate the blood pressure meter. Routine operation of the revised system started in March 2009. Within 9 months, 15 patients (4f, median 74y. IQR[71-83], all NYHA-III) transmitted 17,149 items. 43 events were detected because of body weight gain of more then 2kg within 2 days. 49 therapy adjustments were documented. Three patients stopped using the system, two (1f) because of non-compliance and one (m, 82y) because of death. Overall, the rate of adherence to daily data transfer was 78%.

CONCLUSION

First results confirm the applicability of the revised telemonitoring system in routine operation.

Micro-arrayed wheat seed and grass pollen allergens for component-resolved diagnosis

BACKGROUND

Wheat is a potent allergen source and can cause baker's asthma, food and pollen allergy. The aim of the study was to develop an allergen micro-array for differential diagnosis of baker's asthma, wheat-induced food allergy and grass pollen allergy.

METHODS

We analysed the immunoglobulin-E reactivity profiles of patients suffering from baker's asthma, wheat-induced food allergy and grass pollen allergy to micro-arrayed recombinant wheat flour allergens and grass pollen allergens and compared these results with clinical results and diagnostic tests based on crude wheat flour, wheat pollen and grass pollen allergen extracts.

RESULTS

We identified recombinant wheat flour allergens, which are specifically recognized by patients suffering from baker's asthma, but not from patients with food allergy to wheat or pollen allergy. rPhl p 1 and rPhl p 5 were identified as marker allergens specific for grass pollen allergy. They can be used to replace grass pollen extracts for allergy diagnosis and to identify grass pollen allergic patients among patients suffering from baker's asthma and wheat-induced food allergy. Profilin was identified as a cross-reactive allergen recognized by patients suffering from baker's asthma, food and pollen allergy.

CONCLUSIONS

Our results indicate that it will be possible to design serological tests based on micro-arrayed recombinant wheat seed and grass pollen allergens for the discrimination of baker's asthma, wheat-induced food allergy and grass pollen allergy.

Cloning, expression, and mapping of allergenic determinants of alphaS1-casein, a major cow's milk allergen

Milk is one of the first components introduced into human diet. It also represents one of the first allergen sources, which induces IgE-mediated allergies in childhood ranging from gastrointestinal, skin, and respiratory manifestations to severe life-threatening manifestations, such as anaphylaxis. Here we isolated a cDNA coding for a major cow's milk allergen, alphaS1-casein, from a bovine mammary gland cDNA library with allergic patients' IgE Abs. Recombinant alphaS1-casein was expressed in Escherichia coli, purified, and characterized by circular dichroism as a folded protein. IgE epitopes of alphaS1-casein were determined with recombinant fragments and synthetic peptides spanning the alphaS1-casein sequence using microarrayed components and sera from 66 cow's milk-sensitized patients. The allergenic activity of ralphaS1-casein and the alphaS1-casein-derived peptides was determined using rat basophil leukemia cells transfected with human FcepsilonRI, which had been loaded with the patients' serum IgE. Our results demonstrate that ralphaS1-casein as well as alphaS1-casein-derived peptides exhibit IgE reactivity, but mainly the intact ralphaS1-casein induced strong basophil degranulation. These results suggest that primarily intact alphaS1-casein or larger IgE-reactive portions thereof are responsible for IgE-mediated symptoms of food allergy. Recombinant alphaS1-casein as well as alphaS1-casein-derived peptides may be used in clinical studies to further explore pathomechanisms of food allergy as well as for the development of new diagnostic and therapeutic strategies for milk allergy.

Mobile teledermatology: a feasibility study of 58 subjects using mobile phones

We investigated the diagnostic agreement between teledermatology based on images from a mobile phone camera and face-to-face (FTF) dermatology. Diagnostic agreement was assessed for two teledermatologists (TD) in comparison with FTF consultations in 58 subjects. In almost three-quarters of the cases (TD1: 71%; TD2: 76%), the telediagnosis was fully concordant with the FTF diagnosis. Furthermore, the diagnosed diseases were almost all in the same diagnostic category (TD1: 97%; TD2: 90%). If mobile teledermatology had been used for remote triage, TD1 could have treated 53% subjects remotely and 47% subjects would have had to consult a dermatologist FTF. TD2 could have treated 59% subjects remotely, whereas 41% subjects would have had to consult a dermatologist FTF. Forty-eight subjects responded to a questionnaire, of whom only 10 had any concerns regarding teledermatology. Thirty-one subjects stated that they would be willing to pay to use a similar service in future and suggested an amount ranging from euro5 to euro50 per consultation (mean euro22) (euro = pound0.7, US $1.4). These results are encouraging as patient acceptance and reimbursement represent potential obstacles to the implementation of telemedicine services.

Molecular and immunological characterization of novel weed pollen pan-allergens

BACKGROUND

Pan-allergens like profilins, calcium-binding proteins (CBPs), and nonspecific lipid transfer proteins have been suggested as possible specific markers for multiple pollen sensitizations, and could be used to predict cross-sensitization/poly-sensitization to several pollen allergens. Therefore, the purification and characterization of cross-reacting allergens in pollen is an extremely important task towards correct allergy diagnosis.

METHODS

New pan-allergens were identified by screening a ragweed pollen cDNA library with sera of patients allergic to mugwort pollen. Resulting proteins were cloned, expressed, purified and characterized.

RESULTS

We report complete cDNA sequences of two profilin isoforms (Amb a 8.01 and Amb a 8.02), two isoforms of a 2EF-hand CBP (Amb a 9.01 and Amb a 9.02), a new 3EF-hand CBP (Amb a 10) from ragweed pollen and a 2EF-hand CBP from mugwort (Art v 5). All these proteins were expressed in Escherichia coli, purified to homogeneity and characterized by biochemical and immunological means.

CONCLUSIONS

The identified proteins are novel pan-allergens and can be used as diagnostic markers for polysensitization and used in component-resolved diagnosis.

Changes in brain metabolism after ECT-positron emission tomography in the assessment of changes in glucose metabolism subsequent to electroconvulsive therapy--lessons, limitations and future applications

BACKGROUND

Electroconvulsive therapy (ECT) has been used as an effective treatment option in severe and treatment resistant cases of depression for decades. However the mode of action of ECT is still not fully understood. Advances in neuroimaging created new possibilities to understand the functional changes of the human brain.

METHODS

Literature review of studies assessing possible changes in cerebral glucose metabolism pre- and post-ECT by PET, identified by PubMed.

RESULTS

Studies were limited by small sample size, inhomogeneous study population with uni- and bipolar depressive patients and methodological inconsistencies. Despite considerable variance, reduction in glucose metabolism after ECT in bilateral anterior and posterior frontal areas represented the most consistent findings.

CONCLUSIONS

Future research into this issue should include larger and more consistent cohorts of patients. Assessing clinical improvement of depression after ECT should allow to correlate changes in brain glucose metabolism with functional scores. Follow up PET scans after six or twelve months should be performed to test if changes in brain metabolism are persistent.

Melanoma screening with cellular phones

Background

Mobile teledermatology has recently been shown to be suitable for teledermatology despite limitations in image definition in preliminary studies. The unique aspect of mobile teledermatology is that this system represents a filtering or triage system, allowing a sensitive approach for the management of patients with emergent skin diseases.

Methodology/Principal Findings

In this study we investigated the feasibility of teleconsultation using a new generation of cellular phones in pigmented skin lesions. 18 patients were selected consecutively in the Pigmented Skin Lesions Clinic of the Department of Dermatology, Medical University of Graz, Graz (Austria). Clinical and dermoscopic images were acquired using a Sony Ericsson with a built-in two-megapixel camera. Two teleconsultants reviewed the images on a specific web application (http://www.dermahandy.net/default.asp) where images had been uploaded in JPEG format. Compared to the face-to-face diagnoses, the two teleconsultants obtained a score of correct telediagnoses of 89% and of 91.5% reporting the clinical and dermoscopic images, respectively.

Conclusions/Significance

The present work is the first study performing mobile teledermoscopy using cellular phones. Mobile teledermatology has the potential to become an easy applicable tool for everyone and a new approach for enhanced self-monitoring for skin cancer screening in the spirit of the eHealth program of the European Commission Information for Society and Media.

Characterization of recombinant Mal d 4 and its application for component-resolved diagnosis of apple allergy

BACKGROUND

Profilins are ubiquitous panallergens that have been extensively characterized; yet, their clinical relevance is still unclear.

OBJECTIVE

The aim of the present study was to produce recombinant apple profilin (rMal d 4) and to evaluate its allergenic activity and its potency for component-resolved allergy diagnosis.

METHODS

Complementary DNA-derived Mal d 4 was cloned, expressed in Escherichia coli and subsequently purified via poly (l-proline) sepharose. A total of 28 sera from apple-allergic patients were used for IgE-ELISA, immunoblot, RAST and basophil histamine release (BHR) test. In addition, skin prick tests (SPTs) were performed in five patients.

RESULTS

Four different complementary DNA coding for apple profilin, Mal d 4, each with an open reading frame of 393 nucleotides, were identified. One isoform Mal d 4.0101 was expressed in Escherichia coli and subsequently purified. Mass spectroscopy revealed the expected mass of 13.826 for rMal d 4.0101, and circular dichroism analysis data were typical for a folded protein and small-angle X-ray scattering measurement identified the protein as a monomer. All the serum samples displayed IgE binding to rMal d 4.0101 in IgE ELISA, immunoblot and RAST. In immunoblotting, IgE binding to natural Mal d 4 was partially/completely inhibited by preincubation with rMal d 4.0101, and RAST values to apple extract were significantly reduced upon serum pretreatment with rMal d 4.0101. SPTs and BHR assays using purified rMal d 4.0101 were positive. Purified rMal d 4.0101 was destroyed within seconds when subjected to pepsin digestion.

CONCLUSIONS

Apple profilin complementary DNAs were identified. The physicochemical and allergenic properties of purified recombinant Mal d 4.0101 were evaluated showing that the recombinant protein was equal to the natural protein as shown by inhibition assays. Thus, Mal d 4 represents another example suitable for component-resolved diagnosis of food allergy.

Alternaria alternata NADP-dependent mannitol dehydrogenase is an important fungal allergen

BACKGROUND

Alternaria alternata is one of the most important allergenic fungi worldwide. Mannitol dehydrogenase (MtDH) has previously been shown to be a major allergen of Cladosporium herbarum and cross-reactivity has been demonstrated for several fungal allergens.

OBJECTIVE

The present study's objective was to clone the MtDH from an A. alternata cDNA library, express and purify the recombinant non-fusion protein and test its IgE-binding properties. Methods A cDNA library prepared from A. alternata hyphae and spores was screened for mannitol dehydrogenase by DNA hybridization with the radioactively labelled C. herbarum homologue as a probe. The resulting clone was sequenced and heterologously expressed in Escherichia coli as a recombinant non-fusion protein, which was purified to homogeneity and analysed for its IgE-binding capacity.

RESULTS

The coding sequence of the full-length cDNA clone comprises 798 bp encoding a protein with a molecular mass of 28.6 kDa and a predicted pI of 5.88. Protein sequence analysis revealed an identity of 75% and a homology of 86% between the MtDHs of A. alternata and C. herbarum. The functional mannitol dehydrogenase was expressed in the E. coli strain BL21(DE3) transformed with the vector pMW172 and purified to homogeneity. The enzyme catalyses the NADPH-dependent conversion of d-fructose to d-mannitol. In IgE-ELISA and immunoblots, MtDH is recognized by 41% of A. alternata-allergic patients. In vivo immunoreactivity of the recombinant MtDH was verified by skin prick testing. Finally, inhibition-ELISA experiments confirmed cross-reactivity between the MtDHs of A. alternata and C. herbarum.

CONCLUSION

Mannitol dehydrogenase (Alt a 8) represents an important new allergen of the ascomycete A. alternata that might be suitable for improving diagnostic and therapeutic procedures.

ESPEN Guidelines on Enteral Nutrition: Intensive care

Enteral nutrition (EN) via tube feeding is, today, the preferred way of feeding the critically ill patient and an important means of counteracting for the catabolic state induced by severe diseases. These guidelines are intended to give evidence-based recommendations for the use of EN in patients who have a complicated course during their ICU stay, focusing particularly on those who develop a severe inflammatory response, i.e. patients who have failure of at least one organ during their ICU stay. These guidelines were developed by an interdisciplinary expert group in accordance with officially accepted standards and are based on all relevant publications since 1985. They were discussed and accepted in a consensus conference. EN should be given to all ICU patients who are not expected to be taking a full oral diet within three days. It should have begun during the first 24h using a standard high-protein formula. During the acute and initial phases of critical illness an exogenous energy supply in excess of 20-25 kcal/kg BW/day should be avoided, whereas, during recovery, the aim should be to provide values of 25-30 total kcal/kg BW/day. Supplementary parenteral nutrition remains a reserve tool and should be given only to those patients who do not reach their target nutrient intake on EN alone. There is no general indication for immune-modulating formulae in patients with severe illness or sepsis and an APACHE II Score >15. Glutamine should be supplemented in patients suffering from burns or trauma.