A community-based intervention study involving family gardens with aromatic herbs on changes in dietary and urinary sodium

OBJECTIVE

To measure dietary and urinary changes in sodium (Na) intake and excretion through the implementation of family gardens with aromatic herbs and workshops for cooking, using the herbs as a substitute for salt and seasoning powder.

METHODS

Thirty-five participants from a neighborhood of Mexico City were included. A general questionnaire was administered to collect information on sociodemographic factors. At baseline and 3 months later, a dietary evaluation was conducted, and 24-hour urine samples were collected. Food items reported were classified according to the NOVA classification. Visits to participants´ houses were conducted to measure the amount of salt and seasoning powder added to food during the preparation of meals as well as a home food inventory. All participants were given a family garden with 6 aromatic herbs and a recipe book. The intervention included 7 cooking and 3 garden care workshops. Qualitative information on the experience was also collected. Linear regression models were run in order to estimate the contribution of each NOVA group, salt, and seasoning powder to total dietary Na intake.

RESULTS

Participants were 44 years old on average and were mainly women (91.4%). The participation compliance in the workshops was 69.5%. After 3 months, there was a Na intake mean reduction of 976 mg. There was also a reduction in the excreted urinary Na of 325 mg per day.

CONCLUSION

A positive level of involvement in this program had a direct influence on dietary habits to lower Na consumption.

Clinical outcomes of deep brain stimulation for obsessive-compulsive disorder: Insight as a predictor of symptom changes

AIM

Deep brain stimulation (DBS) is a safe and effective treatment option for people with refractory obsessive-compulsive disorder (OCD). Yet our understanding of predictors of response and prognostic factors remains rudimentary, and long-term comprehensive follow-ups are lacking. We aim to investigate the efficacy of DBS therapy for OCD patients, and predictors of clinical response.

METHODS

Eight OCD participants underwent DBS stimulation of the nucleus accumbens (NAc) in an open-label longitudinal trial, duration of follow-up varied between 9 months and 7 years. Post-operative care involved comprehensive fine tuning of stimulation parameters and adjunct multidisciplinary therapy.

RESULTS

Six participants achieved clinical response (35% improvement in obsessions and compulsions on the Yale Brown Obsessive Compulsive Scale (YBOCS)) within 6-9 weeks, response was maintained at last follow up. On average, the YBOCS improved by 45% at last follow up. Mixed linear modeling elucidated directionality of symptom changes: insight into symptoms strongly predicted (P = 0.008) changes in symptom severity during DBS therapy, likely driven by initial changes in depression and anxiety. Precise localization of DBS leads demonstrated that responders most often had their leads (and active contacts) placed dorsal compared to non-responders, relative to the Nac.

CONCLUSION

The clinical efficacy of DBS for OCD is demonstrated, and mediators of changes in symptoms are proposed. The symptom improvements within this cohort should be seen within the context of the adjunct psychological and biopsychosocial care that implemented a shared decision-making approach, with flexible iterative DBS programming. Further research should explore the utility of insight as a clinical correlate of response. The trial was prospectively registered with the ANZCTR (ACTRN12612001142820).

The promise and challenges of transcranial magnetic stimulation and deep brain stimulation as therapeutic options for obsessive-compulsive disorder

INTRODUCTION

Obsessive compulsive disorder (OCD) represents a complex and often difficult to treat disorder. Pharmacological and psychotherapeutic interventions are often associated with sub-optimal outcomes, and 40-60% of patients are resistant to first line therapies and thus left with few treatment options. OCD is underpinned by aberrant neurocircuitry within cortical, striatal, and thalamic brain networks. Considering the neurocircuitry impairments that underlie OCD symptomology, neurostimulation therapies provide an opportunity to modulate psychopathology in a personalized manner. Also, by probing pathological neural networks, enhanced understanding of disease states can be obtained.

AREAS COVERED

This perspective discusses the clinical efficacy of TMS and DBS therapies, treatment access options, and considerations and challenges in managing patients. Recent scientific progress is discussed, with a focus on neurocircuitry and biopsychosocial aspects. Translational recommendations and suggestions for future research are provided.

EXPERT OPINION

There is robust evidence to support TMS and DBS as an efficacious therapy for treatment resistant OCD patients supported by an excellent safety profile and favorable health economic data. Despite a great need for alternative therapies for chronic and severe OCD patients, resistance toward neurostimulation therapies from regulatory bodies and the psychiatric community remains. The authors contend for greater access to TMS and DBS for treatment resistant OCD patients at specialized sites with appropriate clinical resources, particularly considering adjunct and follow-up care. Also, connectome targeting has shown robust predictive ability of symptom improvements and holds potential in advancing personalized neurostimulation therapies.

Deep Brain Stimulation for Obsessive-Compulsive Disorder: Optimal Stimulation Sites

BACKGROUND

Deep brain stimulation (DBS) is a promising treatment option for treatment-refractory obsessive-compulsive disorder (OCD). Several stimulation targets have been used, mostly in and around the anterior limb of the internal capsule and ventral striatum. However, the precise target within this region remains a matter of debate.

METHODS

Here, we retrospectively studied a multicenter cohort of 82 patients with OCD who underwent DBS of the ventral capsule/ventral striatum and mapped optimal stimulation sites in this region.

RESULTS

DBS sweet-spot mapping performed on a discovery set of 58 patients revealed 2 optimal stimulation sites associated with improvements on the Yale-Brown Obsessive Compulsive Scale, one in the anterior limb of the internal capsule that overlapped with a previously identified OCD-DBS response tract and one in the region of the inferior thalamic peduncle and bed nucleus of the stria terminalis. Critically, the nucleus accumbens proper and anterior commissure were associated with beneficial but suboptimal clinical improvements. Moreover, overlap with the resulting sweet- and sour-spots significantly estimated variance in outcomes in an independent cohort of 22 patients from 2 additional DBS centers. Finally, beyond obsessive-compulsive symptoms, stimulation of the anterior site was associated with optimal outcomes for both depression and anxiety, while the posterior site was only associated with improvements in depression.

CONCLUSIONS

Our results suggest how to refine targeting of DBS in OCD and may be helpful in guiding DBS programming in existing patients.

Phenomenological Changes Associated with Deep Brain Stimulation for Obsessive Compulsive Disorder: A Cognitive Appraisal Model of Recovery

The current scientific enquiry of deep brain stimulation (DBS) does not capture the breadth of DBS-induced changes to an individual's life. Considering that DBS is applied in severe and complex cases, it is ethically and clinically necessary to consider the patient perspective and personally relevant outcomes. This lived experience investigation of people with obsessive compulsive disorder (OCD) undergoing DBS aims to provide a comprehensive evaluation of DBS-induced effects associated with OCD psychopathology. Six patients and six carers completed semi-structured open-ended interviews. A blended approach of interpretative phenomenological, inductive, and thematic analysis techniques was employed. Profound psychopathological changes were expressed; individuals felt more alive, had improved cognitive affective control, greater engagement in the world, and were able to manage their OCD. Through suppression of the condition, self-constructs were able to re-emerge and develop. A framework describing the progression of phenomenological changes, and a theoretical model describing changes in the cognitive appraisal of intrusions influencing recovery are proposed. This is the first identified qualitative investigation of DBS-induced changes in psychiatric patients and carers. Findings have implications for patient education and recovery models of OCD, and scientific understanding of DBS effects.

Anatomical targeting for electrode localization in subthalamic nucleus deep brain stimulation: A comparative study

BACKGROUND AND PURPOSE

In deep brain stimulation (DBS), accurate electrode placement is essential for optimizing patient outcomes. Localizing electrodes enables insight into therapeutic outcomes and development of metrics for use in clinical trials. Methods of defining anatomical targets have been described with varying accuracy and objectivity. To assess variability in anatomical targeting, we compare four methods of defining an appropriate target for DBS of the subthalamic nucleus for Parkinson's disease.

METHODS

The methods compared are direct visualization, red nucleus-based indirect targeting, mid-commissural point-based indirect targeting, and automated template-based targeting. This study assessed 226 hemispheres in 113 DBS recipients (39 females, 73 males, 62.2 ± 7.7 years). We utilized the electrode placement error (the Euclidean distance between the defined target and closest DBS electrode) as a metric for comparative analysis. Pairwise differences in electrode placement error across the four methods were compared using the Kruskal-Wallis H-test and Wilcoxon signed-rank tests.

RESULTS

Interquartile ranges of the differences in electrode placement error spanned 1.18-1.56 mm. A Kruskal-Wallis H-test reported a statistically significant difference in the median of at least two groups (H(5) = 41.052, p < .001). Wilcoxon signed-rank tests reported statistically significant difference in two comparisons: direct visualization versus red nucleus-based indirect, and direct visualization versus automated template-based methods (T < 9215, p < .001).

CONCLUSIONS

All methods were similarly discordant in their relative accuracy, despite having significant technical differences in their application. The differing protocols and technical aspects of each method, however, have the implication that one may be more practical depending on the clinical or research application at hand.

Patient feedback and psychosocial outcomes of deep brain stimulation in people with obsessive-compulsive disorder

Severe and refractory psychiatric patients can experience complex and profound changes in symptomology, functioning and well-being from deep brain stimulation (DBS) therapy. Currently, the efficacy of DBS is assessed by clinician rated scales of primary symptoms, yet this does not capture the multitude of DBS mediated changes or represent the patient perspective. We aimed to elucidate the patient perspective in psychiatric DBS application by investigating 1) symptomatic, and 2) psychosocial changes, 3) therapeutic expectations and satisfaction, 4) decision-making capacity, and 5) clinical care recommendations from treatment refractory obsessive-compulsive disorder (OCD) DBS patients. Participants enrolled in an open label clinical trial of DBS therapy for OCD who had reached clinical response were invited to participate in a follow up survey. Participants completed a 1) feedback survey relating to goals, expectations, and satisfaction of therapy, and 2) self-report questionnaires on psychosocial functioning including quality of life, cognitive insight, locus of control, rumination, cognitive flexibility, impulsivity, affect, and well-being. Greatest change was reported for quality of life, rumination, affect and cognitive flexibility. Participants reported realistic expectations, high satisfaction, adequate pre-operative education and decision-making capacity; and advocated for greater access to DBS care and more widespread support services. This is the first identified investigation on psychiatric patient perspectives of functioning and therapeutic outcomes following DBS. Insights from the study have implications for informing psychoeducation, clinical practices, and neuroethical debates. We encourage a greater patient-centred and biopsychosocial approach in evaluating and managing OCD DBS patients, by considering personally meaningful goals and addressing symptomatic and psychosocial recovery.

Clinical recommendations for the care of people with treatment-refractory obsessive-compulsive disorder when undergoing deep brain stimulation

Deep brain stimulation is an emerging therapy for treatment-refractory obsessive-compulsive disorder patients. Yet, accessibility is limited, treatment protocols are heterogeneous and there is no guideline or consensus on the best practices. Here, we combine evidence from scientific investigations, expert opinions and our clinical expertise to propose several clinical recommendations from the pre-operative, surgical and post-operative phases of deep brain stimulation care for treatment-refractory obsessive-compulsive disorder patients. A person-centered and biopsychosocial approach is adopted. Briefly, we discuss clinical characteristics associated with response, the use of improved educational materials, an evaluative consent process, comprehensive programming by an expert clinician, a more global assessment of treatment efficacy, multi-disciplinary adjunct psychotherapy and the importance of peer support programs. Furthermore, where gaps are identified, future research suggestions are made, including connectome surgical targeting, scientific evaluation of hardware models and health economic data. In addition, we encourage collaborative groups of data and knowledge sharing by way of a clinical registry and a peer group of programming clinicians. We aim to commence a discussion on the determinants of deep brain stimulation efficacy for treatment-refractory obsessive-compulsive disorder patients, a rare and severe patient group, and contribute to more standardized and evidence-based practices.

Digital technology for addressing cognitive impairment in recent-onset psychosis: A perspective

Cognitive impairments in psychosis negatively impact functional recovery and quality of life. Existing interventions for improving cognitive impairment in recent-onset psychosis show inconsistent treatment efficacy, small effects, suboptimal engagement and limited generalizability to daily life functioning. In this perspective we explore how digital technology has the potential to address these limitations in order to improve cognitive and functional outcomes in recent-onset psychosis. Computer programs can be used for standardized, automated delivery of cognitive remediation training. Virtual reality provides the opportunity for learning and practicing cognitive skills in real-world scenarios within a virtual environment. Smartphone apps could be used for notification reminders for everyday tasks to compensate for cognitive difficulties. Internet-based technologies can offer psychoeducation and training materials for enhancing cognitive skills. Early findings indicate some forms of digital interventions for cognitive enhancement can be effective, with well-established evidence for human-supported computer-based cognitive remediation in recent-onset psychosis. Emerging evidence regarding virtual reality is favorable for improving social cognition. Overall, blending digital interventions with human support improves engagement and effectiveness. Despite the potential of digital interventions for enhancing cognition in recent-onset psychosis, few studies have been conducted to date. Implementation challenges affecting application of digital technologies for cognitive impairment in recent-onset psychosis are sustained engagement, clinical integration, and lack of quality in the commercial marketplace. Future opportunities lie in including motivational frameworks and behavioral change interventions, increasing service engagement in young people and lived experience involvement in digital intervention development.

Correction: Acevedo et al. Therapeutic Neurostimulation in Obsessive-Compulsive and Related Disorders: A Systematic Review. Brain Sci. 2021, 11, 948

The authors wish to correct the following error in this paper [...].

Electrically evoked and spontaneous neural activity in the subthalamic nucleus under general anesthesia

OBJECTIVE

Deep brain stimulation (DBS) surgery is commonly performed with the patient awake to facilitate assessments of electrode positioning. However, awake neurosurgery can be a barrier to patients receiving DBS. Electrode implantation can be performed with the patient under general anesthesia (GA) using intraoperative imaging, although such techniques are not widely available. Electrophysiological features can also aid in the identification of target neural regions and provide functional evidence of electrode placement. Here we assess the presence and positional variation under GA of spontaneous beta and high-frequency oscillation (HFO) activity, and evoked resonant neural activity (ERNA), a novel evoked response localized to the subthalamic nucleus.

METHODS

ERNA, beta, and HFO were intraoperatively recorded from DBS leads comprising four individual electrodes immediately after bilateral awake implantation into the subthalamic nucleus of 21 patients with Parkinson's disease (42 hemispheres) and after subsequent GA induction deep enough to perform pulse generator implantation. The main anesthetic agent was either propofol (10 patients) or sevoflurane (11 patients).

RESULTS

GA reduced the amplitude of ERNA, beta, and HFO activity (p < 0.001); however, ERNA amplitudes remained large in comparison to spontaneous local field potentials. Notably, a moderately strong correlation between awake ERNA amplitude and electrode distance to an "ideal" therapeutic target within dorsal STN was preserved under GA (awake: ρ = -0.73, adjusted p value [padj] < 0.001; GA: ρ = -0.69, padj < 0.001). In contrast, correlations were diminished under GA for beta (awake: ρ = -0.45, padj < 0.001; GA: ρ = -0.13, padj = 0.12) and HFO (awake: ρ = -0.69, padj < 0.001; GA: ρ = -0.33, padj < 0.001). The largest ERNA occurred at the same electrode (awake vs GA) for 35/42 hemispheres (83.3%) and corresponded closely to the electrode selected by the clinician for chronic therapy at 12 months (awake ERNA 77.5%, GA ERNA 82.5%). The largest beta amplitude occurred at the same electrode (awake vs GA) for only 17/42 (40.5%) hemispheres and 21/42 (50%) for HFO. The electrode measuring the largest awake beta and HFO amplitudes corresponded to the electrode selected by the clinician for chronic therapy at 12 months in 60% and 70% of hemispheres, respectively. However, this correspondence diminished substantially under GA (beta 20%, HFO 35%).

CONCLUSIONS

ERNA is a robust electrophysiological signal localized to the dorsal subthalamic nucleus subregion that is largely preserved under GA, indicating it could feasibly guide electrode implantation, either alone or in complementary use with existing methods.

Therapeutic Neurostimulation in Obsessive-Compulsive and Related Disorders: A Systematic Review

Invasive and noninvasive neurostimulation therapies for obsessive-compulsive and related disorders (OCRD) were systematically reviewed with the aim of assessing clinical characteristics, methodologies, neuroanatomical substrates, and varied stimulation parameters. Previous reviews have focused on a narrow scope, statistical rather than clinical significance, grouped together heterogenous protocols, and proposed inconclusive outcomes and directions. Herein, a comprehensive and transdiagnostic evaluation of all clinically relevant determinants is presented with translational clinical recommendations and novel response rates. Electroconvulsive therapy (ECT) studies were limited in number and quality but demonstrated greater efficacy than previously identified. Targeting the pre-SMA/SMA is recommended for transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS). TMS yielded superior outcomes, although polarity findings were conflicting, and refinement of frontal/cognitive control protocols may optimize outcomes. For both techniques, standardization of polarity, more treatment sessions (>20), and targeting multiple structures are encouraged. A deep brain stimulation (DBS) 'sweet spot' of the striatum for OCD was proposed, and CBT is strongly encouraged. Tourette's patients showed less variance and reliance on treatment optimization. Several DBS targets achieved consistent, rapid, and sustained clinical response. Analysis of fiber connectivity, as opposed to precise neural regions, should be implemented for target selection. Standardization of protocols is necessary to achieve translational outcomes.

Objective measurement of tinnitus using functional near-infrared spectroscopy and machine learning

Chronic tinnitus is a debilitating condition which affects 10-20% of adults and can severely impact their quality of life. Currently there is no objective measure of tinnitus that can be used clinically. Clinical assessment of the condition uses subjective feedback from individuals which is not always reliable. We investigated the sensitivity of functional near-infrared spectroscopy (fNIRS) to differentiate individuals with and without tinnitus and to identify fNIRS features associated with subjective ratings of tinnitus severity. We recorded fNIRS signals in the resting state and in response to auditory or visual stimuli from 25 individuals with chronic tinnitus and 21 controls matched for age and hearing loss. Severity of tinnitus was rated using the Tinnitus Handicap Inventory and subjective ratings of tinnitus loudness and annoyance were measured on a visual analogue scale. Following statistical group comparisons, machine learning methods including feature extraction and classification were applied to the fNIRS features to classify patients with tinnitus and controls and differentiate tinnitus at different severity levels. Resting state measures of connectivity between temporal regions and frontal and occipital regions were significantly higher in patients with tinnitus compared to controls. In the tinnitus group, temporal-occipital connectivity showed a significant increase with subject ratings of loudness. Also in this group, both visual and auditory evoked responses were significantly reduced in the visual and auditory regions of interest respectively. Naïve Bayes classifiers were able to classify patients with tinnitus from controls with an accuracy of 78.3%. An accuracy of 87.32% was achieved using Neural Networks to differentiate patients with slight/ mild versus moderate/ severe tinnitus. Our findings show the feasibility of using fNIRS and machine learning to develop an objective measure of tinnitus. Such a measure would greatly benefit clinicians and patients by providing a tool to objectively assess new treatments and patients' treatment progress.

Interactive effects of music and prefrontal cortex stimulation in modulating response inhibition

Influential hypotheses propose that alterations in emotional state influence decision processes and executive control of behavior. Both music and transcranial direct current stimulation (tDCS) of prefrontal cortex affect emotional state, however interactive effects of music and tDCS on executive functions remain unknown. Learning to inhibit inappropriate responses is an important aspect of executive control which is guided by assessing the decision outcomes such as errors. We found that high-tempo music, but not low-tempo music or low-level noise, significantly influenced learning and implementation of inhibitory control. In addition, a brief period of tDCS over prefrontal cortex specifically interacted with high-tempo music and altered its effects on executive functions. Measuring event-related autonomic and arousal response of participants indicated that exposure to task demands and practice led to a decline in arousal response to the decision outcome and high-tempo music enhanced such practice-related processes. However, tDCS specifically moderated the high-tempo music effect on the arousal response to errors and concomitantly restored learning and improvement in executive functions. Here, we show that tDCS and music interactively influence the learning and implementation of inhibitory control. Our findings indicate that alterations in the arousal-emotional response to the decision outcome might underlie these interactive effects.

IgE cross-reactivity between Ascaris lumbricoides and mite allergens: possible influences on allergic sensitization and asthma

Nematode infections such as Ascariasis are important health problems in underdeveloped countries, most of them located in the tropics where environmental conditions also promote the perennial co-exposure to high concentrations of domestic mite allergens. Allergic diseases are common, and most of patients with asthma exhibit a predominant and strong IgE sensitization to mites. It is unknown whether co-exposure to Ascaris lumbricoides and the domestic mites Blomia tropicalis and Dermatophagoides pteronyssinus potentiates Th2 responses and IgE sensitization, thereby modifying the natural history of allergy. Recently, we obtained experimental evidence of a high cross-reactivity between the allergenic extracts of these invertebrates, involving well-known allergens such as tropomyosin and glutathione transferases. There is indirect evidence suggesting that the clinical impact of these findings may be important. In this review, we discuss the potential role of this cross-reactivity on several aspects of allergy in the tropics that have been a focus of a number of investigations, some of them with controversial results.

Allergenicity of Ascaris lumbricoides tropomyosin and IgE sensitization among asthmatic patients in a tropical environment

BACKGROUND

Ascaris lumbricoides induces a Th2 response and specific IgE synthesis in humans. This confers antiparasite immunity but could modify the natural history of allergic diseases in the tropics, justifying the study of its allergenic composition. We analyzed the allergenic properties of Ascaris tropomyosin and the frequency of sensitization in subjects exposed to the parasite.

METHODS

cDNA was obtained by reverse transcription PCR, cloned into pQE30-UA and purified as a 6× His-tagged protein. Equivalence with its natural counterpart was analyzed by cross-inhibition and liquid chromatography-tandem mass spectrometry. Specific IgE was measured by ELISA in 175 asthmatics and 170 nonasthmatics naturally exposed to the parasite and sensitized to the Ascaris extract.

RESULTS

The cDNA encoded 287 residues with high sequence identity with other invertebrate tropomyosins. The 40-kDa protein was recognized by human serum and affinity-purified anti-rBlo t 10 IgE. Specific IgE to tropomyosin could represent approximately 50% of the total IgE response to the extract. Ascaris tropomyosin induced wheal and flare in skin prick tests and histamine release from basophils. Although the prevalence of IgE to Ascaris tropomyosin was higher in asthmatic patients, logistic regression analysis suggested that this result was biased by sensitization to mites.

CONCLUSIONS

A. lumbricoides tropomyosin (Asc l 3) is a new allergen that binds specific IgE, induces mediator release from effector cells and is cross-reactive to mite tropomyosins. IgE reactivity to this allergen is very frequent in both asthmatic and normal subjects sensitized to Ascaris extract. The potential role of Ascaris tropomyosin in asthma pathogenesis in tropical regions should be further investigated.

Increased total and mite-specific immunoglobulin E in patients with aspirin-induced urticaria and angioedema

BACKGROUND

An increased prevalence of atopy has been observed in patients with intolerance of aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs).

OBJECTIVE

To investigate total and mite-specific immunoglobulin (Ig) E in serum from patients with hypersensitivity to NSAIDs and healthy controls.

METHODS

Patients who reacted to 2 or more chemically unrelated NSAIDs with urticaria and angioedema, confirmed by a double-blinded provocation test with aspirin, were skin tested with inhalant allergens. Total and specific IgE to Dermatophagoides pteronyssinus (Dp) and Blomia tropicalis (Bt) in the serum was quantified by enzyme-linked immunosorbent assay (ELISA) in patients and a control group of healthy blood donors.

RESULTS

One-hundred-and-fourteen patients and 74 controls were studied. Skin tests were positive in 95 patients (83.3%). Total mean IgE levels were 107.1 (91.3) IU/mL in controls and 161.0 (150.8) IU/mL in patients (P = .006). Mean (SD) levels of IgE to Dp were 0.210 (0.17) optical density (OD) units in controls and 0.473 (0.65) OD units in patients (P = .001). Levels of specific IgE to Bt were 0.230 (0.20) OD units in controls and 0.522 (0.8) OD units in patients (P =.0001). Positive ELISA results for IgE to Dp were found for 29.6% of controls and 70.4% of patients (P =.0001); the corresponding percentages for Bt were 32.4% of controls and 67.6 % of patients (P = .0001).

CONCLUSIONS

Cross-reactive patients with NSAID-induced urticaria and angioedema exhibit an increased prevalence of sensitization to Dp and Bt and increased total serum IgE. Further research is necessary to determine the reasons for this association.

IgE cross-reactivity between Ascaris and domestic mite allergens: the role of tropomyosin and the nematode polyprotein ABA-1

BACKGROUND

Analysis of cross-reactivity between the nematode Ascaris ssp. and dust mites, two important allergen sources in the tropics, will contribute in understanding their influence on asthma and atopy. The objective of this study was to investigate immunoglobulin E (IgE) cross-reactivity between Ascaris and two domestic mites in the tropics.

METHODS

Sera from 24 asthmatic patients were used in ELISA and immunoblotting IgE-binding inhibition assays using Ascaris, Blomia tropicalis and Dermatophagoides pteronyssinus extracts and the recombinants Blo t 10, ABA-1 and Blo t 13 as competitors. Identification of Ascaris allergens was confirmed by mass spectrometry (LC-MS/MS).

RESULTS

We detected at least 12 human IgE-binding components in Ascaris extract. Blomia tropicalis and D. pteronyssinus inhibited 83.3% and 79% of IgE-binding to Ascaris, while Ascaris inhibited 58.3% and 79.3% to B. tropicalis and D. pteronyssinus respectively. Mite tropomyosin inhibited 85% of IgE-binding to Ascaris. Affinity-purified human IgE to rBlo t 10 identified an allergen of 40 kDa in Ascaris extract, further confirmed as tropomyosin by LC-MS/MS. We found no evidence of IgE cross-reactivity between rABA-1 and any allergen component in mite extracts, including rBlo t 13.

CONCLUSIONS

There is cross-reactivity between Ascaris and mites, determined by several allergens including tropomyosin and glutathione-S-transferase. In addition to its potential impact on asthma pathogenesis, Ascaris infection and mite allergy diagnosis relying on the determination of specific IgE could be affected by this cross-reactivity. ABA-1 has no cross-reactive counterpart in mite extracts, suggesting its usefulness as a more specific marker of Ascaris infection.

Association between total immunoglobulin E and antibody responses to naturally acquired Ascaris lumbricoides infection and polymorphisms of immune system-related LIG4, TNFSF13B and IRS2 genes

The 13q33-34 region harbours a susceptibility locus to Ascaris lumbricoides, although the underlying genes are unknown. Immunoglobulin (Ig)E and IgG confer protective immunity and here we sought to investigate in an endemic population whether LIG4, TNFSF13B and IRS2 genes influence IgE and IgG levels against Ascaris and the ABA-1 allergen as a putative resistance marker. Mite-allergic asthmatic patients were analysed for potential relationships between Ascaris predisposition and allergy. One thousand and sixty-four subjects from Cartagena, Colombia, were included. Single nucleotide polymorphisms (SNPs) were genotyped using TaqMan assays. Antibody levels were measured by enzyme-linked immunosorbent assay. Linear and logistic regressions were used to model effects of genotypes on antibody levels. The GG genotype of LIG4 (rs1805388) was associated with higher IgE levels to Ascaris compared with other genotypes. TNFSF13B (rs10508198) was associated positively with IgG levels against Ascaris extract and IgE levels against ABA-1. In asthmatics, IRS2 (rs2289046) was associated with high total IgE levels. Associations held up after correction by population stratification using a set of 52 ancestry markers, age, sex and disease status. There was no association with asthma or mite sensitization. In a tropical population, LIG4 and TNFSF13B polymorphisms are associated with specific IgE and IgG to Ascaris, supporting previous linkage studies implicating the 13q33 region. Our results suggest that genes protecting against parasite infections can be different to those predisposing to asthma and atopy.

Association of G-protein-coupled receptor 154 with asthma and total IgE in a population of the Caribbean coast of Colombia

BACKGROUND

G protein-coupled receptor 154 was described as an asthma susceptibility gene by positional cloning. It has been subsequently associated with asthma and other inflammatory diseases in several populations with different ethnic origin. Replication of associations adds reliability to these findings.

OBJECTIVE

To analyze the association of G protein-coupled receptor 154 with asthma and total and mite-specific IgE levels in a population of the Caribbean Coast of Colombia.

METHODS

We genotyped seven single nucleotide proteins (SNPs) in GPR154 in 475 asthmatics, 394 controls and 116 families from Cartagena, Colombia using either SnaPshot or TaqMan. Total and specific IgE against Blomia tropicalis and Dermatophagoides pteronyssinus were determined by ELISA. Hardy-Weinberg equilibrium was assessed and case-control and family-based analyses were performed to evaluate the association between the SNPs and their haplotypes and asthma and IgE. Association analyses in the case-control dataset were corrected by population stratification using 52 ancestry informative markers.

RESULTS

Allelic distribution was similar to that described in other populations. Two SNPs were associated with the same direction of the effect in both datasets. Allele A of Hopo546333 was protective for asthma (case-control OR: 0.42; 95% CI: 0.17-0.99, P=0.042; P=0.043; families Z score=-2,236; P=0.025). Similarly, allele C of rs740347 conferred low risk for asthma (OR: 0.44; 95% CI: 0.28-0.70, P=0.00017; Pc=0.00037) and total IgE (OR: 0.29; 95% CI: 0.09-0.88, P=0.015; Pc=0.030) in the case-control study and families (Z score=-3.207, P=0.0013; Z score=-3.182, P=0.0014, respectively). Haplotype CCAGGT was associated with total IgE (OR: 1.76; 95% CI: 1.14-2.71, P=0.006, Pc=0.007) in the case-controls group and CGCGGT with both phenotypes (P=0.044 and P=0.032, respectively) in families. Neither SNPs nor haplotypes were associated with levels of mite-specific IgE.

CONCLUSIONS

Our findings in a sample of asthmatics from Colombia suggest a relevant role of G protein-coupled receptor 154 in the pathogenesis of asthma and allergy.

The A-444C polymorphism in the leukotriene C4 synthase gene is associated with aspirin-induced urticaria

BACKGROUND

Cysteinyl leukotriene production seems to be dysregulated in patients with hypersensitivity to aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs). However, the underlying pathogenic mechanisms of these reactions are poorly understood. Previous studies have suggested a role for the A-444C polymorphism on the leukotriene C4 synthase gene (LTC4S) in aspirin-induced urticaria (AIU), but the results are controversial.

OBJECTIVE

To evaluate in a case-control study whether the A-444C polymorphism in the promoter region of LTC4S is associated with AIU and atopic phenotypes in a Venezuelan population.

METHODS

One hundred ten patients with AIU and 165 nonallergic controls were included. AIU was diagnosed by clinical history and confirmed by double-blind placebo-controlled oral provocation tests with NSAIDs. Genotyping of A-444C was performed by real-time polymerase chain reaction using Taqman probes. Atopy was defined as a positive skin test result to any of the 25 aeroallergens tested. Total and mite-specific immunoglobulin (Ig) E levels in serum were quantified using an enzyme-linked immunosorbent assay

RESULTS

A-444C was associated with AIU. The C allele was more frequent in patients with the cutaneous pattern of AIU and in patients with low skin reactivity to histamine. There was no association between A-444C and asthma, atopy, or total IgE levels.

CONCLUSION

The C allele of the A-444C polymorphism is a risk factor for AIU in our population and could be a genetic marker for this phenotype. Furthermore, this single-nucleotide polymorphism is mainly associated with the cutaneous clinical pattern and with low skin response to histamine.