Rishma Chooniedass

Elevated Antigen-Driven IL-9 Responses Are Prominent in Peanut Allergic Humans

Food allergies, and peanut allergy in particular, are leading causes of anaphylactic fatalities worldwide. The immune mechanisms that underlie food allergy remain ill-defined and controversial, in part because studies in humans typically focus on analysis of a limited number of prototypical Th1/Th2 cytokines. Here we determine the kinetics and prevalence of a broad panel of peanut-driven cytokine and chemokine responses in humans with current peanut allergy vs those with stable, naturally occurring clinical tolerance to peanut. Our primary focus is identification of novel indicators of immune dysregulation. Antigen-specific cytokine mRNA and protein responses were elicited in primary culture via peanut or irrelevant antigen (Leishmania extract, milk antigens) mediated stimulation of fresh peripheral blood cells from 40 individuals. Peanut extract exposure in vitro induced a broad panel of responses associated with Th2/Th9-like, Th1-like and Th17-like immunity. Peanut-dependent Type 2 cytokine responses were frequently found in both peanut allergic individuals and those who exhibit clinical tolerance to peanut ingestion. Among Th2/Th9-associated cytokines, IL-9 responses discriminated between allergic and clinically tolerant populations better than did commonly used IL-4, IL-5 or IL-13 responses. Comparison with responses evoked by unrelated control antigen-mediated stimulation showed that these differences are antigen-dependent and allergen-specific. Conversely, the intensity of IL-12, IL-17, IL-23 and IFN-γ production was indistinguishable in peanut allergic and peanut tolerant populations. In summary, the ability to generate and maintain cytokine responses to peanut is not inherently distinct between allergic and peanut tolerant humans. Quantitative differences in the intensity of cytokine production better reflects clinical phenotype, with optimally useful indicators being IL-9, IL-5, IL-13 and IL-4. Equivalent, and minimal, Ag-dependent pro-inflammatory cytokine levels in both healthy and peanut allergic volunteers argues against a key role for such cytokines in maintenance of clinical tolerance to food antigens in humans.

The Canadian Healthy Infant Longitudinal Development Birth Cohort Study: Biological Samples and Biobanking

BACKGROUND It is hypothesised that complex interactions between genetic and environmental factors give rise to allergy and asthma in childhood. The Canadian Healthy Infant Longitudinal Development (CHILD) study was designed to explore these factors. METHODS CHILD is a longitudinal, general population birth cohort study following infants from mid-pregnancy to age 5 years. Over this time period, biological samples, questionnaires, clinical measures and environmental data are collected. RESULTS A total of 3624 families have been recruited, and many thousands of samples and questionnaires have been collected, annotated, and archived. This report outlines the rationale and methodology for collecting and storing diverse biological samples from parents and children in this study, and the mechanisms for their release for analyses. CONCLUSIONS The CHILD sample and data repository is a tremendous current and future resource and will provide a wealth of information not only informing studies of asthma and allergy, but also potentially in many other aspects of health relevant for Canadian infants and children.

In vivo immune signatures of healthy human pregnancy: Inherently inflammatory or anti-inflammatory?

Changes in maternal innate immunity during healthy human pregnancy are not well understood. Whether basal immune status in vivo is largely unaffected by pregnancy, is constitutively biased towards an inflammatory phenotype (transiently enhancing host defense) or exhibits anti-inflammatory bias (reducing potential responsiveness to the fetus) is unclear. Here, in a longitudinal study of healthy women who gave birth to healthy infants following uncomplicated pregnancies within the Canadian Healthy Infant Longitudinal Development (CHILD) cohort, we test the hypothesis that a progressively altered bias in resting innate immune status develops. Women were examined during pregnancy and again, one and/or three years postpartum. Most pro-inflammatory cytokine expression, including CCL2, CXCL10, IL-18 and TNFα, was reduced in vivo during pregnancy (20–57%, p<0.0001). Anti-inflammatory biomarkers (sTNF-RI, sTNF-RII, and IL-1Ra) were elevated by ~50–100% (p<0.0001). Systemic IL-10 levels were unaltered during vs. post-pregnancy. Kinetic studies demonstrate that while decreased pro-inflammatory biomarker expression (CCL2, CXCL10, IL-18, and TNFα) was constant, anti-inflammatory expression increased progressively with increasing gestational age (p<0.0001). We conclude that healthy resting maternal immune status is characterized by an increasingly pronounced bias towards a systemic anti-inflammatory innate phenotype during the last two trimesters of pregnancy. This is resolved by one year postpartum in the absence of repeat pregnancy. The findings provide enhanced understanding of immunological changes that occur in vivo during healthy human pregnancy.

Are Plasma IL-10 Levels a Useful Marker of Human Clinical Tolerance in Peanut Allergy?

Background Food allergies are a major component of the burden of allergic disease. Accurate risk assessment for prediction of future clinical reactivity or clinical tolerance is limited by currently available techniques. Recent studies suggest that constitutively elevated global serum levels of IL-10, a cytokine that down-regulates both Th1 and Th2 cytokine production, may be useful in identifying human clinical tolerance to foods. Objective Determine the usefulness of constitutive IL-10 levels as a marker of clinical tolerance to peanut in children and adults. Methodology/Principal Findings 107 subjects who were clinically tolerant to peanut and 94 subjects who were clinically allergic to peanut participated. Plasma was analyzed via ELISA to quantify the frequency of individuals with constitutive IL-10 levels and the intensity of those responses. The data were then stratified by age, gender and clinical status to assess the utility of this putative biomarker in specific at-risk groups. All 201 subjects had readily quantified plasma IL-10. Levels were no higher in subjects who were clinically tolerant to peanut than those in individuals clinically allergic to peanut. Stratification by age, gender or both did not improve the capacity of IL-10 levels to identify clinical tolerance to peanut. Conclusions/Significance Plasma IL-10 levels are neither a useful biomarker of clinical tolerance to peanut nor a potential tool for identification of clinical tolerance to peanut in humans.

Digital storytelling as a method in health research: a systematic review protocol

BackgroundDigital storytelling is an arts-based research method with potential to elucidate complex narratives in a compelling manner, increase participant engagement, and enhance the meaning of research findings. This method involves the creation of a 3- to 5-min video that integrates multimedia materials including photos, participant voices, drawings, and music. Given the significant potential of digital storytelling to meaningfully capture and share participants’ lived experiences, a systematic review of its use in healthcare research is crucial to develop an in-depth understanding of how researchers have used this method, with an aim to refine and further inform future iterations of its use.MethodsWe aim to identify and synthesize evidence on the use, impact, and ethical considerations of using digital storytelling in health research. The review questions are as follows: (1) What is known about the purpose, definition, use (processes), and contexts of digital storytelling as part of the research process in health research? (2) What impact does digital storytelling have upon the research process, knowledge development, and healthcare practice? (3) What are the key ethical considerations when using digital storytelling within qualitative, quantitative, and mixed method research studies? Key databases and the grey literature will be searched from 1990 to the present for qualitative, quantitative, and mixed methods studies that utilized digital storytelling as part of the research process. Two independent reviewers will screen and critically appraise relevant articles with established quality appraisal tools. We will extract narrative data from all studies with a standardized data extraction form and conduct a thematic analysis of the data. To facilitate innovative dissemination through social media, we will develop a visual infographic and three digital stories to illustrate the review findings, as well as methodological and ethical implications.DiscussionIn collaboration with national and international experts in digital storytelling, we will synthesize key evidence about digital storytelling that is critical to the development of methodological and ethical expertise about arts-based research methods. We will also develop recommendations for incorporating digital storytelling in a meaningful and ethical manner into the research process.Systematic review registrationPROSPERO registry number CRD42017068002.

Stability of pro- and anti-inflammatory immune biomarkers for human cohort studies

BackgroundAlthough discovery research has identified the importance of dozens of pro- and anti-inflammatory immune mediators in the pathogenesis, maintenance, exacerbation and resolution of inflammatory diseases, most human cohort studies have incorporated few or no immunological intermediate phenotypes in their analyses. Significant hindrances have been (1) the limited panel of biomarkers known to be readily detected in healthy human populations and (2) the stability, hence utility, of such biomarkers to repeated analysis.MethodsThe frequency and stability of 14 plasma biomarkers linked to in vivo immune regulation of allergic and autoimmune inflammatory disorders was determined in 140 healthy pediatric and adult participants. The impact of initial and multiple subsequent freeze/thaw cycles on pro-inflammatory (CCL2, CXCL10, IL-18, TNFα, IL-6), anti-inflammatory (IL-10, sTNF-RII, IL-1Ra), acute phase proteins (CRP, PTX3) and other biomarkers (sST2, IL-1RAcP) was subsequently quantified.ResultsMultiple biomarkers capable of providing an innate immune signature of inflammation were readily detected directly ex vivo in healthy individuals. These biomarker levels were unaffected when comparing paired data sets from freshly obtained, never frozen plasma or serum and matched aliquots despite extensive freeze/thaw cycles. Neither age nor sex affected stability. Similarly, no quantitative differences were found following repetitive analysis of inflammatory biomarkers in culture samples obtained following in vitro stimulation with TLR and RLR ligands.ConclusionsA broad panel of in vivo and ex vivo cytokine, chemokine and acute phase protein biomarkers that have been linked to human chronic inflammatory disorders are readily detected in vivo and remain stable for analysis despite multiple freeze thaw cycles. These data provide the foundation and confidence for large scale analyses of panels of inflammatory biomarkers to provide better understanding of immunological mechanisms underlying health versus disease.

Attrition in the Canadian Healthy Infant Longitudinal Development (CHILD) study

Objective 1. To determine the attrition rate across study sites in the CHILD study. 2. To document the principle reasons for attrition. 3. To identify maternal factors associated with attrition. Methods CHILD is a study assessing the environmental impact on children’s health. The study includes 4 recruitment sites across Canada (Vancouver, Edmonton, Manitoba, and Toronto). Women enrolled while pregnant will be followed, along with their child for 5 years. Home assessments were done at 3 months, clinical assessments at 1, 3, and 5 years of age, and questionnaires are administered every 6 months. If a study participant withdraws, staff completes a one page questionnaire to determine reasons for withdrawal. The checklist incudes: no reason given, father not interested, family lacks time, family concern regarding privacy, expense to family, inconvenient to travel, complicated family situation, testing difficult, enrolled in another study, too many questionnaires, separation, personal health issue and others. Maternal factors included: history of asthma or food allergy, marital status, socioeconomic status (post secondary education, income), ethnic/ cultural group, being born in Canada, age, and stress measured by a Perceived Stress Scale. Results CHILD recruited 3628 participants at 4 sites (Vancouver 816, Edmonton 840, Manitoba 1107, and Toronto 865). Of the 316 participants withdrawn from the study, 149 were not eligible due to birth issues and 167 withdrew). Attrition rates for those 167 who declined further study were 4.5% (37/816) in Vancouver, 6.2% (52/840) in Edmonton, 2.3% (25/1107) in Manitoba, and 6.1% (53/ 865) in Toronto. Of the 167, further information is available only for 100. 81% (81/100) withdrew due to a lack of time, 17% (17/100) withdrew due to family issues, and 16% (16/100) due to other reasons, such as moving away, religions reason, etc. We compared 2698 participants with available data with 167 withdrawn active participants. Perceived stress was high in 99% withdrawn vs. 69% of active participants (p=0.02). Other important factors for withdrawing include single mother status (12% vs. 6%, p=0.03), maternal history of asthma (13% vs. 23%, p=0.03), and maternal food allergy (11% vs. 22%, p=0.009).

Enlivening a Community of Authentic Scholarship: A Faculty-Mentored Experience for Graduate Students at the 2016 Qualitative Health Research Conference

Background: Critical and engaged qualitative scholarship depends on high-quality graduate training. The need to reexamine graduate student mentorship has become particularly pressing, given the high level of mental health distress experienced by students. It is unclear whether mentorship emerging within the student–advisor relationship is sufficient to ensure comprehensive mentorship. Innovative, experiential pedagogical approaches that integrate emotional and intellectual aspects are limited but may play a vital role in mentorship. There is a critical need to develop and study creative mentorship initiatives for emerging qualitative scholars. Methods: This study used interpretive description methodology and a community of practice theoretical framework to describe a faculty-mentored experience for graduate nursing students at the 2016 Qualitative Health Research Conference (FM-QHR) hosted by the International Institute for Qualitative Methodology. Participants completed written journals elucidating their experiences throughout FM-QHR. The textual data were analyzed using a constant comparative group analysis process, leading to the development of salient and interconnected themes. Results: Six graduate students and four faculty mentors submitted journals. Three interrelated themes articulate how this FM-QHR initiative enlivened a community of authentic scholarship: Questioning the Academic Self: Unvoiced Experiences of Angst, Uncertainty, and Fear; Cocreating Authentic Community through Shared Vulnerability; and Generative and Emergent Empowerment. Conclusion: These findings provide compelling insights into the importance of assisting students to navigate the emotional experiences that are a part of qualitative graduate training. Relational, mentorship initiatives hold potential to not only alleviate emotional distress but also support student empowerment, socialization, and entrance into a community of international qualitative researchers.

The canadian healthy infant longitudinal development birth cohort study

BACKGROUND It is hypothesised that complex interactions between genetic and environmental factors give rise to allergy and asthma in childhood. The Canadian Healthy Infant Longitudinal Development (CHILD) study was designed to explore these factors. METHODS CHILD is a longitudinal, general population birth cohort study following infants from mid-pregnancy to age 5 years. Over this time period, biological samples, questionnaires, clinical measures and environmental data are collected. RESULTS A total of 3624 families have been recruited, and many thousands of samples and questionnaires have been collected, annotated, and archived. This report outlines the rationale and methodology for collecting and storing diverse biological samples from parents and children in this study, and the mechanisms for their release for analyses. CONCLUSIONS The CHILD sample and data repository is a tremendous current and future resource and will provide a wealth of information not only informing studies of asthma and allergy, but also potentially in many other aspects of health relevant for Canadian infants and children.

The Canadian Healthy Infant Longitudinal Development Birth Cohort Study: Biological Samples and Biobanking: The CHILD study: biological samples

BACKGROUND It is hypothesised that complex interactions between genetic and environmental factors give rise to allergy and asthma in childhood. The Canadian Healthy Infant Longitudinal Development (CHILD) study was designed to explore these factors. METHODS CHILD is a longitudinal, general population birth cohort study following infants from mid-pregnancy to age 5 years. Over this time period, biological samples, questionnaires, clinical measures and environmental data are collected. RESULTS A total of 3624 families have been recruited, and many thousands of samples and questionnaires have been collected, annotated, and archived. This report outlines the rationale and methodology for collecting and storing diverse biological samples from parents and children in this study, and the mechanisms for their release for analyses. CONCLUSIONS The CHILD sample and data repository is a tremendous current and future resource and will provide a wealth of information not only informing studies of asthma and allergy, but also potentially in many other aspects of health relevant for Canadian infants and children.