African American ancestry contribution to asthma and atopic dermatitis

Prediction of asthma using a four-locus gene model including IL13, IL4, FCER1B, and ADRB2 in children of Kazak nationality

BACKGROUND

To study whether the four locus gene model consisting of ADRB2 rs1042713, IL4 rs2243250, FCER1B rs569108 and L13 rs20541 can predict asthma of the Kazak children in Xinjiang, China.

METHODS

Four single nucleotide polymorphisms about the 4 genes were genotyped in asthma group and control group of Han children and Kazak children respectively. The frequencies of different genotypes and alleles were compared between the asthma group and the control group in the two nationalities. Different risk genotypes for asthma were evaluated in the two nationalities.

RESULTS

The differences about frequencies of genotypes in ADRB2 rs1042713 and IL4 rs2243250 and IL13 rs20541 between asthma group and control group were statistically significant in Han children, as were the frequencies of alleles in the 3 single nucleotide polymorphisms, but there were no statistical differences in FCER1B rs569108(P > 0.05). For the Kazak children, no differences were existed among all the genotypes and alleles in asthma group and control group. For the Han children, more children were asthma high risk genotype in the asthma group than those in the control group and no difference was found in the Kazak children.

CONCLUSIONS

The four locus gene model consisting of ADRB2 rs1042713, IL4 rs2243250, FCER1B rs569108 and L13 rs20541 can predict asthma of Han children but not for the Kazak children in Xinjiang, which illustrating that the difference of asthma prevalence between different races is closely related to the genetic background.

Evaluation of Diversity of Clinical Trials Informing Health Technology Assessments in the United States: A 5-Year Analysis of Institute for Clinical and Economic Review Assessments

OBJECTIVES

This study aimed to evaluate the diversity of clinical trials informing assessments conducted by the Institute for Clinical and Economic Review.

METHODS

This was a cross-sectional study of pivotal trials included in completed Institute for Clinical and Economic Review assessments over 5 years (2017-2021). Representation of racial/ethnic minority groups, females, and older adults was compared with the disease-specific and US population, using a relative representation cutoff of 0.8 for adequate representation.

RESULTS

A total of 208 trials, evaluating 112 interventions for 31 unique conditions, were examined. Race/ethnicity data were inconsistently reported. The median participant-to-disease representative ratio (PDRR) for Blacks/African Americans (0.43 [interquartile range (IQR) 0.24-0.75]), American Indians/Alaska Natives (0.37 [IQR 0.09-0.77]), and Hispanics/Latinos (0.79 [IQR 0.30-1.22]) were below the adequate representation cutoff. In contrast, Whites (1.06 [IQR 0.92-1.2]), Asians (1.71 [IQR 0.50-3.75]), and Native Hawaiian/Other Pacific Islanders (1.61 [IQR 0.77-2.81]) were adequately represented. Findings were similar when compared with the US Census, except for Native Hawaiian/Pacific Islanders, which was substantially worse. Relative to all trials, a higher proportion of US-based trials adequately represented Blacks/African Americans (61% vs 23%, P < .0001) and Hispanics/Latinos (68% vs 50%; P = .047), but a lower proportion adequately represented Asians (15% vs 67%, P < .0001). Females were adequately represented in 74% of trials (PDRR: 1.02 [IQR 0.79-1.14]). Nevertheless, older adults were adequately represented in only 20% of trials (PDRR: 0.30 [IQR 0.13-0.64]).

CONCLUSIONS

The representation of racial/ethnic minorities and older adults was inadequate. Efforts are needed to enhance the diversity of clinical trials. Standardized and transparent evaluation of trial diversity should be part of the health technology assessment process.

Assessing Disparities in the Prevalence of Atopic Comorbidities Among Food-Allergic Children

BACKGROUND

Previous studies have reported that Black children with food allergy (FA) have higher risk of atopic comorbidities than White children.

OBJECTIVE

Our study sought to understand if disparities in the prevalence of atopic comorbidities among children with FA are driven by individual and community-level socioeconomic status (SES).

METHODS

We analyzed data from a prospective, multicenter cohort investigating the natural history of pediatric atopy: the Food Allergy Outcomes Related to White and African American Racial Differences (FORWARD) study. A validated, multicomponent area deprivation index (ADI) percentile score was tabulated by the census block group for each subject's home address. The association of ADI with atopic comorbidities in FA was assessed via multivariable regression analysis.

RESULTS

Of the 700 children in this study, the mean ADI was 37.7 (95% confidence interval: 35.6-39.7). The mean ADI was higher in children with asthma (43.3) compared with those without asthma (31.8), which remained significant after adjusting for race (P < .0001). Children with allergic rhinitis (AR) had a higher mean ADI (39.1) compared with those without (33.4) (P = .008). ADI was associated with secondhand smoking, parents' education, and household income. Black children had a higher risk for asthma after adjusting for ADI and SES-related factors.

CONCLUSION

The independent association of ADI with asthma and AR, regardless of race, suggests a role of neighborhood-level socioeconomic deprivation in the development of these conditions among children with FA. Black children with FA remained at higher risk for asthma after adjusting for SES-related variables, which can indicate an independent risk for asthma in these children.

Are There Ethnic Differences in Hand Eczema? A Review

Hand eczema is a common disease with economic and social ramifications. This study undertakes a review of certain existing literature to provide insight into contributory factors which may result in the varying prevalence and severity of hand eczema among different ethnic groups, particularly to identify modifiable risk factors, as well as to ascertain knowledge gaps for future research direction. The existing literature suggests that factors including (a) genes, (b) differing skin physiology, (c) cultural practices, (d) dietary habits and associated food preparation, (e) climate, (f) predominant occupations, (g) socioeconomic factors, and (h) dissimilar laws and regulations may account for the disparity in the risk of hand eczema among different ethnicities. Given that endogenous factors cannot be avoided, but certain exogenous aspects can be modified, especially as the environment plays an important role in hand eczema flares, it is helpful from a practical perspective to focus on addressing the modifiable risk factors. These factors pertain to unique cultural practices, customs, and food preparation methods. Healthcare professionals should be well-acquainted with such factors to tailor the treatment approach for patients of different ethnicities accordingly because, with globalization, physicians face increasingly diverse patient populations such that cultural customs no longer remain limited to particular geographic regions.

Understanding and controlling asthma in Latin America: A review of recent research informed by the SCAALA programme

Asthma is an important health concern in Latin America (LA) where it is associated with variable prevalence and disease burden between countries. High prevalence and morbidity have been observed in some regions, particularly marginalized urban populations. Research over the past 10 years from LA has shown that childhood disease is primarily non-atopic. The attenuation of atopy may be explained by enhanced immune regulation induced by intense exposures to environmental factors such as childhood infections and poor environmental conditions of the urban poor. Non-atopic symptoms are associated with environmental and lifestyle factors including poor living conditions, respiratory infections, psychosocial stress, obesity, and a diet of highly processed foods. Ancestry (particularly African) and genetic factors increase asthma risk, and some of these factors may be specific to LA settings. Asthma in LA tends to be poorly controlled and depends on access to health care and medications. There is a need to improve management and access to medication through primary health care. Future research should consider the heterogeneity of asthma to identify relevant endotypes and underlying causes. The outcome of such research will need to focus on implementable strategies relevant to populations living in resource-poor settings where the disease burden is greatest.

MicroRNAs within the Basal-like signature of Quadruple Negative Breast Cancer impact overall survival in African Americans

We previously found that QNBC tumors are more frequent in African Americans compared to TNBC tumors. To characterize this subtype further, we sought to determine the miRNA-mRNA profile in QNBC patients based on race. Both miRNA and mRNA expression data were analyzed from TCGA and validated using datasets from the METABRIC, TCGA proteomic, and survival analysis by KMPLOT. miRNA-mRNAs which include FOXA1 and MYC (mir-17/20a targets); GATA3 and CCNG2 (mir-135b targets); CDKN2A, CDK6, and B7-H3 (mir-29c targets); and RUNX3, KLF5, IL1-β, and CTNNB1 (mir-375 targets) were correlated with basal-like and immune subtypes in QNBC patients and associated with a worse survival. Thus, QNBC tumors have an altered gene signature implicated in racial disparity and poor survival.

Duration of exposure to epidural anesthesia at delivery, DNA methylation in umbilical cord blood and their association with offspring asthma in Non-Hispanic Black women

Epidural anesthesia is an effective pain relief modality, widely used for labor analgesia. Childhood asthma is one of the commonest chronic medical illnesses in the USA which places a significant burden on the health-care system. We recently demonstrated a negative association between the duration of epidural anesthesia and the development of childhood asthma; however, the underlying molecular mechanisms still remain unclear. In this study of 127 mother-child pairs comprised of 75 Non-Hispanic Black (NHB) and 52 Non-Hispanic White (NHW) from the Newborn Epigenetic Study, we tested the hypothesis that umbilical cord blood DNA methylation mediates the association between the duration of exposure to epidural anesthesia at delivery and the development of childhood asthma and whether this differed by race/ethnicity. In the mother-child pairs of NHB ancestry, the duration of exposure to epidural anesthesia was associated with a marginally lower risk of asthma (odds ratio = 0.88, 95% confidence interval = 0.76-1.01) for each 1-h increase in exposure to epidural anesthesia. Of the 20 CpGs in the NHB population showing the strongest mediation effect, 50% demonstrated an average mediation proportion of 52%, with directional consistency of direct and indirect effects. These top 20 CpGs mapped to 21 genes enriched for pathways engaged in antigen processing, antigen presentation, protein ubiquitination and regulatory networks related to the Major Histocompatibility Complex (MHC) class I complex and Nuclear Factor Kappa-B (NFkB) complex. Our findings suggest that DNA methylation in immune-related pathways contributes to the effects of the duration of exposure to epidural anesthesia on childhood asthma risk in NHB offspring.

A common IL-4 receptor variant promotes asthma severity via a Treg cell GRB2-IL-6-Notch4 circuit

BACKGROUND

The mechanisms by which genetic and environmental factors interact to promote asthma remain unclear. Both the IL-4 receptor alpha chain R576 (IL-4RαR576) variant and Notch4 license asthmatic lung inflammation by allergens and ambient pollutant particles by subverting lung regulatory T (Treg ) cells in an IL-6-dependent manner.

OBJECTIVE

We examined the interaction between IL-4RαR576 and Notch4 in promoting asthmatic inflammation.

METHODS

Peripheral blood mononuclear cells (PBMCs) of asthmatics were analyzed for T helper type 2 cytokine production and Notch4 expression on Treg cells as a function of IL4RR576 allele. The capacity of IL-4RαR576 to upregulate Notch4 expression on Treg cells to promote severe allergic airway inflammation was further analyzed in genetic mouse models.

RESULTS

Asthmatics carrying the IL4RR576 allele had increased Notch4 expression on their circulating Treg cells as a function of disease severity and serum IL-6. Mice harboring the Il4raR576 allele exhibited increased Notch4-dependent allergic airway inflammation that was inhibited upon Treg cell-specific Notch4 deletion or treatment with an anti-Notch4 antibody. Signaling via IL-4RαR576 upregulated the expression in lung Treg cells of Notch4 and its downstream mediators Yap1 and beta-catenin, leading to exacerbated lung inflammation. This upregulation was dependent on growth factor receptor-bound protein 2 (GRB2) and IL-6 receptor.

CONCLUSION

These results identify an IL-4RαR576-regulated GRB2-IL-6-Notch4 circuit that promotes asthma severity by subverting lung Treg cell function.

Spectrum of skin diseases in Maroon villages of the Maroni area, French Guiana

BACKGROUND

Due to their genetic characteristics and their high exposure to infectious diseases, Maroons are likely to suffer from a specific spectrum of skin diseases. However, skin disorders have never been explored in this population. We aimed to describe all skin diseases in Maroon villages of the Maroni region in French Guiana.

METHODS

This retrospective study concerned all patients who consulted in the remote health centers of Apatou, Grand-Santi, Papaichton, and Maripasoula between October 5, 2017, and June 30, 2020. We included all patients registered with a skin disorder (International Classification of Diseases) in the medical database. We excluded patients whose diagnosis was invalidated after cross-checking by a dermatologist.

RESULTS

A total of 4741 patients presented at least one skin disease, for 6058 different disorders. Nonsexually transmitted infections represented 71.6% of all diagnoses, followed by inflammatory diseases (9.8%) and bites/envenomations (4.6%). The three most frequent conditions were scabies, abscesses, and impetigo. Besides scabies, neglected tropical diseases (NTDs) were still prevalent as we reported 13 cases of leprosy and 63 cutaneous leishmaniasis. Atopic dermatitis (AD) represented only 2.5% of our diagnoses.

CONCLUSIONS

With the exception of AD, which was less frequent among Maroons, these results are similar to those previously reported in Amerindians. Therefore, a common exposure to rainforest pathogens seems to induce a common spectrum of skin diseases dominated by infections. The high prevalence of NTDs requires specific public health actions.

Factors Associated With Penicillin Allergy Labels in Electronic Health Records of Children in 2 Large US Pediatric Primary Care Networks

Importance

Penicillin allergy labels influence clinical decision-making, yet most children who are labeled do not have type 1 hypersensitivity allergic reactions and instead have a history of predictable adverse reactions or unspecified illness symptoms while receiving penicillin for viral infections. Studies describing penicillin allergy labeling in the pediatric outpatient setting are lacking.

Objective

To describe the epidemiology and factors associated with penicillin allergy labels across 2 large US pediatric primary care networks.

Design, Setting, and Participants

This retrospective, longitudinal birth cohort study was conducted in 90 primary care pediatric practices serving a diverse population of children across Houston, Texas, Austin, Texas, Philadelphia, Pennsylvania, and parts of New Jersey. Participants were children born between January 2010 and June 2020 who had a health care visit in the first 14 days of life and at least 2 additional visits in the first year of life at one of 90 primary care pediatric practices. Censoring criteria were additionally applied to exclude data from children no longer seeking health care in the 90 clinics over time. Statistical analysis was performed from February to May 2021.

Exposures

Basic patient demographics, health care utilization, penicillin exposure, and primary clinic location.

Main Outcomes and Measures

Addition of penicillin allergy label in the electronic medical record.

Results

Among 334 465 children in the birth cohort, 164 173 (49.1%) were female; 72 831 (21.8%) were Hispanic, 59 598 (17.8%) were non-Hispanic Black, and 148 534 (44.4%) were non-Hispanic White; the median (IQR) age at censoring was 3.8 (1.7-6.6) years; 18 015 (5.4%) were labeled as penicillin allergic, but the prevalence of penicillin allergy labeling ranged from 0.9% to 10.2% across practices. Children were labeled at a median (IQR) age of 1.3 (0.9-2.3) years. Non-Hispanic White children were more likely to be labeled compared with non-Hispanic Black children after controlling for potential confounders (adjusted odds ratio, 1.7 [95% CI, 1.6-1.8]). There were 6797 allergic children (37.7%) labeled after receiving 1 penicillin prescription and 1423 (7.9%) labeled after receiving 0 penicillin prescriptions.

Conclusions and Relevance

In this cohort study of more than 330 000 children, penicillin allergy labeling was common and varied widely across practices. Children were labeled early in life, and almost half were labeled after receiving 1 or 0 penicillin prescriptions. These findings raise questions regarding the validity of penicillin allergy labels. Future work exploring the fidelity of and outcomes associated with penicillin allergy-labeling in children is warranted.

Study on the Molecular Basis of Huanglian Jiedu Decoction Against Atopic Dermatitis Integrating Chemistry, Biochemistry, and Metabolomics Strategies

Atopic dermatitis (AD) is a common chronic relapsing skin inflammation, which severely affect the quality of life of patients. Inhibiting itching and enhancing immunity to mitigate scratching are key elements in the fight against AD. Huanglian Jiedu decoction (HLJDD) has multiple pharmacological effects in the treatment of AD. However, the effective ingredients and underlying molecular mechanisms have not yet been fully explored. Thus, this study integrates chemistry, biochemistry, and metabolomics strategies to evaluate the active substance basis of HLJDD against AD. First, HLJDD was split to five fractions (CPF, 40AEF, 90AEF, PEF and WEF) and 72 chemical components were identified. NSD (Non-similarity degree) among the different fractions showed significant chemical differences (>81%). Interleukin IL-13, IL-17A, IL-3, IL-31, IL-33, IL4, IL-5, TSLP, IgE, and histamine in the serum, and IL-4Rα, JAK1, and HRH4 levels in skin, participating in inhibiting itching and regulating immunity signaling, were found to be restored to varying degrees in AD treating with HLJDD and its fractions, especially 40AEF and CPF. Untargeted metabolomics analysis demonstrated that forty metabolites were differential metabolites in plasma between the HLJDD-treated group and the AD group, involving in histidine metabolism, arginine biosynthesis, pyrimidine metabolism, and so on. Further, targeted metabolomics analysis revealed that eleven differential metabolites, associating with physiological and biochemical indices, were significant improved in the HLJDD and its fractions groups. In conclusion, HLJDD exhibited anti-AD effects by inhibiting itching and enhancing immunity, which in turn regulating the levels of relative metabolites, and CPF and 40AEF were considered the most important components of HLJDD.

Structural racism and its pathways to asthma and atopic dermatitis

Black, Latinx, and Indigenous people in the United States experience a disproportionate burden of asthma and atopic dermatitis. The study of these disease disparities has focused on proximal socioenvironmental exposures and on the biomechanistic (including genetic) differences between racial and ethnic groups. Although biomedical research in allergy and immunology stands to benefit from the inclusion of diverse study populations, the narrow focus on biologic mechanisms disregards the complexity of interactions across biologic and structural factors, including the effects of structural racism. Structural racism is the totality of ways in which society fosters discrimination by creating and reinforcing inequitable systems through intentional policies and practices sanctioned by government and institutions. It is embedded across multiple levels, including the economic, educational, health care, and judicial systems, which are manifested in inequity in the physical and social environment. In this review, we present a conceptual framework and pull from the literature to demonstrate how structural racism is a root cause of atopic disease disparities by way of residential segregation, socioeconomic position, and mass incarceration, which may lead to aberrations in the innate and adaptive immune response and the augmentation of physiologic stress responses, contributing to a disproportionate disease burden for racial and ethnic populations.

Pediatric asthma incidence rates in the United States from 1980 to 2017

BACKGROUND

Few studies have examined longitudinal asthma incidence rates (IRs) from a public health surveillance perspective.

OBJECTIVE

Our aim was to calculate descriptive asthma IRs in children over time with consideration for demographics and parental asthma history.

METHODS

Data from 9 US birth cohorts were pooled into 1 population covering the period from 1980 to 2017. The outcome was earliest parental report of a doctor diagnosis of asthma. IRs per 1,000 person-years were calculated.

RESULTS

The racial/ethnic backgrounds of the 6,283 children studied were as follows: 55% European American (EA), 25.5% African American (AA), 9.5% Mexican-Hispanic American (MA) and 8.5% Caribbean-Hispanic American (CA). The average follow-up was 10.4 years (SD = 8.5 years; median = 8.4 years), totaling 65,291 person-years, with 1789 asthma diagnoses yielding a crude IR of 27.5 per 1,000 person-years (95% CI = 26.3-28.8). Age-specific rates were highest among children aged 0 to 4 years, notably from 1995 to 1999, with a decline in EA and MA children in 2000 to 2004 followed by a decline in AA and CA children in 2010 to 2014. Parental asthma history was associated with statistically significantly increased rates. IRs were similar and higher in AA and CA children versus lower but similar in EA and MA children. The differential rates by sex from birth through adolescence principally resulted from a decline in rates among males but relatively stable rates among females.

CONCLUSIONS

US childhood asthma IRs varied dramatically by age, sex, parental asthma history, race/ethnicity, and calendar year. Higher rates in the 0- to 4-year-olds group, particularly among AA/CA males with a parental history of asthma, as well as changes in rates over time and by demographic factors, suggest that asthma is driven by complex interactions between genetic susceptibility and variation in time-dependent environmental and social factors.

Longitudinal atopic dermatitis endotypes: An atopic march paradigm that includes Black children

BACKGROUND

The atopic march has been studied mostly in White populations, biasing our current paradigms.

OBJECTIVE

We sought to define the atopic march in Black and White children and explore mechanisms for racial differences.

METHODS

Utilizing the Mechanisms of Progression of Atopic Dermatitis to Asthma in Children (MPAACH) cohort (n = 601), we assessed longitudinal sensitization, food allergy (FA), allergic rhinitis, risk of asthma development (through the Pediatric Asthma Risk Score), Scoring for Atopic Dermatitis (SCORAD), transepidermal water loss, skin filaggrin (FLG) expression, exposures, and genetic heritability to define AD progression endotypes in Black and White children.

RESULTS

White MPAACH children were more likely to be sensitized to aero and food allergens (P = .0001) and over 3 times more likely to develop FA and/or allergic rhinitis (AR) without asthma risk (P < .0001). In contrast, Black children were over 6 times more likely to proceed to high asthma risk without FA, sensitization, or AR (P < .0001). White children had higher lesional and nonlesional transepidermal water loss (both P < .001) as well as decreased nonlesional keratinocyte FLG expression (P = .02). Black children had increased genetic heritability for asthma risk and higher rates of exposures to secondhand smoke and traffic-related air pollution.

CONCLUSIONS

Black and White children with AD have distinct allergic trajectories defined by different longitudinal endotypes. Black children exhibit higher asthma risk despite a more intact skin barrier and less sensitization, FA, and AR. White children have less asthma risk, despite a more dysfunctional skin barrier, and more FA, AR, and sensitization. The observed racial differences are likely due in part to increased genetic heritability for asthma risk and harmful environmental exposures in Black children. Collectively, our findings provide a new paradigm for an atopic march that is inclusive of Black children.

Whole-genome sequencing in diverse subjects identifies genetic correlates of leukocyte traits: The NHLBI TOPMed program

Many common and rare variants associated with hematologic traits have been discovered through imputation on large-scale reference panels. However, the majority of genome-wide association studies (GWASs) have been conducted in Europeans, and determining causal variants has proved challenging. We performed a GWAS of total leukocyte, neutrophil, lymphocyte, monocyte, eosinophil, and basophil counts generated from 109,563,748 variants in the autosomes and the X chromosome in the Trans-Omics for Precision Medicine (TOPMed) program, which included data from 61,802 individuals of diverse ancestry. We discovered and replicated 7 leukocyte trait associations, including (1) the association between a chromosome X, pseudo-autosomal region (PAR), noncoding variant located between cytokine receptor genes (CSF2RA and CLRF2) and lower eosinophil count; and (2) associations between single variants found predominantly among African Americans at the S1PR3 (9q22.1) and HBB (11p15.4) loci and monocyte and lymphocyte counts, respectively. We further provide evidence indicating that the newly discovered eosinophil-lowering chromosome X PAR variant might be associated with reduced susceptibility to common allergic diseases such as atopic dermatitis and asthma. Additionally, we found a burden of very rare FLT3 (13q12.2) variants associated with monocyte counts. Together, these results emphasize the utility of whole-genome sequencing in diverse samples in identifying associations missed by European-ancestry-driven GWASs.

Reframing racial and ethnic disparities in atopic dermatitis in Black and Latinx populations

Black people in the United States experience greater atopic dermatitis (AD) prevalence, severity, and persistence when compared with White people. Although very little published literature describes AD in the Latinx population, additional differences in severity, persistence, and age of onset exist in contrast to White people. Thus far, genetic polymorphisms associated with increased risk and/or severity of AD are less common among Black people, so should confer reduced, rather than the observed increased, AD risk among Black people. Little is known regarding genetic risk factors in Latinx people. In contrast, there is consistent evidence that socioeconomic, environmental, and health care factors influence AD prevalence, severity, and/or persistence, and these same risk factors are more common among racial and ethnic minority populations as a result of racism. Researchers too often pursue genetic explanations for racial and ethnic AD disparities when the evidence points to the importance of contextual, rather than genetic, causes of these disparities. Reframing the prevailing view that innate differences among racial and ethnic groups are responsible for these disparities by emphasizing the role of racism and its downstream effects on contextual factors will be a critical first step toward shrinking these disparities.

Immune and barrier characterization of atopic dermatitis skin phenotype in Tanzanian patients

BACKGROUND

Atopic dermatitis (AD) is a common disease, with particularly high prevalence found in Africa. It is increasingly recognized that patients with AD of different ethnic backgrounds have unique molecular signatures in the skin, potentially accounting for treatment response variations. Nevertheless, the skin profile of patients with AD from Africa is unknown, hindering development of new treatments targeted to this patient population.

OBJECTIVE

To characterize the skin profile of patients with AD from Africa.

METHODS

Gene expression studies, including RNA sequencing (using threshold of fold change of >2 and false discovery rate of <0.05) and real-time polymerase chain reaction, were performed on skin biopsies of Tanzanian patients with moderate-to-severe AD and controls.

RESULTS

Tanzanian AD skin presented robust up-regulations of multiple key mediators of both T helper 2 (TH2) (interleukin 13 [IL-13], IL-10, IL-4R, CCL13,CCL17,CCL18,CCL26) and TH22 (IL22, S100As) pathways. Markers related to TH17 and IL-23 (IL-17A, IL-23A, IL-12, PI3, DEFB4B) and TH1 (interferon gamma, CXCL9,CXCL10,CXCL11) were also significantly overexpressed in AD tissues (FDR<.05), albeit to a lesser extent. IL-36 isoforms revealed substantial up-regulations in African skin. The barrier fingerprint of Tanzanian AD revealed no suppression of hallmark epidermal barrier differentiation genes, such as filaggrin, loricrin, and periplakin, with robust attenuation of lipid metabolism genes (ie, AWAT1).

CONCLUSION

The skin phenotype of Tanzanian patients with AD is consistent with that of African Americans, exhibiting dominant TH2 and TH22 skewing, minimal dysregulation of terminal differentiation, and even broader attenuation of lipid metabolism-related products. These data highlight the unique characteristic of AD in Black individuals and the need to develop unique treatments targeting patients with AD from these underrepresented populations.

No Association of filaggrin copy number variation and atopic dermatitis risk in White and Black Americans

Atopic dermatitis (AD) is a chronic, inflammatory skin condition with a multifactorial pathophysiology. The filaggrin gene (FLG) has particularly been implicated given loss of function (LoF) mutations in this gene lead to skin barrier dysfunction and such mutations can increase a patient's likelihood of developing AD. FLG has intragenic copy number variation (CNV), which impacts the total amount of filaggrin produced. Previous research reported a dose-dependent effect such that as amount of FLG increases, risk of AD decreases. To gain a better understanding, we evaluated FLG CNV in a large case-control study of Whites and Blacks with and without AD. The goal of our study was to determine whether FLG CNV has a dose-dependent effect on the risk of developing AD and to determine whether FLG CNV varies by race. The frequencies and odds ratios comparing a given CNV by race or race within those with AD did not significantly vary. It had been thought that FLG CNV might vary by race and represent an important association with AD in Black AD subjects. However, our work suggests that while there are racial differences with respect to CNV, these differences do not appear to explain AD risk.

Intergenerational Impacts of Maternal Stress on Early Childhood Atopy in Black Americans

OBJECTIVE

Black children are disproportionately affected by atopic diseases (i.e., atopic dermatitis, allergic rhinitis, asthma, and food allergies), with health disparities present in early life. Studies in White samples suggest that maternal stress confers risk for offspring atopy, yet little is known about these relationships in Black populations. This study seeks to (a) examine the relationship between self-reported and physiological indicators of maternal stress and offspring atopy and (b) explore warm and responsive caregiving as a potential protective factor in Black Americans.

METHODS

A sample of 179 Black mother-child dyads of varying socioeconomic status participated in a prospective longitudinal study. Mothers completed self-reports of childhood trauma, prenatal stress, postnatal stress, and physician diagnosis of offspring atopy; provided blood samples to assess physiological responses to chronic stress exposure; and participated in a behavioral task with their infant.

RESULTS

Maternal self-reports of childhood trauma, prenatal stress, and postnatal stress were not associated with offspring diagnosis of atopy by 2-3 years of age. Mothers who produced a smaller inflammatory response during pregnancy were more likely to have an offspring with atopy by 2-3 years of age. Warm and responsive parenting demonstrated a protective effect; the positive association between maternal stress and offspring atopy was less apparent in cases of mother-child interactions characterized by high levels warm and responsive parenting.

CONCLUSION

Failure to replicate previous findings suggests that the maternal stress-offspring atopy relationship is complex. Future studies must examine the unique stressors in Black Americans, as well as caregiving as a potential protective factor.

Polygenic prediction of atopic dermatitis improves with atopic training and filaggrin factors

BACKGROUND

While numerous genetic loci associated with atopic dermatitis (AD) have been discovered, to date, work leveraging the combined burden of AD risk variants across the genome to predict disease risk has been limited.

OBJECTIVES

This study aims to determine whether polygenic risk scores (PRSs) relying on genetic determinants for AD provide useful predictions for disease occurrence and severity. It also explicitly tests the value of including genome-wide association studies of related allergic phenotypes and known FLG loss-of-function (LOF) variants.

METHODS

AD PRSs were constructed for 1619 European American individuals from the Atopic Dermatitis Research Network using an AD training dataset and an atopic training dataset including AD, childhood onset asthma, and general allergy. Additionally, whole genome sequencing data were used to explore genetic scoring specific to FLG LOF mutations.

RESULTS

Genetic scores derived from the AD-only genome-wide association studies were predictive of AD cases (PRS_AD: odds ratio [OR], 1.70; 95% CI, 1.49-1.93). Accuracy was first improved when PRSs were built off the larger atopy genome-wide association studies (PRS_AD+: OR, 2.16; 95% CI, 1.89-2.47) and further improved when including FLG LOF mutations (PRS_AD++: OR, 3.23; 95% CI, 2.57-4.07). Importantly, while all 3 PRSs correlated with AD severity, the best prediction was from PRS_AD++, which distinguished individuals with severe AD from control subjects with OR of 3.86 (95% CI, 2.77-5.36).

CONCLUSIONS

This study demonstrates how PRSs for AD that include genetic determinants across atopic phenotypes and FLG LOF variants may be a promising tool for identifying individuals at high risk for developing disease and specifically severe disease.

Transcriptomic analysis of atopic dermatitis in African Americans is characterized by Th2/Th17-centered cutaneous immune activation

Atopic dermatitis (AD) often presents more severely in African Americans (AAs) and with greater involvement of extensor areas. To investigate immune signatures of AD in AAs with moderate to severe pruritus, lesional and non-lesional punch biopsies were taken from AA patients along with age-, race-, and sex-matched controls. Histology of lesional skin showed psoriasiform dermatitis and spongiotic dermatitis, suggesting both Th2 and Th17 activity. Gene Set Variation Analysis showed upregulation of Th2 and Th17 pathways in both lesional versus non-lesional and lesional versus control (p < 0.01), while Th1 and Th22 upregulation were observed in lesional versus control (p < 0.05). Evidence for a broad immune signature also was supported by upregulated Th1 and Th22 pathways, and clinically may represent greater severity of AD in AA. Furthermore, population-level analysis of data from TriNetX, a global federated health research network, revealed that AA AD patients had higher values for CRP, ferritin, and blood eosinophils compared to age-, sex-, and race-matched controls as well as white AD patients, suggesting broad systemic inflammation. Therefore, AA AD patients may feature broader immune activation than previously thought and may derive benefit from systemic immunomodulating therapies that modulate key drivers of multiple immune pathways.

Health disparities in allergic and immunologic conditions in racial and ethnic underserved populations: A Work Group Report of the AAAAI Committee on the Underserved

Health disparities are health differences linked with economic, social, and environmental disadvantage. They adversely affect groups that have systematically experienced greater social or economic obstacles to health. Renewed efforts are needed to reduced health disparities in the United States, highlighted by the disparate impact on racial minorities during the coronavirus pandemic. Institutional or systemic patterns of racism are promoted and legitimated through accepted societal standards, and organizational processes within the field of medicine, and contribute to health disparities. Herein, we review current evidence regarding health disparities in allergic rhinitis, asthma, atopic dermatitis, food allergy, drug allergy, and primary immune deficiency disease in racial and ethnic underserved populations. Best practices to address these disparities involve addressing social determinants of health and adopting policies to improve access to specialty care and treatment for the underserved through telemedicine and community partnerships, cross-cultural provider training to reduce implicit bias, inclusion of underserved patients in research, implementation of culturally competent patient education, and recruitment and training of health care providers from underserved communities. Addressing health disparities requires a multilevel approach involving patients, health providers, local agencies, professional societies, and national governmental agencies.

Tractor uses local ancestry to enable the inclusion of admixed individuals in GWAS and to boost power

Admixed populations are routinely excluded from genomic studies due to concerns over population structure. Here, we present a statistical framework and software package, Tractor, to facilitate the inclusion of admixed individuals in association studies by leveraging local ancestry. We test Tractor with simulated and empirical two-way admixed African-European cohorts. Tractor generates accurate ancestry-specific effect-size estimates and P values, can boost genome-wide association study (GWAS) power and improves the resolution of association signals. Using a local ancestry-aware regression model, we replicate known hits for blood lipids, discover novel hits missed by standard GWAS and localize signals closer to putative causal variants.

Personalized medicine for asthma in tropical regions

PURPOSE OF REVIEW

Precision medicine could help to improve diagnosis and treatment of asthma; however, in the tropics there are special conditions to be considered for applying this strategy. In this review, we analyze recent advances of precision allergology in tropical regions, highlighting its limitations and needs in high-admixed populations living under environments with high exposure to house dust mites and helminth infections.

RECENT FINDINGS

Advances have been made regarding the genetic characterization of the great diversity of populations living in the tropics. Genes involved in shared biological pathways between immune responses to nematodes and the allergic responses suggested new mechanisms of predisposition. Genome wide association studies of asthma are progressively focusing on some highly replicated genes such as those in chromosome 17q31-13, which have been also replicated in African ancestry populations. Some diagnostic difficulties, because of the endemicity of helminth infections, are now more evident in the context of phenotype definition.

SUMMARY

The clinical impact of the advances in precision medicine for asthma in the tropics is still limited and mainly related to component resolved diagnosis. More basic and clinical research is needed to identify genetic, epigenetic, or other biologic markers that allow and accurate definition of phenotypes and endotypes of this heterogeneous disease. This will substantially improve the selection of personalized treatments.