Biomedical subjects

Elizabeth C Matsui

Publications and source records attributed to Elizabeth C Matsui.

12 recordsLinked to original sources

PubMed2006

Household mouse allergen exposure and asthma morbidity in inner-city preschool children.

BACKGROUND: Inner-city children experience disproportionate asthma morbidity, and suspected reasons include indoor environmental exposures. OBJECTIVE: To determine if mouse allergen exposure is a risk factor for asthma morbidity. METHODS: Preschool children with asthma were recruited from inner-city Baltimore, MD. Skin testing was performed and blood was collected at the baseline visit for quantification of mouse allergen specific IgE. A questionnaire evaluated symptoms, medication, and health care use at baseline, 3 months, and 6 months. A trained technician collected dust samples from the child's home for analysis of Mus m 1 at baseline, 3 months, and 6 months. Outcomes were compared between mouse-sensitized, highly exposed children and all other children. RESULTS: A total of 127 children had complete data for mouse sensitization status and bedroom settled dust mouse allergen levels at baseline. The mean age of the children was 4.4 years, 92% were African American, and 26% were sensitized to mouse. Mouse-sensitized children exposed to higher levels of Mus m 1 (>0.5 microg/g) had 50% more days of symptoms (incidence rate ratio [IRR], 1.5; 95% confidence interval [CI], 1.1-2.1) and 80% more days of beta-agonist use than other children (IRR, 1.8; 95% CI, 1.3-2.5). Children in the sensitized and highly exposed group were also more likely to have an unscheduled physician visit (odds ratio [OR], 3.1; 95% CI, 1.6-6.3), emergency department visit (OR, 2.1; 95% CI, 1.1-4.1), and hospitalization (OR, 36.6; 95% CI, 4.1-327.3) than other children. These associations between mouse allergen exposure and asthma symptoms and morbidity remained statistically significant after adjusting for potential confounders, including atopy and cockroach sensitization and exposure. CONCLUSIONS: In mouse-sensitized inner-city children, exposure to mouse allergen may be an important cause of asthma morbidity.

Allergens↗

PubMed2006

Room-specific characteristics of suburban homes as predictors of indoor allergen concentrations.

BACKGROUND: Room characteristics predicting indoor allergen exposure in suburban homes have not been clearly identified. OBJECTIVE: To examine relationships between room characteristics and concentrations of indoor allergens in homes of suburban asthmatic patients. METHODS: The homes of 339 asthmatic children ages 6 to 17 years were studied. Home inspections were conducted by a trained technician, and dust samples were analyzed for indoor allergen content. A high allergen concentration was defined as 8 microg (U)/g or more of fine dust. RESULTS: Infrequent sheet washing and wall-to-wall carpet were risk factors for high bedroom dust mite concentrations. Infrequent sheet washing was also a risk factor for high Fel d 1 concentrations. Food remains in the bedroom was a risk factor for high bedroom Bla g 1 levels, and exposed food, leaks, and dirty pots were all risk factors for high kitchen Bla g 1 levels. The combination of lack of mattress or pillow encasements, infrequent sheet washing, and carpeting was associated with a 24-fold increase in odds of a high dust mite concentration (odds ratio [OR], 24.1; 95% confidence interval [CI], 3.2-181.4). Among non-cat owners, the combination of stuffed toys on the bed, lack of mattress or pillow encasements, and infrequent sheet washing was associated with a 49-fold increase in odds of a high Fel d 1 level (OR, 49.4; 95% CI, 2.8-887.3). The combination of leaks, exposed food, and dirty pots was associated with a high kitchen Bla g 1 concentration (OR, 10.6; 95% CI, 2.8-40.5). CONCLUSIONS: Specific room characteristics predict high indoor allergen exposure among children with asthma, and a combination of these characteristics may further increase the risk of high allergen exposure.

Adolescent↗

PubMed2006

Diagnosis and management of food-induced anaphylaxis: a national survey of pediatricians.

BACKGROUND: Food allergy is a common pediatric problem, affecting as many as 6% of young children, yet it is unclear whether pediatricians are well prepared to manage food-induced anaphylaxis. OBJECTIVE: The purpose of this work was to assess pediatricians' knowledge of diagnosis and management of children with food-induced anaphylaxis. METHODS: A survey designed to assess food allergy diagnosis and management was mailed to a US national random sample of 1130 pediatricians. Survey questions were based on a clinical scenario involving a child having an anaphylactic reaction after ingesting peanut. Primary outcome measures included correct responses to the 11 questions about anaphylaxis. RESULTS: A total of 468 pediatricians (41%) responded to the survey. The majority of the respondents were women (58%), spent > 50% of their time in a clinical setting (78%), and reported providing care for food allergy patients (86%). Overall, 70% of the pediatricians agreed that the clinical scenario was consistent with anaphylaxis, and 72% chose to administer epinephrine. However, only 56% of respondents agreed with both the diagnosis of anaphylaxis and treating with epinephrine. Most pediatricians (70%) did not recognize that a 30-minute observation period after anaphylaxis was too short. Pediatricians who reported providing care for food allergy patients were more likely to agree with the diagnosis of anaphylaxis (73% vs 59%), with treating the reaction with epinephrine (73% vs 64%), and with prescribing self-injectable epinephrine (83% vs 66%) than pediatricians who did not care for food allergy patients. The more certain that pediatricians were that the child was having an anaphylactic reaction, the more likely they were to agree with treating the reaction with epinephrine. In general, recent continuing medical education was not predictive of improved knowledge. CONCLUSION: Although the majority of pediatricians seem to have some knowledge of food-induced anaphylaxis, a substantial proportion has knowledge deficits that may hinder their ability to provide optimal care to children with food-induced anaphylaxis. Pediatricians who provide health care for patients with food allergy may be better equipped to manage food-induced anaphylaxis than those who do not. Because continuing medical education was not a significant predictor of increased knowledge, ensuring that pediatric residents develop experience managing patients with food allergies may be a better strategy to educate primary care pediatricians about food allergy.

Anaphylaxis↗

PubMed2005

The natural history of tree nut allergy.

BACKGROUND: Although 20% of children outgrow peanut allergy, the natural history of tree nut (TN) allergy has not been well studied. OBJECTIVE: The goals of the study were to estimate the proportion of children who outgrow TN allergy and examine predictors of outgrowing it. METHODS: Patients with TN allergy, defined as a history of reaction on ingestion and evidence of TN-specific IgE (TN-IgE) or positive TN-specific IgE level but no history of ingestion, were evaluated. If all current TN-IgE levels were less than 10 kilounits of antibody (kU(A))/L, double-blind, placebo-controlled food challenges were offered. Patients who had undergone open TN challenges as part of routine clinical care were also included. RESULTS: Two hundred seventy-eight patients with TN allergy were identified. One hundred one (36%) had a history of acute reactions, 12 (12%) of whom had reactions to multiple TNs and 73 (63%) of whom had a history of moderate-to-severe reactions. Nine of 20 patients who had previously reacted to a TN passed challenges, so that 9 (8.9%; 95% CI, 4% to 16%) of 101 patients with a history of prior TN reactions outgrew TN allergy. Fourteen of 19 who had never ingested TNs but had detectable TN-specific IgE levels passed challenges. One hundred sixty-one did not meet the challenge criteria, and 78 met the criteria but declined challenges. Looking at specific TN-IgE cutoffs, 58% with TN-IgE levels of 5 kU(A)/L or less and 63% with TN-IgE levels of 2 kU(A)/L or less passed challenges. CONCLUSIONS: Approximately 9% of patients outgrow TN allergy, including some who had prior severe reactions. Although ideal cutoffs for challenge cannot be firmly recommended on the basis of these data, patients aged 4 years or older with all TN-IgE levels of 5 kU(A)/L or less should be considered for challenge.

Adolescent↗

PubMed2005

Airborne mouse allergen in the homes of inner-city children with asthma.

BACKGROUND: Airborne mouse allergen has not previously been measured in inner-city homes, and its relationship to settled dust mouse allergen levels is unknown. OBJECTIVE: To quantify airborne and settled dust Mus m 1 levels in homes of inner-city patients with asthma and to identify risk factors for mouse allergen exposure. METHODS: One hundred inner-city school-age children with asthma in Baltimore underwent skin testing to a panel of aeroallergens, and their homes were inspected by a trained technician. Air and settled dust were sampled in the child's bedroom. Mus m 1, particulate matter smaller than 10 microns (PM 10 ), and particulate matter smaller than 2.5 microns were quantified in air samples, and Mus m 1 was quantified in settled dust samples. RESULTS: Mus m 1 was detected in settled dust samples from 100% of bedrooms. Airborne mouse allergen was detected in 48 of 57 (84%) bedrooms, and the median airborne mouse allergen concentration was 0.03 ng/m 3 . The median PM 10 concentration was 48 microg/m 3 . Airborne and settled dust mouse allergen levels were moderately correlated ( r = .52; P < .0001), and airborne Mus m 1 and PM 10 levels were weakly correlated ( r = .29; P = .03). Having cracks or holes in doors or walls, evidence of food remains in the kitchen, and mouse infestation were all independently associated with having detectable airborne mouse allergen. CONCLUSION: Airborne mouse allergen concentrations in many inner-city homes may be similar to those found in animal facilities, where levels are sufficiently high to elicit symptoms in sensitized individuals. Exposed food remains, cracks and holes in doors or walls, and evidence of mouse infestation appear to be risk factors for having detectable airborne Mus m 1.

Air Pollution, Indoor↗

PubMed2004

Association of Foxp3 regulatory gene expression with graft-versus-host disease.

Graft-versus-host disease (GVHD) is characterized by an impairment of mechanisms that underlie the development of immunologic tolerance. Although the cytokine storm associated with GVHD leads to expression of cell surface markers on both effector and regulatory T cells, regulatory CD4+ T cells that play an instrumental role in the maintenance of tolerance appear to uniquely express the Foxp3 transcriptional repressor. Foxp3 mRNA expression was significantly decreased in peripheral blood mononuclear cells from patients with either allogeneic GVHD or autologous GVHD compared with patients without GVHD. Expression of Foxp3 negatively correlated with the severity of GVHD but positively correlated with recent thymic emigrants. The results suggest that defective thymic function contributes to the impaired reconstitution of immune regulatory mechanisms following transplantation. The decrease in regulatory mechanisms after transplantation appears to provide an environment permissive to the development of GVHD.

Adolescent↗

PubMed2004

Mouse allergen exposure and mouse skin test sensitivity in suburban, middle-class children with asthma.

BACKGROUND: Exposure to mouse allergen is prevalent in inner-city homes and is associated with an increased risk of mouse skin test sensitivity in inner-city children with asthma. OBJECTIVE: To determine the distribution of mouse allergen and its relationship to mouse skin test sensitivity in a primarily suburban, middle-class population of asthmatic children. METHODS: Children with asthma, 6 to 17 years old, were recruited from 3 pediatric practices located in counties surrounding the city of Baltimore and from 1 practice located within the city limits. Participants underwent skin prick testing and completed a baseline questionnaire. Their homes were inspected, and settled dust samples were collected for allergen analysis. RESULTS: Two hundred fifty-seven of 335 (76.7%) participants resided outside the city, and 53.7% had annual incomes >$50,000. Mouse allergen was detected in 74.9% of bedrooms, and 13.1% were sensitized to mouse. Lower maternal education (odds ratio [OR], 2.17; 95% CI, 1.28-3.67), city residence (OR, 5.39; 95% CI, 2.23-13.02), and higher bedroom cockroach allergen levels (OR, 9.61; 95% CI, 1.17-79.03) were independent predictors of high bedroom mouse allergen. The risk of mouse skin test sensitivity increased with increasing bedroom Mus m 1 exposure (OR, 1.43; 95% CI, 1.04-1.96, with each increase in quartile), and dog skin test sensitivity was a strong independent predictor of mouse skin test sensitivity (OR, 7.23; 95% CI, 3.03-17.22). CONCLUSION: Mouse allergen exposure is common among suburban, middle-class asthmatic children. Increasing bedroom levels of Mus m 1 and dog skin test sensitivity are risk factors for mouse skin test sensitivity.

Adolescent↗

PubMed2004

The relationship of allergen-specific IgE levels and oral food challenge outcome.

BACKGROUND: Oral food challenges remain the gold standard for the diagnosis of food allergy. However, clear clinical and laboratory guidelines have not been firmly established to determine when oral challenges should be performed. OBJECTIVE: We sought to determine the value of food-specific IgE levels in predicting challenge outcome. METHODS: A retrospective chart review of 604 food challenges in 391 children was performed. All children had food-specific IgE levels measured by means of CAP-RAST before challenge. Data were analyzed to determine the relationship between food-specific IgE levels and challenge outcome, as well as the relationship between other clinical parameters and challenge outcome. RESULTS: Forty-five percent of milk challenges were passed compared with 57% for egg, 59% for peanut, 67% for wheat, and 72% for soy. Specific IgE levels were higher among patients who failed challenges than among those who passed (P </=.03 for each food). When seeking a specific IgE level at which a 50% pass rate could be expected, a cutoff level of 2 kUA/L was determined for milk, egg, and peanut. Data were less clear for wheat and soy. Coexistent eczema or asthma was associated with failed egg challenges, but other atopic disease was otherwise not associated with challenge outcome. CONCLUSIONS: Allergen-specific IgE concentrations to milk, egg, and peanut and, to a lesser extent, wheat and soy serve as useful predictors of challenge outcome and should be considered when selecting patients for oral challenge to these foods.

Allergens↗

PubMed2004

Risk of oral food challenges.

BACKGROUND: Oral food challenges are essential to the diagnosis of food allergy; however, little has been reported regarding the risks of performing food challenges in children with suspected food allergy. OBJECTIVE: To examine the risk and reaction severity of failed oral food challenges. METHODS: A retrospective chart review was performed on children who underwent food challenges to milk, egg, peanut, soy, and/or wheat in a university-based pediatric allergy clinic over a 7-year period. RESULTS: Of the 584 challenges completed, 253 (43%) resulted in an allergic reaction. There were 90 milk, 56 egg, 71 peanut, 21 soy, and 15 wheat failed challenges. Of patients who failed, there were 197 (78%) cutaneous, 108 (43%) gastrointestinal, 66 (26%) oral, 67 (26%) lower respiratory, and 62 (25%) upper respiratory reactions. No patients had cardiovascular symptoms. There was no difference between foods in the severity of failed challenges or the type of treatment required to reverse symptoms. All reactions were reversible with short-acting antihistamines +/- epinephrine, beta-agonists, and/or corticosteroids. No children required hospitalization, and there were no deaths. CONCLUSIONS: There are risks associated with food challenges, and the risks are similar for each of the foods studied. Given the benefits that result from a negative challenge, these risks are reasonable when challenges are performed under the guidance of an experienced practitioner in a properly equipped setting.

Child, Preschool↗

PubMed2004

Mouse allergen exposure and immunologic responses: IgE-mediated mouse sensitization and mouse specific IgG and IgG4 levels.

BACKGROUND: Although there is evidence that contact with mice is associated with IgE-mediated mouse sensitization and mouse specific antibody responses, the exposure-response relationships remain unclear. OBJECTIVE: To determine whether IgE-mediated mouse sensitization and mouse specific IgG (mIgG) and mIgG4 levels increase with increasing Mus m 1 exposure. METHODS: One hundred fifty-one workers at a mouse research and production facility were studied. Exposure assignments were made by linking participants to airborne Mus m 1 concentrations in their respective work areas. Cumulative exposure was estimated by multiplying airborne Mus m 1 concentration by duration of employment. Serum mIgG and mIgG4 levels were quantified by antigen-binding assays, and IgE-mediated mouse sensitization was evaluated by skin prick testing (SPT). RESULTS: Prevalence rates of mouse SPT sensitivity and of high levels of mIgG and mIgG4 were increasingly higher by quintiles of increasing cumulative exposure (P < .01 for SPT, mIgG, and mIgG4). After adjusting for age, sex, and atopy, the log odds ratio (OR) of having positive mouse SPT results was linearly related to cumulative exposure (r2 = 0.87), as was the log OR of having a high mIgG level (r2 = 0.86). Quintile of cumulative exposure was an independent predictor of both SPT sensitivity (OR, 1.7; 95% confidence interval, 1.2-2.5) and a high mIgG level (OR, 1.7; 95% confidence interval, 1.2-2.4). CONCLUSIONS: IgE-mediated mouse sensitization and mIgG and mIgG4 levels were related to cumulative exposure in a dose-dependent manner. Thus, strategies to prevent allergy to mice should remain focused on reducing mouse allergen exposure.

Adult↗

PubMed2003

Peanut allergy.

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Case-Control Studies↗

PubMed2003

Cockroach allergen exposure and sensitization in suburban middle-class children with asthma.

BACKGROUND: Exposure to cockroach allergen is prevalent in inner-city homes and is associated with an increased risk of cockroach sensitization. OBJECTIVE: We sought to determine the prevalence of cockroach allergen exposure in suburban middle-class homes and to study its relationship to cockroach sensitization. METHODS: Children with asthma, 6 to 17 years of age, were recruited from 3 pediatric practices located in counties surrounding Baltimore city and from 1 practice located within Baltimore city limits. Participants underwent skin prick testing and completed baseline questionnaires. In addition, their homes were inspected, and settled dust samples were collected for allergen analysis. RESULTS: Forty-one percent of the total study population (n = 339) had kitchen Bla g 1 levels of greater than 1 U/g. Forty-nine percent were white, 53% had annual incomes of greater than US dollars 50000, and 48% of mothers had college degrees. Seventy-seven percent of the study population resided in a suburban or rural location, and 30% of kitchens in these homes had Bla g 1 levels of greater than 1 U/g. Among the suburban-rural subgroup, 21% were sensitized to cockroach compared with 35% of the city group. In multivariate analysis, exposure to kitchen Bla g 1 levels of greater than 1 U/g was associated with cockroach sensitization for both the total study population (odds ratio, 2.29; 95% CI, 1.28-4.11) and the suburban-rural subgroup (odds ratio, 2.37; 95% CI, 1.23-4.57). CONCLUSIONS: Cockroach allergen exposure might be more common in suburban middle-class homes of asthmatic children than previously thought. Moreover, the data suggest that low-level cockroach exposure is a risk factor for cockroach sensitization.

Adolescent↗