J.M. El-Dahr

Fish allergy: is cross-reactivity among fish species relevant? Double-blind placebo-controlled food challenge studies of fish allergic adults

BACKGROUND Allergic reactions to fish are a common cause of food allergy in many areas of the world where fish is a major source of protein. Although different species of fish may be consumed, possible cross-reactivity has received limited investigation. OBJECTIVE The aim of this study was to assess potential cross-reactivity to different species of fish species using double-blind, placebo-controlled food challenges (DBPCFC) in fish-allergic adults and to compare skin test and RAST reactivity with the challenge response. METHODS Nine skin prick test and/or RAST-positive adult individuals with histories of an immediate-type reaction following fish ingestion were challenged with different fish species using double-blind, placebo-controlled food challenge. RESULTS Of a total of 19 double-blind, placebo-controlled fish challenges performed, 14 challenges (74%) resulted in the induction of objective signs that were consistent with an IgE-mediated response. The most common sign observed was emesis (37%); the most prevalent subjective symptoms reported were compatible with the oral allergy syndrome (84%). Three subjects reacted to at least three fish species and one subject reacted to two fish species tested. In regard to the positive challenges, predictive accuracy of skin prick test and RAST was 84% and 78%, respectively. CONCLUSION Our results indicate that clinically relevant cross-reactivity among various species of fish may exist. Advising fish-allergic subjects to avoid all fish species should be emphasized until a species can be proven safe to eat by provocative challenge.

The Severity of Autism Is Associated with Toxic Metal Body Burden and Red Blood Cell Glutathione Levels

This study investigated the relationship of childrens autism symptoms with their toxic metal body burden and red blood cell (RBC) glutathione levels. In children ages 3–8 years, the severity of autism was assessed using four tools: ADOS, PDD-BI, ATEC, and SAS. Toxic metal body burden was assessed by measuring urinary excretion of toxic metals, both before and after oral dimercaptosuccinic acid (DMSA). Multiple positive correlations were found between the severity of autism and the urinary excretion of toxic metals. Variations in the severity of autism measurements could be explained, in part, by regression analyses of urinary excretion of toxic metals before and after DMSA and the level of RBC glutathione (adjusted R 2 of 0.22–0.45, P < .005 in all cases). This study demonstrates a significant positive association between the severity of autism and the relative body burden of toxic metals.

Mold exposure and health effects following hurricanes Katrina and Rita.

The extensive flooding in the aftermath of Hurricanes Katrina and Rita created conditions ideal for indoor mold growth, raising concerns about the possible adverse health effects associated with indoor mold exposure. Studies evaluating the levels of indoor and outdoor molds in the months following the hurricanes found high levels of mold growth. Homes with greater flood damage, especially those with >3 feet of indoor flooding, demonstrated higher levels of mold growth compared with homes with little or no flooding. Water intrusion due to roof damage was also associated with mold growth. However, no increase in the occurrence of adverse health outcomes has been observed in published reports to date. This article considers reasons why studies of mold exposure after the hurricane do not show a greater health impact.

Safety and efficacy of oral DMSA therapy for children with autism spectrum disorders: Part B - Behavioral results

BackgroundThis study investigated the effects of oral dimercapto succinic acid (DMSA) therapy on the behavioural symptoms of children with autism spectrum disorders (ASD) ages 3-8 years.MethodsPhase 1 involved 65 children with ASD who received one round of DMSA (3 days). Participants who had high urinary excretion of toxic metals were selected to continue on to phase 2. In phase 2, 49 participants were randomly assigned in a double-blind design to receive an additional 6 rounds of either DMSA or placebo.ResultsThe groups receiving one round and seven rounds of DMSA had significant improvements on all the assessment measures. For the seven round group, the degree of improvement on the assessment measures could be partially explained by a regression analysis based on excretion of toxic metals and changes in glutathione (adjusted R2 of 0.28-0.75, p < 0.02 in all cases). One round of DMSA had nearly the same benefit as seven rounds. The assessment measures correlated reasonably with one another at the beginning of the study (r = 0.60-0.87) and even better at the end of the study (r = 0.63-0.94).ConclusionOverall, both one and seven rounds of DMSA therapy seems to be reasonably safe in children with ASD who have high urinary excretion of toxic metals, and possibly helpful in reducing some of the symptoms of autism in those children.

Aspergillus fumigatus: Identification of 16, 18, and 45 kd antigens recognized by human IgG and IgE antibodies and murine monoclonal antibodies

The immunochemical properties of antigens produced by Aspergillus fumigatus were investigated with biochemical purification techniques in conjunction with the production of murine monoclonal antibodies (MAbs) and binding studies with human IgG and IgE antibodies. A. fumigatus antigens were partially purified by gel filtration and hydrophobic interaction chromatography on phenyl-Sepharose. Two fractions that eluted with either 2 mol/L or 0.15 mol/L of NaCl demonstrated strong binding to human IgG and IgE antibodies. Immunoprecipitation analysis with IgG antibodies from six patients with different Aspergillus-related diseases demonstrated that the 2M and 0.15M fractions contained major antigens of molecular weight 18 kd (Asp f I) and 45 kd, respectively. The 125I-labeled 2M fraction was used to compare IgG antibodies to A. fumigatus in sera from 25 patients with Aspergillus-related diseases. IgG antibodies were significantly higher in patients with allergic bronchopulmonary aspergillosis (geometric mean, 437 U/ml) than in patients with asthma (geometric mean, 14 U/ml; p less than 0.001), but undetectable (less than 5 U/ml) in 43/48 control subjects. A good correlation was found between levels of IgG antibodies to the 125I-labeled 0.15M fraction and the 125I-labeled 2M fraction in sera from 106 patients with cystic fibrosis (r = 0.77; p less than 0.001). Five murine IgG MAbs and two IgM MAbs were raised against the 2M fraction, and immunoprecipitation with the IgG MAb demonstrated two distinct antigens within the 2M fraction, Asp f I, and a 16 kd antigen. The results of a solid-phase RIA with IgG MAb 4A6 demonstrated that approximately 85% of A. fumigatus-allergic patients with allergic bonchopulmonary aspergillosis had IgE antibodies to Asp f I. The three protein antigens defined in these studies are useful probes for investigating the immunopathogenesis of diseases associated with colonization by A. fumigatus.

Do shrimp‐allergic individuals tolerate shrimp‐derived glucosamine?

Background There is concern that shrimp‐allergic individuals may react to glucosamine‐containing products as shrimp shells are a major source of glucosamine used for human consumption.

Implementation of evidence-based asthma interventions in post-Katrina New Orleans: the Head-off Environmental Asthma in Louisiana (HEAL) study.

Background: Childhood asthma morbidity and mortality in New Orleans, Louisiana, is among the highest in the nation. In August 2005, Hurricane Katrina created an environmental disaster that led to high levels of mold and other allergens and disrupted health care for children with asthma. Objectives: We implemented a unique hybrid asthma counselor and environmental intervention based on successful National Institutes of Health asthma interventions from the National Cooperative Inner City Asthma (NCICAS) and Inner-City Asthma (ICAS) Studies with the goal of reducing asthma symptoms in New Orleans children after Hurricane Katrina. Methods: Children (4–12 years old) with moderate-to-severe asthma (n = 182) received asthma counseling and environmental intervention for approximately 1 year. HEAL was evaluated employing several analytical approaches including a pre–post evaluation of symptom changes over the entire year, an analysis of symptoms according to the timing of asthma counselor contact, and a comparison to previous evidence-based interventions. Results: Asthma symptoms during the previous 2 weeks decreased from 6.5 days at enrollment to 3.6 days at the 12-month symptom assessment (a 45% reduction, p < 0.001), consistent with changes observed after NCICAS and ICAS interventions (35% and 62% reductions in symptom days, respectively). Children whose families had contact with a HEAL asthma counselor by 6 months showed a 4.09-day decrease [95% confidence interval (CI): 3.25 to 4.94-day decrease] in symptom days, compared with a 1.79-day decrease (95% CI: 0.90, 2.67) among those who had not yet seen an asthma counselor (p < 0.001). Conclusions: The novel combination of evidence-based asthma interventions was associated with improved asthma symptoms among children in post-Katrina New Orleans. Post-intervention changes in symptoms were consistent with previous randomized trials of NCICAS and ICAS interventions.

Indoor environmental exposures for children with asthma enrolled in the HEAL study, post-Katrina New Orleans.

Background: Rain and flooding from Hurricane Katrina resulted in widespread growth of mold and bacteria and production of allergens in New Orleans, Louisiana, which may have led to increased exposures and morbidity in children with asthma. Objectives: The goal of the Head-off Environmental Asthma in Louisiana (HEAL) study was to characterize post-Katrina exposures to mold and allergens in children with asthma. Methods: The homes of 182 children with asthma in New Orleans and surrounding parishes were evaluated by visual inspection, temperature and moisture measurements, and air and dust sampling. Air was collected using vacuum-pump spore traps and analyzed for > 30 mold taxa using bright field microscopy. Dust was collected from the children’s beds and bedroom floors and analyzed for mouse (Mus m 1), dust mite (Der p 1), cockroach (Bla g 1), and mold (Alternaria mix) allergens using ELISA. Results: More than half (62%) of the children were living in homes that had been damaged by rain, flooding, or both. Geometric mean indoor and outdoor airborne mold levels were 501 and 3,958 spores/m3, respectively. Alternaria antigen was detected in dust from 98% of homes, with 58% having concentrations > 10 µg/g. Mus m 1, Der p 1, and Bla g 1 were detected in 60%, 35%, and 20% of homes, respectively, at low mean concentrations. Conclusions: Except for Alternaria antigen in dust, concentrations of airborne mold (ratio of indoor to outdoor mold) and dust allergens in the homes of HEAL children were lower than measurements found in other studies, possibly because of extensive post-Katrina mold remediation and renovations, or because children moved into cleaner homes upon returning to New Orleans.

The Head-off Environmental Asthma in Louisiana (HEAL) Study—Methods and Study Population

Background: In the city of New Orleans, Louisiana, and surrounding parishes (NOLA), children with asthma were perilously impacted by Hurricane Katrina as a result of disrupted health care, high home mold and allergen levels, and high stress. Objectives: The Head-off Environmental Asthma in Louisiana (HEAL) study was conducted to examine relationships between the post-Katrina environment and childhood asthma in NOLA and assess a novel asthma counselor intervention that provided case management and guidance for reducing home mold and allergen levels. Methods: Children (4–12 years old) with moderate-to-severe asthma were recruited from NOLA schools. Over 1 year, they received two clinical evaluations, three home environmental evaluations, and the asthma intervention. Quarterly end points included symptom days, medication use, and unscheduled emergency department or clinic visits. A community advisory group was assembled and informed HEAL at all phases. Results: Of the children (n = 182) enrolled in HEAL, 67% were African American, and 25% came from households with annual incomes <

A comparison of seasonal trends in asthma exacerbations among children from geographic regions with different climates.

15,000. HEAL children were symptomatic, averaging 6.6 symptom days in the 2 weeks before baseline, and had frequent unscheduled visits to clinics or emergency departments (76% had at least one unscheduled visit in the preceding 3 months). In this report, we describe study design and baseline characteristics of HEAL children. Conclusions: Despite numerous challenges faced by investigators, study staff, and participants, including destroyed infrastructure, disrupted lives, and lost jobs, HEAL was successful in terms of recruitment and retention, the high quality of data collected that will provide insight into asthma-allergen relationships, and the asthma intervention. This success was attributable to using an adaptive approach and refining processes as needed.