Linda R. Freidhoff

Atopic Dermatitis Is Associated with a Functional Mutation in the Promoter of the C-C Chemokine RANTES

Up-regulation of C-C chemokine expression characterizes allergic inflammation and atopic diseases. A functional mutation in the proximal promoter of the RANTES gene has been identified, which results in a new consensus binding site for the GATA transcription factor family. A higher frequency of this allele was observed in individuals of African descent compared with Caucasian subjects (p < 0.00001). The mutant allele was associated with atopic dermatitis in children of the German Multicenter Allergy Study (MAS-90; p < 0.037), but not with asthma. Transient transfections of the human mast cell line HMC-1 and the T cell line Jurkat with reporter vectors driven by either the mutant or wild-type RANTES promoter showed an up to 8-fold higher constitutive transcriptional activity of the mutant promoter. This is the first report to our knowledge of a functional mutation in a chemokine gene promoter. Our findings suggest that the mutation contributes to the development of atopic dermatitis. Its potential role in other inflammatory and infectious disorders, particularly among individuals of African ancestry, remains to be determined.

Inadequate outpatient medical therapy for patients with asthma admitted to two urban hospitals.

PURPOSE To determine the patterns of chronic outpatient management in urban patients with moderate and severe asthma, and to assess medical practice adherence to the Guidelines for the Diagnosis and Management of Asthma from the National Asthma Education Program (NAEP). PATIENTS AND METHODS This is a cross-sectional survey of adult patients with asthma admitted to the general medical services at the Johns Hopkins Medical Institutes (Johns Hopkins Hospital and Johns Hopkins Bayview Medical Center) Baltimore, Maryland. Subjects were 101 adults admitted with an asthma exacerbation from February 1992 through January 1993. Using a validated questionnaire, these subjects were surveyed within 48 hours of admission concerning their chronic outpatient medical management and the measures patients or their physicians took to alleviate symptoms during the asthma exacerbation leading to hospitalization. RESULTS The average asthma admission rate in the past year for this group of patients was 2.5, indicative of moderate to severe disease. Less than half of these patients had been prescribed inhaled anti-inflammatory therapy. Of the patients who had previously been shown the metered dose inhaler technique by a health care professional, 11% could perform all components of this technique correctly. Only 28% of patients had been given an action plan by their physician in the event of an acute exacerbation. Sixty percent of patients who contacted their physician during the exacerbation that preceded admission had no changes made in their treatment regimen. In those whose exacerbation lasted at least 24 hours, the average beta-agonist metered dose inhaler use during the 24 hour prior to admission was 44.8 +/- 7.8 puffs (mean +/- standard error of the mean). Older age, (current smoking, and race (black) were the most significant correlates of inhaled beta-agonist use during this period. CONCLUSIONS This is the first documentation of multiple problems in conforming with the standards of care delineated by the NAEP as they relate to the outpatient management of inner-city patients with moderate to severe asthma in the United States. In this population of patients with asthma, management was characterized by underutilization of anti-inflammatory therapy, inability to use inhalation devices properly, inadequate communication between patient and physician of an action plan to be utilized in the event of an acute exacerbation and inadequate physician intervention during the acute stages of the exacerbation. There was also overutilization of inhaled beta-agonists during exacerbations. It is imperative that these aspects of management, for which the NAEP has set standards of care, are addressed as part of the effort to reduce asthma morbidity in the urban United States.

Genetic regulation of Dermatophagoides pteronyssinus–specific IgE responsiveness: A genome-wide multipoint linkage analysis in families recruited through 2 asthmatic sibs

BACKGROUND Dermatophagoides pteronyssinus (Der p) is one of the most frequently implicated allergens in atopic diseases. Although HLA could play an important role in the development of the IgE response to the Der p allergens, genetic regulation by non-HLA genes influences certain HLA-associated IgE responses to complex allergens. OBJECTIVE To clarify genetic control for the expression of Der p-specific IgE responsiveness, we conducted a genome-wide search for genes influencing Der p-specific IgE antibody levels by using 45 Caucasian and 53 African American families ascertained as part of the Collaborative Study on the Genetics of Asthma (CSGA). METHODS Specific IgE antibody levels to the Der p crude allergen and to the purified allergens Der p 1 and Der p 2 were measured. Multipoint, nonparametric linkage analysis of 370 polymorphic markers was performed with the GENEHUNTER program. RESULTS The best evidence of genes controlling specific IgE response to Der p was obtained in 2 novel regions: chromosomes 2q21-q23 (P = .0033 for Caucasian subjects) and 8p23-p21 (P = .0011 for African American subjects). Three regions previously proposed as candidate regions for atopy, total IgE, or asthma also showed evidence for linkage to Der p-specific IgE responsiveness: 6p21 (P = .0064) and 13q32-q34 (P = 0.0064) in Caucasian subjects and 5q23-q33 (P = 0.0071) in African American subjects. CONCLUSIONS No single locus generated overwhelming evidence for linkage in terms of established criteria and guidelines for a genome-wide screening, which supports previous assertions of a heterogeneous etiology for Der p-specific IgE responsiveness. Two novel regions, 2q21-q23 and 8p23-p21, that were identified in this study merit additional study.

Dense mapping of chromosome 12q13.12-q23.3 and linkage to asthma and atopy

BACKGROUND Asthma is a complex disease characterized by a high prevalence of allergic diathesis and the almost ubiquitous presence of upper airway disease (eg, rhinitis). Previously, we observed linkage of asthma among Afro-Caribbean families to markers in chromosome 12q, which contains a number of genes encoding for products closely related to allergic airway inflammation and disease. OBJECTIVE To identify susceptibility loci in chromosome 12q contributing to the genetics of upper and lower airway diseases and to expand the region to include genes encoding IFN-gamma (IFNG ) and one of the signal transducers and activators of transcription (STAT6 ), we conducted further linkage studies among 33 multiplex families. METHODS We characterized 528 subjects from Barbados for asthma; 82% were characterized for allergic rhinitis. Two-point and multipoint linkage analysis of 22 microsatellite markers (spanning approximately 79 centimorgan) was performed. RESULTS Affected sib-pair analysis revealed significant evidence for linkage to asthma over approximately 30 cM (P <.05 to.002), with the best evidence for linkage at a CA repeat polymorphism in the first intron of IFNG in 12q21.1 (P =.002). Evidence of linkage to allergic rhinitis was observed in the same region (D12S313, P = 0.006, and IFNGCA, P =.01, respectively). Multipoint linkage analysis also provided evidence for linkage to asthma, with the best nonparametric linkage analysis score at D12S326 (nonparametric linkage score = 3.8, P =.0008). Modest evidence for linkage to allergic rhinitis was observed next to D12S326 at D12S1052 (P =.036). CONCLUSIONS Our findings suggest that (1) one or more loci in the chromosome 12q13. 12-q23.3 region are contributing to the expression of the clinical phenotype asthma and the strongest evidence for linkage is in a region near the gene encoding IFNG and (2) a susceptibility locus for both asthma and allergic rhinitis maps to this region.

Human immune responsiveness to Lolium Perenne pollen allergen Lol p III (Rye III) is associated with HLA-DR3 and DR5☆

A well-characterized allergen of Lolium perenne (perennial rye grass) pollen, Lol p III, has been used as a model antigen to study the genetic control of the human immune response. Associations between HLA type and IgE or IgG antibody (Ab) responsiveness to Lol p III were studied in two groups of skin-test-positive Caucasoid adults (N = 135 and 67). We found by nonparametric and parametric analyses that immune responsiveness to Lol p III was significantly associated with HLA-DR3 and DR5. No association was found between any DQ type and immune responsiveness to Lol p III. Geometric mean IgE or IgG Ab levels to Lol p III were not different between B8+, DR3+ subjects and B8-, DR3+ subjects, showing that HLA-B8 had no influence on the association. Lol p III IgG Ab data obtained on subjects after grass antigen immunotherapy showed that 100% of DR3 subjects and 100% of DR5 subjects were Ab+. A comparison of all the available protein sequences of DRB gene products showed that the first hypervariable region of DR3 and DR5 (and DRw6), and no other region, contains the sequence Glu9-Tyr-Ser-Thr-Ser13. Our observations are consistent with the possibility that immune responsiveness to the allergen Lol p III is associated with this amino acid sequence in the first hypervariable region of the DR beta 1 polypeptide chain.

Clinical aspects of allergic disease: A double-blind study of the discontinuation of ragweed immunotherapy

BACKGROUND Immunotherapy effectively treats the symptoms of allergic rhinitis and improves its pathophysiology. We studied whether the effects of immunotherapy on the early response to nasal challenge with antigen and seasonal symptoms persist after discontinuation. METHODS Twenty subjects with ragweed allergy who were receiving immunotherapy and who had nasal challenges performed before initiation of treatment were selected. The patients had been receiving maintenance therapy with aqueous ragweed extract at a dose of 12 microg of Amb a 1 equivalent for a minimum of 3 years, at which point they were randomized to receive either placebo injections or to continue with the maintenance dose. Nasal challenges were performed before and 1 year after randomization. Nasal challenges were monitored by counting the number of sneezes and measuring histamine, N-alpha-tosyl-L-arginine methyl ester-esterase activity, and kinins in recovered nasal lavages. In the same year symptom diaries were collected during the ragweed season. RESULTS The initial immunotherapy significantly reduced responses to nasal challenge in both groups. The group continuing to receive active treatment showed no significant changes from the response before randomization. In contrast, the group randomized to placebo treatment showed a partial return of histamine, kinins, and N-alpha-tosyl-L-arginine methyl ester-esterase in nasal secretions and the numbers of sneezes. IgG antibodies to ragweed declined only in the group switched to placebo treatment. Seasonal rises of IgE antibodies to ragweed did not return during the first season after treatment was stopped. Symptoms reported during the ragweed season were not different between the groups. CONCLUSIONS One year after discontinuation of ragweed immunotherapy, nasal challenges showed partial recrudescence of mediator responses even though reports during the season appeared to indicate continued suppression of symptoms.

Immune responsiveness to Ambrosia artemishfolia (short ragweed) pollen allergen Amb a VI (Ra6) is associated with HLA-DR5 in allergic humans

The relationship between HLA type and specific immune responsiveness toward ultrapure Ambrosia artemisiifolia (short ragweed) pollen allergen Amb a VI (Ra6) was explored in a genetic-epidemiologic study of groups of 116 and 81 Caucasoid subjects who were skin-test \ positive (ST−) toward common environmental allergens. Specific immune responsiveness to Amb a VI was assessed by measuring serum IgE and IgG antibodies (Abs) by double Ab radioimmunoassay in both ST− groups. Significant associations were found between IgE Ab responsiveness to Amb a VI and the possession of HLA-DR5; P values for the two groups were, respectively, 7 × 10−7 and 1 × 10−3 by nonparametric analyses, and 4 × 10−11 and 5 × 10−8 by parametric analyses. The levels of significance for the associations between HLA-DR5 and IgG Ab responsiveness were highly dependent on the extent of ragweed immunotherapy (Rx) within the patient group; by parametric statistics, the associations were 10−11 for the group that had received relatively little Rx and 2 × 10−3 for the group that had received more intensive Rx. These results provide further striking evidence for the existence of specific HLA-linked human Ir genes involved in responsiveness toward inhaled allergens and illustrate the usefulness of the allergy model in studies of the genetic basis of human immune responsiveness. Extension of these studies to investigation of structure-function relationships involved in antigen recognition by Ia molecules and the T-cell receptor will lead to a better understanding of human susceptibility toward immunologic diseases.

The effect of cetirizine on early allergic response

A double blind, placebo‐controlled, cross‐over study was performed to determine the effect of cetirizine, an H1 antihistamine, on the immediate nasal allergic response. Ten persons underwent nasal challenge with antigen after premedication with 20 mg of cetirizine or placebo QD for 2 days. The response was monitored by counting the number of sneezes and by measuring the levels of histamine, prostaglandin D2, leukotriene C4, albumin, and TAME‐esterase activity in recovered nasal lavages. The results showed a significant reduction in sneezing and in the amounts of recovered albumin, TAME‐esterase activity, and leukotriene C4 but no reduction in the amounts of recovered histamine and prostaglandin D2. These results suggest that cetirizine does not inhibit mast cell activation but inhibits the consequences of the released histamine on H1 receptors: sneezing and increased vascular permeability. The results further suggest that mast cell release of histamine is the direct result of antigen stimulation, as opposed to reflex activation, and that other cells in addition to mast cells generate leukotrienes during the early allergic response.

Genetic influences of chromosomes 5q31-q33 and 11q13 on specific IgE responsiveness to common inhaled allergens among African American families

BACKGROUND We have recently conducted a genome-wide screening for genes influencing Dermatophagoides pteronyssinus-specific IgE responsiveness as a part of the Collaborative Study on the Genetics of Asthma (CSGA), which showed evidence for linkage in some regions, including chromosomes 5131-q33 and 11q13 in African American families. OBJECTIVES To clarify relative contributions of these regions to atopy in the same African American population, we have conducted further genetic linkage studies of specific IgE responses toward common inhaled allergens. METHODS We studied 328 individuals in 58 African American families participating in the CSGA. Specific IgE responses toward Dermatophagoides farinae, cat, dog, American cockroach, rye grass, and Bermuda grass, as measured by skin tests, were used for multipoint linkage analysis with polymorphic markers on chromosomes 5q31-q33 and 11q13. RESULTS Specific IgE response toward American cockroach showed evidence for linkage to chromosomes 5q31-q33 (P = .0050) and 11q13 (P = .017). Specific IgE response toward dog showed evidence for linkage with chromosome 5q31-q33 (P = .0043). Evidence for linkage with chromosome 11q13 was obtained for specific IgE responses toward Dermatophagoides farinae (P = .012), cat (P = .035), and Bermuda grass (P = .017). The presence of a positive ST response for at least 1 of 30 common allergens showed evidence for linkage to chromosomes 5q31-q33 (P = .017) and 11q13 (P = .00058). CONCLUSIONS These data support that genes on both chromosomes 5q31-q33 and 11q13 confer susceptibility to upregulated IgE-mediated immune responses in this African American population. The putative genes on chromosomes 5q31-q33 and 11q13, however, showed contrasting effects on atopy, which may result from strong gene-environmental interactions.

Genetics of human immune response to allergens

In today’s economically developed societies, IgEmediated allergic responses are regarded more as a hindrance than a help. Nevertheless, the ability to make such responses has probably played an important role in protecting our distant ancestors from the scourges of parasitic disease and, indeed, this function is probably still important in many underdeveloped countries.’ We may, therefore, regard the current relatively high prevalence of atopic allergy in the Western world as an unwanted vestige of a previously useful immune function. It seems likely that a genetic capacity toward hyperresponsiveness of the IgE system and concomitant high prevalence of allergy have exerted a weak selective disadvantage in white Europeans since Neolithic times, as parasitic disease became a decreasingly less severe problem. In modem man, the main selective pressure on specijc immune response has almost certainly been infectious disease-in particular, that caused by pathogens which strike before puberty with a high rate of mortality. Several authorP5 have argued convincingly that many of today’s common infectious diseases probably evolved only in the last 5,000 or 6,000