Serum metalloproteinase leukolysin (MMP-25/MT-6): a potential metabolic marker for atopy-associated inflammation

BACKGROUND

Leukolysin is a novel matrix metalloproteinase (MMP-25/MT-6) released mainly by granulocytic cells, primarily neutrophils, which are implicated in chronic airways inflammation.

OBJECTIVE

To determine if leukolysin might be a serum marker for atopic asthma or chronic obstructive pulmonary disease (COPD).

METHODS

Three study populations were evaluated: (1) nuclear families with medical history of atopic asthma (N=337), (2) married-in individuals from an independent study of asthma genetics (N=122) and (3) randomly selected males with diagnosis of COPD (N=100). Each person was screened for asthma or COPD symptoms, respiratory function by standardized spirometry and serum total IgE and leukolysin and anti-IL1 levels by immunoassay. Study groups (1 and 2) were also screened by skin prick test using a battery of 14 common aeroallergens. Heritability estimates for leukolysin and total IgE were made by variance components analysis.

RESULTS

For those without asthma or who had asthma defined as having symptoms, a physician's diagnosis and bronchial hyper-reactivity as demonstrated by reversibility in response to albuteral and/or bronchial reactivity as measured by a methacholine challenge, serum leukolysin levels were found to be higher for those with any positive skin test result. This paralleled trends for serum total IgE. In the nuclear families and COPD patients, serum leukolysin levels were significantly elevated for those who also had elevated total IgE levels (log[IgE]>2.0) compared with those with lower IgE (log[IgE]<2.0). Serum IL-1 levels correlated with the leukolycin levels. In contrast to IgE, leukolysin showed no apparent inherited component.

CONCLUSION

Among individuals with history of chronic airways inflammation (asthma and COPD) serum leukolysin may be a metabolic marker associated with chronic atopy-associated respiratory inflammation. Common factors may stimulate increased production or release of both leukolysin from myeloid cells and IgE from lymphoid cells.

Genome scan for loci linked to mite sensitivity: the Collaborative Study on the Genetics of Asthma (CSGA)

Mite sensitivity has been reported to be a major risk factor for asthma. As part of the Collaborative Study on the Genetics of Asthma (CSGA), a genome scan using mite reactivity (Dermatophagoides Pteronyssinus (Der p) and Dermatophagoides farinae (Der f)) as the phenotype was conducted. In 287 CSGA families, 122 were informative for linkage. Evidence supporting linkage was observed for regions on chromosome 19 (D19S591, lod=2.43, P=0.0008; D19S1037, lod=1.57, P=0.007) and chromosome 20 (D20S473/D20S604, lod=1.41, P=0.01). All three ethnic groups appeared to contribute to the evidence for linkage on chromosome 20. African-American families gave strongest support for linkage on chromosomes 3 (D3S2409, lod=1.33, P=0.01), 12 (D12S373, lod=1.51, P=0.008) and 18 (ATA82B02, lod=1.32, P=0.01). Caucasian families showed strong evidence for linkage on chromosome 19 (D19S591, lod=3.51, P=0.00006). Hispanic families supported linkage on chromosomes 11 (D11S1984, lod=1.56, P=0.007), 13 (D13S787, lod=1.30, P=0.01) and 20 (D20S470, lod=1.71, P=0.005). These results suggest that multiple genes may be involved in controlling skin reactivity to Dermatophoigoies.

Random outcomes of allergen-specific responses in atopic families

BACKGROUND

Allergens are common non-infectious antigens to which people will mount T cell dependent humoral responses. Among genetically susceptible individuals, an antigen-specific response results involving the production of allergen-specific IgE (atopy).

OBJECTIVE

Determine if this susceptibility is manifested as an inherited, allergen-specific trait or a random response to allergens among susceptible people.

METHODS

We evaluated allergen-specific outcomes in 1099 members of families with positive atopic history (26 multi-generation and 112 nuclear families). Each was tested for sensitivity to 14 common allergens by standardized skin prick test (SPT), a marker of specific IgE production. Over 15,000 individual SPT's were evaluated. Among five randomly selected multi-generation families (N=163), semi-quantitative determinations of Amb a 1-specific IgA1,2 and IgG1-4 were determined in three groups: (A) Amb a SPT(+)/Amb a 1-IgE(+), (B) Amb a SPT(-)/Amb a 1-IgE(+), (C) Amb a SPT(-)/Amb a 1-IgE(-).

RESULTS

By rank correlation statistics, there were no discernible 'patterns' of specific SPT outcomes among any of the multi-generation families, suggesting that environmental exposure rather than allergen-specific inheritance determined the responses. This was confirmed among the nuclear families since the conditional SPT outcomes among children were independent of the SPT responses of their parents. Among five randomly selected multi-generation families, the relative proportionate concentrations of the Amb a 1-specific IgA and IgG subclasses were comparable, regardless of atopic sensitization to the ragweed allergen Amb a.

CONCLUSION

While the general propensity for atopy may be inherited, an individual's specific atopic outcome is a random variable independent of familial sensitization patterns.

Evidence of an affinity threshold for IgE-allergen binding in the percutaneous skin test reaction

BACKGROUND

Atopy is an aberrant immune response involving allergen-specific IgE production, though serum IgE concentration is not an entirely reliable diagnostic tool, particularly for epidemiological and genetic studies. There is no clear correlation between IgE and other indicators of atopy such as skin prick tests (SPT)s, and physiological associations are difficult to justify in cases with detectable IgE but negative SPT results.

OBJECTIVE

IgE reflects the number of molecules available to produce an atopic response, but the degree of the response is determined by the binding strength (affinity) between receptor-bound IgE and the allergen. We sought to determine if there was an association between binding affinity and SPT results in people with histories of atopy.

METHODS

Standard SPTs (whole allergen extracts) were administered to people with histories of sensitivities to ragweed and house dust mite. The concentrations and affinities of serum allergen-specific IgEs were determined using the purified allergens Amb a 1 and Der p 1.

RESULTS

There was a positive correlation between weal area and allergen-specific IgE among SPT-positive donors. However, for those individuals with detectable amounts of allergen-specific IgE, there was considerable overlap of IgE values between SPT-positive and -negative groups. Among sensitized donors, IgE-allergen interactions were characterized by two or three specific reactions of very high affinity (K(A) range 10(8) -10(11) M). Negative SPT reactions were associated with lowered IgE binding affinities to major allergens. This delimited two groups with atopic disorders: specific IgE(+)/ SPT(+) and specific IgE(+)/SPT(-).

CONCLUSION

The product of antibody affinity and concentration, which we define as antibody capacity (CAP = K(A) x IgE), is more informative with regard to describing allergen sensitivity than antibody concentration alone. Antibody binding capacity provides physiological evidence of atopy in some subjects who do not test positively by common methods and suggests an affinity threshold to produce a positive SPT reaction.

Ethnic differences in asthma and associated phenotypes: collaborative study on the genetics of asthma

BACKGROUND

In the Collaborative Study on the Genetics of Asthma, 314 families with 2584 subjects were characterized for asthma and allergy.

OBJECTIVE

The purpose of this investigation was to examine clinical heterogeneity observed in asthma and allergic characteristics among 3 ethnic groups (African American, white, and Hispanic family members).

METHODS

Pulmonary function parameters and asthma associated phenotypes were compared among the ethnic groups.

RESULTS

In comparison with the other groups, African American sibling pairs had a significantly lower baseline FEV(1) percent of predicted (P =.0001) and a higher rate of skin test reactivity to cockroach allergen (P =.0001); Hispanic sibling pairs had significantly more skin reactivity overall (P =.001); and white sibling pairs had significantly lower total serum IgE (P <.05). In addition, there were significantly more relatives with asthma among the African American families than among the white and the Hispanic families (P =.001).

CONCLUSION

Although different environmental backgrounds should be considered, these clinical differences could be due to differences in genetic susceptibility among the ethnic groups, such as those suggested by our previous genome screen.

Genome-wide linkage analyses of total serum IgE using variance components analysis in asthmatic families

Variance components models were used to analyze total IgE levels in families ascertained though the Collaborative Study of the Genetics of Asthma (CSGA) using a genome-wide array of polymorphic markers. While IgE levels are known to be associated with clinical asthma and recognized to be under strong genetic control (here the heritability was estimated at 44-60% in the three racial groups), specific genes influencing this trait are still largely unknown. Multipoint analysis of 323 markers yielded little indication of specific regions containing a trait locus controlling total serum IgE levels (adjusted for age and gender). Although a number of regions showed LOD statistics above 1.5 in Caucasian families (chromosome 4) and in African-American families (chromosomes 2 and 4), none yielded consistent evidence in all three racial groups. Analysis of total IgE adjusted for gender, age and Allergy Index (a quantitative score of skin test sensitivity to 14 common aeroallergens) was conducted on these data. In this analysis, a much stronger signal for a trait locus controlling adjusted log[total IgE] was seen on the telomeric end of chromosome 18, but only in Caucasian families. This region accounted for most of the genetic variation in log[total IgE], and may represent a quantitative trait locus for IgE levels independent of atopic response. Oligogenic analysis accounting simultaneously for the contribution of this locus on chromosome 18 and other chromosomal regions showing some evidence of linkage in these Caucasian families (on chromosomes 2, 4 and 20) failed to yield significant evidence for interaction.

Nedocromil sodium 2% ophthalmic solution for the treatment of ragweed pollen seasonal allergic conjunctivitis

PURPOSE

To determine the efficacy and safety of nedocromil sodium 2% ophthalmic solution in the treatment of seasonal allergic conjunctivitis.

METHODS

A combined analysis of two multicenter, randomized, comparative, double-masked, placebo-controlled clinical trials involving 261 patients diagnosed with seasonal allergic conjunctivitis was used. Patients were randomly assigned to receive either topical 2% nedocromil sodium or placebo twice daily for eight weeks. Diary card scores and clinician assessments of allergic symptoms were recorded throughout the study; efficacy was determined by comparing symptom severity at the peak pollen period with symptom severity at baseline. Clinician and patient evaluations of treatment effectiveness were used as secondary measurements of efficacy.

RESULTS

Patients treated with nedocromil sodium experienced improvement in allergy symptoms, with reductions in the summary symptom score, itch, redness, conjunctival injection, and conjunctival edema significantly (p<0.05) greater than those observed in the patients treated with placebo. Clinicians' and patients' opinions of nedocromil sodium treatment effectiveness were significantly (p<0.02) superior to those of placebo treatment effectiveness.

CONCLUSION

Nedocromil sodium is effective in the management of seasonal allergic conjunctivitis.

Characterization of polyclonal allergen-specific IgE responses by affinity distributions

Polyclonal IgE responses have been previously characterized by allergen-specific antibody levels and by identification of amino acid sequences related to immunodominant epitopes. However, the binding affinities related to these antibody families are not well known. Using sera from donors with known sensitivities to ragweed or house dust mite allergens, we studied the binding reactions between the purified allergens Amb a 1 and Der p 1 and allergen-specific IgE's by determining affinity distribution functions. The distributions of binding affinities only exhibited a few dominant reactions indicated by peaks in an affinity distribution display. In all the donors tested, there were two dominant peaks and in 2/3 of the cases there was a third peak for both Amb a 1 and Der p 1. We further characterized the polyclonal interactions between IgE and Der p 1 by inhibiting the specific binding of IgE using peptide fragments known to be constituents of Der p 1 epitopes. Each peptide inhibited only a single peak in the affinity distributions. It would appear that the peaks in the affinity distribution represent antibodies directed to single epitopes. These results suggest that in our atopic population the response is surprisingly uniform. The bulk of the IgE response (70-80%) is of high affinity (10(8)-10(11) M(-1)) and directed towards a few epitopes. The relative affinities towards epitopes seem to be determined by the structure of the epitope and not variations of individuals' immune responses.

Efficacy and safety of nedocromil sodium 2% ophthalmic solution b.i.d. in the treatment of ragweed seasonal allergic conjunctivitis

The efficacy and safety of twice-daily nedocromil sodium 2% ophthalmic solution and vehicle were compared in the treatment of ragweed seasonal allergic conjunctivitis. Two separate multicenter, randomized, double-masked, placebo-controlled studies were subjected to a combined analysis. Following a one-week baseline period during the beginning of the ragweed pollen season, 189 patients with seasonal allergic conjunctivitis received either nedocromil sodium or vehicle b.i.d. for eight weeks. Efficacy was evaluated by patient diary cards and clinical eye examinations. Safety was assessed by reports of adverse events. Compared with vehicle, nedocromil sodium produced significantly greater decreases in summary symptom score (p = 0.005), itch (p = 0.005), tearing (p = 0.004), overall eye condition (p = 0.001), and clinician-evaluated conjunctival edema (p = 0.018), and significantly better (p = 0.001), and patient (p = 0.001) opinions of treatment effectiveness at the peak pollen period. Additionally, the superiority of nedocromil sodium compared to vehicle approached statistical significance in redness reduction (p = 0.087) and clinician-evaluated conjunctival injection (p = 0.087). There were no serious treatment-related adverse events in either treatment group. In summary, nedocromil sodium 2% ophthalmic solution b.i.d. was found to be effective and to have a favorable safety profile in the treatment of seasonal allergic conjunctivitis.

Genetics of asthma and allergy

Asthma and allergies are complex conditions involving multiple steps and pathways, which are influenced by both genetic and environmental factors. The genes involved in these processes are just being identified. Most likely asthma is a result of several genes and their interaction with other genes as well as the environment. Management involves the proper diagnosis, modulating the genetic and environmental factors involved as well as interfering with the activated pathways. Using this approach will lead to a more rational method of managing individuals with allergies and asthma.

Approaches and issues in defining asthma and associated phenotypes map to chromosome susceptibility areas in large Minnesota families. The Collaborative Study for the Genetics of Asthma (CSGA)

Evidence for linkage of asthma and its associated phenotypes with susceptibility genes on chromosome 12 has been demonstrated in one group of Minnesota families. The evidence is strong in affected sib pairs and weakens in analysis of the large pedigrees. A second group of families provided little evidence for such linkage. A discrepancy has been demonstrated in different families. This may be due to several factors, including genetic heterogeneity and gene-gene, or gene-environmental interaction effects as well as the statistical power of the sample population used.

Evaluation of a non-chlorofluorocarbon formulation of cromolyn sodium (Intal) metered-dose inhaler versus the chlorofluorocarbon formulation in the treatment of adult patients with asthma: a controlled trial

BACKGROUND

Cromolyn sodium is a nonsteroidal inhaled antiinflammatory agent for the treatment of asthma. As with other pressurized aerosol medications, the metered-dose inhaler (MDI) formulation currently contains chlorofluorocarbon (CFC) propellants. Because of their harmful effects on the environment CFCs are now generally banned from production and use. Alternative propellants under production for MDIs include derivatives of hydrofluoroalkane (HFA). This study uses HFA-227 in an MDI formulation of cromolyn sodium.

OBJECTIVES

The objectives of the study were (1) to examine the efficacy and safety of an HFA formulation of cromolyn sodium (Intal) MDI and (2) to compare the HFA formulation with the CFC formulation.

METHODS

A multicenter, randomized, double-blind, placebo-controlled, parallel study with two active groups (HFA-cromolyn sodium [n = 113] and CFC-cromolyn sodium [n = 107]) and a placebo-treated group (n = 105).

RESULTS

Patients treated with either formulation of cromolyn sodium MDI showed a statistically significant (p < 0.05) improvement of 12% to 18% compared with placebo in symptom summary score, daytime asthma symptoms, and albuterol use. No statistically significant differences were observed in pulmonary function. Patient and physician opinions of overall effectiveness favored HFA-cromolyn sodium over placebo (p = 0.01), with no other significant between-treatment differences. No statistically significant differences existed among groups in the incidence of treatment-related adverse events.

CONCLUSION

The HFA formulation of cromolyn sodium MDI is a well- tolerated and active alternative treatment for asthma patients aged 12 years and more.

B-cell epitopes recognized by IgE from patients sensitive to Amb a 5

BACKGROUND

The response to allergens characterized by IgE-mediated hypersensitivity is selective. The search for the inherited contribution to atopy has among other things, focused on the linkage of sensitivity to the presence of specific alleles in the DR and DQ locus. More than 90% of the responders to Amb a 5, an allergen from ambrosia artemisifolia, are DR-2 positive. This relationship is logically linked to the T-cell epitope presentation by the HLA complex.

OBJECTIVES

This study aims to investigate a possible relationship between T-cell epitopes, B-cell epitopes and the alleles of the DR and DQ loci in Amb a 5 sensitive DR-2+ and DR-2- individuals.

METHODS

Inhibition of solid state Elisa assays by IgE-enriched and IgG-depleted, heated sera. The inhibition was carried out in checkerboard pattern, bidirectionally; A inhibits B and B inhibits A.

RESULTS

The B-cell epitopes defined by the inhibition pattern were all found to be conformational. Three different epitope patterns (A, B, C) were recognized. The IgE and IgG complexes were found in only one responder. The DR and DQ locus alleles were all sequenced. Although all the individuals studied responding to Amb a 5 show presence of alleles such as 1501, associated with DR-2, our data indicates no correlation between the B-cell epitopes recognized and the DR and DQ locus alleles. A well known, general T-cell motif was recognized in the known sequence of Amb a 5.

CONCLUSIONS

Our investigation suggests that the choice of B-cell recognition is regulated independently of a putative link between T-cell epitope recognition and the D locus.

Managing allergies in active people

Though exercise does not appear to cause allergies, active patients require special attention when allergies appear. Physical activity may increase contact with substances that cause hay fever, trigger asthma episodes, or result in contact dermatitis. Nonspecific irritants (like chlorine or air pollutants) and allergens often interact in the context of exercise, and strenuous activity may produce allergic-like symptoms that complicate the clinical picture. An athletic patient's exercise patterns and preferences should be kept in mind in evaluating allergies, devising treatment strategies, and choosing medication.

Absence of linkage between 5q markers and serum IgE levels in four large atopic families

BACKGROUND

Both genetic and environmental influences have been suggested to control the immunoglobulin (Ig)E response to allergens and, as a result, provide susceptibility to atopic disease. Two recent reports suggested that a major gene controlling basal IgE levels in humans was transmitted in a pattern consistent with autosomal recessive inheritance and was located on the long arm of chromosome 5 in the interleukin (IL)-4 gene complex.

OBJECTIVE

The purpose of this report is to evaluate evidence for linkage of IgE with polymorphic genetic markers in the candidate region of 5q in four large pedigrees originally selected for studies of atopy.

METHOD

Four large, highly characterized pedigrees in which IgE levels had been determined and genotypes at markers in the 5q candidate region were evaluated using both lod score and sib pair methods of analysis.

RESULTS

In these pedigrees, we reject close to moderate linkage (up to 5 cM) of an IgE locus with markers on 5q.

CONCLUSION

The genetic aspects of IgE regulation and its role in atopy remain controversial. The data suggest that should major genes be involved in the inheritance of atopy susceptibility, they are likely to be multiple in number and likely to involve interaction with other (exogenous) environmental exposures.

The affinity of allergen specific IgE and the competition between IgE and IgG for the allergen in Amb a V sensitive individuals

We have calibrated a solid state RAST assay with affinity purified allergen-specific IgE. We then utilized the calibrated assay to measure the average affinity of individual IgE-containing sera in terms of the average association constant < K > for purified allergen Amb a V. The binding data yielded linear reciprocal plots indicating that the range of affinities of the responding clones was narrow. The range of the average association constant for the IgE-Amb a V complex was 0.9-26 x 10(10) M-1. The average affinity of the corresponding IgG response in the same individual, estimated by inhibition studies of IgE binding, was 10(7) M-1 in one case and lower than 10(6) M-1 in all the other cases.

Once daily intranasal fluticasone propionate is effective for perennial allergic rhinitis

The efficacy of intranasal fluticasone propionate 200 micrograms once daily or 100 micrograms twice daily in treating perennial allergic rhinitis was evaluated in a randomized, double-blind, placebo-controlled study of 24 weeks' duration in 365 patients. Clinician-rated and patient-rated total nasal symptom severity scores were improved within 1 week of treatment with either regimen of fluticasone propionate and improvement was maintained over the 24-week treatment period. Clinician-rated overall evaluation indicated a significantly better response in the two fluticasone propionate groups compared with the placebo group. All efficacy evaluations indicated no difference in response between the fluticasone propionate 200 micrograms once-daily and 100 micrograms twice-daily groups. Patients in both fluticasone propionate groups had significantly less nasal obstruction upon awakening than the placebo group at all assessment periods. Fewer patients in either fluticasone propionate group used antihistamine rescue medication compared with the placebo group. The percentage of patients with nasal eosinophils and basophils at the end of the 24-week treatment period was significantly lower in both fluticasone propionate groups compared with the placebo group. Safety evaluations indicated that intranasal fluticasone propionate was as safe as placebo when given as 200 micrograms once daily or 100 micrograms twice daily. The incidence of drug-related adverse events was similar among the fluticasone propionate and placebo groups except for the incidence of epistaxis and blood in nasal mucus which was somewhat higher in the fluticasone propionate twice-daily group. There was no changes in the opthalmic examinations to suggest corticosteriod-induced posterior subcapsular cataract formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Genetic analysis of atopy in three large kindreds: no evidence of linkage to D11S97

Both genetic and environmental influences have been implicated in the pathogenesis of atopic disease. A recent report suggested that a major gene providing susceptibility to atopy was transmitted in a pattern consistent with autosomal dominant inheritance and evidence was presented that places the disease locus near the D11S97 marker on human chromosome 11q. In this report, we present three large, highly characterized pedigrees in which atopy is transmitted in a pattern consistent with autosomal dominant inheritance. Genotypes at the D11S97 and HLA loci were evaluated using both lod score and sib pair methods of analysis. In these pedigrees, we reject close moderate linkage (up to 10 cM) of atopy with both D11S97 and HLA.

Atopic disease and immunoglobulin E in twins reared apart and together

Both genetic and environmental influences have been implicated in the etiology of atopic disease and in the determination of serum IgE levels. To quantify the relative contribution of these influences, we studied the prevalence of asthma and seasonal rhinitis, skin-test response, total serum IgE levels, and specific IgE, as measured by RAST, in a sample of MZ and DZ twins reared apart or together. Concordance rates for asthma, rhinitis, positive skin tests, and RAST were calculated. MZ twins, whether reared apart or together, showed a greater concordance than dizygotic twins reared apart or together. Maximum-likelihood tests of genetic and environmental components of the variation of total IgE levels revealed a substantial genetic component and a negligible contribution from common familial environmental effects.

Transmission of gram-negative bacilli to asthmatic children via home nebulizers

Home use of nebulizers has increased in recent years, although adequate studies have not been performed to evaluate for possible contamination or transmission of potentially harmful bacteria. This study of 20 asthmatic children demonstrated that transmission of pathogenic bacteria occurs.

Sports-Aggravated Allergies

In brief Many people suffer from asthma MH and other allergic conditions. Participating in sports exposes these people both to specific allergens and to nonspecific factors that will influence the presentation of their allergic symptoms. Allergy patients experience both beneficial and deleterious effects of sports participation. For the patient whose symptoms are triggered or aggravated by sports activity, treatment should focus on avoiding or modifying the triggering factors either through physical means or through the use of pharmacologic agents.

A multicenter evaluation of the clinical benefits of cromolyn sodium aerosol by metered-dose inhaler in the treatment of asthma

The efficacy and safety of cromolyn sodium by metered-dose inhaler (MDI) (1 mg per actuation) was evaluated with a double-blind, placebo-controlled, parallel-study design. Subjects with asthma, aged 8 to 58 years, whose asthma was well controlled taking cromolyn sodium capsules by Spinhaler turboinhaler, plus beta 2-agonists, entered the study after being maintained with cromolyn sodium capsules for a minimum of 4 weeks. The investigation began with a 2-week control interval with cromolyn sodium capsules followed by a 4-week single-blind period with placebo capsules. Subjects whose asthma significantly worsened while they were receiving placebo therapy were then randomized to a 10-week double-blind phase in which they received either active cromolyn sodium or placebo by MDI. Efficacy variables included diary data, physician evaluation, and spirometry. Comparisons were made between baseline period scores and each assessment variable over time. Of 155 subjects entered, 93 qualified for the double-blind, randomized phase. Eighty-three subjects completed the study and were analyzed. At baseline there existed no significant differences between the active-treatment and placebo-treatment groups. Significant differences (p less than 0.05) in favor of the cromolyn sodium-treatment group, however, were noted at all time points for daily diary symptoms (cough, breathlessness, and overall asthma severity), physician's assessments at each clinic visit, physician's and patient's overall final assessments, FEV1 at each clinic visit, and FVC and peak expiratory flow rate at the final visit. Concomitant bronchodilator medication use was less in the cromolyn sodium-treatment group. Cromolyn sodium by MDI is highly effective for (1) controlling asthmatic symptoms, (2) improving lung functions, and (3) decreasing the need for concomitant bronchodilators.

Genetic and immunologic basis of atopic responses

We summarize current understanding of the genetics of human diseases and of the major histocompatibility complex related factors regulating immune responsiveness. Special factors are involved in atopic diseases as a result of the intersection between the immune system, the targets in the tracheobronchial tree and the endocrine, neurologic and genetic mechanisms affecting both the effectors and the targets. The evidence from investigations of human subjects and their families and from laboratory animals for the underlying genetic and immunologic mechanisms of asthma are reviewed. The genetic control of asthma is complex. The evidence suggests a gene or genes associated with and linked to HLA. The disease phenotype may also be regulated by genetically determined levels of IgE and the outcome of the balance between immune response and immunosuppression.

Antistaphylococcal IgE in patients with atopic dermatitis

Levels of IgE antibodies to Staphylococcus aureus and Staphylococcus epidermidis were determined in eleven patients with typical atopic dermatitis, with no history of furuncles or severe staphylococcal infection. Increased IgE binding to S. aureus but not to S. epidermidis was observed. Fifteen patients with hyperimmunoglobulinemia E-staphylococcal abscess syndrome had increased IgE binding not only to S. aureus but also to S. epidermidis. Other control groups of patients with elevated IgE levels or recurrent staphylococcal infection had normal IgE binding activity to both strains of staphylococci. Interaction of staphylococcal antigens from bacteria on skin with antistaphylococcal IgE antibodies on mast cells could induce mast cell release, evoke itch, and aggravate atopic dermatitis.

Ra3 skin test response and HLA-A2, antigen E, and IgE: evidence of interactions between antigen E and HLA

A positive association of Ra3 skin test responses with HLA-A2 has previously been reported to be evident in individuals with low IgE levels and to a greater extent in these individuals than those with high IgE levels. We give evidence based on an analysis of data from 133 individuals that Ra3 response is positively correlated with HLA-A2 among individuals with low Antigen E response and negatively associated with HLA-A2 among individuals with high Antigen E response. Furthermore, we have evidence that any observed interaction between Ra3, IgE, and HLA-A2 can be explained by the correlation between IgE and Antigen E response, and that it is Antigen E response which interacts in the relationship between HLA-A2 and Ra3 skin test response.

Aging and serum immunoglobulin E levels, immediate skin tests, RAST

The changes of the serum IgE levels, specific immediate skin-test responses, and RAST measurements with age were evaluated. A total of 331 unrelated individuals were studied, consisting of 166 subjects with ragweed allergic rhinitis and/or asthma, 67 with idiopathic (intrinsic) asthma, and 98 who appeared in good health with no clinical evidence of atopic diseases. All subjects were evaluated by history and physical examination, intradermal skin testing to the common aeroallergens, measurements of IgE antibody to common aeroallergens with the RAST, and serum IgE levels. Results demonstrated a significant decrease in serum IgE levels with aging in atopic individuals. This decline was exponential in character. In addition, a tendency for RAST and immediate type skin-test responses for selected antigens and histamine to decrease with age was observed.

Immunoglobulin E anti-Staphylococcus aureus antibodies in atopic patients

Sera from 56 patient and normal adults were examined to quantitate total immunoglobulin E (IgE) and IgE antibodies to Staphylococcus aureus and Staphylococcus epidermidis. Patients were divided into six groups based on clinical symptoms; a seventh group consisted of normal adults. Anti-S, aureus IgE binding was significantly higher in three groups of patients (those with eczema, those with or without series staphylococcal abscesses, and allergic patients with staphylococcal skin infections) than it was in the control group. Patients with high IgE due to allergies or parasitic infections without staphylococcal infections and patients with low or normal IgE and serious staphylococcal infection showed low levels of binding. The assay measured specific binding of IgE to bacterial antigens.

Genetic transmission of serum IgE Levels

Genetic aspects of IgE levels were studied in three large pedigrees, many of whose members had atopic sensitivities to ragweed. Data on 184 persons (80 M, 104 F) were analyzed by the methods of Elston and Stewart after logarithmic transformation and appropriate adjustment for sex and age effects. Several modes of transmission were fitted to the data. The environmental model (of equal transmission frequency for all genotypes) clearly did not fit the data (chi 2 23.03, df 3); this suggested a strong hereditary involvement in IgE distribution. High IgE levels being determined by a dominant allele gave the best fit among the hypotheses examined in pooled data. Under a pure polygenic model, the estimated heritability was 49.5%. Using a mixed model of major gene and polygenic transmission (in an analysis which approximates, but is biased toward inflating the major gene component) polygenic inheritance was found to be 11%, but has no significant improvement over the major gene model. When families are analyzed separately, there was evidence of significant heterogeneity among families. The genetic picture was blurred, with one family favoring recessive inheritance of high IgE levels, one with no clear mode, and the third leaning slightly in favor of dominant inheritance. This suggests that the mechanism is not as simple as was thought and that there may be either two alleles or one gene involved in the determination of IgE levels. The findings are consistent with IgE levels being genetically determined with heritability estimated to be about 50%.

Multicenter study of flunisolide aerosol in adult patients with steroid-dependent asthma

Seventy-three adult, steroid-dependent asthmatic patients participated in a 16-wk, double-blind study testing the efficacy of flunisolide aerosol. Forty received flunisolide, and 33 received placebo. The mean daily prednisone requirement of patients receiving flunisolide fell 59.2% during the testing period, and that of the patients receiving placebo fell 19.7%. The median daily prednisone dose dropped 74.4% in the flunisolide group and 4.2% in the placebo group (p = 0.006). In the flunisolide group 75% tapered use of oral steroids 50% or more, and 27.5% stopped taking oral steroids completely. In the placebo group 36% tapered use of oral steroids 50% or more, and only 12% stopped taking them completely. Despite their reduction in systemic steroids, those patients receiving flunisolide achieved significantly greater reduction in the daily severity of wheezing (p = 0.014) and frequency of asthma attacks (p = 0.049) than did those receiving placebo. In the final evaluation of therapeutic response, 70% of patients receiving flunisolide were rated as having a very good or good response, and 30% were rated as having a fair or poor response. In contrast 33% of patients receiving placebo were rated as very good or good, and 67% were rated as fair or poor (p = 0.0009). No serious reactions were reported. Plasma cortisols showed an average increase of 42.9% in the flunisolide group but no change in the placebo group. Flunisolide aerosol is a well-tolerated and effective agent in the treatment of steroid-dependent asthma.

Lack of linkage between hereditary angioedema and the A and B loci of the HLA system

A large 81 member, four-generation black family with hereditary angioedema is reported with regards to its clinical course and the association with the histocompatibility system. No mortality was seen related directly to the disease. Assuming that this trait is autosomal dominant it appeared to have no linkage with the histocompatibility system as noted by an estimated recombination rate in males and females of 0.5 and a maximum lod score of 0.0. Further evidence of no linkage is given by the fact that lod scores below -3.0 were observed for values of theta less than 0.5.

Multiliter production and immunochemical cross-reactivity of plant tissue culture antigens

Cells of short ragweed suspension culture were successfully propagated in a multiliter fermentor. Proteins were isolated from tissue cultures (short ragweed, cantaloupe, marigold, and Ammi) and plants (short ragweed pollen, cantaloupe fruit, and marigold flowers) by ammonium sulfate precipitation, cross-linked dextran gel filtration, and anion-exchange chromatography. Some fractions elicited allergenic responses in ragweed-sensitive patients but not in ragweed-nonsensitive control patients. Double-immunodiffusion analysis of these fractions showed their nonidentity with short ragweed antigen E.

Genetic mapping of Ir locus in man: linkage to second locus of HL-A

Fifty-seven members of a family that spanned three generations were studied for antigen E and ragweed skin sensitivity and HL-A antigens. There was significant association between the haplotype HL-A 2-12 and antigen E skin hypersensitivity (F = .22 to .26) in this family. The map order is first locus of HL-A, second locus of HL-A, and IrE. These determinants are considered to be part of the linkage group HL-1.