Allergic rhinitis: a growing primary care challenge.

PURPOSE: To describe the growing problem of allergic rhinitis (AR) and the latest recommendations on its diagnosis and management for the nurse practitioner (NP) in primary care settings. DATA SOURCES: Recent clinical research, review articles and consensus guidelines, and the author's clinical experience. CONCLUSIONS: The prevalence of AR is increasing, possibly due to increased airborne pollutants, poor ventilation, and rising levels of indoor allergens. Allergic disease is systemic and rarely involves a single symptom. Treatments include reducing exposure to allergens as well as pharmacotherapy. IMPLICATIONS FOR PRACTICE: Patient education is crucial for successful management and includes understanding the allergic basis of symptoms, reducing allergen exposure, understanding proper use of medications, and reassessing the plan on a regular basis.

Treatment of late-onset asthma with fluconazole.

BACKGROUND: Although the etiology of intrinsic or late-onset asthma is generally not known, some cases are associated with overt dermatophyte infection and immediate hypersensitivity to proteins derived from fungi of the genus Trichophyton. OBJECTIVE: We sought to test the efficacy of oral antifungal treatment for Trichophyton-induced asthma by using fluconazole in a placebo-controlled trial. METHODS: Eleven patients with severe or moderately severe asthma were randomized to treatment with fluconazole 100 mg daily or placebo for 5 months (phase 1); during the following 5 months, all patients received active drug (phase 2). Subjects were evaluated by skin tests, bronchial provocation tests, and measurement of serum antibodies to Trichophyton species antigens. Clinical response was monitored by changes in peak flow values measured during a 2-week period at the end of each phase and by changes in bronchial sensitivity, symptoms, and steroid requirements. RESULTS: At the end of the first 5 months of active treatment, there was a highly significant decrease in bronchial sensitivity to Trichophyton (P =.012) and in oral steroid requirement (P =.01). At the end of phase 2, mean peak expiratory flow rates increased in 9 of 11 patients. An improvement in symptoms, peak flow, and steroid use was maintained up to 36 months after starting fluconazole in patients who continued to receive treatment. CONCLUSION: The results show that fluconazole can be useful in the treatment of patients with severe or moderately severe asthma who have dermatophytosis. These findings are consistent with the argument that proteins derived from fungi on the skin and nails can contribute to allergic disease.

Dust mite allergen avoidance in the treatment of hospitalized children with asthma.

BACKGROUND: Asthma is a leading cause of hospital admission in children. The majority of children with asthma are sensitized and exposed to inhalant allergens that may contribute to chronic airway inflammation. OBJECTIVE: To evaluate the practicality and effects of dust mite (D. farinae and D. pteronyssinus) allergen avoidance in homes of children hospitalized with acute asthma. METHODS: Children 5 to 18 years of age who were admitted with asthma to a suburban Atlanta hospital were randomly assigned, without knowledge of allergen sensitization or exposure in their houses, to active (n = 13) or placebo (n = 10) treatment group. Active treatment included encasing mattress, box springs, and pillows in allergen impermeable covers; weekly hot water wash of bed linens; replacement of bedroom carpet with polished flooring; and 3% tannic acid spray to living room carpet. Placebo treatment included permeable encasing for bedding, cold water wash, and water spray for carpet. Dust samples were analyzed for dust mite, cockroach, and cat allergens, while serum samples were analyzed for IgE antibodies to the same allergens. Outcome measures included daily peak expiratory flow rates, spirometry, methacholine inhalation challenge, and hospital readmission. RESULTS: Children in both groups were similar by demographics, sensitization, and exposure to dust mite allergen. Allergen levels fell > 3-fold in many active and placebo homes. Children in the active group had improved PEFR at 3 and 6 months after intervention (P < .04, P < .05, respectively). Six of seven children in the study who were sensitized and exposed to dust mite allergen demonstrated improved PEFR at 3 months when allergen levels fell in both bedding and bedroom floor. There was no difference in FEV1 or methacholine challenge, although a few children in either group could tolerate methacholine because of bronchial hyperreactivity. Six children (four active and two placebo) were readmitted to hospital during the study. CONCLUSION: Increases in PEFR were recorded among children in the active treatment group and also among sensitized patients whose dust mite allergens fell. These results support the hypothesis that avoidance can be effective even among children admitted to hospital. The study was complicated by insufficient numbers of mite-allergic children and poor compliance with diaries and the protocol. Recruitment from the hospital resulted in participants with more severe asthma than anticipated. The results also suggest that many of the patients in this group will continue to have exacerbations triggered by upper or lower respiratory tract infections.

Induction of IgE antibody responses by glutathione S-transferase from the German cockroach (Blattella germanica).

We report that a major 23-kDa allergen from German cockroach (Blattella germanica) is a glutathione S-transferase (EC 2.5.1.18; GST). Natural B. germanica GST, purified from cockroach body extracts by glutathione affinity chromatography, and recombinant protein expressed in Escherichia coli using the pET21a vector, showed excellent IgE antibody binding activity. B. germanica GST caused positive immediate skin tests in cockroach-allergic patients using as little as 3 pg of recombinant protein. The NH2-terminal sequence of the natural protein and the deduced amino acid sequence from cDNA were identical except for one substitution (Phe9 --> Cys). Assignment of this protein to the GST superfamily was based on binding to glutathione and sequence identity (42-51%) to the GST-2 subfamily from insects, including Anopheles gambiae and Drosophila melanogaster. B. germanica GST contained 18 of the 26 invariable residues identified in mammalian GST by x-ray crystallography and exhibited enzymic activity against a GST substrate. Our results show that cockroach GST causes IgE antibody responses and is associated with asthma. The data strongly support the view that the immune response to GST plays an important role in allergic diseases.

The immune response to Trichophyton tonsurans: distinct T cell cytokine profiles to a single protein among subjects with immediate and delayed hypersensitivity.

Skin testing with an extract from the dermatophyte fungus Trichophyton tonsurans can result in either immediate (IH) or delayed hypersensitivity (DH). These experiments were designed to examine in vitro T cell cytokine production in response to purified proteins from T. tonsurans in subjects with different skin test reactivities. Peripheral blood mononuclear cells were obtained from subjects with immediate, delayed, or negative skin tests, and cellular proliferation was studied. Subjects with either IH or DH had positive proliferative responses to crude extracts and two purified proteins, protein IV (83 kDa) and Tri t 1 (30 kDa). Nine cell lines were established from 5 IH subjects, which produced a cytokine profile characteristic of Th2/Th0 cells, i.e., ratio of IFN-gamma to IL-4 or IL-5 <2:1. By contrast 8 of 10 cell lines from DH subjects had a Th1 profile, i.e., IFN-gamma to IL-4 or IL-5 >20:1. Lymphocytes from subjects with negative skin tests show very poor proliferative responses; however, 6 cell lines derived from these individuals showed a cytokine profile characteristic of Th1 cells. Levels of IL-5 were significantly different when comparing the IH group with the DH group (p < 0.001). The results demonstrate that a single defined protein from T. tonsurans can produce distinct T cell cytokine profiles that correspond to in vivo skin test reactivities and serum Ab levels.

Definition of a Trichophyton protein associated with delayed hypersensitivity in humans. Evidence for immediate (IgE and IgG4) and delayed hypersensitivity to a single protein.

Dermatophytes of the genus Trichophyton cause infections of human skin, nails, and hair. Unlike most Ags, Trichophyton can elicit either immediate (IH) or delayed (DH) hypersensitivity skin reactions. Previous studies isolated a 30-kDa Ag (Tri t 1) that caused IH skin tests. The study presented here used skin testing and in vitro T cell proliferation assays to monitor purification of an Ag, designated Protein IV, associated with DH reactions. Protein IV was purified by cation exchange HPLC; amino acid sequence analysis of the N-terminus and nine internal peptides (143 residues) revealed no homologies to Tri t 1 or to any other known proteins. A mAb-based ELISA was developed to measure Protein IV. Protein IV elicited DH skin reactions in subjects with a history of athlete's foot but also caused IH skin reactions. Serologic responses to Protein IV were studied in 59 adults who had been skin tested with Trichophyton extract. IH skin reactions were associated with a positive RAST (14/23) as well as with specific IgE (13/23) and IgG4 (14/23) Abs to Protein IV. DH skin tests were not associated with IgE or IgG4 Abs. IgE anti-Protein IV Abs were quantitatively correlated with IgG4 Abs (r = 0.57, p < 0.001). Specific IgG Abs to Protein IV were highest in IH subjects (gm = 230 U/ml), and lowest in those with DH (gm = 91 U/ml) or negative (gm = 81 U/ml) skin tests; furthermore, the prevalence of IgG Abs increased significantly with age. Protein IV is the first defined protein associated with both DH and IH skin reactions; these reactions are characterized by distinct serologic responses. The results establish that diverse immune responses in humans can be directed against the same protein.

Cloning of cockroach allergen, Bla g 4, identifies ligand binding proteins (or calycins) as a cause of IgE antibody responses.

An allergen cloned from a Blattella germanica (German cockroach) cDNA library, encoded a 182-amino acid protein of 20,904 Da. This protein, designated B. germanica allergen 4 (Bla g 4), was expressed as a glutathione S-transferase fusion protein in Escherichia coli and purified by affinity chromatography and high-performance liquid chromatography. The prevalence of serum IgE antibody to recombinant Bla g 4 in 73 cockroach allergic patients with asthma ranged from 40% (antigen binding radioimmunoassay) to 60% (plaque immunoassay). Cockroach allergic patients gave positive intradermal skin tests to recombinant Bla g 4 at concentrations of 10(-3)-10(-5) micrograms/ml, whereas non-allergic controls, or cockroach allergic patients with no detectable serum IgE antibody to Bla g 4, gave negative skin tests to 1 microgram/ml. Polymerase chain reaction and Southern analysis identified a 523-base pair DNA encoding Bla g 4 in both B. germanica and Periplaneta americana (American cockroach). However, Northern analysis showed that mRNA encoding Bla g 4 was transcribed in B. germanica but not in P. americana, suggesting that allergen expression was species specific. Sequence similarity searches showed that Bla g 4 was a ligand binding protein or calycin and unexpectedly revealed that this family contained several important allergens: beta-lactoglobulin, from cow milk, and rat and mouse urinary proteins. Although the overall sequence homology between these proteins was low (approximately 20%), macromolecular modeling techniques were used to generate two models of the tertiary structure of Bla g 4, based on comparisons with the x-ray crystal coordinates of bilin binding protein and rodent urinary proteins. The results show that members of the calycin protein family can cause IgE antibody responses by inhalation or ingestion and are associated with asthma and food hypersensitivity.

Chemical treatment of carpets to reduce allergen: comparison of the effects of tannic acid and other treatments on proteins derived from dust mites and cats.

BACKGROUND: Several chemical treatments have been recommended for reducing mite and other allergen levels in carpets, including the protein-denaturing agent tannic acid (TA). OBJECTIVE: We evaluated the efficacy of TA and other treatments on mite and cat allergens in carpets within houses. The effects of TA were assessed on Der p 1 and Der f 1, on group II mite allergens, and on the major cat allergen Fel d 1. METHOD: Carpet treatments tested were benzyl benzoate moist powder, a 3% TA spray, and two carpet cleaners (Host and Capture). Carpets were treated twice and dust samples collected on a biweekly basis for 8 weeks: these samples were extracted in saline solution alone. Additional studies evaluated the effects of TA on 17 carpets. Carpets were treated twice (on days 0 and 28) and samples collected on days 0, 1, 7, 14, 28, and 42. Eighteen carpets were untreated controls. Dust samples were extracted separately in both saline solution and in the presence of 5% bovine serum albumin. RESULTS: Benzyl benzoate and the two carpet cleaners reduced group 1 dust mite allergen concentrations in carpet dust. In addition, benzyl benzoate and TA reduced airborne group 1 mite allergens by more than 64%. Further studies showed that, in keeping with in vitro studies, TA inhibited the assay and bovine serum albumin abrogated this effect. Significant reductions after treatment occurred only for Der f 1 and group 2 dust mite allergens (p = 0.005 and p = 0.035, respectively). However, for all mite allergens the percentage changes after treatment were significant when compared with untreated carpets (p < 0.005 for Der f 1 and group 2 mite, p < 0.02 for Der p 1) but not for cat allergen (p > 0.3). The results suggested that repeated application of TA was necessary to maintain reduced allergen concentrations. CONCLUSION: Carpet treatments can reduce mite-derived allergen levels in airborne and carpet dust. However, the effects do not appear to be maintained for long periods, are not dramatic, and are different for different allergens.

Molecular cloning of a major cockroach (Blattella germanica) allergen, Bla g 2. Sequence homology to the aspartic proteases.

Inhalation of allergens produced by the German cockroach (Blattella germanica) elicits IgE antibody formation and the development of asthma in genetically predisposed individuals. We compared the allergenic importance of two cockroach (CR) allergens, Bla g 1 and Bla g 2, and determined the complete amino acid sequence of the major 36-kDa allergen, Bla g2. A survey of 106 sera from CR allergic patients showed the prevalence of IgE antibodies to Bla g 1 and Bla g 2 to be 30.2% and 57.6%, respectively. Immediate skin tests on 7 selected patients gave positive reactions using 10(-3) micrograms/ml either allergen, whereas controls showed no response to 10 micrograms/ml. Natural Bla g 2 was purified and the sequence of the NH2 terminus and tryptic peptides, comprising 36% of the molecule, was determined. The cDNA for Bla g 2 was cloned from a B. germanica expression library and encoded a 24-amino acid signal peptide and a 328-amino acid mature protein, which showed the highest degree of identity to mosquito (Aedes aegypti) lysosomal aspartic protease (30.8%), with similar identity to pepsin, cathepsins D and E, renin, and chymosin. Bla g 2 mRNA and protein were detected in B. germanica, but not in Periplaneta americana, the other principal domiciliary CR species in the U.S. High concentrations of Bla g 2 were found in CR digestive organs (esophagus, gut, and proventriculus). The results show that Bla g 2 is a major species-specific allergen of B. germanica and suggest that the allergen functions as a digestive enzyme in the cockroach.

Chemical treatment of carpets to reduce allergen: a detailed study of the effects of tannic acid on indoor allergens.

Tannic acid (TA), a protein-denaturing agent, has been reported to reduce allergen levels in house dust and is marketed for that purpose as 1% and 3% solutions. We investigated the effects of TA on dust allergens by using monoclonal antibody-based ELISAs for mite (Der p I, Der f I, and group II) and cat (Fel d I) allergens. Initial studies confirmed that TA reduced allergen levels in carpet dust. However, when dust samples from treated carpets are extracted in saline solution, residual TA redissolves and may interfere with the assessment of allergens. In the laboratory, concentrations of TA as low as 0.1% inhibited the assays, but this effect may be prevented by addition of 5% bovine serum albumin (BSA). After treatment of dust samples in the laboratory with 3% TA, the apparent reductions in Der p I and Der f I levels were 89% and 96%, respectively, but when the samples were extracted in 5% BSA the reductions were 74% and 92%. Similar effects were seen with dust samples from carpets treated with TA. In an extreme case in which a carpet had been repeatedly treated with TA, the apparent concentration of Der p I was < 0.05 microgram/gm without BSA and 2.1 and 8.4 microgram/gm when extracted in the presence of 1% and 5% BSA, respectively. Our testing of the ability of TA to denature Fel d I demonstrated an 80% reduction in allergen, but only in samples with an initial concentration of less than 200 micrograms Fel d I/gm dust.(ABSTRACT TRUNCATED AT 250 WORDS)

Benzyl benzoate moist powder: investigation of acaricidal [correction of acarical] activity in cultures and reduction of dust mite allergens in carpets.

Despite advances in the understanding of dust mites, it remains difficult to control exposure to mite allergens, and it is particularly difficult to reduce mites in fitted carpets or sofas. Several chemicals have been demonstrated to kill mites or denature mite allergens, and some of these chemicals have been investigated in carpets. Benzyl benzoate (BB), which has been widely used to kill scabies mites and is known to kill mites of the genus Dermatophagoides, has been used as a method of treating carpets. The present article describes experiments in the laboratory and in houses in testing two preparations of BB, a moist powder and a foam. The moist powder is composed of two ingredients, a wetted "inert" cellulose, which is designed to act as a cleaning agent, and the active BB adsorbed onto silicates. The active powder kills 90% of mites in culture within 12 hours and 100% in 24 hours, whereas the cellulose is not acaricidal. The moist-powder preparation was highly effective at killing D. farinae and D. pteronyssinus mites in the laboratory. In carpets the moist powder, applied for 12 hours with repeated brushing, was demonstrated to reduce the concentrations of group I and group II dust mite allergens in dust recovered at 1 month. This decrease in concentration could, in part, be explained by a persistent increased recovery of dust caused by residual white powder. However, when the recovery of group II allergens was calculated as the total allergen recovered, the decrease was highly significant at 2 weeks and 4 weeks after treatment (p less than 0.001). Application of the powder to carpets for 4 hours or of the foam to sofas was less effective. After 2 months the effect on mite antigen in carpets was still present, but some increase was apparent, suggesting that repeat application after 2 or 3 months would be necessary to control mite-allergen levels.

Trichophyton tonsurans allergen. I. Characterization of a protein that causes immediate but not delayed hypersensitivity.

Fungal infections of skin or nails are extremely common and often caused by dermatophyte fungi of the genus Trichophyton. These fungi are unusual in that they can give rise to delayed hypersensitivity (DH) or immediate hypersensitivity (IH) responses. Recently, IH to Trichophyton tonsurans has been demonstrated in patients by skin tests, serum IgE antibody test (RAST), and positive nasal and bronchial challenges. To further investigate the immunology of Trichophyton, a 30-kDa T. tonsurans allergen was isolated by gel filtration and hydrophobic interaction chromatography. This protein, Tri t I, gave a single band on SDS-PAGE, and the 30 amino-terminal amino acids have been determined. Among patients with positive IH skin tests, 34 of 48 (71%) had IgG antibody and 26 of 48 (54%) had IgE antibody to Tri t I. Among those who had positive responses to both skin tests and RAST, 22 of 30 (73%) had IgE antibodies to Tri t I; thus, this protein represents a major allergen. Twelve clones of murine IgG mAb antibodies were produced. Two clones, 2F2-F7 and 6B11-C2, were found to define separate epitopes on Tri t I and were used to develop an immunometric assay for the quantitation of Tri t I. Twenty-three of 38 volunteers with a history of athlete's foot were found to have either IH and/or DH to Trichophyton mix and underwent further testing with purified Tri t I. Of the nine found to have IH to the mix, eight were sensitive to Tri t I. Seven of these eight had IgG and IgE antibodies to Tri t I, by Ag-binding RIA, and all were RAST positive to the unpurified extract. An additional 14 had either DH alone (n = 7) or a wheal and flare response followed by DH at 48 h (n = 7). Of these 14 who had DH responses to Trichophyton mix, only one showed DH to an equivalent quantity of purified Tri t I; among this group, none showed IH or serum IgE antibodies and only one had detectable IgG antibody to Tri t I. The results suggest that the majority of subjects with DH to Trichophyton are responding to a protein other than Tri t I and that the wheal that precedes DH reactions is some patients is not associated with IgE antibodies.

Identification, quantitation, and purification of cockroach allergens using monoclonal antibodies.

A panel of murine IgG monoclonal antibodies (MAbs) was raised against German cockroach (CR) (Blattella germanica) extract and selectively screened to identify MAb directed against allergen(s) recognized by IgE antibodies. Sera from 28 CR-allergic patients were used as sources of IgE antibodies to detect allergens "presented" by the MAb. Four clones (10A6, 3G12, 8F4, and 1D4) produced MAb to allergen(s) that bound IgE antibodies. Quantitative radioimmunoassays were used to compare levels of the MAb-defined allergens in CR extracts. MAb 10A6 reacted with a cross-reacting allergen that was detected in 9/14 CR species, including Blattella, Periplaneta, Blatta, Leucophea, and Supella spp, at concentrations of 100 to 10,000 U/ml. In contrast, MAb 3G12, 8F4, and 1D4 were Blattella specific. The allergen defined by MAb 8F4 was purified by MAb affinity chromatography and size-exclusion by high-performance liquid chromatography. It is a 36 kd heat-sensitive protein, isoelectric point, 5.2 to 5.4. Allergen 10A6 was partially purified by isoelectric focusing and high-performance liquid chromatography. It is a heat-stable, acidic protein (isoelectric point 3.15). Based on comparison of their properties with properties of previously described CR allergens, the allergens defined by MAb 10A6 and 8F4 have been provisionally designated Blattella germanica allergen I (Bla g I) and Blattella germanica allergen II (Bla g II), respectively. Assays of six commercial CR skin test extracts demonstrated a 200-fold difference in Bla g I levels (4.7 to 1085 U/ml) and only two extracts that contained detectable Bla g II (248 and 324 U/ml). The results demonstrate that MAb can be used to identify and define CR allergens and that the strategy of the use of MAb as a first step in allergen analysis and purification can be very effective, especially for poorly characterized allergen extracts.

Absorption of amlodipine unaffected by food. Solid dose equivalent to solution dose.

The oral bioavailability of amlodipine in healthy volunteers was compared in two separate studies after solution and capsule doses, and after capsule doses in fed and fasting states. The bioavailability of amlodipine was equivalent both in terms of rate and in extent of absorption between solution and capsule doses and in the fed and fasting states.

Seasonal variation in dust mite and grass-pollen allergens in dust from the houses of patients with asthma.

In order to study seasonal variation in dust-mite allergen, we obtained dust samples from bedding, carpet, and/or sofas in 12 houses in central Virginia, monthly, for 1 year. The houses included those of nine patients with asthma of whom six were allergic to dust mites. Dust samples were assayed with an inhibition radioimmunoassay for mite allergen that detects cross-reacting determinants on Der f and Der p I from Dermatophagoides farinae and D. pteronyssinus, respectively. The results are expressed as micrograms of antigen P1 equivalent (AgP1Eq). The results demonstrate that large seasonal variations in allergen, i.e., more than twentyfold, can occur in dust from all sites and are not restricted to the houses of allergic patients. However, dust from some sites, particularly sofas, remained "high" (greater than 10 micrograms AgP1Eq per gram), whereas dust from other sites remained "low" (less than 1 microgram AgP1Eq per gram) throughout the year. Levels of mite allergen generally started to rise in July about 1 month after the rise in humidity. In August to December, the mean levels of AgP1Eq in house dust were highly significantly increased relative to April to May. In keeping with this finding, in 31 of 37 sites, the highest level for the year was observed in August through December. In four sites, mite bodies were counted, and the numbers increased sharply in June to July; however, they decreased in September in parallel with falls in humidity but several months before the fall in mite allergen. Ryegrass-pollen allergen in 12 sites was also assayed in house dust, and pollen-allergen levels demonstrated a sharp increase in May or June that fell back to preseason values within 2 months. Dust was also obtained from the houses of 50 patients with acute or severe asthma. The results on these samples suggest that mite-allergic patients are more likely to have attacks in the fall at a time when their houses have greater than 10 micrograms AgP1Eq per gram of dust. The magnitude of changes observed seasonally within individual houses and of differences between houses within a close geographic area suggests that interpretation of the relationship between allergic symptoms and mite-allergen exposure will require measurement of mite-allergen levels in individual houses.

Serum IgE antibodies to Trichophyton in patients with urticaria, angioedema, asthma, and rhinitis: development of a radioallergosorbent test.

A series of patients was identified who demonstrated immediate positive skin tests to intradermal Trichophyton extract. These skin responses did not correlate with other fungal skin tests and were present both in atopic and nonatopic patients. The individuals demonstrating positive immediate skin tests included patients with urticaria, angioedema, asthma, and/or rhinitis, as well as five of 34 normal control subjects. Most skin test positive individuals had a history of local fungal infection and clinical signs suggestive of fungal infection. By use of Trichophyton tonsurans extract linked to Sepharose as the immunosorbent, it was possible to measure IgE antibodies in 26/30 sera from skin test positive individuals. With strongly positive sera, RAST bound up to 30% of the radiolabeled anti-IgE added. The results confirm that most skin test positive individuals have IgE-mediated hypersensitivity to Trichophyton. These observations support the older view that absorption of dermatophyte allergen through the skin should be considered as a possible cause of allergic disease.