Serial determinations of Der p 1 and Der f 1 show predominance of one Dermatophagoides species

One dust sample each month was collected for an average of 11 months throughout the year from the bedroom carpet of 39 mite allergic, asthmatic individuals living in the Tampa Bay area of Florida. Dust samples were collected from a square meter area from the bedroom carpet for 2 min using a portable vacuum cleaner and analyzed using two-site monoclonal antibody assays. The geometric mean of Dermatophagoides allergens Der p 1 and Der f 1 levels measured in each individual home was used in the statistical analysis of the results and reflects the average allergen level per year per home. Der p 1 levels were greater than Der f 1 in 21 homes; five homes had between 1.1 and 5 times more; one home had between 5 and 10; and 15 had between 10 and 175. Der f 1 levels were greater than Der p 1 in 18 homes; seven homes had between 1.1 and 5 times more; four had between 5 and 10; and seven homes had between 10 and 44. Spearman rank analysis of the results yielded a negative correlation coefficient (Rho) = -0.213 (p = 0.19) between Der p 1 and Der f 1 levels. These data suggest that when mite allergen levels reach a geometric mean value of approximately 2 micrograms/gram of dust throughout a year, one mite species predominates over the other.

Endotoxin exposure and symptoms in asthmatic children

Endotoxins (ET) are pro-inflammatory substances present in house dust which may increase non-specific bronchial reactivity in asthmatic patients. Endotoxins (EU/g) and Der p 1 levels were compared in the homes of ten asthmatic and ten control children, aged 6-16 years, living in São Paulo, Brazil. The houses were visited once a month from February 1993 to February 1994 and dust samples were collected from the bedding and floor of each subject's house. No significant differences were observed in ET and Der p 1 levels in the homes of asthmatics and controls. The highest ET levels were detected in January and November, whereas the lowest levels were detected in April and August (p < 0.05), demonstrating a distinct seasonal distribution. The highest Der p 1 levels in bedding were observed in July and the lowest in February (p < 0.05), while Der p 1 levels in floor did not show significant differences throughout the year. Symptom and medication scores were evaluated monthly in the group of asthmatic children. There was a significant correlation (p < 0.05, r = 0.63) between clinical symptom scores and ET exposure, however no significant correlation was found for mite exposure (p > 0.05, r = 0.19). The results suggest that ET exposure exacerbates asthmatic symptoms in mite allergic, asthmatic children.

Skin test and crossreactivity studies with Euroglyphus maynei and Dermatophagoides pteronyssinus

BACKGROUND

The prevalence of sensitization to Euroglyphus maynei (E. maynei) in the United States has not been reported previously.

OBJECTIVES

To determine: (1) the prevalence of skin-test reactivity in allergic subjects to E. maynei compared to D. pteronyssinus, D. farinae, and B. tropicalis and (2) the allergenic crossreactivity between D. pteronyssinus and E. maynei.

METHODS

Skin testing with extracts of B. tropicalis and E. maynei (1:50 w/v) and standardized D. pteronyssinus and D. farinae extracts (1:50 w/v; 10,000 AU/mL) provided data on 250 subjects (87 males and 163 females) aged 9-77 years (mean age, 39.8 years) with possible allergic respiratory diseases. RAST inhibition assays were used to study crossreactivity between D. pteronyssinus and E. maynei.

RESULTS

One hundred (40%) of 250 subjects had insignificant or no allergic diseases. Of the 150 allergic subjects (53 males, 97 females), 101 (67.3%) had a positive test (a percutaneous test with a weal diameter > or = 3 mm larger than the saline control) to at least one mite species; 60.7%, 60.0%, 28.7%, and 52.0% reacted to D. farinae, D. pteronyssinus, B. tropicalis, and E. maynei, respectively; 40 (26.7%) reacted to the four mite species. Positive tests to D. farinae, D. pteronyssinus, B. tropicalis, or E. maynei alone occurred in six (4.0%), four (2.7%), two (1.3%), and 0%, respectively. D. pteronyssinus and E. maynei showed moderately high crossreactivity in RAST inhibition assays.

CONCLUSION

There is a high rate of skin-test reactivity to E. maynei in Florida. Moderately high crossreactivity exists between E. maynei and D. pteronyssinus.

Zafirlukast for symptomatic mild-to-moderate asthma: a 13-week multicenter study. The Zafirlukast Trialists Group

The efficacy of the oral leukotriene-receptor antagonist zafirlukast was assessed as maintenance therapy for patients with mild-to-moderate asthma. A total of 762 patients aged 12 to 76 years were enrolled in a 13-week, multicenter, double-masked, placebo-controlled, parallel-group trial and randomly assigned to receive either zafirlukast (20 mg twice daily) or placebo. Patients were maintained on as-needed beta-agonist therapy throughout the study and had to have a cumulative daytime asthma symptoms score > or = 8 (on a daily scale of 0 to 3) over 7 consecutive days before randomization. Efficacy was assessed by changes in symptoms, beta-agonist use, and pulmonary function. Safety was assessed by adverse experiences, laboratory test results, physical examination, and electrocardiography. Zafirlukast significantly decreased daytime asthma symptoms scores (-26.5%), nighttime awakenings (-19.8%), mornings with asthma (-29.0%), and beta-agonist use (-22.3%) and significantly increased morning peak expiratory flow rate (6.9%) and forced expiratory volume in 1 second (6.3%) compared with placebo. Changes in symptoms, beta-agonist use, and pulmonary function occurred within 2 days of zafirlukast treatment and continued throughout the trial. Zafirlukast was well tolerated. Pharyngitis and headache were the most common adverse events, occurring with similar frequency in both the zafirlukast and placebo groups. No clinically significant changes were observed in laboratory test results, findings on physical examination, or electrocardiographic findings. We conclude that zafirlukast produces early and sustained effects in the treatment of mild-to-moderate asthma.

Purification and characterization of a soybean hull allergen responsible for the Barcelona asthma outbreaks. II. Purification and sequencing of the Gly m 2 allergen

BACKGROUND

A low MW allergen from soybean hull, Gly m 1, with two isoallergens, Gly m 1 A and Gly m 1 B, was associated with the asthma outbreaks that occurred in Cartagena, Spain. Using sera of asthmatic epidemic patients (AEP) from Barcelona, three main soybean hull allergens, two of them with MWs and pIs identical to those reported for Gly m 1 A and Gly m 1 B, were identified.

OBJECTIVE

The purpose of this study was to purify and to study the N-terminal amino acid sequence of the third allergen, which has a MW of 8 kDa.

METHOD

The purification procedure combined the double dialysis method and preparative isoelectofocusing (IEF). Specific IgE determination to the fractions obtained demonstrated three peaks, one of them corresponding to the 8 kDa allergen. The pooled fractions containing this allergen were studied by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE), SDS-PAGE/Western blot and IEF/Western blot. Only a band with a MW of 8 kDa and a pI of 6 was obtained. Its allergenic activity was measured and it was demonstrated that the allergenicity of soybean hull correlates with the presence of the 8 kDa allergen. The N-terminal amino acid sequence of the first 20 amino acids, which was registered at the PIR Data Submission as the N-terminal partial sequence of Gly m 2, was determined according the Edman degradation method.

RESULTS

Gly m 2 N-terminal amino acid sequence lacks homology with that reported for the allergen Gly m 1 but has a homology of 71% with a storage protein from cotyledon of Vigna radiata (cow pea) and 64% with a "disease response protein' from Pisum sativum (green pea). These results suggest that Gly m 2 in soybeans could protect against diseases which affect soybean plants.

CONCLUSION

This study demonstrates the existence of another soybean hull allergen, Gly m 2, partially responsible for the soybean asthma outbreaks that occurred in Barcelona, Spain.

Specific immunoglobulins to soybean hull allergens in soybean asthma

Soybean asthma, which occurred as an epidemic among patients in Barcelona, Spain, is associated with specific IgE to soybean hull allergens. The purpose of this study was to investigate the possible role of specific IgG, IgG subclasses, IgA, and IgM in the pathogenesis of soybean asthma. We studied 3 groups of subjects from Barcelona: group 1, 12 asthmatic epidemic patients; group 2, 23 asthmatic nonepidemic patients; and group 3, 32 nonallergic subjects. Specific IgE was determined by radioimmunoassay and specific IgG, IgG subclasses (1, 2, 3, and 4), IgA, and IgM by amplified enzyme-linked immunosorbent assay. Cross-inhibition studies were performed for specific IgE and IgG4. We partially characterized the soybean hull allergens that bind specific IgE, IgG, and IgG4 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis/Western blot. Percentage of positive results for the assays of the 8 Igs are as follows: for group 1, 100% (IgE), 75% (IgG), 16.6% (IgG1), 8.3% (IgG2), 0% (IgG3), 66.6% (IgG4), 25% (IgA), and 25% (IgM); for group 2, 4.3% were positive for specific IgE only; and for group 3, 0% (IgE), 0% (IgG), 6.2% (IgG1), 9.4% (IgG2), 9.4% (IgG3), 9.4% (IgG4), 6.2% (IgA), and 6.2% (IgM). The correlation between the specific IgE and the other specific Igs was significant between IgE and IgG4 in group 1 only (r = 0.752, p < 0.01). Cross-inhibition studies demonstrated a higher inhibitory capacity for IgG4 than for IgE. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis/ Western blot demonstrates three low molecular weight protein bands that bind specific IgE, IgG, and IgG4. This study suggests that specific IgG4 to soybean hull allergens plays a role in the pathogenesis of soybean asthma and corroborates the role of specific IgE in the same disease.

Nucleotide sequence analysis of a complementary DNA coding for a Blomia tropicalis allergen

Blomia tropicalis is a mite of allergenic importance in tropical and subtropical areas. A clone (Bt11a) from a B. tropicalis complementary DNA library was expressed in lambda phage and analyzed by plaque radioimmunoassay. The recombinant allergen produced by this clone was bound by IgE in 16 of 32 sera from individuals with asthma with a positive RAST response and none of 3 control sera from healthy individuals with negative RAST response to B. tropicalis. The cDNA insert was amplified by polymerase chain reaction with use of universal primers. A 582-base-pair (bp) fragment was cloned into a pCR II vector. The complete sequence of both strands was determined by using T7, SP6, and internal primers. The sequence shows a 432 bp reading frame with a 34 bp 5' untranslated region and a 116 bp 3' untranslated region with a poly A tail. Analysis of the sequence suggests that it encodes a putative signal peptide of 20 residues and a 124-residue mature protein allergen of 14,206 Da. The nucleotide and the inferred amino acid sequences did not show homology to any known sequence. No potential N-linked glycosylation site was found. The recombinant protein appears to represent a major allergen of the mite B. tropicalis.

Mite sensitivity and exposure in the city of Santa Fe, Argentina

Little information is available on mite allergen levels and rates of sensitization to domestic mites in South America. The purpose of this study was to establish the rate of sensitization to domestic mites in asthmatics and measure mite allergen levels in pillows and mattresses of mite allergic individuals in Santa Fe, Argentina. Dust samples were collected from the pillows and mattresses of 56 asthmatics (24 females and 32 males, mean age 17.6 +/- 11.5 years), who had been previously skin tested with standardized extracts of Dermatophagoides pteronyssinus, Dermatophagoides farinae and (1:50 w/v) extracts of Aleuroglyphus ovatus, Blomia tropicalis, Chortoglyphus arcuatus. A wheal > or = 3 mm was considered positive. Sensitization to Lepidoglyphus destructor and Euroglyphus maynei was determined by RAST and considered positive when a serum bound > or = 1% of the total counts added. Forty six individuals had a positive skin test to D. pteronyssinus, 43 to D. farinae, 27 to A. ovatus, 38 to B. tropicalis, 27 to C. arcuatus; 38 of 54 individuals had a positive RAST to E. maynei and 22 of 54 to L. destructor. The mean Group 1 (Der p 1 + Derf 1) level in pillows (n = 48) was 6.7 micrograms/g (1-55.4) and in mattresses (n = 52) 4.3 micrograms/g (1-38.8). There is a high degree of sensitization to domestic mites among asthmatics in Santa Fe. High mite allergen levels (> 2 micrograms/g) can be detected very often in pillows and mattresses.

Allergen-specific IgE levels and mite allergen exposure in children with acute asthma first seen in an emergency department and in nonasthmatic control subjects

BACKGROUND

Sensitization to allergens has been shown to be a risk factor for adults with acute asthma first seen in the emergency department.

OBJECTIVE

The purpose of this study was to evaluate the prevalence of specific IgE to common aeroallergens in children with asthma first seen in the emergency department and in control subjects.

METHODS

Fifty-four children, aged 3 to 16 years (mean age, 8.34 years) who visited the emergency department for treatment of acute bronchospasm or other illness, were evaluated. Specific IgE to seven common aeroallergens and four common storage mites was determined. Group I consisted of 29 patients who had acute bronchospasm and histories of recurrent asthma. Group II consisted of 25 control subjects who had no clinical history of atopic disease. Group I and II were compared for differences in the prevalence of positive RAST responses to the 11 allergens tested. Dust samples were collected from 17 homes of subjects in group I and from 13 homes of subjects in group II and were analyzed for levels of Der p 1 and Der f 1.

RESULTS

Statistically significant differences in the prevalence of positive RAST results between groups I and II were found in response to: Dermatophagoides pteronyssinus, 89.6% versus 36% (p = 0.0001); Blattella germanica, 45.8% versus 9.5% (p = 0.018); Alternaria tenuis, 44.8% versus 4% (p = 0.001); and the storage mites Aleuroglyphus ovatus, 39.2% versus 4% (p = 0.002); Blomia tropicalis, 42.8% versus 0% (p = 0.0002); Chortoglyphus arcuatus, 46.4% versus 0% (p = 0.0001); and Lepidoglyphus destructor, 32.1% versus 0% (p = 0.0019). Mean specific IgE levels, expressed as percent of the total counts bound, were significantly higher in group I compared with group II only in response to D. pteronyssinus, 21.9% versus 2.1% (mean percent of total counts bound) (p = 0.0001). Analysis of dust samples revealed no significant differences between the two groups, except for a higher concentration of Der f 1 in the sofas of subjects in group II.

CONCLUSION

Sensitization to D. pteronyssinus, storage mites, and, to a lesser extent, to A. tenuis and B. germanica is associated with acute childhood asthma that requires emergency treatment in Florida.

Partial characterization of the silk allergens in mulberry silk extract

Although there have been reports of allergic reactions such as asthma and hypersensitivity pneumonitis to silk allergens (especially in oriental countries), these allergens have not been characterized. We report an in vivo and in vitro study of subjects allergic to silk, as well as a partial characterization of the allergens involved. Forty-one subjects with a clinical history of silk allergy who had asthma, allergic rhinitis or both, and who had a positive intradermal skin test to mulberry silk extract, were evaluated in the study. Four asthmatic subjects with negative skin tests and RASTs to mulberry silk extract were used as controls. RAST specific lgE was present in 37/41 (90%) subjects. SDS-PAGE of mulberry silk extract demonstrated 13 protein bands of less than 21-95 kD. lgE which bound to protein bands was present in 13/32 (41%) sera, twelve of which bound to a single protein with a molecular weight between 35.1 and 50 kD. A pool made with the four control sera did not react with any protein band. The patients allergic to silk showed evidence of sensitivity to mulberry silk extract, both in vivo and in vitro, but sera from 19/32 (59%) subjects did not have antibodies reactive with the mulberry silk extract immunoblot protein bands. The low avidity of the lgE may be responsible for this discrepancy between in vivo and in vitro results.

Positive nasal challenge responses to Blomia tropicalis

BACKGROUND

Blomia tropicalis, a dust mite commonly found in subtropical and tropical environments, is the fourth most common mite in the United States. Thirty-eight percent of 167 consecutive subjects evaluated for allergic respiratory symptoms in the Tampa Bay area had positive skin test responses to B. tropicalis.

METHODS

Nasal challenges were performed in 19 subjects with allergic rhinitis; 12 had positive skin test responses to B. tropicalis (group I), and seven had negative skin test responses to B. tropicalis but positive skin test responses to Dermatophagoides pteronyssinus and D. farinae (group II). Subjects were challenged with a normal saline control solution and increasing concentrations of a 1 mg/ml in-house extract of B. tropicalis (1:125,000 vol/vol, 1:25,000 vol/vol, 1:5000 vol/vol, 1:1000 vol/vol, and 1:200 vol/vol). Inspiratory nasal airway resistance (was measured every 5 minutes for 15 minutes by posterior rhinomanometry at 50 Pa after each nasal challenge.

RESULTS

Nasal challenge response was considered positive and stopped when the mean inspiratory nasal airway resistance was greater than twice the mean inspiratory nasal airway resistance after the normal saline challenge. Ten of 12 (83%) subjects in group I and none of seven (0%) subjects in group II had positive nasal challenge responses to B. tropicalis (p = 0.0024).

CONCLUSION

B. tropicalis is allergenic and should be considered as a cause of allergic rhinitis when evaluating a patient who lives in an area where it is endemic.

A review of allergic bronchopulmonary aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) occurs in 1-2% of patients with asthma and in 10% of patients with cystic fibrosis. We introduce the acronym "ARTEPICS" in this review article on ABPA to facilitate its diagnosis: A: Asthma; R: Roentgenographic infiltrates; T: Tests for Aspergillus fumigatus (Af) positive in the skin; E: Eosinophilia; P: Precipitating antibody to Af; I: IgE in serum elevated; C: Central bronchiectasis; and S: Serum specific IgE-Af and IgG-Af elevated (ARTEPICS).

Comparative study of cetirizine and terfenadine versus placebo in the symptomatic management of seasonal allergic rhinitis

BACKGROUND

Cetirizine is a new antihistamine with greater selectivity for the histamine H1 receptor and a low rate of hepatic metabolism. Cetirizine once daily is effective in the symptomatic treatment of seasonal and perennial allergic rhinitis and chronic idiopathic urticaria.

OBJECTIVE

The efficacy and safety of cetirizine 10 mg qd, terfenadine 60 mg bid, and placebo were compared in patients with seasonal allergic rhinitis.

METHODS

A multicenter, prospective, double-blind, randomized, parallel study was conducted for 2 weeks during the ragweed pollen season in patients with documented allergic rhinitis. Total symptom complex and total symptom complex plus nasal congestion scores, global efficacy, overall satisfaction, and adverse events were assessed at baseline and after 1 and 2 weeks of treatment.

RESULTS

Of the 311 patients randomized to treatment, 283 completed the study. Cetirizine produced a marked improvement in symptoms scores compared with placebo after 1 week of therapy (P = .001). By the end of week 1, total symptom complex scores were improved by 37% with cetirizine compared with 29% for terfenadine, and 23% for placebo. An overall treatment effect was evident at week 1 (P = .0019), with marked differences between cetirizine and both placebo (P = .0004) and terfenadine (P = .0464) but not between terfenadine and placebo (P = .1215). A more marked treatment effect was evident during the first week of the study; this appeared to be related to spontaneous resolution of symptoms, since mean pollen counts derived for each patient declined significantly each week of the study. Therapy was generally well tolerated. Headache was the most common side effect in each group. Four patients on cetirizine, one on terfenadine, and two on placebo withdrew because of side effects. Somnolence was reported in 12 patients on cetirizine (P < .05), 2 on terfenadine, and 3 on placebo.

CONCLUSION

Cetirizine produced a greater improvement in symptoms of seasonal allergic rhinitis than terfenadine or placebo.

Management of chronic sinusitis

Most acute cases originate in the narrow spaces of the ostiomeatal complex, which is easily transformed into a fertile environment for bacteria. Rhinoscopy and perhaps CT scanning are in order when the condition becomes chronic; in addition, acute therapy should be altered to include anaerobic antibiotic coverage and a nasal steroid spray. Some chronic cases will require endoscopic surgery.

Sequential determinations of Dermatophagoides spp. allergens in a tropical city

The purpose of this study was to establish seasonal levels of Der p 1, Der f 1 and D. pteronyssinus allergens in mattress and floor dust samples in the homes of 20 mite-allergic asthmatic patients in Cartagena, Colombia. Dust samples were collected using a portable vacuum cleaner once monthly for the same 12 months in all houses. The highest Der p 1 levels in mattress samples were detected in August (geometric mean = 109.49 ng/g) and represented a 2.2-times increase from the lowest level observed in November. Der f 1 was detected in only 3 mattresses, ranging from 90 ng to 1.6 micrograms per gram of dust. The highest levels were detected in February and March. The highest level of D. pteronyssinus allergens in mattress dust samples, quantitated by RAST-inhibition, was 8, 994 AU/g (80% inhibition); the lowest level detected was 150 AU/g (5% inhibition). Allergen levels were significantly higher in mattresses than in floor samples (p < 0.001). Overall, a Spearman rank correlation coefficient of 0.48, p < 0.001, was obtained between Der p 1 and D. pteronyssinus allergens. There was a good correlation between mite allergens and absolute humidity (r = 0.8, p = 0.007). Der p 1, Der f 1 and D. pteronyssinus allergen levels show minimal variations in this tropical environment. Allergens derived from various mite species must be considered when assessing mite allergen exposure in these environments.

Sequential determinations of Blomia tropicalis allergens in mattress and floor dust samples in a tropical city

BACKGROUND

The mite species Blomia tropicalis is commonly found in tropical and subtropical regions, and it is an important source of allergen in the city of Cartagena, Columbia.

AIM

The study was designed to determine seasonal allergen levels of B. tropicalis in homes of patients with asthma and mite allergy.

METHODS

Dust samples from mattresses and floors in 20 homes were collected on a monthly basis for 1 year. Outdoor temperature, relative humidity, and rainfall were recorded. RAST inhibition was performed on extracts of dust samples. Allergen levels were compared with variations in climate.

RESULTS

B. tropicalis allergens were detected in all mattress samples. More than 50% RAST inhibition was detected in 30% of mattress samples and in 4.3% of floor samples, reflecting a high concentration of allergen. Significant correlations were only found between allergen levels and absolute humidity.

CONCLUSION

Levels of B. tropicalis allergen fluctuated minimally in Cartagena, Colombia.

Serum total and specific IgE levels in children infected with human immunodeficiency virus

BACKGROUND

Human immunodeficiency virus (HIV) infection is associated with polyclonal B-cell activation, and elevated IgE levels are found in infected adults. Chronic nasal symptoms, sinusitis, and otitis media are particularly common in children infected with HIV. The possible allergic cause of nasal symptoms in children infected with HIV has not been explored.

OBJECTIVE

The study was designed to evaluate the relationship between HIV infection and IgE levels in a group of children infected with HIV.

METHODS

Total serum IgE was measured by enzyme immunoassay and compared with values for age-matched normal subjects. Specific IgE was determined by RAST test to Dermatophagoides pteronyssinus, American cockroach, Bahia grass, short ragweed, cat, and oak. Lymphocyte subpopulations were determined by standard flow cytometry.

RESULTS

Fifty-seven total IgE and 342 specific IgE levels were determined from 29 infected children (19 girls and 10 boys; ages, 7 to 150 months; mean age, 49 months). Initial IgE levels of 29 subjects ranged from 1.4 to 787.6 IU/ml (mean = 123.4 +/- 34.4 IU/ml). Nine of 29 (31%) subjects had initial IgE levels greater than two standard deviations higher than age-matched normal subjects. No patients had detectable specific IgE to any of the six aeroallergens. There was no correlation, as determined by linear regression analysis, between IgE levels and absolute CD4 number or CD4:CD8.

CONCLUSION

Elevated total but not specific IgE is common in children infected with HIV and does not correlated with absolute CD4 lymphocyte count, suggesting that the elevated IgE level reflects a somewhat independent polyclonal activation of B-lymphocytes.

Diagnosis of pediatric human immunodeficiency virus infection by means of a commercially available polymerase chain reaction gene amplification

OBJECTIVE

To assess the sensitivity and specificity of polymerase chain reaction (PCR) in infants and children at risk for human immunodeficiency virus (HIV) infection.

DESIGN

A prospective, blinded study of 286 HIV-seropositive infants and children. Infection was diagnosed by antibody detection after 18 months of age, two positive direct tests (p24 antigen and HIV culture), or the presence of an illness that defines the acquired immunodeficiency syndrome.

SETTING

University of South Florida and All Children's Hospital, St Petersburg, inpatient and outpatient centers.

PARTICIPANTS

Two hundred eighty-six infants and children seropositive for HIV who were examined between July 1988 and September 1992.

MAIN OUTCOME MEASURES

Sensitivity, specificity, and predictive values of a commercially available PCR test.

RESULTS

Five hundred sixty-seven PCR tests were performed on samples from 286 seropositive subjects followed up for a minimum of 16 months. Of the subjects, 105 were confirmed to be infected and 181 uninfected. Overall, 96 of 105 initial PCRs in infected subjects were positive (sensitivity, 91.4%; positive predictive value, 99%). If samples obtained during the first week of life are excluded, 95 to 100 samples were positive (sensitivity, 95%). Of 181 initial PCR tests from seropositive subjects who seroreverted, 180 were negative (specificity, 99.4%,; negative predictive value, 95.2%). The predictive value of a positive test was 90.9% and that of a negative test was 93.1% in the first month of life. All 145 initial samples obtained between 5 weeks and 12 months of age correctly predicted infection status (positive predictive value, 100%).

CONCLUSIONS

Gene amplification by means of a commercially available PCR is useful in the diagnosis of HIV infection for infants born to seropositive mothers. Between day 7 through 1 year of age, HIV infection is accurately diagnosed by the PCR assay.

Adverse reactions associated with skin testing and immunotherapy

Fatalities have been associated with allergen skin testing and immunotherapy. Therefore, physicians using such tests and therapy should be knowledgeable in their use and take proper precautions to decrease the risk of anaphylaxis. The American Academy of Allergy and Immunology recommends a 20-minute wait that can be extended for high risk patients following an injection, and that the physician in charge of administering immunotherapy should be familiar with and prepared to appropriately treat anaphylaxis. Future treatment with peptides rather than whole allergens may increase safety.

Anaphylaxis. A review of 266 cases

BACKGROUND

A presentation of findings from a large population of anaphylaxis cases.

METHODS

Retrospective chart review and follow-up questionnaire provided data on 266 subjects (113 males and 153 females) aged 12 to 75 years (mean age, 38 years) who were referred to a university-affiliated private allergy-immunology practice in Memphis, Tenn, for evaluation and management of anaphylaxis from January 1978 through March 1992.

RESULTS

Of 266 subjects, 162 (61%) had three or more anaphylactic episodes, 41 (15%) had two episodes, and 63 (24%) had one episode. Atopy was present in 98 individuals (37%). Physicians thought foods, spices, and food additives caused anaphylaxis in 89 individuals (34%); crustaceans and peanut accounted for about half of these cases. Medications were thought to have caused the anaphylactic episodes in 52 individuals (20%); nonsteroidal anti-inflammatory drugs in about half of these cases. Other probable causes included exercise (n = 19), latex (n = 2), hormonal changes (n = 2), and insect bites (n = 4). A suspected cause could not be determined in 98 individuals (37%). These subjects were diagnosed as having idiopathic anaphylaxis. Of the 266 subjects, 102 responded to a follow-up survey; 68 (67%) of the 102 were thought to have identifiable causes of anaphylaxis (32 of whom [47%] failed to carry epinephrine syringes for self-administration despite instructions to do so). In contrast, of 34 subjects with idiopathic anaphylaxis who responded to the survey, only three (9%) did not carry epinephrine.

CONCLUSIONS

(1) Atopy is common in subjects who experience anaphylaxis, regardless of its origin; (2) crustaceans and nonsteroidal anti-inflammatory drugs are the most common food and medication groups, respectively, thought to cause anaphylaxis; (3) causative agents can be identified for two thirds of the subjects, and recurrent attacks are the rule; and (4) subjects with idiopathic anaphylaxis are more likely to carry epinephrine for self-administration than those with identifiable causes.

Modulation of endothelin-1 production by a pulmonary epithelial cell line. I. Regulation by glucocorticoids

Endothelin-1 (ET-1) is one of the most potent bronchoconstrictor agents yet described. Bronchial epithelial cells of asthmatic patients in vivo express preproET-1 and in vitro release high amounts of ET-1. Healthy and chronic bronchitic controls do not express preproET-1 or release ET-1. Interleukin-2 (IL-2) and other cytokines up-regulate the in vitro ET-1 release in guinea pig airway epithelial cells. We explored whether two glucocorticoids, dexamethasone (Dex) and triamcinolone acetonide (TA), inhibit the synthesis and release of ET-1 by A549 cells, a transformed human pulmonary epithelial cell line, since ET-1 may have a basic role in the pathogenesis of asthma. Cells were grown to confluence in RPMI 1640 plus 10% fetal bovine serum (FBS). Cells were then cultured for 3 days without serum to obtain ET-1 basal levels. The effects of 10% FBS, IL-2 (10 U/mL), Dex, TA or mifepristone, a steroid antagonist (1, 10 or 100 nM), were evaluated on ET-1 as measured by radioimmunoassay (RIA). ET-1 production increased from 57.6 +/- 5 pg/mg cell protein at 6 hr to 170 +/- 9 pg/mg cell protein at 72 hr in control cultures. Ten percent FBS increased ET-1 production from 58.7 +/- 9.6 to 399 +/- 14.5 pg/mg cell protein. IL-2 significantly increased ET-1 from 100.7 +/- 6.1 to 144 +/- 6.7 at 24 hr and from 170 +/- 9 to 207.7 +/- 24 at 72 hr. Dex and TA (10 and 100 nM) at 24-72 hr decreased ET-1 under basal conditions. Both drugs (only at 100 nM) decreased ET-1 production in 10% FBS- and IL-2-stimulated cells. Mifepristone (10 and 100 nM) reversed the decreased production of ET-1 induced by Dex (100 nM) at 24-72 hr. Northern blot analysis showed that Dex (100 nM) decreased the expression of ET-1 mRNA at 6 and 24 hr, but that mifepristone (100 nM) reversed this effect in cells cultured with Dex. In conclusion, Dex and TA down-regulate the synthesis and production of ET-1 by this human pulmonary epithelial cell line under basal or stimulated conditions, and these effects are reversed by mifepristone. These findings suggest a novel mechanism of glucocorticoid effect during the treatment of asthma.

Sensitization to Blomia tropicalis: skin test and cross-reactivity studies

This study evaluated the prevalence of positive percutaneous skin test results to Blomia tropicalis, Dermatophagoides pteronyssinus, and D. farinae in 167 consecutive persons (61 males, 106 females; mean age, 38.7 years; range, 14 to 75 years) with asthma or rhinitis, or both, in Tampa, Fla. Forty-nine had asthma with or without rhinitis, and 118 had rhinitis alone. RAST and RAST inhibition analysis of all three mite species were performed by using pooled patient sera. Prepared extracts of B. tropicalis and standardized D. pteronyssinus and D. farinae (1:50 wt/vol) were used for percutaneous skin tests. One hundred twelve subjects (67%) had a positive result to at least one mite species; 38%, 62%, and 60% reacted to B. tropicalis, D. pteronyssinus, and D. farinae, respectively. Positive skin test results to both D. pteronyssinus and D. farinae occurred in 96 subjects (57%); 56 of these subjects (58%) were also positive to B. tropicalis. Positive skin test results to B. tropicalis, D. pteronyssinus, or D. farinae alone occurred in four (2%), five (3%), and four (2%), respectively. RAST and RAST inhibition data indicate that B. tropicalis contains unique allergens. The high rate of skin test reactivity to B. tropicalis extracts, and its unique allergenic composition, warrants its use in the diagnosis and treatment of allergic disorders in Tampa.

Comparison of oral pulse methotrexate with placebo in the treatment of severe glucocorticosteroid-dependent asthma

BACKGROUND

This study compared the efficacy of weekly oral administration of methotrexate and placebo in treatment of 24 subjects with chronic glucocorticosteroid-dependent asthma.

METHODS

The 33-week randomized, double-blind, placebo-controlled crossover trial compared once weekly 15 mg doses of methotrexate with placebo. At the time of entry, the subjects' mean dosage of prednisone was 23.8 mg/day (range, 12.5 to 85 mg) and glucocorticosteroid therapy had been used continuously for a mean duration of 78 months (range, 5 to 360 months).

RESULTS

Of the 21 subjects who completed the study, 13 tolerated lower daily prednisone doses during methotrexate treatment compared with placebo. When treated with methotrexate, subjects required 14.2% less prednisone than when treated with placebo (p = 0.0447), their subjective symptom scores improved 21.4% (p < 0.05), and mean forced expiratory volume in 1 second values tended to improve. Mean serum theophylline levels did not change significantly between the methotrexate and placebo arms of the study. Adverse effects were minimal, with nausea and headache occurring twice as often during methotrexate therapy compared with placebo.

CONCLUSION

Short-term, low-dose, pulse therapy with orally administered methotrexate results in a decrease in the daily glucocorticosteroid requirement in a majority of subjects with severe asthma and is accompanied by improvement in subjective symptom scores without unacceptable side effects or deterioration of pulmonary function.

Elevated serum levels of IL-8 in patients with HIV infection

Serum levels of IL-8 were determined in HIV-infected individuals and the results were compared with those for HIV- controls. The IL-8 levels were measured by an ELISA with a MoAb and a polyclonal antibody to recombinant IL-8. The means and 95% confidence intervals of IL-8 in sera of 36 HIV-infected individuals and 32 matched controls were 275 and 216-349 pg/ml, and 8 and 4-14 pg/ml, respectively, showing a 34-fold increase in IL-8 in the circulation of HIV-infected individuals. This increase does not appear to be related to the disease state, infection or systemic medical agents. This finding suggests the possible involvement of IL-8 in the pathogenesis of HIV-induced disease.

Mite allergy in the tropics: sensitization to six domestic mite species in Cartagena, Colombia

Sensitization to the domestic mites Blomia tropicalis, Chortoglyphus arcuatus, Lepidoglyphus destructor and Aleuroglyphus ovatus was investigated in 77 subjects with clinical symptoms of asthma and/or allergic rhinitis and a positive skin prick test (wheal > or = 3 mm) to Dermatophagoides pteronyssinus and/or D. farinae. Seventy patients were skin test-positive to D. pteronyssinus and 73 to D. farinae. Serum samples from 29 nonallergic, skin test-negative individuals were used as negative controls. Specific IgE was determined by RAST and the results expressed as the % of the total counts bound (% TCB). A positive result (> or = 1% TCB) to D. farinae was detected in 89.6% of subjects, to B. tropicalis in 80.5%, to D. pteronyssinus in 75.3%, to C. arcuatus in 71.4%, to A. ovatus in 68.8% and to L. destructor in 59.7%. None of the controls had a positive RAST to any of the mite species. Different IgE binding patterns were observed among these subjects, suggesting sensitization to unique as well as common allergens in the different mite species. Sensitization to Pyroglyphidae (D. pteronyssinus and D. farinae) and non-Pyroglyphidae mites (B. tropicalis, C. arcuatus, L. destructor and A. ovatus) is common among allergic individuals in Cartagena. Extracts of these mites may be needed for a more accurate diagnosis and effective treatment of respiratory diseases due to mite allergy in tropical environments.

Survey of fatalities from skin testing and immunotherapy 1985-1989

BACKGROUND

The Committee on Allergen Standardization of the American Academy of Allergy and Immunology (AAAI) began a study of fatalities associated with skin testing and immunotherapy in an effort to identify risk factors and to ascertain whether any additional precautions are required to prevent and treat serious reactions.

METHODS

Questionnaire data was obtained from members of the AAAI and the American College of Allergy and Immunology, regarding 17 fatalities associated with immunotherapy for the years 1985 to 1989. In this period, no fatalities were reported with skin testing. The mean age of patients who died was 36.0 years (range: 10 to 77 years), and 69% were female. Of the patients who died, 76% had asthma, and most were reported to have had factors associated with severity (i.e., lability, required steroids, and/or prior hospitalizations). The only patient who had rhinitis alone had cardiovascular disease and was receiving a beta-blocker. High sensitivity by skin test or RAST was reported by 71%, and 36% reported prior systemic reactions. Sixty-five percent of the patients were undergoing build-up therapy. Fatalities involved use of allergen doses between 1:1 million to 1:10 wt/vol. Other factors associated with fatalities were: changing to a new vial of extract, 5; dosing error or inappropriate dose adjustment, 5; allergen season, 5; symptomatic before injection, 4; not waiting after injection, 2; and home injection, 1. Onset of anaphylaxis occurred within 20 minutes in eleven patients, within 20 to 30 minutes in one, and after more than 30 minutes in one. In eleven cases the cause of death was associated with respiratory compromise. These data reinforce the need for special precautions in treating high-risk patients with asthma. The annual fatality rate from administration of allergenic extracts in the United States remains very low: 1 fatality per 2 million doses, but additional educational efforts to further reduce the fatality rate are needed.

Suggested approaches for research protocols involving the potential for life-threatening reactions

These guidelines are intended to reduce the potential for serious or life-threatening reactions when clinical research is conducted. The following issues were addressed: identifying the risks involved in the research, providing adequate safeguards in the protocol design and during withholding of medication, anticipating risks, minimizing the chances for human error, providing resuscitative equipment sufficient to deal with the most serious anticipated life-threatening reactions, planning for medical support in case of a life-threatening emergency, and optimizing the use of medical personnel and expertise to handle emergency situations. The guidelines also discuss important general issues about protocol design and implementation and the human subject consent form, which should facilitate the approval of protocols by the governing institutional review board. The guidelines are not meant to be inflexible or applicable to all research situations. However, it is our hope that they will allow for clinical research to be conducted in a manner that affords the research subjects a high degree of protection from unnecessary and possibly fatal injuries.

Polycythemia as a complication of human immunodeficiency virus infection

HIV infection is commonly associated with cytopenias. The occurrence of erythrocytosis is rare, with only one report in the medical literature. We have described the case of an asymptomatic patient found to be seropositive for HIV. The blood counts were initially normal except for mild eosinophilia and thrombocytopenia. Over the next 18 months erythrocytosis developed and thrombocytopenia worsened. Workup at that time revealed elevated red cell mass, suppressed erythropoietin, normal arterial oxygen saturation, and splenomegaly documented by abdominal computed tomography. Zidovudine therapy was started in April 1990, when the CD4 cell count dropped below 500/mm3. Over the next 4 months the hematologic indexes returned to normal levels. The patient remains asymptomatic.

Allergenicity of the cat flea (Ctenocephalides felis felis)

Adult fleas, spent and unspent culture media were extracted and the radio-allergosorbent test (RAST) performed with sera of 48 cat flea skin test-positive individuals from the Tampa Bay area of Florida. Sixteen sera (33.6%) had a positive RAST to the cat flea extract prepared in our laboratory [1.7-11.4% of the total counts (TC) added]. Six of the 16 sera (12.5%) also contained specific IgE to allergens in the spent medium (0.8-3.3% TC). The allergen composition and strength were studied by RAST inhibition of two commercial cat flea extracts and compared with our in-house flea extract. The results demonstrated similar allergen compositions and different potencies. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of the in-house flea extract showed several Coomassie blue-stained bands (10-85 kD). SDS-PAGE immunoblots revealed five IgE-binding bands at 34, 35, 39, 54 and 60 kD. Flea allergens were quantified in eight house dust samples using RAST inhibition assays and expressed as RAST inhibition units; five of these samples contained detectable levels. Cat flea allergens may contribute to the allergenicity of house dust in areas of heavy flea infestation.

Mite fauna, Der p I, Der f I and Blomia tropicalis allergen levels in a tropical environment

Fifty dust samples were collected from the mattresses and bedroom floors of 25 subjects with allergic asthma in Cartagena, Colombia, in order to identify house dust mites and quantitate Der p I, Der f I and Blomia tropicalis allergens. The geometric mean of the total mite density per gram of dust was 418 (range, 40-2280). Twenty-two samples (44%) had more than 500 mites and four, less than 100. B. tropicalis and Dermatophagoides pteronyssinus were found in 96% and 90% of the samples, accounting for 40.1% and 35.7% of the total mites, respectively. Cheyletus malaccensis, Chortoglyphus arcuatus, Pyroglyphus africanus, Oribatids, Grallacheles bakeri, Tarsonemus spp., Suidasia spp., Dermatophagoides farinae and unidentified mites accounted for the rest. The geometric mean of the total mites/gram of dust in mattresses (563.9) was significantly higher than in floor dust (309.1), P < 0.01. Allergen concentrations and mite numbers were analysed by Spearman rank correlations: B. tropicalis mites vs B. tropicalis allergen, r = 0.54, P < 0.001; D. pteronyssinus mites vs Der p I, r = 0.52, P < 0.001. A negative correlation was obtained between B. tropicalis mites and Der p I. Allergens derived from B. tropicalis and other domestic mite species may play an important role in sensitization and allergic symptoms in Cartagena, Colombia.

Effects of cetirizine versus terfenadine in seasonal allergic rhinitis

The purpose of this study was to compare the efficacy and safety of cetirizine, 10 mg, once daily in the morning to terfenadine, 60 mg, BID in the treatment of seasonal allergic rhinitis. The multicenter, single-blind, parallel study involved 160 patients, who were all included in the safety and efficacy analysis. The results of the study showed that both cetirizine, 10 mg, QD and terfenadine, 60 mg, BID used for 1 week are safe and effective in the management of allergic rhinitis. By repeated measures analysis, cetirizine improved symptoms more than terfenadine for the treatment period of days four to seven. Standard Cochran-Mantel-Haenszel statistics test showed the relative degree of patient satisfaction to be higher in the cetirizine group.

Sensitization to Chortoglyphus arcuatus and Aleuroglyphus ovatus in Dermatophagoides spp. allergic individuals

The prevalence of specific IgE to the storage mites Aleuroglyphus ovatus (Ao) and Chortoglyphus arcuatus (Ca) was studied in 77 individuals with allergic asthma and/or chronic allergic rhinitis. All these individuals had a positive skin test (weal > or = 3 mm) to extracts of Dermatophagoides pteronyssinus (Dp) and/or Dermatophagoides farinae (Df). Sera from 29 non-atopic individuals were used as controls. A RAST was considered positive when a serum bound > or = 1% of the total counts added. The prevalence of a positive RAST to Dp was 75.3%, and to at least one of the two storage mites (Ao and Ca), 76.6%. Among patients with a positive RAST to Dp, 79.3% and 75.8% were RAST positive to Ao and Ca, respectively. RAST inhibition studies with a pool of sera from 13 subjects with high RAST binding to all three mites showed significant crossreactivity between Ao and Ca and minimal to moderate crossreactivity between Dp and Ao and Ca. This study demonstrates that sensitization to Ao and Ca is common in individuals with respiratory allergies in Cartagena, Colombia and suggests that Ao, Ca and Dp have unique and common allergenic determinants.

Nasal and bronchial provocation challenges with bayberry (Myrica cerifera) pollen extract

Southern bayberry, distributed throughout the southeastern United States, is the source of the fifth most common windborne tree pollen in Tampa, Fla. Fifteen percent of 400 consecutive subjects evaluated for allergic respiratory symptoms in the Tampa Bay area had positive skin tests to bayberry pollen extract. Bayberry pollen extract was obtained commercially and used to perform 25 nasal and 22 bronchial challenges on 45 subjects. Twelve of 13 (92%) study subjects with allergic rhinitis and positive skin tests to bayberry pollen extract and two of 12 (17%) control subjects with negative skin tests had positive nasal challenges (p = 0.0001). Four of seven (57%) study subjects with extrinsic asthma and positive skin tests to bayberry pollen extract and none of the 15 (0%) control subjects with negative skin tests had positive bronchial challenges (p = 0.001). Sera from 30 subjects who underwent 31 challenges were assayed for bayberry pollen extract-specific IgE by plate radioimmunoassay. Specific IgE antibodies were present in the sera of 8 of 13 (62%) subjects with positive challenges and absent in 15 of 18 (83%) subjects with negative challenges (p = 0.01). Intradermal skin tests with bayberry pollen extract were more predictive of provocation challenge results than plate radioimmunoassay (positive predictive value of 80%, 95% CI 62% to 98%; versus 73%, 95% CI 47% to 99%). Bayberry pollen extract is allergenic, and the Southern bayberry tree fulfills Thommen's criteria defining aeroallergen-producing plants.

Respiratory allergies and skin test reactivity in high school students in Tenerife, Canary Islands, Spain

The prevalence of skin test reactivity to 22 aeroallergens and of allergic respiratory diseases was determined in 501 high school students on the island of Tenerife, Spain. Two hundred seventy-seven students (55.2%) had at least one positive prick skin test (wheal > or = 2 mm). Two hundred sixteen students (43.1%) had symptoms of upper or lower respiratory tract allergies [24 (4.7%) had asthma with or without rhinitis and 192 (38.3%) seasonal or perennial rhinitis alone]. Two hundred eighty-five students (56.8%) were asymptomatic. One hundred per cent of the students with asthma, 87.5% of the students with rhinitis and 27.7% of the asymptomatic students had at least one positive skin test. The prevalence of positive skin tests was significantly higher in symptomatic than in asymptomatic students (p = 0.0001). One hundred seventy students (33.9%) had a family history of respiratory allergic diseases. The prevalence of positive skin tests among these students was significantly higher than in students without such history (p = 0.0001). Thus, there is a high prevalence of allergic respiratory diseases and skin test reactivity to aeroallergens among high school students in Tenerife. Significant correlations were found between family history, positive skin tests and respiratory allergic symptoms.

Sensitization to Blomia tropicalis and Lepidoglyphus destructor in Dermatophagoides spp-allergic individuals

Serum was collected from 77 atopic subjects from Cartagena, Colombia, who had a positive skin test (greater than or equal to 3 mm) to either Dermatophagoides farinae (Df) (73) or D. pteronyssinus (Dp) (70). Twenty-nine healthy volunteers with negative allergy histories and negative skin tests were used as control subjects. RAST and RAST-inhibition assays were used to study the prevalence of specific IgE to Blomia tropicalis (Bt), Lepidoglyphus destructor (Ld), and Df. RAST results were considered positive when a serum bound greater than or equal to 1% of the total counts added; 69 atopic subjects (89.6%) were positive to Df, 66 (85.5%) to Bt, and 46 subjects (59.7%) were positive to Ld. RAST results, analyzed by regression analysis, revealed the following correlation coefficients: Df versus Bt, r = 0.59; Df versus Ld, r = 0.44; and Bt versus Ld, r = 0.52. RAST-inhibition assays with a serum pool of 11 individuals highly allergic to all three mites (mean specific IgE to all mites, greater than or equal to 18.2 percent total counts bound) demonstrated considerable cross-reactivity between Bt and Ld and moderate cross-reactivity between Df and Bt and Ld. Bt, Df, and Ld possess unique, as well as common, allergens. Sensitization to Bt and Ld is very common in mite-allergic individuals in Cartagena, Colombia.

A three-year aerobiologic pollen survey of the Tampa Bay area, Florida

An aerobiologic survey using a rotoslide sampler was conducted daily (January 1979 through December 1981) in Tampa, Florida. A major tree pollen season (Dec. through May) consisted of oak, pine, Australian pine, bald cypress, cedar, bayberry and mulberry. A minor tree season (Oct. and Nov.) consisted of Australian pine and elm. Grass pollen was found throughout the year and most prevalent April through October. A major weed pollen season (May through Dec.) consisted of ragweed, Mexican tea, pigweed, dog fennel, and false nettle. A minor weed season (March through July) consisted of sorrel and dock.