ABSTRACT
BACKGROUND: Cockroach is an important allergen in inner-city asthma. The diagnosis and treatment of cockroach allergy has been impeded by the lack of standardized cockroach extracts. OBJECTIVE: We investigated the utility of a mediator release assay based on rat basophil leukemia (RBL) cells for comparing the potency of German cockroach extracts. METHODS: RBL cells (line 2H3) transfected with human FcepsilonRI were passively sensitized with sera from subjects with cockroach allergy and stimulated with serial dilutions of 3 commercial cockroach extracts (1:10 weight/volume). In addition, the in-house prepared extract was tested in separate experiments with pooled sera that produced optimal performance in the RBL assay. N-hexosaminidase release (NHR) was used as a marker of RBL cell degranulation and was examined in relation to the intradermal skin test (ID(50)EAL) and serum cockroach-specific and total IgE levels. RESULTS: The median cockroach-specific IgE concentration in 60 subjects was 0.72 kU(A)/L (interquartile range, 0.35-2.97 kU(A)/L); 19 sera (responders) produced a minimum 10% NHR to more than 1 extract. Responders had higher median cockroach-specific IgE (7.4 vs 1.0 kU(A)/L) and total IgE (429 vs 300 kU/L) levels than nonresponders. Ranking of extract potency was consistent between the mediator release assay and the ID(50)EAL. For the in-house prepared cockroach extract, the dose-response curves were shifted according to the concentration of the extract. NHR was reproducible between different experiments by using pooled sera. CONCLUSION: The mediator release assay measures biologic potency and correlates with the ID(50)EAL. It should be further evaluated to determine whether it could be used to replace intradermal skin test titration for assessing the potency of cockroach extract.
Subject(s)
Allergens/immunology , Basophils/physiology , Cockroaches/immunology , Hexosaminidases/metabolism , Adolescent , Adult , Aged , Animals , Cell Degranulation , Cell Line , Histamine Release , Humans , Immunoglobulin E/blood , Middle Aged , Rats , Receptors, IgE/physiology , Reproducibility of ResultsABSTRACT
BACKGROUND: Animal models that mimic the pulmonary features observed in human asthma are important tools to study the mechanism(s) of allergen-induced asthma. Cockroach and dust mite allergens are two common allergens found in the 'inner city' environment. In this study, we examined the interaction between recombinant cockroach (r Bla g 2) and dust mite (r Der f 1) allergens in inbred mouse strain (A/J). The tested hypothesis was that there are enhanced effects of exposure to r Bla g 2 and r Der f 1 allergens in the airway inflammatory response in A/J mice. METHODS: Five groups of mice (male, 6-8 weeks) were examined: vehicle (saline) controls; adjuvant (alum) controls; r Bla g 2 immunized (0.01-10 microg/mouse), r Der f 1 immunized (0.01-10 microg/mouse), and combined immunization with r Der f 1 (0.05 microg/mouse) and r Bla g 2 (0.0 5 microg/mouse). Mice were immunized at days 0 and 7, challenged by oro-tracheal inhalation with r Der f 1 and/or r Bla g 2 allergen at day 14, and were studied and sacrificed on day 17. Airway hyperreactivity was measured by peak airway pressure and airway pressure time index (APTI). Differential cell analysis and total proteins in bronchoalveolar lavage returns were used to assess airway inflammation and epithelial injury. RESULTS: Dose-related statistically significant increases in peak pressure, APTI, total cells, eosinophils, epithelial cells, but not total proteins, were induced by r Bla g 2 challenge in r Bla g 2-immunized mice. Similar allergen-induced dose-related increases in airway total cells, eosinophils, epithelial cells and total proteins were observed in r Der f 1 immunized mice. Compared to either allergen alone, enhanced airway inflammation and epithelial damage, but not airway reactivity, were detected in the combined group. CONCLUSION: This novel mouse model will allow investigation of the immunopathogenesis of human asthma and should provide insight into the common form of 'inner city asthma'.
Subject(s)
Antigens, Dermatophagoides/immunology , Aspartic Acid Endopeptidases/immunology , Asthma/immunology , Bronchial Hyperreactivity/immunology , Disease Models, Animal , Airway Resistance/immunology , Animals , Arthropod Proteins , Bronchoalveolar Lavage Fluid/cytology , Bronchoalveolar Lavage Fluid/immunology , Cell Count , Cockroaches/immunology , Cysteine Endopeptidases , Dose-Response Relationship, Immunologic , Histocytochemistry , Hypersensitivity, Immediate/immunology , Male , Mice , Mice, Inbred A , Mites/immunology , Recombinant Proteins/immunology , Urban PopulationABSTRACT
BACKGROUND: X-linked agammaglobulinemia (XLA) is a primary immunodeficiency characterized by failure of B-cell differentiation and hypogammaglobulinemia. In addition to being susceptible to bacterial infections, patients with XLA are also susceptible to enteroviruses. Systemic enterocytopathogenic human orphan virus (ECHO), coxsackie virus, and vaccine-related polio infections have caused severe morbidity and high mortality rates in XLA patients. OBJECTIVE: We report a 54-year-old male with molecularly defined XLA who survived wild poliomyelitis in childhood before the diagnosis of XLA. METHODS: At age 5, in 1951, the patient contracted wild polio, characterized by diarrhea and motor weakness. He subsequently developed recurrent sinusitis, bronchitis, and pneumonia, and at age 31 was found to be hypogammaglobulinemic and was started on immunoglobulin replacement. Laboratory evaluation at age 47 revealed an immunoglobulin G of 256 mg/dL, and B-cells (CD19) of 0.1%. Mutation analysis of Bruton's tyrosine kinase revealed a 26-basepair deletion between nucleotides 146 and 173 within the plextrin homology domain, resulting in a frameshift and premature termination. CONCLUSIONS: Resolution of wild poliovirus infection is possible in patients with XLA.
