Do shrimp-allergic individuals tolerate shrimp-derived glucosamine?

BACKGROUND: There is concern that shrimp-allergic individuals may react to glucosamine-containing products as shrimp shells are a major source of glucosamine used for human consumption. OBJECTIVE: The purpose of this study was to determine whether shrimp-allergic individuals can tolerate therapeutic doses of glucosamine. METHODS: Subjects with a history of shrimp allergy were recruited and tested for both shrimp reactivity via a prick skin test and shrimp-specific IgE by an ImmunoCAP assay. Fifteen subjects with positive skin tests to shrimp and an ImmunoCAP class level of two or greater were selected for a double-blind placebo-controlled food challenge (DBPCFC) using glucosamine-chondroitin tablets containing 1,500 mg of synthetically produced (control) or shrimp-derived glucosamine. Immediate reactions, including changes in peak flow and blood pressure, and delayed reactions (up to 24 h post-challenge) via questionnaire were noted and assessed. RESULTS: All subjects tolerated 1,500 mg of both shrimp-derived or synthetic glucosamine without incident of an immediate hypersensitivity response. Peak flows and blood pressures remained constant, and no subject had symptoms of a delayed reaction 24 h later. CONCLUSION: This study demonstrates that glucosamine supplements from specific manufacturers do not contain clinically relevant levels of shrimp allergen and therefore appear to pose no threat to shrimp-allergic individuals.

Persistent specific bronchial reactivity to occupational agents in workers with normal nonspecific bronchial reactivity.

Specific bronchial reactivity (SBR) to common inhalants is related to the degree of nonspecific bronchial reactivity (NSBR) and to specific allergen sensitivity. We investigated 16 workers with normal NSBR who had been previously diagnosed with occupational asthma caused by high-molecular-weight agents. The agents were flour in seven workers, psyllium in five, and guar gum in four. The subjects had been removed from exposure to these agents for a mean of 5.7 (+/- 4.0 SD) yr, no longer showed evidence of persisting asthma, and had a normal lung function. In the present study, the workers were reexposed to the sensitizing agent by specific inhalation challenges, in the same way they were as at the time of the diagnosis, to assess their current SBR to the sensitizer. SBR was estimated as the duration of exposure that induced a 20% decrease in FEV(1). Eleven of the 16 subjects had an asthmatic reaction at the time of the study; the duration of exposure necessary to induce the asthmatic reaction was the same as that needed at the time of diagnosis (3.55 +/- 0.5 min and 4.2 +/- 0.7 min, respectively, p = 0.8). The decrease in specific IgE levels between the two events was much greater in the subjects who failed to react to the second challenge test (from 24.2 +/- 37.5% to 3.0 +/- 16.9% binding) than in those who reacted on both occasions (from 31.2 +/- 27.0% to 21.6 +/- 36.7% binding); however, in both groups the change was significant (p = 0.05 and 0.04, respectively). We conclude that SBR to high-molecular-weight agents persists in most cases despite a normalization of NSBR, and that this persistence is associated with a persistence of specific immunization to the agent.

Quantification of the major brown shrimp allergen Pen a 1 (tropomyosin) by a monoclonal antibody-based sandwich ELISA.

BACKGROUND: Among 13 allergens found in extracts of cooked brown shrimp (Penaeus aztecus) the 36 kd muscle protein tropomyosin has been identified as the only major shrimp allergen (Pen a 1). Cross-reacting molecules with similar molecular weights were detected in other crustacea species such as crab, lobster, and crawfish. Because Pen a 1 and Pen a 1-like allergens are important in crustacea allergy, the aim of this study was to develop a monoclonal antibody (mAb)-based sandwich ELISA to quantify Pen a 1 and to evaluate Pen a 1 levels in four commercial shrimp, crab, and lobster extracts. METHODS: Two Pen a 1-specific mAbs with different epitope specificities were selected. ELISA plates coated with captured mAb 3.2 were incubated with samples containing Pen a 1. Bound Pen a 1 was detected by a combination of biotinylated mAb 4.9.5 and alkaline phosphatase-labeled streptavidin. RESULTS: The optimized sandwich ELISA could detect Pen a 1 concentrations ranging from 4 to 125 ng/ml. Four commercial shrimp extracts demonstrated a 40-fold difference in Pen a 1 levels (24 to 920 microg/ml). Crab and lobster extracts contained detectable levels of Pen a 1-like proteins. No reactivity to cockroach, house dust mite, oyster, codfish, or peanut extracts was detected, which indicates that the developed assay is crustacea-specific. CONCLUSION: A sensitive sandwich assay was developed to quantify Pen a 1. This assay will be helpful to standardize shrimp extracts in regard to the content of the major allergen, Pen a 1, and to study cross-reactivities among and evaluate occupational exposure to different crustacea species.

Reactivity of carrot-specific IgE antibodies with celery, apiaceous spices, and birch pollen.

Although carrot allergy is not well recognized in North America, the celery-carrot-mugwort-spice syndrome is well known in Europe. In the current study, cross reactivity of carrot, stalk celery, and spices, all members of the Apiaceae and birch pollen was assessed with serum from a patient reporting raw carrot-induced, raw stalk celery-induced, or spice-induced laryngeal edema and bronchospasm. By RAST inhibition, some cross-reactivity was demonstrated between raw carrot and stalk celery and other members of the Apiaceae. Immunoprint inhibition revealed common allergic epitopes on a 17-kD band shared by carrot, celery, and birch pollen. The results suggest that subjects sensitized to carrot may also have allergic reaction to other vegetables of spices of the Apiaceous family. Furthermore, carrot hypersensitivity can be associated with birch pollen allergy.

Effects of a GnRH agonist on fertility following administration to prepubertal male and female rats.

Leuprolide, a GnRH agonist, was administered daily to male and female rats for 90 days. Animals were sexually immature (25 days old) at the outset. Dosages were 20 and 200 micrograms/kg/day. Five males and five females were euthanized on Day 91. Sex organs were weighed and evaluated for histopathologic changes. These procedures were repeated 140 days later. Following a recovery period lasting 45 days (onset of normal-appearing estrous cycles) in females and 140 days (two spermatogenic cycles) in males, the fertility of these rats was assessed by mating with untreated animals. Treated males gained less weight while treated females gained more weight than controls. Weights of primary and secondary sex organs were reduced below control, but returned to normal following 140 days of recovery. Treated males were fertile and produced normal litters. Reproductive performance of low-dosage (20 micrograms/kg/day) females was normal 45 days after treatment cessation, but half of the high-dosage (200 micrograms/kg/day) females failed to become pregnant. However, reproductive performance of this group compared well with control performance after an additional 6 weeks of recovery. Atrophic changes were noted in male and female sex organs. Following 140 days of recovery, ovaries, uterus, vagina, prostate, and seminal vesicle were normal. Although testes and epididymides showed partial recovery at this time, multifocal or segmental atrophy and mineralization were noted in portions of some seminiferous tubules.

Common seasonal and environmental allergens.

House dust represents a complex mixture of individual, clinically important allergens that includes insects, danders, and pollens. Characterization and standardization of each of these allergens will provide significant advancement in our understanding and treatment of allergic respiratory disease.

Crawfish and lobster allergens: identification and structural similarities with other crustacea.

Antigenic and allergenic components in crawfish and lobster extracts were studied using crossed immunoelectrophoretic techniques. Crossed immunoelectrophoresis with rabbit antisera revealed 23 antigens in crawfish and 17 antigens in lobster extracts. Both extracts exhibited structural similarities in antigens mutually and with other crustacea in cross-line immunoelectrophoresis. Crossed radioimmunoelectrophoresis (CRIE) demonstrated 6 crawfish and 4 lobster allergens when individual or pooled sera from radioallergosorbent test (RAST)-positive crustacea-sensitive subjects were used. Since radiostaining was also observed with sera from RAST-negative nonsensitive subjects, specificity of IgE binding was tested using CRIE-inhibition. Preincubation of RAST-positive sera with crawfish or lobster extract decreased radiostaining in CRIE, while no changes occurred when using control sera. These results confirmed the presence of IgE-mediated mechanisms in seafood allergy and demonstrated a number of shared antigenic determinants among crustacea allergens.

Tobacco smoke "sensitivity"--is there an immunologic basis?

This study was undertaken to determine if there is an immunologic basis for reported tobacco-smoke hypersensitivity in man. Ninety-three individuals who were recruited on the basis of their smoking history and/or claimed sensitivity to tobacco smoke were skin prick tested with tobacco smoke and leaf extracts and their sera analyzed for reaginic and precipitating antibodies to these antigens. Results demonstrated that a significant number of the individuals who were tested had positive skin test and RAST responses to tobacco leaf antigens, whereas only a small number responded to smoke antigens. RAST or skin test responses of study subjects to leaf or smoke antigens did not correlate with symptoms of tobacco-smoke "sensitivity" or smoking history but did correlate with atopic status. Precipitins were detected only to tobacco leaf C in 46 of the 93 individuals who were tested but did not correlate with smoking history or smoke "sensitivity." These results suggest that subjective tobacco-smoke sensitivity is not caused by hypersensitivity to tobacco leaf or smoke antigens.

Lung function consequences of exposure and hypersensitivity in workers who process green coffee beans.

Three hundred seventy-two workers were examined at two coffee processing plants in New Orleans. Workplace dust concentrations were relatively low, and respiratory symptom prevalences were not different in various areas of the plants. After controlling for other variables, men with lengthy employment and exposure to dust of green (unroasted) coffee had lower mean residual FEV1 values (regression coefficient, -0.011 L/yr employed, p less than 0.05). Similarly, workers with serum IgE antibodies to green coffee beans had lower mean residual FEV1 (-0.244 L, p less than 0.05). Each effect remained significant after controlling for the other. In a subset that included all workers exposed to green coffee, acute changes in expiratory flow rates were not related to differences in exposure. The finding of adverse impacts of exposure and sensitization, in a work force relatively free of overt asthma, has important implications for worker health protection.

Analysis of green coffee bean and castor bean allergens using RAST inhibition.

Coffee workers with occupational allergic symptoms and positive skin tests to green coffee bean and factor dust antigens have elevated serum IgE antibodies (by radioallergosorbent test--RAST) to green coffee and castor bean allergens. These antibodies were used in a RAST inhibition assay to analyse coffee and castor allergens. Bean allergens were extracted by homogenization in PBS, centrifugation and concentration of supernates by ultrafiltration. Green coffee bean allergens, fractionated by gel filtration and Pevikon block electrophoresis, were shown to be very heterogeneous with a molecular weight range of 50 000 to 500 000 daltons. Castor allergens were more homogeneous with a molecular weight of 14 000 daltons and were partially purified by Pevikon block electrophoresis, gel filtration and isoelectrofocusing. Chemical analysis showed that protein was the major component in both allergen extracts. However, proteolytic enzymes could only partially destroy allergenic activity. Such isolation and characterization of these allergens should result in better methods of diagnosis and treatment of coffee workers with occupational allergic disease.

Castor bean allergens: evidence for distinct heat-labile and stable entities.

Castor beans contain one of the most potent allergens known to man. Previous studies suggested that these allergens are heat-stable; but our current data suggest that both heat-stable and labile allergens are present in castor bean extracts. The heat-labile allergen is of large molecular weight and is immunochemically distinct from the smaller molecular weight heat-stable allergen. Both allergens have different isoelectric points. These antigens may be clinically relevant since coffee workers sensitized to castor have IgE antibodies to both allergens.

Detection of castor allergens in castor wax.

The presence of castor bean allergens in castor wax products was determined by in vivo and in vitro analysis of castor wax extracts. Allergens were detected in one extract of castor wax by the PCA reaction in mice, the RAST inhibition reaction, and skin prick test in castor bean sensitive individuals. However, these allergens in the wax were of much lower potency than those in the bean, and were not detectable in a deodorant product utilizing castor wax.

Extraction and analysis of coffee bean allergens.

Workers in the coffee industry can develop occupational allergic disease upon exposure to dust associated with coffee manufacturing. Since controversy exists as to the source or chemical nature of these allergens, the mouse model of reaginic antibody production was used to assess the potential sources of allergens in samples obtained from a local coffee manufacturing plant. Mice were immunized with extracts of coffee dust and beans and the resulting reaginic antibody response determined by the passive cutaneous anaphylaxis reaction. Cross-reacting allergens were detected in samples of coffee dust, cleaner can debris and green coffee beans, but not in chaff or roasted coffee beans. None of the allergens detected in coffee samples cross-reacted with extract of castor beans, although these extracts contained the potent castor bean allergen. Green coffee bean allergens partially purified by gel filtration were heterogeneous with respect to molecular size, although quite similar in their reactivity with reaginic antiserum. These results suggest that the green coffee bean is the major source of allergen in coffee manufacturing plants. This allergen is heterogeneous with respect to size and heat lability, and is immunochemically different from the castor bean allergen.

Immunologic and biochemical properties of the histamine-sensitizing factor from Bordetella pertussis.

A highly potent extract of the histamine sensitizing factor (HSF) of Bordetella pertussis was isolated by extraction of bacterial cells with urea buffer and subsequent gel filtration. This preparation of HSF also contained leukocytosis-promoting activity and adjuvant activity for reaginic and hemagglutinating antibodiesl Digestion of this extract with pronase or trypsin partially destroyed histamine-sensitizing activity, leukocytosis-promoting activity, and adjuvant activity for reaginic antibody, but did not affect adjuvant activity for hemagglutinating antibody. Antisera to HSF was prepared by immunizing rabbits with either whole bacteria or partially purfied extract. These antisera contained several precipitating antibodies to Bordetella pertussis extract demonstrated by immunodiffusion and immunoelectrophoresis. Antisera added in vitro to Bordetella pertussis extracts or passively administered in vivo to mice, reduced or abolished all biologic activities except adjuvant activity for hemagglutinating antibody. These results suggest that HSF might be an antigenic component of Bordetella pertussis which also possesses leukocytosis-promoting activity and adjuvant activity for reaginic antibody.