Fish allergy: is cross-reactivity among fish species relevant? Double-blind placebo-controlled food challenge studies of fish allergic adults.

BACKGROUND: Allergic reactions to fish are a common cause of food allergy in many areas of the world where fish is a major source of protein. Although different species of fish may be consumed, possible cross-reactivity has received limited investigation. OBJECTIVE: The aim of this study was to assess potential cross-reactivity to different species of fish species using double-blind, placebo-controlled food challenges (DBPCFC) in fish-allergic adults and to compare skin test and RAST reactivity with the challenge response. METHODS: Nine skin prick test and/or RAST-positive adult individuals with histories of an immediate-type reaction following fish ingestion were challenged with different fish species using double-blind, placebo-controlled food challenge. RESULTS: Of a total of 19 double-blind, placebo-controlled fish challenges performed, 14 challenges (74%) resulted in the induction of objective signs that were consistent with an IgE-mediated response. The most common sign observed was emesis (37%); the most prevalent subjective symptoms reported were compatible with the oral allergy syndrome (84%). Three subjects reacted to at least three fish species and one subject reacted to two fish species tested. In regard to the positive challenges, predictive accuracy of skin prick test and RAST was 84% and 78%, respectively. CONCLUSION: Our results indicate that clinically relevant cross-reactivity among various species of fish may exist. Advising fish-allergic subjects to avoid all fish species should be emphasized until a species can be proven safe to eat by provocative challenge.

Detection of snow-crab antigens by air sampling of a snow-crab production plant.

BACKGROUND AND OBJECTIVE: We previously assessed the prevalence of occupational asthma (OA) to snow-crab in production plant workers. We also showed that this type of OA is related to immediate immunological reactivity as demonstrated by skin reactivity and increased specific IgE antibodies. However, we did not show that snow-crab antigens causing immunological reactivity and OA could be found in the air sampling in the plants atmosphere. This was the purpose of the current work. MATERIAL AND METHODS: Area air samples worn by workers at four different worksites of a snow-crab producing plant were obtained on PVC filters with an SKC pump run at 1.5 L/min for 2 h. Snow-crab was being boiled and processed during the air sampling periods. Filters were analysed by RAST inhibition in a blind manner (i.e. without knowledge of the worksite where the filter originated). RESULTS: Eluate from one of the four sites (#2) had the highest protein concentration and yielded the highest per cent inhibition of RAST--13% inhibition with the snow-crab meat, 23% and 28% inhibition with the snow crab water RAST in two separate assays. An eluate taken from a filter at another site (#1) showed borderline reactivity (1% and 10% inhibition in two assays) whereas the two other ones and a control filter were negative. The two filters that contained snow-crab proteins were the ones nearest the boiling process, site #2 being the nearest followed by site #1. It was estimated that a 28% inhibition corresponded to approximately 8.6 micrograms of proteins and to approximately 1.5 micrograms of allergens on the filter. CONCLUSION: This study suggests that airborne snow-crab-derived proteins, released during the boiling process, are the cause of immunological reactivity and of OA to snow-crab.

Immunopathogenesis of fish allergy: identification of fish-allergic adults by skin test and radioallergosorbent test.

BACKGROUND: As the consumption of fish increases in the United States, the importance of allergic reactions to fish has become clear. Since most previous studies on fish allergy have focused on children reacting mainly to codfish, there is a need to investigate allergic reactions to other fish in adults. OBJECTIVE: To identify fish-allergic adults, and to assess cross-reactivity among different species of fish by RAST inhibition. METHODS: Thirty-nine individuals who reported fish allergy were selected for study; 32 (82%) were atopic as defined by two or more positive skin tests to common inhalant allergens and a history of allergic reactions and 33 (85%) experienced allergic symptoms within 30 minutes after ingesting fish. The most frequently reported symptoms were hives (69%), itching (69%), and wheezing/chest tightness (54%). Study subjects were skin tested with fish extracts and their sera assayed for IgE antibodies to different fish species. RESULTS: Thirty-six (92%) of the subjects tested had a positive skin test to at least one of 17 fish extracts tested; 9/35 (26%) reacted to all 17 extracts. Of the atopic (two or more positive skin tests to common inhalant allergens plus a personal and/or family history of allergy) and nonatopic fish-tolerant controls, 20/26 (77%) reacted by skin test to one or more fish extracts tested; the most prevalent positive reaction was to anchovy (73%). A significant correlation (P < .01) was observed between skin test reactivity of fish-allergic subjects to most fish extracts and fish RAST reactions. Radioallergosorbent inhibition testing demonstrated significant cross-reactivity among pollack, salmon, trout, and tuna; and between mackerel and anchovy. CONCLUSION: These results suggest that fish-allergic subjects may be clinically sensitive to more than one species of fish. Skin test reactivity to fish by itself is not an adequate criterion for the confirmation of clinically relevant fish allergy; consequently, fish-allergic subjects with positive skin tests to several fish species should exercise caution when eating fish until tolerance can be demonstrated by double-blind, placebo-controlled food challenge, at the patient's earliest convenience.

Occupational IgE-mediated sensitization and asthma caused by clam and shrimp.

BACKGROUND: To confirm occupational asthma caused by clam and shrimp in a food company worker, the following investigation was planned in 60 other exposed workers (56 participants). METHODS: Before the production period of clam and shrimp, a medical and occupational questionnaire was carried out and skin and RAST testing were done with common inhalants and clam, shrimp, crab, and lobster extracts. During the production period, environmental monitoring was performed with personal and general samplers; inhalation testing with methacholine was proposed to subjects with immediate skin reactivity to clam, shrimp, or both. After the production period, all subjects with an immediate skin reactivity to clam, shrimp, or both and either a history of rhinoconjunctivitis, asthma, or bronchial hyperresponsiveness were seen by a specialist. RESULTS: Including the index case in whom occupational asthma to clam and shrimp had been confirmed, four (7%) subjects had a history of rhinoconjunctivitis and two (4%) had a history of asthma during the period of clam production, whereas three (5%) subjects had rhinoconjunctivitis and two (4%) had asthma during the shrimp production. Three (5%) subjects had immediate skin reactivity to clam, and nine (16%) subjects to shrimp. Four (7%) subjects had increased specific IgE antibodies (RAST binding > or = 3%) to clam and eight (14%) to shrimp. Significant associations were found between immunologic reactivity to clam and shrimp on the one hand and to crab and lobster on the other. Environmental monitoring demonstrated clam and shrimp on the air sampling filters. Occupational asthma caused by clam was confirmed by specific inhalation challenges in one subject in addition to the index case. These two subjects had skin reactivity and increased specific IgE antibodies to clam, shrimp, or both. CONCLUSION: By including the initial subject, the prevalence of immediate sensitization is 5% to 7% to clam and 14% to 16% to shrimp. Two (4%) subjects had occupational asthma caused by clam, and one (2%) had occupational asthma caused by shrimp.

Chronological assessment of asbestos exposure on cell composition in murine lung.

To elucidate immune pathogenic mechanisms in asbestosis, lung and spleen lymphoid cell populations were analyzed at defined time intervals (1, 2, 3, 6, and 12 weeks during exposure and 4, 24, and 48 weeks post-exposure) in asbestos-exposed and unexposed (control) mice. Polymorphonuclear leukocytes and macrophages were increased in the lung tissue histologic sections of asbestos-exposed mice compared to controls. No consistent changes were observed in percentages of lung or spleen helper, suppressor, or total lymphocyte populations after asbestos exposure. The numbers of B cells (identified by anti-IgG) in minced lung preparations of asbestos-exposed animals were increased after 12 weeks of exposure. There also was an increase in IgG production in asbestos-exposed mice after 12 weeks exposure and at 4 weeks post-exposure with a return to near baseline levels 24 and 48 weeks after initial exposure. Collectively, these studies demonstrate stimulatory effects of inhaled asbestos fibers on B cells and IgG production after 12 weeks of continuous inhalation of asbestos fibers in a dust generation chamber.

Characterization of water-soluble shrimp allergens released during boiling.

Water-soluble shrimp allergens released during boiling (shrimp water) were characterized and compared to allergen extracts from boiled shrimp (shrimp meat). Both shrimp extracts contained acidic proteins (isoelectrofocusing) and demonstrated similar allergenic activity (RAST and RAST inhibition). Shrimp-water extract was analyzed further by immunoprinting with sera from 14 shrimp-sensitive, RAST-positive subjects, and six nonsensitive, RAST-negative individuals. Although none of the sera from shrimp-tolerant individuals reacted, 12/14 sera (85.7%) from shrimp-sensitive subjects reacted with shrimp-water proteins with acid isoelectric points. Shrimp-water extract was fractionated by chromatofocusing with pH and NaCl gradients. A number of eluted ultraviolet-absorbing peaks contained allergens as determined by RAST inhibition. Isoelectrofocusing demonstrated many protein bands present in these peaks, some of which bound IgE from a RAST-positive sera pool. These studies indicate that shrimp water is an excellent source of shrimp allergens, that chromatofocusing is a useful method for fractionation of shrimp allergens, and that shrimp allergens are generally protein molecules with acid isoelectric points.

Food specific skin-test reactivity in atopic subjects.

It has been proposed that a permanent or transitory increase in gut permeability is an important facet in the development of food allergy. If this occurs, then individuals with a history of a specific food allergy should have a higher incidence of immunological reactivity to other food allergens as compared to food tolerant subjects. To test this hypothesis, we evaluated the prevalence of food-specific IgE responses by skin-prick testing in 60 individuals. Subjects were classified by a history of food allergy (shrimp hypersensitivity) and atopic status. Prevalence of skin-prick test reactivity to shrimp and a panel of nine other food extracts was determined. Skin-test reactivity to shrimp was related both a history of shrimp sensitivity and atopic status. However, the prevalence of skin-test reactivity to other foods was not related to clinical history of shrimp allergy, although it was related to atopy. A subset of subjects with shrimp allergy had multiple positive skin reactions to many of the nine other foods. This reactivity was associated with a history of pulmonary symptoms following shrimp ingestion. In general our results do not support non-specific increases in gut permeability being important in the development of food allergy.

Patterns of improvement in spirometry, bronchial hyperresponsiveness, and specific IgE antibody levels after cessation of exposure in occupational asthma caused by snow-crab processing.

Thirty-one workers with occupational asthma caused by snow-crab processing were assessed by a long-term follow-up on three occasions at mean +/- SD intervals of 12.8 +/- 5.4, 31.4 +/- 6.3, and 64.4 +/- 6.3 months after leaving work. The diagnosis of work-related asthma was initially confirmed in all of them by specific inhalation challenges at the workplace or by laboratory inhalation of snow-crab boiling water (n = 24) or by serial monitoring of airway caliber and bronchial responsiveness to histamine at work and off work (n = 7). Total duration of work-related exposure was 12.8 +/- 5.6 months (range, 3 to 21 months), and the duration of symptoms after onset was 6.8 +/- 4.2 months (range, 1 to 18 months). At the time of diagnosis, all 31 subjects required medication for asthma, 11 had a FEV1 less than or equal to 85% predicted, and all subjects had a PC20 less than or equal to 16 mg/ml. Twelve of 25 serum samples assessed showed high levels of specific immunoglobulin E (IgE) antibodies to crab meat and/or boiling water. At the time of the first follow-up, there was a reduction in the number of subjects still requiring medication, with a significant reduction in FEV1, and a PC20 less than or equal to 16 mg/ml. However, no further change was observed afterwards. Similarly, the mean FEV1 and FEV1/FVC improved significantly from the time of diagnosis to the first follow-up (p less than 0.01), with a plateau thereafter.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunologic evaluation of shrimp-allergic individuals.

Thirty-three individuals with a history of immediate hypersensitivity reactions after shrimp ingestion and 29 nonshrimp-sensitive control subjects were evaluated for evidence of crustacea-specific immunity by skin prick test titration end point, RAST, and ELISA, with extracts of shrimp, crab, crayfish, and lobster. Individuals were categorized as either atopic or nonatopic on the basis of history and skin test reactivity to common inhalant allergens. Most (28/33) shrimp-sensitive subjects had positive skin prick tests to shrimp extract, whereas skin tests were negative in 27/29 control subjects. Eighty-one percent of atopic and 41% of nonatopic shrimp-sensitive subjects had elevated shrimp-RAST ratios. The RAST ratios of atopic individuals were significantly higher than ratios of nonatopic individuals, and there was a significant correlation between shrimp-RAST ratios and historical clinical symptom scores. RAST determinations of all control subjects were negative. Shrimp-sensitive subjects also had significantly elevated serum levels of shrimp-specific IgG and IgA as compared to control individuals. Both IgG and IgA shrimp-specific reactivity demonstrated a significant positive correlation with shrimp-RAST ratios. These studies indicate that IgE-mediated, type I mechanisms, detected by positive shrimp skin tests and RASTs, appear to be operative in crustacea-sensitive individuals, particularly those with concurrent respiratory allergy. Although the role of shrimp-specific IgG and IgA antibodies in the immunopathogenesis of crustacea allergy remains unclear, such antibodies appear to represent increased immunologic recognition of shrimp allergens/antigens in shrimp-sensitive subjects.

Reactivity of IgE antibodies with crustacea and oyster allergens: evidence for common antigenic structures.

IgE-antibody reactivity to oysters and crustacea of sera from six oyster-sensitive, seven oyster- and crustacea-sensitive, and 12 crustacea-sensitive subjects was investigated. All six subjects with a history of only oyster sensitivity had minimal RAST reactivity (ratios 2 to 5) to extracts of raw or boiled oysters. Three of the seven oyster- and crustacea-sensitive subjects and six of the 12 crustacea-sensitive, oyster-tolerant or unexposed subjects had elevated RAST ratios to oyster (14 to 41). Generally, elevated oyster RAST correlated with skin prick test reactivity to oyster but not with total serum IgE levels. The oyster RAST values of the 19 crustacea-sensitive subjects (with or without oyster sensitivity) correlated with crustacea RAST reactivity (crab RAST, most significant; shrimp RAST, least significant). Rabbit antisera to crustacea extracts detected precipitating antigens present in extracts of raw or boiled oysters. Significant inhibition of the oyster RAST was obtained with oyster or crustacea extracts. These studies suggest that in the diagnosis of oyster sensitivity the RAST may not be useful and that oyster and crustacea contain common antigenic structures.

Anaphylaxis to cabbage: detection of allergens.

Allergy to cabbage and other foods in the Brassica family has rarely been observed in man. We report a case of facial and throat swelling in an atopic female after she ingested coleslaw on two separate occasions. She had 4+ reactions to cabbage, mustard plant, cauliflower, and broccoli by skin testing. A RAST using cabbage extract was positive for specific IgE antibody. Analysis of cabbage extract by gel filtration showed five peaks of ultraviolet-absorbing material at 280 nm. Allergenic activity was demonstrated by RAST inhibition in two fractions of the cabbage extract. This report confirms IgE sensitivity can occur to foods in the Brassica family.

IgE sensitization in snow crab-processing workers.

Occupational asthma is a highly prevalent disease among snow crab-processing workers, but its immunologic mechanism has not been identified. Prick skin tests with snow crab-meat extract, commercial extracts from other crab genera, and snow crab cooking water collected in 1984 were performed on 119 workers. Crab-specific IgE was assessed by RAST in sera from 115 workers with meat and water extracts. Both skin and RAST tests were performed in 58 individuals. Diagnosis of occupational asthma had previously been confirmed in 54 individuals. A highly significant relationship was demonstrated between the presence of immediate skin reactivity or increased serum levels of specific IgE to crab extracts and the occurrence of occupational asthma. There was good agreement between the results of skin and RAST tests with extracts of either meat or snow crab cooking water. Cooking water and snow crab-meat extracts were more sensitive than commercial preparations. Water extract was more potent and more sensitive than meat extract. We conclude that there is evidence that occupational asthma in snow crab-processing workers is mediated through an IgE mechanism.

Fusarium solani: prevalence of skin reactivity and antigenic allergenic analysis.

The prevalence of Fusarium solani reactivity in atopic individuals with symptoms of mold allergy was assessed with skin test and RAST. In addition, F. solani preparations were evaluated for antigenic/allergenic activity. Atopic individuals tested, 24.5% (n = 69), had positive skin reactions to a phosphate-buffered saline extract of F. solani, and these responses were statistically correlated with RAST results. Immunoelectrophoretic techniques demonstrated that this extract was antigenic in rabbits and allergenic in man. Gel filtration of F. solani extract on a Bio-Gel A 0.5 m column demonstrated three peaks of ultraviolet-absorbing material. The column eluate with the greatest RAST inhibition activity was associated with a protein peak having a molecular weight greater than 341 kilodaltons; however, all peaks demonstrated inhibitory activity. These studies suggest that extracts of F. solani contain several allergens that differ in molecular weight and charge.

Hypersensitivity reactions to ingested crustacea: clinical evaluation and diagnostic studies in shrimp-sensitive individuals.

Adverse reactions to ingested crustacea are common and may be life-threatening. We studied 14 individuals with histories of such reactions to shrimp by immediate skin tests and RAST with extracts of shrimp, crab, crayfish, and lobster. Nine of these subjects (8/8 atopics and 1/6 nonatopics) had positive immediate skin tests (wheal greater than or equal to 2 mm) and RAST (ratios greater than 3.0) to shrimp. Their skin tests and RAST ratios to the other crustacea were also frequently positive even, in several cases, in the absence of prior exposure. In contrast, only 1/10 volunteers with no history of intolerance to crustacea had a weak positive skin test to raw shrimp. These studies suggest that both skin tests and RAST are useful in the confirmation of hypersensitivity to shrimp in atopic individuals and that cross-reactivity among crustacea may exist.

Analysis of tobacco leaf allergens by crossed radioimmunoelectrophoresis.

The reactivity of eleven 'tobacco smoke sensitive' and eight 'non-sensitive' individuals to tobacco leaf allergens was tested by Crossed Radioimmunoelectrophoresis (CRIE). All nineteen study subjects had IgE antibodies to tobacco leaf antigens as measured by Radioallergosorbent Test (RAST) and seventeen of the nineteen individuals were atopic. Of the thirty-seven tobacco leaf precipitins detected by Cross Immunoelectrophoresis (CIE), three were identified as allergens by CRIE. All nineteen subjects reacted to at least one of the three allergens detected. However, neither the intensity nor the incidence of reactivity with any of the three allergens correlated with smoking or 'smoke sensitivity'.

Effects of anti-epsilon on total and specific IgE levels in adult mice.

Adult (2- to 3-month-old) female CBA/J mice were injected intraperitoneally with heavy chain specific rabbit anti-IgE (anti-epsilon) to determine its effects on total and specific serum IgE. Animals receiving 10 X 250 micrograms injections over a 50-day period displayed significantly increased (10 X levels of serum IgE compared to rabbit gamma-globulin or untreated controls. If animals were immunized with castor allergen (CA) prior to anti-epsilon treatments their IgE anti-CA titers were significantly suppressed, although their total IgE levels were not significantly different compared to controls. In a second series of experiments, mice which received increased quantities (3 X more) of anti-epsilon had no detectable serum IgE (within 30 days post anti-epsilon treatment), significantly decreased titers of IgE antibody, and reduced numbers of IgE bearing spleen and mesenteric lymph node cells. These studies indicate that anti-epsilon injections in adult mice can significantly alter total and specific IgE levels.

Basidiomycete allergy: what is the best source of antigen?

Skin prick test activity and antigenicity of extracts of in vitro growth of the Basidiomycete Pleurotus ostreatus (PO) were compared to extracts of spores from PO growing in the wild. Patients demonstrated significant differences in skin test reactivity to the PO extracts. Some reacted only to in vitro growth extracts, others only to the spore extracts and 1 patient to all extracts. Further studies analyzed antigens present in all extracts with rabbit antisera to PO. Common as well as unique antigens were present in the spore extracts as compared to those from in vitro preparations. The fact that spores contain unique antigens suggests that basidiospores may be the best source of relevant allergens for clinical studies.

Identification of crustacea allergens by crossed radioimmunoelectrophoresis.

Crossed immunoelectrophoresis (CIE) detected 18 precipitating antigens in extracts of shrimp. Of these antigens, crossed-line immunoelectrophoresis (CLIE) of shrimp extract demonstrated that 5 cross-reacted with crayfish, 3 with lobster and 1 with crab extract. Allergens present in the shrimp CIE plates were identified by crossed radioimmunoelectrophoresis (CRIE) using sera from 6 study subjects who were skin-test and RAST positive to shrimp extract. Of the 7 allergens detected, 3 (precipitins 1, 3 and 6) reacted with most of the 6 sera tested from shrimp-sensitive subjects. Precipitins 1 and 6 appear to be common crustacea allergens (present in shrimp, crayfish, lobster and crab) whereas precipitin 3 may be a specific allergen since it is present only in shrimp.