M.L. McCants

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.

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.

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.

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.

Mesenchymal Lineage Stem Cells Have Pronounced Anti‐Inflammatory Effects in the Twitcher Mouse Model of Krabbe's Disease

The twitcher mouse is an animal model of Krabbes disease (KD), which is a neurodegenerative lysosomal storage disorder resulting from the absence of functional lysosomal enzyme galactocerebrosidase (GALC). This disease affects the central and peripheral nervous systems and in its most severe form results in death before the age of 2 in humans and approximately 30–40 days in mice. This study evaluates the effect of intracerebroventricular administration of mesenchymal stem cells derived from adipose tissue (ASCs) and bone marrow (BMSCs) on the pathology of KD. Subsequent to the intracerebroventricular injection of ASCs or BMSCs on postnatal day (PND) 3–4, body weight, lifespan, and neuromotor function were evaluated longitudinally beginning on PND15. At sacrifice, tissues were harvested for analysis of GALC activity, presence of myelin, infiltration of macrophages, microglial activation, inflammatory markers, and cellular persistence. Survival analysis curves indicate a statistically significant increase in lifespan in stem cell‐treated twitcher mice as compared with control twitcher mice. Body weight and motor function were also improved compared with controls. The stem cells may mediate some of these benefits through an anti‐inflammatory mechanism because the expression of numerous proinflammatory markers was downregulated at both transcriptional and translational levels. A marked decrease in the levels of macrophage infiltration and microglial activation was also noted. These data indicate that mesenchymal lineage stem cells are potent inhibitors of inflammation associated with KD progression and offer potential benefits as a component of a combination approach for in vivo treatment by reducing the levels of inflammation. STEM CELLS 2011;29:67–77

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.

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 patients earliest convenience.

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.

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.

Occupational asthma caused by roasted coffee: Immunologic evidence that roasted coffee contains the same antigens as green coffee, but at a lower concentration

controlled studies, in which the numbers of patients with a positive history ranged from 24 to 37. Although reactions occurred to both non-[3-1actam antimicrobials and nonantimicrobial drugs, the frequency of these reactions was not greater in group A or B, compared with group C, which suggests that the existence of a history of penicillin allergy causing a change in prescribing habits was not a factor and that there was no significant difference in reporting patterns. Only one patient in the vasomotor rhinitis group gave a history of penicillin allergy, and this patient had no history of a reaction to non-[3-1actam drugs. Because patients with a history of penicillin allergy in this study have an incidence of reactions to non[3-1actam drugs that is equal to that found in the vasomotor rhinitis group, they do have multiple drug reactions, because they reacted to both [3-1actarn and non-[~-lactam drugs. But the risk of reacting to non-[3-1actams is not increased in either patients with a positive history of penicillin allergy or those with skin test-proven penicillin allergy, when compared with the control rhinitis group. So although this survey is also subject to the deficiencies of retrospective evaluation and limited by the preponderance of female subjects and sample size, it does suggest, in contrast to previous studies, that the development of penicillin allergy and non-[3-1actam allergy are not associated, but occur independently.