Shrimp Sensitization Research Articles

Antennular Morphology and Contribution of Aesthetascs in the Detection of Food-related Compounds in the Shrimp Palaemon adspersus Rathke, 1837 (Decapoda: Palaemonidae).

Shrimp are an essential ecological component of marine ecosystems, and have commercial importance for human consumption and aquaculture. Like other decapod crustaceans, shrimp rely on chemical senses to detect and localize food resources by means of chemosensilla that are located mainly on the cephalothoracic appendages. Using the shrimp Palaemon adspersus, a model organism with omnivorous feeding behavior, we aimed to provide comparative information on the role of aesthetascs, antennular sensilla, and flicking behavior in food detection. To this end, we examined i) the morphology of antennular sensilla by field emission scanning electron microscopy, ii) the shrimp's sensitivity to a number of food-related compounds (amino acids and sugars) by means of whole-animal bioassays, and iii) the contribution of the aesthetasc sensilla to food detection. Our results showed that, aside from the aesthetascs, only three other main morphotypes of setae with chemoreceptive features were present in the antennules, thus accounting for relatively simple sensillar equipment. Nevertheless, we found broad-spectrum sensitivity of the shrimp to a number of amino acids (i.e., isoleucine, leucine, methionine, phenylalanine, glycine, tryptophan, cysteine, and tyrosine) and carbohydrates (trehalose, maltose, cellobiose, and fructose) that was consistent with the omnivorous or scavenging habits of the animal. Although aesthetasc ablation attenuated flicking behavior in a chemical stimulus-independent manner, success in detection and short-range localization of food did not rely on the presence of aesthetasc sensilla. This finding confirms the existence of a non-aesthetasc alternative pathway for feeding, with functional redundancy in simple generalist feeder models such as shrimp.

Tumor necrosis factor receptor-associated factor 6 (TRAF6) participates in peroxinectin gene expression in Fenneropenaeus penicillatus

Tumor necrosis factor receptor-associated factor 6 (TRAF6) is an important cytoplasm signal adaptor that mediates signals activated by tumor necrosis factor receptor (TNFR) superfamily and the Interleukin-1 receptor/Toll-like receptor (IL-1/TLR) superfamily. In the study, the full-length cDNA of a TRAF6 homolog (FpTRAF6) was identified from Fenneropenaeus penicillatus. The full-length cDNA of FpTRAF6 is 2033 bp long, with an open reading frame (ORF) encoding a putative protein of 594 amino acids, including a RING type Zinc finger, two TRAF-type Zinc fingers, and a conserved C-terminal meprin and TRAF homology (MATH) domain. The overall amino acid sequence identity between FpTRAF6 and other TRAF6s ranged from 62.7 to 94.1% for crustaceans and from 45.6 to 59.3% for mollusca. Real-time qRT-PCR indicated that FpTRAF6 was constitutively expressed in various tissues of F. penicillatus. The temporal expression patterns of FpTRAF6 mRNA were different in the different tissues after microbial challenge. FpTRAF6 was downregulated in the heart, no obvious changes in the gill, intestine and hemocytes, and upregulated in other tested tissues after WSSV challenge. After V. alginolyticus injection, FpTRAF6 was downregulated in the heart and intestine, upregulated in the gill, lymphoid organ and hematopoietic organ, and no obvious changes in other tested tissues. RNAi assay was carried out to investigate the function of FpTRAF6. The results showed that silencing FpTRAF6 gene could inhibit peroxinectin expression in vivo, and enhance the sensitivity of shrimps to WSSV and V. alginolyticus challenge, suggesting FpTRAF6 could play a positive role against bacterial and viral pathogens. In conclusion, the results of the study provide some insights into the function of FpTRAF6 in activating TLRs signaling pathway and the host defense against invading pathogens.

Characterization and function analysis of interleukin-1 receptor-associated kinase-1 (IRAK-1) from Fenneropenaeus penicillatus

The interleukin-1 receptor-associated kinase-1 (IRAK-1) is an important adapter protein which links downstream of MyD88, and involved in the complex composed of MyD88 and TRAF6 to activate TLRs signaling pathway. In this study, an IRAK-1 homolog (FpIRAK-1) was cloned from the red tail shrimp Fenneropenaeus penicillatus. The ORF of FpIRAK-1 consisted of 2874 bp encoding a protein of 957 amino acids which contains a death domain (DD) and a catalytic domain of serine/threonine kinases (STKc). Homology analysis revealed that the predicted amino acid sequence of FpIRAK-1 shared 71% similarities with IRAK-1 of Litopenaeus vannamei. Real-time RT-PCR indicated that FpIRAK-1 was constitutively expressed in various tissues of F. penicillatus. The expression level of FpIRAK-1 mRNA was significantly up-regulated and then decreased gradually after white spot syndrome virus (WSSV) and Vibrio alginolyticus challenge. Gene knockdown of FpIRAK-1 enhanced the sensitivity of shrimps to WSSV and V. alginolyticus challenge, suggesting FpIRAK-1 could play a positive role against bacterial and viral pathogens. In conclusion, the results of this study provide some insights into the function of FpIRAK-1 in activating Toll signaling pathway and the host defense against invading pathogens.

Changes in Food-Specific IgE Over Time in the National Health and Nutrition Examination Survey (NHANES)

Food allergy prevalence appears to have recently risen, with larger increases among non-Hispanic blacks. However, it is unclear whether these trends represent shifts in recognition of food allergy or in sensitization. The objective of this study was to determine whether sensitization to common food allergens increased in US children from 1988-1994 to 2005-2006 and whether these trends differed by race and/or ethnicity. Food-specific immunoglobulin E (IgE; to peanut, milk, egg, and shrimp) was measured by ImmunoCAP in stored sera from subjects aged 6-19 in the National Health and Nutrition Examination Survey (NHANES) III (1988-1994) and was compared with NHANES 2005-2006. Sensitization to foods was defined as overall (IgE ≥ 0.35 kU/L), moderate level (IgE ≥ 2 kU/L), and high level (IgE ≥ commonly used 95% predictive values). Sensitization to individual and combined foods was compared between surveys, with analyses further stratified by race and/or ethnicity. A total of 7896 subjects (NHANES III: n= 4995, NHANES 2005-2006: n= 2901) were included. In NHANES III, the prevalence of food sensitization was 24.3% (95% confidence interval [CI]: 22.1-26.5) compared with 21.6% (95% CI: 19.5-23.7) in NHANES 2005-2006. There were no significant changes in the prevalence of any level of milk, egg, or peanut sensitization, but shrimp sensitization at all levels decreased markedly; overall sensitization NHANES III: 11.2% (95% CI: 10.0-12.5) versus NHANES 2005-2006: 6.1% (95% CI: 4.5-7.7). There was a trend toward the increased prevalence of moderate- and high-level sensitization to the combination of milk, egg, and peanut among non-Hispanic blacks but not other groups. In contrast to our expectations, sensitization to common food allergens did not increase between the late 1980s/early 1990s and the mid-2000s among US 6-19 year olds, and in fact decreased to shrimp.

Cloning, identification and functional analysis of a β-catenin homologue from Pacific white shrimp, Litopenaeus vannamei.

Wnt signaling is known to control multiple of cellular processes such as cell differentiation, communication, apoptosis and proliferation, and is also reported to play a role during microbial infection. β-catenin is a key regulator of the Wnt signaling cascade. In the present study, we cloned and identified a β-catenin homologue from Litopenaeus vannamei termed Lvβ-catenin. The full-length of Lvβ-catenin transcript was 2797bp in length within a 2451bp open reading frame (ORF) that encoded a protein of 816 amino acids. Lvβ-catenin protein was comprised of several characteristic domains such as an N-terminal region of GSK-β consensus phosphorylation site and Coed coil section, a central region of 12 continuous Armadillo/β-Catenin-like repeat (ARM) domains and a C-terminal region. Real-time PCR showed Lvβ-catenin expression was responsive to Vibrio parahaemolyticus and white spot syndrome virus (WSSV) infection. Dual-reporter analysis showed that over-expression of Lvβ-catenin could induce activation of the promoter activities of several antimicrobial peptides (AMPs) such as shrimp PEN4, suggesting that Lvβ-catenin could play a role in regulating the production of AMPs. Knockdown of Lvβ-catenin enhanced the sensitivity of shrimps to V.parahaemolyticus and WSSV challenge, suggesting Lvβ-catenin could play a positive role against bacterial and viral pathogens. In summary, the results presented in this study provided some insights into the function of Wnt/β-catenin of shrimp in regulating AMPs and the host defense against invading pathogens.

Identification and characterization of MKK7 as an upstream activator of JNK in Litopenaeus vannamei.

Mitogen-activated protein kinase kinase 7 (MKK7) is a key signal transduction regulator in c-Jun N-terminal kinase (JNK) signaling pathway, which is involved in a wide range of physiological and pathological processes. In this study, we described the molecular cloning of a new member of MKK7 group from Litopenaeus vannamei named as LvMKK7. The full-length cDNA of LvMKK7 was 3093bp in length, with an open reading frame (ORF) of 1440bp encoding a putative protein of 479 amino acids. LvMKK7 contained a conserved kinase domain of 261 amino acids in which there was a characteristic S-K-A-K-T motif as a potential target site of phosphorylation by MKKK. Moreover, subcellular localization showed LvMKK7 was located in both the cytoplasm and the nucleus of Drosophila S2 cells. Real-time PCR indicated that LvMKK7 was universally expressed in all tested tissues and its expression in hepatopancreas was responsive to the challenge of LPS, Poly (I:C), Vibrio parahaemolyticus, Staphhylococcus aureus and white spot syndrome virus (WSSV). In addition, co-immunoprecipitation assay demonstrated that LvJNK was phosphorylated and activated by LvMKK7, which suggested LvMKK7 was the upper regulator of LvJNK. Furthermore, RNAi-mediated knockdown of LvMKK7 enhanced the sensitivity of shrimps to V.parahaemolyticus infection. Overall, our results suggested that LvMKK7 may play important roles in the shrimp innate immunity.

Shellfish and House Dust Mite Allergies: Is the Link Tropomyosin?

Crustacean shellfish allergy is an important cause of food allergy and anaphylaxis in Asia. The major allergen in shellfish allergy is tropomyosin, a pan-allergen that is also found in house dust mites and cockroaches. Tropomyosins from house dust mites (HDMs) have a high sequence homology to shellfish tropomyosins, and cross-reactivity between HDM and shrimp tropomyosins has been demonstrated. Exposure to inhaled tropomyosins from house dust mites has been postulated to be the primary sensitizer for shellfish allergy, in a reaction analogous to the oral allergy (inhalant-food) syndrome. This notion is supported by indirect data from the effects of HDM immunotherapy on shellfish allergy, and strong correlations of shellfish and HDM sensitization. HDM immunotherapy has been reported to induce both shrimp allergy in non-allergic patients and shrimp tolerance in shrimp-allergic patients. Epidemiological surveys have also demonstrated a strong correlation between shellfish and HDM sensitization in both hospital-based and community-based studies. Unexposed populations have also been shown to develop sensitization-shellfish sensitization in orthodox Jews with no history of shellfish consumption was associated with HDM sensitization. Reciprocally, HDM sensitization in an Icelandic population living in a HDM-free environment was associated with shrimp sensitization. In vitro IgE inhibition studies on sera in shrimp-allergic Spanish patients indicate that mites are the primary sensitizer in shrimp-allergic patients living in humid and warm climates. Current data supports the hypothesis that tropomyosin is the link between HDM and shellfish allergies. The role of tropomyosin in HDM and shellfish allergies is a fertile field for investigation as it may provide novel immunotherapeutic strategies for shellfish allergy.

Molecular Diagnosis of Shrimp Allergy: Efficiency of Several Allergens to Predict Clinical Reactivity

The diagnosis of shellfish allergy remains a challenge for clinicians. Several shellfish allergens have been characterized and their IgE epitopes identified. However, the clinical relevance of this sensitization is still not clear. The objective of this study was to identify allergens and epitopes associated with clinical reactivity to shrimp. Shrimp-sensitized subjects were recruited and grouped based on the history of shrimp-allergic reactions and challenge outcome. IgE reactivity to recombinant crustacean allergens, and IgE and IgG4 reactivity to peptides were determined. Subjects sensitized to dust mites and/or cockroach without shrimp sensitization or reported allergic reactions, as well as nonatopic individuals, were used as controls. A total of 86 subjects were recruited with a skin prick test to shrimp; 74 reported shrimp-allergic reactions, 58 were allergic (38 positive double-blind placebo-controlled food challenge and 20 recent anaphylaxis), and 16 were tolerant. All subjects without a history of reactions had negative challenges. The individuals with a positive challenge more frequently recognized tropomyosin and sarcoplasmic calcium-binding proteins than those found tolerant by the challenge. Especially a sarcoplasmic-calcium-binding-protein positive test is very likely to result in a positive challenge, though the frequency of recognition is low. Subjects with dust mite and/or cockroach allergy not sensitized to shrimp recognized arginine kinase and hemocyanin. Several epitopes of these allergens may be important in predicting clinical reactivity. Tropomyosin and sarcoplasmic-calcium-binding-protein sensitization is associated with clinical reactivity to shrimp. Myosin light chain testing may help in the diagnosis of clinical reactivity. Arginine kinase and hemocyanin appear to be cross-reacting allergens between shrimp and arthropods. Detection of IgE to these allergens and some of their epitopes may be better diagnostic tools in the routine workup of shrimp allergy.

The role of native salinity regime on grass shrimp (Palaemonetes pugio) sensitivity to cadmium

In euryhaline crustaceans, sensitivity to toxic trace metals may be linked to osmoregulation and salinity conditions. This study investigated if grass shrimp (Palaemonetes pugio) populations from different salinity regimes differed in sensitivity to cadmium (Cd). Grass shrimp were collected in May 2011 from two marsh sites with average salinities of ~3.0 ppt and 24.0 ppt. Groups were acclimated for 3-32 weeks in either their respective native salinity (3.0 ppt → 3.0 ppt and 24.0 ppt → 24.0 ppt), or the average of the salinities of the two collection sites (3.0 ppt → 13.5 ppt and 24.0 ppt → 13.5 ppt). After acclimation, groups were exposed to equivalent free-ion Cd concentration (4.8 ± 0.3 mg/L, Cd(2+)) in their respective acclimated salinity to compare survival among salinity treatments. Results of Kaplan-Meier survival analysis indicated that 3.0 ppt → 3.0 ppt shrimp were more sensitive to Cd(2+) than any other group (p < 0.0001). Additionally, 3.0 ppt → 13.5 ppt shrimp were less sensitive to Cd(2+) than were 24.0 ppt → 13.5 ppt shrimp (p = 0.0013). These results suggest that sensitivity of grass shrimp to Cd is dependent upon the salinity during exposure, and the salinity regime from which the tested population originated. The implication is that toxicity studies and risk assessments using euryhaline crustaceans should consider the salinity of test population collection sites when interpreting and comparing results.

Greater epitope recognition of shrimp allergens by children than by adults suggests that shrimp sensitization decreases with age

Shellfish allergy is a long-lasting disorder typically affecting adults. Despite its high prevalence, there is limited information about allergenic shrimp proteins and the epitopes implicated in such allergic reactions. We sought to identify the IgE-binding epitopes of the 4 shrimp allergens and to characterize epitope recognition profiles of children and adults with shrimp allergy. Fifty-three subjects, 34 children and 19 adults, were selected with immediate allergic reactions to shrimp, increased shrimp-specific serum IgE levels, and positive immunoblot binding to shrimp. Study subjects and 7 nonatopic control subjects were tested by means of peptide microarray for IgE binding with synthetic overlapping peptides spanning the sequences of Litopenaeus vannamei shrimp tropomyosin, arginine kinase (AK), myosin light chain (MLC), and sarcoplasmic calcium-binding protein (SCP). The Wilcoxon test was used to determine significant differences in z scores between patients and control subjects. The median shrimp IgE level was 4-fold higher in children than in adults (47 vs 12.5 kU(A)/L). The frequency of allergen recognition was higher in children (tropomyosin, 81% [94% for children and 61% for adults]; MLC, 57% [70% for children and 31% for adults]; AK, 51% [67% for children and 21% for adults]; and SCP, 45% [59% for children and 21% for adults]), whereas control subjects showed negligible binding. Seven IgE-binding regions were identified in tropomyosin by means of peptide microarray, confirming previously identified shrimp epitopes. In addition, 3 new epitopes were identified in tropomyosin (epitopes 1, 3, and 5b-c), 5 epitopes were identified in MLC, 3 epitopes were identified in SCP, and 7 epitopes were identified in AK. Interestingly, frequency of individual epitope recognition, as well as intensity of IgE binding, was significantly greater in children than in adults for all 4 proteins. Children with shrimp allergy have greater shrimp-specific IgE antibody levels and show more intense binding to shrimp peptides and greater epitope diversity than adults.

Specific allergy to Penaeus monodon (seawater shrimp) or Macrobrachium rosenbergii (freshwater shrimp) in shrimp‐allergic children

Allergy to specific shrimp species has not been studied systematically by oral challenges. A comparison of allergy to different shrimp species, especially seawater or freshwater varieties treatment, would be useful in testing shrimp-allergic subjects. The aim of the study was to identify cases of specific allergy to seawater shrimp, Penaeus monodon (Pm), or freshwater shrimp, Macrobrachium rosenbergii (Mr), among shrimp-allergic children. Comparisons of skin tests using commercial and crude shrimp extracts plus the prick-to-prick (PTP) method were investigated. Sixty-eight children with a history of shrimp allergy and skin tests positive to shrimp were orally challenged to both shrimp species. Reactivity to skin prick tests using extracts of Pm (PmSPT), Mr (MrSPT), commercial shrimp (ComSPT), and PTP tests (PmPTP, MrPTP) was compared. Food challenges identified specific allergy to Pm and Mr in 17.65% and 23.53% of the subjects, respectively. Positive and negative challenges to both shrimp species were found in 47.06% and 11.76% of the subjects, respectively. Correlations between the mean weal diameter (MWD) from ComSPT-PmSPT, ComSPT-PmPTP, ComSPT-MrPTP, PmSPT-PmPTP and MrSPT-MrPTP, but not ComSPT-MrSPT, were observed. The MWD from PmSPT and PmPTP were significantly larger in patients with positive than negative challenges to P. monodon (P<0.05). There was a trend that MWD from MrSPT were larger in patients with positive than negative challenges to M. rosenbergii (P=0.058). In the Pm allergy group, PmSPT with an MWD of 30 mm provided 80% predictive probability for positive challenges. PmPTP and ComSPT with an MWD of 22.5 and 20 mm provided 95% predictive probability, respectively. In the Mr allergy group, MrSPT with an MWD of 30 mm provided 95% predictive probability. Specific allergy to Pm or Mr was confirmed by food challenges. SPT using crude extracts and the PTP test are useful tools for screening shrimp sensitization before a food challenge. The predictive probability of SPT is helpful where a food challenge is not feasible.

Analysis of basophil activation by flow cytometry in pediatric house dust mite allergy

Detection of allergen-induced basophil activation by flow cytometry has been shown to be a useful tool for allergy diagnosis. The aim of this study was to assess the potential of this technique for the diagnosis of pediatric house dust mite allergy. Quantification of total and specific IgE and basophil activation test were performed to evaluate mite allergic (n = 24), atopic (n = 23), and non-allergic children (n = 9). Allergen-induced basophil activation was detected as a CD63-upregulation. Receiver operating characteristics (ROC) curve analysis was performed to calculate the optimal cut-off value of activated basophils discriminating mite allergic and non-allergic children. ROC curve analysis yielded a threshold value of 18% activated basophils when mite-sensitized and atopic children were studied [area under the curve (AUC) = 0.99, 95% confidence interval (CI) = 0.97-1.01, p < 0.001] with a sensitivity and specificity of 96% for 16 microg/ml mite extract. Analysis of the data obtained with 1.6 microg/ml mite extract defined a cut-off value of 8% activated basophils (AUC = 0.96, 95% CI = 0.91-1.01; p < 0.001) with a sensitivity of 82% and specificity of 100%. Comparison between mite allergic and non-allergic children produced a cut-off of 8% activated basophils (AUC = 1.0) with 16 microg/ml allergen extract and a sensitivity and specificity of 100%. The same threshold and specificity values were obtained with 1.6 microg/ml extract (AUC = 97%, 95% CI = 0.92-1.02; p < 0.001) but sensitivity decreased to 83%. Two atopic children showed negative skin prick and basophil activation tests and high specific IgE (>43 kU/l) values for Dermatophagoides pteronyssinus allergen. They also showed positive prick (wheal diameter >1.0 cm) and basophil activation (>87%) tests and high specific IgE (>100 kU/l) with shrimp allergen. Shrimp sensitization was demonstrated by high levels of Pen a 1-specific IgE (>100 kU/l). Cross-reactivity between mite and shrimp was confirmed by fluorescence enzyme immunoassay (FEIA-CAP) inhibition study in these two cases. This study demonstrated that the analysis of allergen-induced CD63 upregulation by flow cytometry is a reliable tool for diagnosis of mite allergy in pediatric patients, with sensitivity similar to routine diagnostic tests and a higher specificity. Furthermore, this method can provide additional information in case of disagreement between in vivo and in vitro test results.

Effects of Copper, Cadmium, and Zinc on the Hatching Success of Brine Shrimp (Artemia franciscana)

Previous studies indicate that the hatching success of brine shrimp (Artemia franciscana) cysts is surprisingly sensitive to ambient metal concentrations. These studies estimated median effective concentrations (EC50s) of 7, 5, and 28 microg l-1 for Cd, Cu, and Zn, suggesting that the hatching end point for A. franciscana is the most sensitive tested to date for Cd and Zn in saline environments and comparable in sensitivity with the most sensitive tested to date for Cu. Furthermore, these data suggest that brine shrimp are at significant risk from Cu and Zn in Great Salt Lake (GSL), UT, where ambient concentrations as high as 10 and 14 microg l-1, respectively, have been measured. Given that brine shrimp appear to be successfully reproducing in GSL, we hypothesized that these toxicity values were either biased low as a result of an artifact of the test method used or that site-specific water-quality conditions in the lake had decreased metal bioavailability such that brine shrimp could successfully reproduce. To test these hypotheses, we initiated a step-wise series of experiments. First we investigated the effects of pretreatment of brine shrimp cysts with antibiotics on brine shrimp sensitivity to metals because previous investigators as part of their test methods have used antibiotics. Next we considered the effect of ionic composition of the artificial test media on sensitivity. Finally, we evaluated the effects of the site-specific water quality of the GSL on metal bioavailability and toxicity. Results indicate that pretreatment of cysts with antibiotics had no effect on sensitivity. However, we were unable to repeat the previous values for Cd and Zn, obtaining EC50s of 11,859 and 289 microg l-1 for Cd and Zn, respectively. For Cu, however, we estimated an EC50 of 12 microg l-1, so we conducted further testing on the artificial media, adjusting the media composition to better reflect the Ca2+ and HCO3- concentration of normal seawater. This increased the EC50 to 28 microg l-1. Finally we evaluated the toxicity of Cu in GSL water and obtained an EC50 of 68 microg l-1, suggesting that the increased dissolved organic carbon in GSL has a significant protective effect. Overall, the results of this study suggest that brine shrimp hatching success is not particularly sensitive to Cd and Zn, but it is sensitive to Cu. However, site-specific water-quality conditions ensure that brine shrimp cyst hatching success is not significantly affected by any of these metals at the normal background concentrations that occur in GSL (<15 microg l-1).

Lack of de novo Sensitization to Tropomyosin in a Group of Mite-Allergic Patients Treated by House Dust Mite-Specific Immunotherapy

Background: There is some evidence that specific immunotherapy may induce de novo sensitization to proteins contained in the allergen extract. This raises the possibility that the novel sensitization to cross-reacting allergens may cause food allergies. Objective: The aim of this study was to assess whether injection of mite-specific immunotherapy (SIT) may induce sensitization to shrimp tropomyosin. Methods: Seventy mite-allergic subjects who did not show any shrimp sensitization at baseline were followed up for at least 3 years. Thirty-one of them underwent a 3-year SIT course, 39 served as controls. At the follow-up visit, SPTs with both fresh shrimp and commercial extract were performed, and patients underwent an open oral challenge with shrimp. Results: Neither patient nor control had become sensitized to shrimp allergens at the end of the study period. Both patients and controls reported the regular intake of crustaceans and/or molluscs. Conclusion: Injection SIT with house dust mite extracts does not seem to induce de novo tropomyosin sensitization in mite-allergic patients.

Evaluation of the relationship between cockroach sensitivity and house-dust-mite sensitivity in Turkish asthmatic patients

Exposure to cockroach has been identified as an important source of indoor allergens in patients with asthma and allergic rhinitis. We evaluated the relationship between cockroach sensitivity and other allergens in patients with asthma. A total of 114 patients, defined asthma according to GINA, were enrolled in this study. A questionnaire including age, sex, duration of asthma, history of cockroach presence at home, and total IgE, blood eosinophil count, pulmonary function tests, standard skin prick test additional cockroach and shrimp allergen were performed. There were 84 (73.7%) female and 30 (26.3%) male patients with a mean age of 38.1+10.1 years. The average duration of asthma was 7.7+7.2 years. Sixty five (57%) patients were determined atopic and 49 (43%) nonatopic. Pollen allergen was the most common allergen in 59 (51.8%) patients with asthma, and second common allergen was mite allergen in 43 (37.7%) patients. Cockroach sensitivity were detected in 23 (20.2%) of 114 all asthmatics and 23 (35%) of atopic asthmatics. High rates of house-dust-mite allergy (73.9%) was determined in patients with cockroach sensitivity (P<0.05), while we found no relationship with other allergens. There was no difference for cockroach sensitivity between rural and urban population. Cockroach sensitivity was more common in mild bronchial asthmatics and a female predominance was observed. In addition, there was no association between shrimp and cockroach sensitivity. As a result, a high rate of cockroach sensitivity alone or with mite sensitivity was seen in patients with bronchial asthma in Turkish population. Because of cross-reactivity between mites and cockroach, cockroach sensitivity should be investigated in patients with house-dust-mite allergy. In addition, a high rate of cockroach sensitivity, in terms of IgE sensitization, may be important for the development of new sensitizations.

STUDYING STRESS: THE IMPORTANCE OF ORGANISM-LEVEL RESPONSES

The importance of studying the effects of stress on individual organisms is addressed by considering the use of individual-level information to: (1) elucidate the mechanistic bases of interpopulation variation; (2) predict population-level effects; and (3) monitor stress in natural communities. Examples discussed include interpopulation variation in the sensitivity of freshwater shrimps to zinc stress; the use of individual-based models to predict the effects of copper stress on earthworm populations; the use of single-species in situ assays to monitor pollution. It is contended that knowledge of organism-level responses is essential for understanding how stressors cause adverse biological effects and the strategies adopted by organisms to tolerate stress. It is also contended that the effects of stressors on populations can be predicted from a knowledge of the effects of stressors on individual energy budgets. Organism-level responses can be used to monitor stress in natural environments. In situ assays,...

The relationships among shrimp-specific IgG subclass antibodies and immediate adverse reactions to shrimp challenge

High levels of shrimp-specific IgE, in association with a positive prick test, are not always predictive of a positive, immediate response to double-blind, placebo-controlled, food challenge (DBPCFC) with shrimp. The observation that shrimp-sensitive individuals in general have increased levels of circulating shrimp-specific IgG is of interest because antigen/allergen-specific IgG subclasses have been associated with adverse reactions to foods. Therefore, this current study measured shrimp-specific IgG subclass and IgE antibodies in 31 individuals with histories of immediate, adverse reactions to shrimp immediately before DBPCFC and 20 shrimp-tolerant subjects. Individuals with a history of shrimp sensitivity had significantly raised shrimp-specific IgG2 and IgG4 compared to shrimp-tolerant individuals. Challenge-positive subjects were distinguished from subjects with negative or equivocal responses by an increased IgG2 (p less than or equal to 0.001). Specific IgG4 was not raised (p less than or equal to 0.065). These studies indicate that some shrimp-specific IgG subclass levels are increased in shrimp-sensitive subjects. However, none of the subclass responses were significantly predictive of a positive response to DBPCFC and therefore were not diagnostic of shrimp intolerance.

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.