Microplastics in the maximum chlorophyll layer along a north-south transect in the Mediterranean Sea in comparison with zooplankton concentrations

The aim of this study was to characterize and quantify microplastics (MPs) at the chlorophyll maximum layer (CML), around 30 to 60 m depth, during a cruise dedicated to the study of contaminants in plankton, the MERITE-HIPPOCAMPE project, along a north-south transect in the western Mediterranean Sea (Tedetti et al., 2023). Plankton were collected by horizontal net tows in this layer using a multinet Hydrobios Midi equipped with 60 μm mesh-size nets. The collected plankton were fractionated through a sieve column for various later contaminant measurements and for zooplankton analysis (Fierro-González et al., 2023). For all stations, samples were also fully examined for microplastics (MPs) for fractions >300 μm. MPs were found at all stations in the CML layer (mean: 42.9 ± 45.4 MPs m-3), of which 96 ± 4 % were fibers. The ratios of mesozooplankton/MPs and detritus/MPs in this CML were respectively 223 ± 315 and 2544 ± 2268. These data are analyzed together with MPs concentrations from sea- surface sampled with a 300 μm net-size Manta net at the same stations. Overall, our observations highlight the very high density of fibers at the CML, mainly associated with aggregates, raising the hypothesis of their interactions with marine snow. Therefore, the importance of marine snow and vertical layering will have to be considered in future MP distribution modelling efforts.

Temporal changes in zooplankton indicators highlight a bottom-up process in the Bay of Marseille (NW Mediterranean Sea)

Sixteen years (2005-2020) of zooplankton monitoring in the Bay of Marseille (N-W Mediterranean Sea) are analyzed in relation to physical, meteorological, climatic and biotic data. Samples were collected every two weeks by a vertical haul (0-55 m) of a 200 μm plankton net. Different indices characterizing the mesozooplankton are compared: biomass dry weight of four size fractions between 200 and 2000 μm; abundances of the whole of the mesozooplankton and of 13 main taxonomic groups defined from plankton imagery; seasonal onset timing of each zooplankton group; and two other types of indices: the first characterized diversity based on abundance data, and the second was derived from zooplankton size spectra shape. The clearest pattern in the environmental compartment was an overall decreasing trend in nutrients, shifts in phytoplankton metrics (i.e. size structure and particulate organic matter), and changes in winter conditions (i.e. increasing temperatures, precipitation and NAO). Interannual patterns in the mesozooplankton community were: (i) a decrease of total abundance (ii) a decrease in biomass for the four size fractions, with an earlier decrease for the 1000-2000 μm size fraction (in 2008); (iii) a reduced dominance of copepods (calanoids and oithonoids) and a concomitant increase in abundance of other taxonomic groups (crustaceans, pteropods, chaetognaths, salps) which induced higher diversity; (iv) a first shift in size spectra towards smaller sizes in 2009, when the 1000-2000 μm size fraction biomass decreased, and a second shift towards larger sizes in 2013 along with increased diversity; and (iv) a later onset in the phenology for some zooplankton variables and earlier onset for salps. Concomitant changes in the phytoplankton compartment, winter environmental conditions, zooplankton community structure (in size and diversity) and zooplankton phenology marked by a shift in 2013 suggest bottom-up control of the pelagic ecosystem.

Isotopic and biochemical trophic markers reveal the complexity of interactions at the base of pelagic food webs (Mediterranean sea)

To gain insight into the impact of bottom-up changes in the plankton community on planktivorous fish in the context of the decline of small pelagic fisheries in the Northwestern Mediterranean Sea, we have conducted an extensive year-long study. The investigation combined biochemical analyses (proteins, carbohydrates, and lipids) with C and N stable isotope analyses (SIA) to simultaneously study phytoplankton, zooplankton, and eight planktivorous fish species (Engraulis encrasicolus, Sardina pilchardus, Sardinella aurita, Sprattus sprattus, Cepola macrophthalma, Chromis chromis, Boops boops, and Spicara maena). This study is the first to analyze both stable isotope and biochemical compositions in coastal particulate organic matter (POM) size classes (0.7-2.7 μm, 2.7-20 μm, and 20-200 μm), zooplankton size classes (200-300 μm, 300-500 μm, 500-1000 μm, 1000-2000 μm, and >2000 μm), and taxonomic groups. We demonstrated that: (1) POM stable isotope compositions varied based on its spatial origin, the taxonomic composition of its biota, and its biochemical content; (2) δ15N values increased with zooplankton size classes and groups, indicating different trophic levels; (3) Phytoplankton exhibited a lipid-rich composition (∼55%), while zooplankton and fish muscles were protein-rich (∼61% and ∼66%, respectively). Bayesian stable isotope mixing models revealed that, on average: (1) POM from oceanic waters contributed the most to the POM in the bay (>51%), with a dominance of pico-POM (∼43%); (2) The 200-1000 μm zooplankton primarily consumed nano-POM, the 1000-2000 μm zooplankton mostly consumed micro-POM (∼64%), and the >2000 μm zooplankton also mostly consumed micro-POM; (3) Mesozooplankton (200-2000 μm) constituted the main portion (∼42%) of the diet for planktivorous fish species, while macrozooplankton organisms (>2000 μm) were the primary food resource (∼43%) for both B. boops and S. sprattus. Our study underscores the complexity of the pelagic food web and highlights the bottom-up transfer of organic matter from the smallest phytoplankton size fractions to planktivorous fish.

Zooplankton biomass, size structure, and associated metabolic fluxes with focus on its roles at the chlorophyll maximum layer during the plankton-contaminant MERITE-HIPPOCAMPE cruise

Recent studies have demonstrated that plankton can be a key pathway for the uptake and transfer of contaminants entering the marine environment up to top predators. The plankton-contaminant MERITE-HIPPOCAMPE cruise was devoted to quantifying contaminants in water and the whole plankton size range (10 size fractions) at 10 stations along a north-south transect in the western Mediterranean Sea from the French to the Tunisian coasts through the Provençal and Algerian basins. Pumping and filtering devices and net sampling have been used for collecting very high amounts of small particles and planktonic organisms in the chlorophyll maximum layer (CML). The present paper characterizes the zooplankton components for which the contaminant measurements were carried out. At each station, a horizontal towed Hydro-Bios net with a 60 μm mesh-size net was used to discriminate 5 size-fractions from 60 μm to a few mm. For each size-fraction, one part of the sample was used for dry weight measurements and the other one for estimating the contribution to biomass of detritus, phytoplankton, and among zooplankton of the major taxonomic groups based on the imagery tools ZOOSCAN and FLOWCAM. In each zooplankton size fraction, metabolic rates were calculated from the size spectrum to estimate trophic and excretion fluxes flowing through this fraction. These observations were compared to a similar analysis of tows in the upper layer (vertical) and the surface layer (horizontal). The total sampled biomass concentration at the CML was higher than in the water column (COL) and much higher than at the surface (SURF) in most of the stations, but in the CML and COL a substantial contribution was due to detritus mostly concentrated in the smallest size-fractions (60-200 μm and 200-500 μm). Absolute values of zooplankton biomass show neither a clear spatial pattern nor a significant difference between strata. The CML layer was dominated by copepods similarly to COL and SURF, but presented a higher contribution of nauplii and a near absence of appendicularians. At some stations, crustaceans and gelatinous plankton could be important contributors to CML. The zooplankton biomass composition of the two smallest fractions (<500 μm) was dominated by nauplii, small copepods and, occasionally, by small miscellaneous organisms (mostly pteropodes). In contrast, clear differences between stations appeared for the largest fractions (>500 μm) due to large crustaceans, gelatinous organisms, and chaetognaths. These changes in biomass composition according to size fractions suggest a progressive trophic shift from dominant herbivory in the smallest fractions to more contrasted trophic structure (including carnivory) in the largest fractions. The daily carbon demand and the N and P excretion of zooplankton were on average higher at the CML but with no significant difference with COL. The zooplankton grazing represented 2.7 to 22.7 % of the phytoplankton stock per day, whereas its excretion represented a daily N and P recycling compared to dissolved inorganic nitrogen and phosphorus stocks ranging respectively from 0.2 to 19 % and from 0 to 21 %. This information should help in the interpretation of the content of various contaminants in zooplankton fractions.

Contamination of planktonic food webs in the Mediterranean Sea: Setting the frame for the MERITE-HIPPOCAMPE oceanographic cruise (spring 2019)

This paper looks at experiential feedback and the technical and scientific challenges tied to the MERITE-HIPPOCAMPE cruise that took place in the Mediterranean Sea in spring 2019. This cruise proposes an innovative approach to investigate the accumulation and transfer of inorganic and organic contaminants within the planktonic food webs. We present detailed information on how the cruise worked, including 1) the cruise track and sampling stations, 2) the overall strategy, based mainly on the collection of plankton, suspended particles and water at the deep chlorophyll maximum, and the separation of these particles and planktonic organisms into various size fractions, as well as the collection of atmospheric deposition, 3) the operations performed and material used at each station, and 4) the sequence of operations and main parameters analysed. The paper also provides the main environmental conditions that were prevailing during the campaign. Lastly, we present the types of articles produced based on work completed by the cruise that are part of this special issue.

Investigation of dynamic change in microplastics vertical distribution patterns: The seasonal effect on vertical distribution

This paper analyzes the variability of microplastics vertical distributions in the oceanic water column. Data were obtained from targeted sampling in the Bay of Marseille (France) and from a numerical simulation forced by realistic physical forcings. By fitting model and in-situ data in a simplified vertical dimension, three microplastics classes may be deduced: settling, buoyant and winter neutrally-buoyant microplastics. Buoyant microplastics are mainly concentrated at the surface but they can be mixed throughout the whole water column during episodes with strong winds and no water stratification, inducing an implicit underestimation of buoyant microplastics in surface sampling. Almost symmetrical to the distribution of buoyant microplastics, settling microplastics are mainly found at the bottom but they can sometimes reach the surface under the mixing conditions cited above. They could thus contribute to surface sampling. Winter neutrally-buoyant microplastics are more homogenously mixed during the winter but are under the stratified layers during summer.

Spatial variations of biochemical content and stable isotope ratios of size-fractionated plankton in the Mediterranean Sea (MERITE-HIPPOCAMPE campaign)

Plankton represents the main source of carbon in marine ecosystems and is consequently an important gateway for contaminants into the marine food webs. During the MERITE- HIPPOCAMPE campaign in the Mediterranean Sea (April-May 2019), plankton was sampled from pumping and net tows at 10 stations from the French coast to the Gulf of Gabès (Tunisia) to obtain different size fractions in contrasted regions. This study combines various approaches, including biochemical analyses, analyses of stable isotope ratios (δ¹³C, δ¹⁵N), cytometry analyses and mixing models (MixSiar) on size-fractions of phyto- and zooplankton from 0.7 to >2000 μm. Pico- and nanoplankton represented a large energetic resource at the base of pelagic food webs. Proteins, lipids, and stable isotope ratios increased with size in zooplankton and were higher than in phytoplankton. Stable isotope ratios suggest different sources of carbon and nutrients at the base of the planktonic food webs depending on the coast and the offshore area. In addition, a link between productivity and trophic pathways was shown, with high trophic levels and low zooplankton biomass recorded in the offshore area. The results of our study highlight spatial variations of the trophic structure within the plankton size-fractions and will contribute to assess the role of the plankton as a biological pump of contaminants.

Seasonal dynamics of marine protist communities in tidally mixed coastal waters

Major seasonal community reorganizations and associated biomass variations are landmarks of plankton ecology. However, the processes of plankton community turnover rates have not been fully elucidated so far. Here, we analyse patterns of planktonic protist community succession in temperate latitudes, based on quantitative taxonomic data from both microscopy counts (cells >10 μm) and ribosomal DNA metabarcoding (size fraction >3 μm, 18S rRNA gene) from plankton samples collected bimonthly over 8 years (2009–2016) at the SOMLIT‐Astan station (Roscoff, Western English Channel). Based on morphology, diatoms were clearly the dominating group all year round and over the study period. Metabarcoding uncovered a wider diversity spectrum and revealed the prevalence of Dinophyceae and diatoms but also of Cryptophyta, Chlorophyta, Cercozoa, Syndiniales and Ciliophora in terms of read counts and or richness. The use of morphological and molecular analyses in combination allowed improving the taxonomic resolution and to identify the sequence of the dominant species and OTUs (18S V4 rDNA‐derived taxa) that drive annual plankton successions. We detected that some of these dominant OTUs were benthic as a result of the intense tidal mixing typical of the French coasts in the English Channel. Our analysis of the temporal structure of community changes point to a strong seasonality and resilience. The temporal structure of environmental variables (especially Photosynthetic Active Radiation, temperature and macronutrients) and temporal structures generated by species life cycles and or species interactions, are key drivers of the observed cyclic annual plankton turnover.

Identification of a polygalacturonase (Cup s 2) as the major CCD-bearing allergen in Cupressus sempervirens pollen

As IgE glyco-epitopes, also referred to as cross-reactive carbohydrate determinants (CCDs), can share significant structural homologies between different plants, they are prone to extensive cross-reactivity among allergen pollen extracts. Here, cypress pollen allergens, especially a polygalacturonase (PG), were further characterized using double one-dimensional electrophoresis (D1-DE). The presence of specific IgE directed against CCDs was investigated by bromelain IgE inhibition and concanavalin A binding assays using sera of cypress pollen-sensitized patients. Our results showed that IgE reactivity to CCDs in Cupressus sempervirens pollen extracts is mainly related to bromelain-type epitopes of a newly identified cypress PG. This glycoprotein has been further characterized through an immunoproteomic approach and officially indexed as Cup s 2 by the WHO/IUIS allergen nomenclature. Cup s 2 could thus be associated with the increased prevalence of IgE reactivity to cypress pollen extracts because of CCD interference.

Asthma among workers in healthcare settings: role of disinfection with quaternary ammonium compounds

INTRODUCTION

An increased incidence of asthma has been reported among healthcare workers. The role of quaternary ammonium compounds (QACs), commonly used in cleaning/disinfection products, has not been clearly defined. The aim of this study was to analyse associations between asthma and occupational exposure to disinfectants, especially QACs.

METHODS

The study was performed on a stratified random sample of the various healthcare departments of 7 healthcare settings. The study included: questionnaire, physical examination and specific IgE assays. Occupational exposure assessment was performed by means of a work questionnaire, workplace studies and a review of products ingredients. Data were analysed by logistic regression.

RESULTS

Response rate was 77%; 543 workers (89% female) participated; 37.1% were registered nurses (RNs), 16.4% auxiliary nurses (ANs), 17.3% cleaners; 32.8% were atopic. 335 participants were exposed to QACs. Nursing professionals reported a significantly higher risk of reported physician-diagnosed asthma and, for RNs, of nasal symptoms at work than administrative staff working in healthcare sector. This risk was particularly marked during disinfection tasks and when exposure to QACs. Exposure to QACs increased significantly the risk of reported physician-diagnosed asthma and nasal symptoms at work (adjusted OR = 7.5 and 3.2, respectively). No significant association was found with other exposures such as latex glove use, chlorinated products/bleach or glutaraldehyde.

CONCLUSION

RNs and ANs presented a higher risk of reported asthma than administrative staff. The highest risk was associated with tasks involving dilution of disinfection products by manual mixing, suggesting possible exposure to repeated peaks of concentrated products known to be strong respiratory irritants. Workplace interventions should be conducted to more clearly determine QAC exposure and improve disinfection procedures.

Ragweed pollen in France: origin, diffusion, exposure

PURPOSE OF THE STUDY

To detect the origin of ragweed pollen and to measure the impact of this pollen exposure on allergic patients, so their sensitivity can be noted (using specific IgE production: sIgEw1) in order to inform the population about an "allergy" against those ragweed pollen grains.

MATERIAL AND METHODS

To measure population exposure to ragweed pollen, the R.N.S.A (National Aerobiological Monitoring Network, a French association) has a pollen trap network located in urban areas. These traps allow continuous recording of airborne pollen, the light microscope analysis (with a bi-hourly time step) allows one to know the daily concentrations of ragweed grains and the circadian rhythm of grains impaction. It is thus possible to follow the evolution of pollination during each day ofeach season and to compare seasons and years at each station. Biomnis is a biological laboratory which performs more than 85% of ragweed specific IgE assay in France. It seems to be clear that when allergists ask ragweed IgE for a patient, it is because they think that this patient seems to be allergic to this specific pollen. The statistical analysis of results about specific IgE (for ragweed) from the Allergology laboratories Biomnis (located in Lyon and Paris) can determine the number ofpatients sensitized to ragweed in French departments.

RESULTS

The distribution ofsensitized patients to ragweed is compared to ragweed pollen distribution studied by the R.N.S.A from the year 2005 to 2008 in France, whatever the ragweed plant' origin: local (closed topollen trap) or imported (by wind).

CONCLUSION

The biological database (Health impact) allows a correlation between the geographical distribution ofragweed pollen and the number ofpatients with specific IgE against ragweed (sIgEw1), i.e., whose sensitization is due to local plants. That also permits one to estimate the expected number of allergy cases in the next years, because the sensitivity precedes the allergy.

Systematic follow-up increases incidence of anaphylaxis during adverse reactions in anesthetized patients

BACKGROUND

The incidence of hypersensitivity reactions during anesthesia is underestimated because clinical symptoms may vary and diagnosis is not obvious. Our aim was to investigate the consequences of a systematic follow-up of patients on the estimated incidence of allergic reactions during anesthesia.

METHODS

We conducted a prospective study over a 2-year period (70,000 anesthesias). When patients were suspected with hypersensitivity reactions or with unexplained adverse reactions during anesthesia, blood was sampled to measure histamine and tryptase, and then skin tests were performed 4-6 weeks later.

RESULTS

During the studied period, 39 patients were enrolled in the database. Eight were excluded because of lack of skin tests. Twenty-two patients had clinical features compatible with immediate hypersensitivity reaction, and nine had reactions rated as 'unexplained' by the attending physician. Following systematic investigation, we found 22 hypersensitivity reactions (15 patients with obvious and seven with unexplained reactions) during anesthesia. This increases the estimated incidence of hypersensitivity reactions from 1 : 4667 to 1 : 3180 anesthesias. Tryptase concentrations were increased in only 50% of these patients. In our series, positive and negative predictive values of tryptase at T(0) for the diagnosis of anaphylaxis were 100% and 60%, respectively. Latex was the major causative agent, followed by neuromuscular blocking agents and antibiotics.

CONCLUSIONS

Systematic follow-up of patients with unexplained reactions during anesthesia increases the estimated incidence of IgE-mediated hypersensitivity reactions during anesthesia by 50%.

Anaphylactic shock induced by gadoterate meglumine (DOTAREM)

The use of contrast agent for magnetic resonance imaging improves the effectiveness of this diagnostic examination. Complexes of godolinium, which appear to be well tolerated, are used for this purpose. A few cases of anaphylactic shock have been attributed to these agents. We report a case of anaphylactic shock due to gadoterate meglumine (DOTAREM). While undergoing a magnetic resonance imaging examination, a 33-year-old nonatopic female patient became severely hypotensive, lost consciousness, and had generalized erythema immediately after the intravenous injection of this product. She recovered rapidly after she was given injection of epinephrine and her blood volume was restored with intravenous fluids. That DOTAREM had caused this immediate hypersensitivity reaction was proven by the positivity of prick-test and intradermal test at 10-3 (0.37 mg/ml) and in vitro leukocyte histamine release test. The results of these tests indicated that it was the gadoteric acid rather than the meglumine component of DOTAREM that was responsible: positivity of IDR at 10 mg/ml. Skin tests and leukocyte histamine release test to gadopentetate dimeglumine (MAGNEVIST) were negative. In addition of the exceptional character, this observation provides evidence for an immediate hypersensitivity without cross reactivity with gadopentetate dimeglumine.

Human serum IgE-mediated mast cell degranulation shows poor correlation to allergen-specific IgE content

BACKGROUND

Although allergen-specific IgE content in serum can be determined immunochemically, little is known about the relationship between this parameter and the strength of the degranulation response upon allergen triggering.

OBJECTIVES

Analyse the degranulation capacity of immunochemically defined purified and serum IgE after challenge with anti-IgE or allergen using a rat mast cell line (RBL) transfected with the alpha-chain of the human high-affinity IgE receptor (FcepsilonRI).

METHODS

Purified IgE specific for 4-hydroxy-3nitrophenylacetyl, purified IgE of unknown specificity, and sera from allergic patients sensitive to Dermatophagoides pteronyssinus and Dactylis glomerata were assessed. Degranulation was measured by a beta-hexosaminidase release assay after anti-IgE or allergen-specific challenge.

RESULTS

For purified monoclonal IgE a significant correlation (r = 0.97) was found between the proportion of bound allergen-specific IgE and the strength of the degranulation response. In contrast, no correlation (r = 0.27) was detected after sensitization with serum IgE.

CONCLUSION

Our studies demonstrate that mast cell activation mediated through IgE from allergic patients is a result of complex relationships that are not only dependent on allergen-specific IgE content but also relate to the capacity to efficiently sensitize and trigger the signalling responses that lead to degranulation.

Flow cytometry versus histamine release analysis of in vitro basophil degranulation in allergy to Hymenoptera venom

BACKGROUND

Flow cytometry (FCM) has been proposed for specific allergy in vitro testing. We investigated its biological significance for allergy to Hymenoptera venoms and compared it with the routinely performed basophil histamine release test (HRT).

METHODS

Blood samples from 26 allergic and 8 nonallergic donors were incubated with venom at serial concentrations. Basophils were analyzed with anti-CD45-PE-Cyanin 5, Anti-IgE-FITC, and Anti-CD63-Phycoerythrine. HRT was measured by radioimmunoassay.

RESULTS

FCM was as convenient as HRT for measuring basophil reactivity in at least 87% of allergic and 75% of nonallergic subjects. CD63 outer expression was specifically induced in 91% of releaser subjects (86% on HRT) and in 1 of 10 tests in nonallergic donors, or one of six tests (16% on HRT) in allergic patients tested with an irrelevant allergen. Both methods were concordant in 85.7% of the tests. The three discordant patients had low-grade reactions and borderline biological responses on FCM (n = 2) or HRT (n = 1).

CONCLUSIONS

The dynamic, physiologic significance of CD63, the dose-response curve, and dependency on ethylene-diaminetetra acetic acid suggested that both tests reflect the same mechanism.

Prevalence of muscle relaxant sensitivity in a general population: implications for a preoperative screening

BACKGROUND

Muscle relaxants (MR) are responsible for 59% of peroperative anaphylactic reactions. A major issue would be to determine whether a systematic preoperative screening in the general population should be recommended.

OBJECTIVE

The purpose of the study was to evaluate the prevalence of muscle relaxant sensitivity in a sample of the general population and to assess the role of possible risk factors.

METHODS

Two hundred and fifty-eight subjects, aged 20-40 years, visiting a health care centre for a check-up were evaluated. Protocol included a questionnaire (occupation, symptoms of atopy, previous surgery, history of drug allergy), skin-prick tests to four commercial muscle relaxants and measurement of specific IgE against quaternary ammonium ions. Atopy was evaluated by skin-prick tests to common inhalant allergens and by a Phadiatop test.

RESULTS

Of the study group, 9.3% had either a positive skin test to one or more muscle relaxant or a presence of specific IgE to quaternary ammonium ions. No risk factor was identified in the studied group.

CONCLUSION

Since the rate of MR sensitivity is much higher than the anticipated rate of peroperative reactions due to allergy, a systematic preoperative screening for MR allergy should not be recommended for adults in a general population.

Cross-reactivity between terrestrial snails (Helix species) and house-dust mite (Dermatophagoides pteronyssinus). II. In vitro study

Epidemiologic and in vitro data have shown that the association of house-dust mite (HDM) allergy and snail allergy in the same patients was due to cross-reactivity between HDM and snail allergenic components. However, the cross-reacting allergen(s) have not yet been identified. In vitro reactivity of seven patients' sera to the various extracts and hemolymph of four different Helix snail species was analyzed by IgE detection and immunodots and Western blots. Cross-reactivity between snails and Dermatophagoides pteronyssinus was assessed by immunodot and ELISA inhibition in two patients. Heterologous inhibition of the snail immunodot and ELISA was observed in one serum. Western blotting showed a specific binding on all four snail species extracts; molecular weights of snail allergens ranged from < 21 to 200 kDa. Marked individual differences were observed in the seven sera under study; most sera demonstrated IgE recognition of multiple bands, illustrating that no single allergen is responsible for cross-reactivity between snail and mite. These results confirm that cross-reactivity exists between snails of the Helix genus and HDM. This cross-reactivity, involving more than a single allergen, may be of clinical significance in atopic patients allergic to D. pteronyssinus. The identity of the cross-reacting allergens remains to be determined. Potential candidates include the thermostable minor allergens of D. pteronyssinus, tropomyosin and hemocyanin.

Prevalence of latex sensitization in subjects attending health screening: implications for a perioperative screening

BACKGROUND

Because latex is a common allergen, the rate of latex sensitization may be high in the general population. A major issue would then be to determine whether a systematic preoperative screening in the general population should be recommended.

OBJECTIVE

The purpose of the study was to evaluate the prevalence of latex sensitization in a sample of the general population and to assess the role of possible risk factors.

METHODS

The subjects were 258 people, aged from 20 to 40 yr, visiting a health care centre for a check-up. The protocol included: a questionnaire (occupation, symptoms of atopy, use of latex goods and possible reactions, history of previous surgery), a skin-prick test, and a CAP RAST to latex. Atopy was evaluated by a skin-prick test to common allergens and a Phadiatop test.

RESULTS

Some 6.6% of the study group had either a positive skin test or a positive RAST to latex. These subjects had a four-fold higher prevalence of symptoms when wearing gloves. The rate of latex sensitization was higher by fivefold in subjects with a history of reactions to latex goods and by fourfold in atopic subjects.

CONCLUSIONS

Because the rate of latex sensitization is much higher than the anticipated rate of perioperative reactions due to latex allergy, a systematic preoperative screening for latex allergy should not be recommended for adults.

Hypersensitivity to banana in latex-allergic patients. Identification of two major banana allergens of 33 and 37 kD

BACKGROUND

Allergy to banana often occurs in patients sensitized to latex. The spectrum of IgE-mediated responses to latex allergens is more and more documented but banana allergens and epitopes shared by these two allergens have not yet been characterized, even though the existence of cross-reacting IgE antibodies has been demonstrated.

OBJECTIVE

The purpose of this study was to assess the relationship between banana hypersensitivity and latex allergy in a population of 19 latex-allergic patients and to identify allergenic components in banana and the common structures shared with latex.

METHODS

The in vivo study was conducted in our outpatient department in patients with well-documented latex allergy. Clinical histories were evaluated and skin prick tests were performed with banana and latex extracts. IgE responses from 19 patients were investigated by means of CAP RAST assay and SDS PAGE immunoblotting. Epitopes shared by banana and latex were investigated by means of immunoblotting experiments.

RESULTS

Eight of 16 patients (50%) reported symptoms after eating bananas and banana skin prick tests were positive in 5 of 14 patients (36%). Banana RAST results were positive in 12 of the 19 patients (63%). In immunoblot experiments, 17 of the 19 patients (89%) exhibited specific banana IgE antibodies and 16 allergenic components were identified with molecular weights ranging from 17 to 128 kD. Two were considered as major allergens: 33 kD was detectable in 15 of 19 sera (88%) and 37 kD in 13 of 19 sera (76%). Inhibition studies by preincubation of two individual sera with banana or latex extract demonstrated the complete disappearance of IgE binding on banana blotted allergens.

CONCLUSION

This study confirms the "latex-fruit syndrome" already described by Blanco et al. Two major allergens were revealed in banana at 33 and 37 kD and the presence of more than ten common components with latex was observed.

Hypersensitivity to latex and Ficus benjamina allergens

BACKGROUND

Association between allergy to Ficus benjamina and Hevea brasiliensis, two botanically unrelated plants, was suspected in consequence of two clinical observations. Symptoms were rhinitis and asthma. This study was undertaken to assess the in vivo and in vitro cross-reactivity between Ficus benjamina and Hevea brasiliensis allergens.

METHODS

The two patients were asked about use and contact with latex devices and relationship between symptoms and Ficus benjamina exposure. Skin prick tests were performed with Ficus benjamina, Hevea brasiliensis extracts and common allergens. Double-blind nasal and bronchial challenge tests were done using the rinse fluid from a brand of latex gloves. Total and specific IgE antibodies to Ficus benjamina and Hevea brasiliensis were determined. In vitro cross-reactivity was investigated by means of CAP RAST and immunodot inhibition experiments.

RESULTS

We observed that for the first patient the primary phenomenon is probably allergy to latex followed by allergy to Ficus benjamina. For the second patient, allergy to Ficus benjamina was diagnosed (improvement related to the avoidance of exposure to Ficus benjamina allergens) and positivity to latex skin prick tests may be due to the cross-reacting allergens. In vitro assays showed specific IgE antibodies to both allergens and cross-reactivity was confirmed in the two cases by reciprocal inhibition of the two extracts.

CONCLUSION

The increasing risk of sensitization to widely used latex devices and extensive exposure to Ficus species in households and offices indicates increased allergenic risk from this newly recognized cross-reactivity.

Histamine release assay and radioimmunoassay for the detection of IgE antibodies against neuromuscular blocking drugs

It is well established that muscle-relaxant drugs may be responsible for anaphylactoid reactions during anaesthesia. In the present work we evaluated in 41 patients who had experienced anaphylactoid reactions during general anesthesia, the value of different radioimmunoassays (RIAs) and of an histamine release assay (HRA). The RIA was performed with different solid phases as PAPPC (para amino phenyl phosphoryl choline), morphine, TMA (trimethylamine) and TEA (triethylamine). The results were expressed as the percentage of 125I anti-human IgE adsorbed onto the solid phase. The sensitivity was estimated respectively at 95, 82, 93 and 64%. The results were significantly in accordance with those obtained with QAS-RIA (from Guéant) but a weak correlation was seen with Phadebas Rast succinylcholine (r = 0.85 and 0.53 respectively). The HRA gave with the NMBD incriminated a sensitivity of 88%. The correlation between HRA and IDR for the drug involved was 89% and 43% for the other NMBDs. The PAPPC RIA was apparently the most efficient test to screen sera for the presence of IgE antibodies whatever the NMBDs involved in anaphylaxis. An advantage is that this solid phase is commercially available and therefore this RIA can be used routinely with a high sensitivity, allowing the comparison of the results obtained by different laboratories.

A new radioimmunoassay using a commercially available solid support for the detection of IgE antibodies against muscle relaxants

It is well established that muscle-relaxant drugs may be responsible for anaphylactoid reactions during anesthesia. In this study, we developed an in vitro test with a commercially available solid phase for the detection of specific IgE directed to the tertiary or quaternary ammonium groups of neuromuscular-blocking drugs. The solid-phase complex was P-aminophenylphosphoryl-choline (PAPPC) immobilized on agarose, and an RIA was performed with an antihuman IgE labeled with 125I. The results, expressed as the percentage of 125I-labeled anti-IgE linked to the solid phase, were at 0.41 +/- 0.19 for 34 control sera from nonallergic healthy adults, with an upper limit estimated at 1%. The values obtained with the sera of 31 allergic patients ranged from 0.6% to 41% with a sensitivity of 97%. The specificity and the positive predictive value of the PAPPC RIA were 97% and 94%, respectively. These results were compared with results of other RIAs with morphine, trimethylamine, triethylamine immobilized on epoxy-activated Sepharose, and choline hydrochloride immobilized on Sepharose (quaternary ammonium Sepharose RIA) and with Phadebas RAST succinylcholine and Phadebas RAST alcuronium. The PAPPC RIA appears to be the most efficient test to screen sera for the presence of IgE antibodies directed to neuromuscular-blocking drugs. One major advantage is that this solid phase is commercially available and ready to use. This advantage will improve the accuracy in the comparison of the results with results from different laboratories.

Evolution of sensitivity to Hymenoptera venom in 200 allergic patients followed for up to 3 years

Duration of venom immunotherapy still remains questionnable, since some patients outgrow their sensitivity. Two hundred venom-allergic patients (4 to 82 years; mean +/- SD, 37.3 +/- 14.2 years) who were first observed with systemic reactions (SRs) were investigated yearly for up to 3 years. Among these patients, 72 were allergic to honeybee venom, 83 to yellow jacket venom, and 45 to both yellow jacket and Polistes venom. At each visit patients had skin tests and RAST to venom. All patients had the same semirush protocol and a monthly maintenance dose of 200 micrograms. After 1 year of treatment, 19% of bee venom-allergic subjects and 35% of vespid venom-allergic individuals had a negative skin test and RAST to the corresponding venom. The percentage of negativation of tests increased after 3 years to 30.5% in bee venom-allergic patients and to 54% in vespid venom-allergic individuals. This rapid and relatively important negativation of skin tests and RAST may be due to a monthly maintenance dose of 200 micrograms; 76 patients experienced a field sting without any SR, two patients had a severe SR, and three patients had a mild SR. Although we tried to define parameters that might predict the abolition of venom sensitivity before starting immunotherapy, we could not find any parameter except venom species. Children and adults behave similarly in terms of evolution of venom sensitization. Mean serum venom-specific IgG levels were significantly lower in patients who had lost their sensitivity.

[The role of phadiatop in the screening of respiratory allergy]

Phadiatop is a new in vitro screening test for respiratory allergy. This test, based on the RAST procedure, detects in serum, the presence of specific IgE to a mixture of common inhalent allergens. Among 70 patients (26 children and 44 adults) consulting for respiratory syndrome, Phadiatop was positive in 31 cases. There were a good correlation between this new test and skin tests (59% for adults and 92% for children), total IgE (70% for adults and 65% for children) and RAST (93% for adults and 96% for children). Phadiatop, with a specificity of 100%, a sensitivity of 82% (76% for adults and 92% for children) and an efficiency of 90% (86% for adults and 96% for children), is a more accurate test than total IgE and could be an excellent in vitro screening test for respiratory allergy.

[A simple test for the detection of respiratory allergy to current pneumallergens]

Phadiatop is a new in vitro test used for screening patients with allergic respiratory diseases. This test, based on the RAST procedure, is performed with a paper disc to which a balanced mixture of relevant inhalant allergens has been coupled. One hundred and one adults ranging in age from 18 years to 73 years and 38 children (4 months to 15 years) were studied. We found a good correlation between this new test and total IgE (adults: 74.3 p. 100, children: 68.4 p. 100), specific IgE (adults: 91.1 p. 100, children: 100 p. 100) and skin test (adults: 79.2 p. 100, children: 97.1 p. 100). There was a high correlation between clinical atopy assessment and the result of Phadiatop, its efficiency was 83 p. 100 in adults and 97 p. 100 in children.

[Sequential analysis of specific IgE and IgG titres as a function of the cumulated doses of venoms injected in allergies to Hymenoptera and correlation with specific IgE, clinical manifestations and skin tests]

The numbers of IgE and specific IgE in ten desensitized to wasp-venom patients are retrospectively analysed, in order to study their variation according to the cumulated dose of administered venom during the desensitization (mean-time 18.4 months). Our results allow to find after a latency period, a growth of the specific IgE number, then their gradual decrease, while the specific IgE number gradually rises to reach a deal-level.

[Allergy to Thyrophagus putrescentiae and Lepidoglyphus destructor in a population of young asthmatic adults]

In the present work a study has been made of the prevalence of allergy to two storage mites, Tyrophagus putrescentiae and Lepidoglyphus destructor in a population of 105 young adults in the east of France. Combination of skin tests and specific IgE measurements shows that 43.10% of the subjects were sensitive to Tyrophagus and 44.95% to Lepidoglyphus. Interpretation of skin tests remains uncertain, particularly concerning the source of the allergen used and it is most often also necessary to measure the specific serum IgE. As in many studies, most sensitization was found amongst farmers. In contrast, no difference was seen between rural and city dwellers, subjects who were in contact with small animals and those in contact with food for livestock if they were not farmers, not between declared asthmatics who lived in a humid place and those who lived in an environment that was drier. Certainly these mites appeared in the present study to be much more ubiquitous than supposed previously and the fact that they seemed to be carriers of allergens and antigens that were different from those of Dermatophagoides raises the question as to whether the need for hyposensitization treatment for them has been under-estimated.

[Allergy to Tyrophagus putrescentiae and Lepidoglyphus destructor in a population of young adult asthmatics]

The goal of this work was the study of the prevalence of allergy to two mites, Tyrophagus putrescentiae and Lepidoglyphus destructor in a population of 105 young asthmatic men from East of France. The association of skin tests and specific IgE shows that 43.10% are allergic to Tyrophagus and 44.95% to Lepidoglyphus destructor. The significance of skin tests is doubtful and depends on the laboratories which provide the allergens. Therefore, specific IgE has to be performed. As in other studies it has been observed that farmers are very often sensitized. But, nose difference has been noticed between people living in town or in country, between those having contacts with pets or not, feeding the cattle or not (except for the farmers). In the same way, no difference has been noticed between the asthmatics living in a wet country and/or wet house and those living in a dry area.

Blotting methods applied to investigations of the mitogenic activity of phytohaemagglutinin (PHA)

PHA polypeptides were separated by SDS-polyacrylamide gel electrophoresis and transferred to nitrocellulose filters which were then cut into identical discs and used to perform blastogenic stimulation on cultured human peripheral blood lymphocytes. This method offers the following advantages: the high resolution of SDS-polyacrylamide gel electrophoresis, the sensitive immunochemical identification of the polypeptides involved in the mitogenic responses of lymphocytes, the determination in the same experiment of the molecular weight, antigenicity and biological activities of the proteins.

[Serum assay of anti-wasp venom IgG by radioimmunoprecipitation. Application to patients during desensitization]

Rapid, specific and reproducible radioimmunoprecipitation assay (RIP) for measuring IgG antibodies against Yellow Jacket Venom (YJV) has been developed. The YJV-I125 is added to serum sample and the immune complexes are precipitated by a second antibody with polyethylene glycol. IgG antibodies were measured by RIP in 24 patients receiving Yellow Jacket Venom immunotherapy. RIP assays were compared for 159 sera to a solid phase procedure (RAST IgG).