Cross-reactivity to fish and chicken meat - a new clinical syndrome.

BACKGROUND: Fish is one of the most allergenic foods. While clinical cross-reactivity among different fishes is a widely accepted feature of fish allergy, associations with other food allergies are not well understood. This study aims at analyzing the relevance of clinical cross-reactivity between fish and chicken meat in patients with allergy to chicken meat without sensitization to hen's eggs. METHODS: Patients with food allergy to fish and chicken meat (n = 29) or chicken meat only (n = 7) were recruited. IgE-reactive chicken proteins were identified (Edman, MS analysis) and quantified (ELISA). Allergens were used in IgE ELISA and skin testing. RESULTS: Chicken parvalbumin and two new allergens, aldolase and enolase, were identified at 12, 40, and 50 kDa, respectively. They were recognized by sIgE of 61%, 75%, and 83% of all patient sera which were in the majority of the cases positive for the fish homologues as well. Fish and chicken meat allergens were highly cross-reactive while high inhibition rates with fish or chicken allergens correlated with the patients' primary sensitization to fish or chicken. In cooked or roasted foods, enolase and aldolase were detectable in chicken breast while parvalbumin was detectable in chicken legs and wings. CONCLUSIONS: Fish and chicken meat are cross-reactive foods; both fish-allergic and chicken meat-allergic patients might be at risk of developing a food allergy to chicken meat or to fish, respectively. This clinical phenomenon is proposed to be termed 'fish-chicken syndrome' with cross-reactive allergens involved being parvalbumins, enolases, and aldolases.

The importance of EN ISO 15189 accreditation of allergen-specific IgE determination for reliable in vitro allergy diagnosis.

BACKGROUND: Allergen-specific serum immunoglobulin E detection and quantification have become an important step in allergy diagnosis and follow-up. In line with the current trend of laboratory test accreditation to international standards, we set out to design and assess an accreditation procedure for allergen-specific serum IgE. METHODS: Method validation according to the accreditation procedure under the EN ISO 15189 standard was carried out for allergen-specific immunoglobulin E determination using the fluoroimmunoenzymatic method ImmunoCAP(®) (ThermoFisher). Data were produced by 25 hospital laboratories in France. A total of 29 allergen specificities including mixes, extracts, and molecular allergens were assayed. Allergen-specific serum immunoglobulin E concentrations ranged from 0.1 to 100 kUA /l. RESULTS: Repeatability, reproducibility, and accuracy results fulfilled method validation criteria for automated laboratory tests and proved similar irrespective of the allergen specificity, allergen-specific serum immunoglobulin E concentration, or individual laboratory. CONCLUSION: Allergen-specific serum immunoglobulin E determination with the fluoroimmunoenzymatic method ImmunoCAP(®) is a highly repeatable, reproducible, and accurate method which may be considered as a single analyte assay in view of the EN ISO 15189 accreditation procedure.

Molecular allergens in the diagnosis of latex allergy.

BACKGROUND: Molecular allergens enable the definition of sensitization profiles in allergic patients. AIM: To validate the most helpful allergens for the diagnosis of latex allergy in different clinical situations. METHODS: 130 patients suspected to be allergic to latex with positive IgE against natural rubber latex (NRL) have been studied: 97 were confirmed as latex allergic (among which 55 professionally exposed to latex and 35 with a peranaesthetic anaphylactic shock) and 33 were only sensitized to latex without clinical allergy. Each serum was tested for IgE against 9 recombinant latex allergens and bromelain using Phadia ImmunoCAP 250. RESULTS: rHev b 6.01, 6.02, 2 and 5 were the major allergens in the allergic population. An excellent correlation (94%) was observed between IgE against rHev b 6.01 and latex prick test positivities. IgE against rHev b 1, 3 and 5 were more frequent and their levels significantly higher in patients with peranaesthetic anaphylactic shock. Among the asymptomatic patients (29/33 allergic to pollen), NRL IgE positivity is explained by the presence of anti-rHev b 8 and/or anti-carbohydrate IgE. CONCLUSIONS: rHev b 6.01 and rHev b 5 specific IgE are of major interest to confirm latex allergy diagnosis. rHev b 5 is particularly useful in case of monosensitization where clinical symptoms and latex skin prick tests may be discordant, rHev b1 and rHev b 3 are interesting to document multi-operated and peranaesthetic latex allergy. Finally, rHev b 8 is a helpful marker to highlight latex/pollen cross-reactivity which improves the specificity of the serological tests.

Interleukin 10 induces B lymphocytes from IgA-deficient patients to secrete IgA.

We have previously shown that human B lymphocytes cultured in the CD40 system, composed of an anti-CD40 mAb presented by a CD32-transfected fibroblastic cell line, proliferate but do not secrete antibodies. However, the addition of particles of Staphylococcus aureus Cowan (SAC) induces B cell differentiation even in the absence of exogenous cytokines (CD40/SAC system). Additionally, B lymphocytes cultured in the CD40 system in the presence of human IL-10, produce IgM, IgG, and IgA, and Ig levels are further increased by SAC. Here, we have studied the capacity of peripheral blood lymphocytes from patients with IgA deficiency (IgA-D) to secrete Igs, particularly IgA after CD40 triggering. Peripheral blood mononuclear cells (PBMNC) from IgA-D patients cultured in the CD40/SAC system produced IgM and IgG, but not IgA. The addition of IL-10 to the cultures, enhanced the production of IgM and IgG and most strikingly induced the production of high amounts of IgA. The addition of IL-10 to PBMNC from IgA-D patients activated through CD40 alone resulted in the production of IgA. Thus, SAC and anti-CD40 mAb stimulate B cells to differentiate into cells secreting IgG and IgM whereas IL-10 plays a central role in inducing B cells from IgA-D patients to differentiate into IgA secreting cells.

Comparison of serum copper determination by colorimetric and atomic absorption spectrometric methods in seven different laboratories. The S.F.B.C. (Société Française de Biologie Clinique) Trace Element Group.

An interlaboratory collaborative trial was conducted on the determination of serum copper using two different methods, based on colorimetry (test combination Copper, Boehringer Mannheim, Mannheim, Germany) and flame atomic absorption spectrometry (FAAS). The general performance of the colorimetric method was below that of FAAS, except for sensitivity and linear range, as assessed by detection limit (0.44 versus 1.32 mumol/L) and upper limit of linearity (150 versus 50 mumol/L). The range of the between-run CVs and the recovery of standard additions were, respectively, 2.3-11.9% and 92-127% for the colorimetric method and 1.1-6.0% and 93-101% for the FAAS method. Interferences were minimal with both methods. The two techniques correlated satisfactorily (the correlation coefficients ranged from 0.945-0.970 among laboratories) but the colorimetric assay exhibited slightly higher results than the FAAS method. Each method was transferable among laboratories.

Enzyme-linked immunoadsorbent assay for serum IgE: evaluation in four centres.

We report an evaluation of a commercially available kit, the Biomérieux IgE-kit, for determination of total IgE in serum by the EIA double antibody sandwich method. Results by this procedure and PRIST (Pharmacia) show a degree of association (r) of 0.98 and a regression equation of log Y = 0.79 log PRIST + log 3.31. Correlation between the IgE kit and RIST shows a degree of association of 1.00 and a regression equation of log Y = 1.01 log RIST--log 1.05. Between-laboratory standard deviations are 3%, 3%, and 15% for the IgE concentrations of, respectively, 83, 285, and 900 IU/ml. Similarly, intra- and inter-assay correlations were performed on 60 lyophilised serum samples tested in the four centres. No protein interference was found except for cryoprecipitates. The favourable correlation with existing procedures and the feasibility of this kit offer a new way of measuring IgE levels.

[Methods of determination of selenium in biological matter]. / Méthodes de dosage du sélénium dans les milieux biologiques.

Main techniques used: graphite furnace atomic absorption direct or after preliminary treatment of the sample, graphite furnace atomic absorption by generation of hydrides, fluorometry, gaz chromatography, differential pulse voltammetry. The various quality criteria of these methods are compared as well as the usual values in the different biological fluids (whole blood, plasma, serum, erythrocytes, urine).

[Multicenter study of commercial kits for the determination of human IgG subclasses, using the ELISA technique]. / Etude multicentrique des trousses commercialisées pour le dosage des sous-classes d'IgG humaines par technique ELISA.

We evaluated two commercially available sandwich type Elisa procedures for the measurement of IgG subclasses in human serum. Assay kits from The Binding Site and the Central Laboratory of the Netherlands Red Cross Blood Transfusion Service were tested in six laboratories. The performance of spectrophotometers, pipettes and dilutors were assessed at each center. Within-run precision was estimated according to the Valtec method (Société Française de Biologie Clinique). The overall coefficient of variation ranged from 4 to 50% depending on subclass and kit. We also evaluated the IgG2 and IgG4 specificity using four sera containing a monoclonal IgG2 or IgG4 (kappa or lambda type). Using total IgG and immunoelectrophoresis as a comparative technique, IgG2 kappa and IgG4 kappa were both underestimated, IgG2 lambda was overestimated while IgG4 lambda compared favorably. Polyclonal IgG subclasses were frequently overestimated in these sera suggesting cross-reactions with either monoclonal IgG or other polyclonal IgG. Antigen excess was investigated and not encountered with either kit. Our results demonstrate that these procedures are insufficiently accurate or precise for routine clinical use.

[Severe bronchospasm using Diprivan® in a patient allergic to peanut and birch]. / Bronchospasme sévère au Diprivan® chez un enfant allergique à l'arachide et au pollen de bouleau.

Diprivan® is composed of propofol, refined soybean oil and purified egg phosphatide. One must eliminate any allergy to one of its components before use. We report the story of a child who underwent nevus surgery under general anesthesia which was associated with an hypersensitivity reaction. In fact, this child had asthma and allergy to peanuts, raising the problem of cross allergy between birch, peanut, soy and Diprivan®.

[Serum ferritin in premature infants]. / Ferritine sérique chez le prématuré.

This study was carried out in twenty-two newborn of birthweight lower than 2 000 g at four and six weeks to determine normal values of serum ferritin in preterm infants and pathological factors who influenced this evolution. Serum ferritin was measured by a kit using a sandwich radioimmunometric method. Elevated values are found in the series of fifteen preterm infants without pathology, with a decreasing evolution. There is no difference in median values at four (266 +/- 91 ng/ml) and six (279 +/- 162) weeks. There is no correlation between serum ferritin values and gestational age nor with hemoglobin values. Serum ferritin values are elevated by inflammatory pathology, blood transfusions and in this case no represent stain pool.

[Immunochemical methods for measuring specific proteins]. / Méthods immunochimiques de mesure des protéines spécifiques.

Immunochemical methods are based on the antigen-antibody reaction. Two groups of techniques can be made: group I in which the visualization of the antigen-antibody reaction is direct (radial immunodiffusion, immunonephelometry, immunoturbidimetry...), group II which needs a label to detect the complex (radioimmuno assay, immunoenzymology). The characteristics of the principal methods (time needed, sensitivity, apparatus, applications) and their causes of error are compared. Thanks to their precision, the possibility of micromethod and their rapidity, immunonephelometric technics are recommended in pediatrics.

Cyclin D1 represses STAT3 activation through a Cdk4-independent mechanism.

STAT3 transcription factors are cytoplasmic proteins that induce gene activation in response to cytokine receptor stimulation. Following tyrosine phosphorylation, STAT3 proteins dimerize, translocate into the nucleus, and activate specific target genes. Activation is transient, and down-regulation of STAT3 signaling occurs within a few hours. In this study, we show that cyclin D1 inhibits STAT3 activation. In co-immunoprecipitation and pull-down assays, cyclin D1 was found to associate with the activation domain of STAT3 upon interleukin-6 stimulation. Overexpression of cyclin D1 inhibited transcriptional activation by STAT3 proteins. This effect was not shared by cyclin E, was independent of association with Cdk4, and was unaffected by inhibitors of Cdk4. Whereas cyclin D1 had no effect on the steady-state level of STAT3 proteins in the cytoplasm, it was found to reduce the STAT3 nuclear level in HepG2 cells. These results suggest a model by which cyclin D1 is part of a feedback network controlling the down-regulation of STAT3 activity and highlight a new activity for this cell cycle regulatory protein.

[The normal protein profile in newborn infants]. / Le profil protéique normal du nouveau-né.

The authors report the results of the immunonephelometric determination of 9 proteins in the serum of 74 newborns: CRP, orosomucoid, haptoglobin, alpha-1-antitrypsin, C3, C4, transferrin, prealbumin and apo B have been studied. The influence of gestational and postnatal ages are shown. Results are compared with those of the literature. The respective role of the transfer of plasma proteins from mother to foetus and of foetal synthesis in the concentration of a protein in the serum of a neonate is discussed.

[Course of inflammatory and nutrition proteins in bacterial infections in newborn infants]. / L'évolution des protéines de l'inflammation et de la nutrition dans les infections bactériennes du nouveau-né.

A study of 214 neonates (with 87 premature infants) reveals that C-reactive protein (CRP), orosomucoid and prealbumin are the most interesting proteins for the diagnosis of neonatal sepsis and for studying its follow-up. Orosomucoid is high in 85% of bacterial infections and CRP in 75%. Early type strep B infections give often false negative results. The evolution of CRP and of prealbumin corresponds to the effects of treatment and the evolution of orosomucoid is parallel to the healing of the patients. The ratio orosomucoid/prealbumin allows an earlier appreciation of the healing.

[Plasmatic and urinary zinc in rheumatoid arthritis (author's transl)]. / Le zinc plasmatique et urinaire dans la polyarthrite rhumatoïde.

The analysis of the plasmatic and urinary levels of zinc in 50 patients presenting a non inflammatory disease and in 50 rheumatoid arthritis, points out to an high significative difference between plasmatic data (13,37 +/- 2,72 mumol/l and 11,32 +/- 2,22 mumol/l respectively ; p less than 0,001). No difference was found in urinary levels and neither age, nor sex, duration of the disease, most biologic parameters, nor long term medications can explain the difference which seems related to the inflammatory tissue process.