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PubMed1995

Serum reactivities to latex proteins (Hevea brasiliensis).

BACKGROUND: In recent years there has been an increasing incidence of allergy to latex among health care workers and children with spina bifida. The allergic response in these individuals can be severe and occasionally fatal. Several allergens have been identified with the use of sera from different patient groups. In our effort to identify reagents for in vitro testing and clinical use, we investigated the reactivities of latex proteins to sera collected from a wide range of patients with latex allergy. METHODS: Twenty-six serum samples were obtained from adult patients with latex allergy, both hospital workers and non-hospital workers. Serum pools were made either from sera of children with spina bifida or sera of adult patients with latex allergy. Proteins from C-serum and latex particles of latex sap (nonammoniated) were separated by different gel electrophoresis techniques and evaluated for specific IgE binding by immunoblotting. RESULTS: More than 50% of the sera tested reacted to an 18 kd protein, a 25.6 kd acidic protein with an isoelectric point of 3.5, or to both proteins; whereas only 23% of the individual serum samples tested reacted to the rubber elongation factor, which has been reported to be a major latex allergen. The immunoreactive patterns of children's and adults' serum pools were similar but not identical. CONCLUSIONS: With the use of gel electrophoresis and immunoblotting techniques, different immunoreactive proteins were identified in C-serum and particles of latex. Rubber elongation factor, which reacted to only 23% of sera tested, did not appear to cross-react immunologically with other latex allergens.

Adult↗
PubMed1998

Identification of hevein (Hev b 6.02) in Hevea latex as a major cross-reacting allergen with avocado fruit in patients with latex allergy.

BACKGROUND: Recent studies demonstrated that allergy to natural rubber latex is frequently associated with hypersensitivity to avocado fruit. The responsible cross-sensitizing allergen has not been identified. OBJECTIVE: The purpose of this study was to investigate the cross-reactivity of a latex major allergen, hevein, with avocado proteins. METHODS: Serum samples from 118 health care workers (HCWs) allergic to latex (HCW group) and 78 patients with spina bifida (SB) allergic to latex (SB group) were included in this study. Anti-hevein and anti-avocado IgE antibodies were measured by enzyme-linked allergosorbent assay. Cross-reactivity of hevein to avocado proteins was assessed by inhibition of the IgE binding in individual patients' sera containing IgE antibodies to both hevein and avocado. RESULTS: The prevalence of seropositive IgE antibodies to avocado was found to be strongly associated with the presence of hevein-specific IgE antibodies in subjects of both groups (P < .001). Sixty-seven of 91 (73%) subjects from the HCW group and all 19 subjects in the SB group with positive IgE antibodies to hevein also had elevated IgE values to avocado. Competitive RAST inhibition with 42 sera showed that IgE binding to avocado could be completely inhibited in 27 (64%) sera by preincubation with hevein. By contrast, the degrees of inhibition of IgE to hevein by avocado extract ranged from 0% to 36% (n = 16). These results indicate that sensitization to avocado in most patients allergic to latex is caused exclusively by IgE-binding epitopes present in hevein. Results of immunoblots and immunoblot inhibition with 11 serum samples confirmed that a 30-kd protein in avocado was the major IgE-binding component; the IgE-binding reactivity to this protein could be inhibited by hevein in all sera tested. CONCLUSION: Hevein is the major cross-reacting allergen with avocado in subjects with latex allergy.

Adolescent↗
PubMed1999

The prevalence of immunoglobulin E antibodies to the proteins of rubber (Hevea brasiliensis) latex and grass (Phleum pratense) pollen in sera of British blood donors.

BACKGROUND: Although there have been many studies of the prevalence of latex allergy in populations deemed to be at risk, little is known of the potential allergic susceptibility to latex products prevailing in the general population. OBJECTIVE: To assess the possible prevalence of allergy to latex goods in a population of blood donors by measurement of specific antilatex immunoglobulin (Ig) E in blood, to relate this to prevalence of antigrass IgE in the blood donations, and to assess the prevalence of antibodies to grass, house dust mite and cat allergens in those donors having antilatex IgE antibodies. METHODS: Sera from two groups of donations obtained in the English West Midlands were assayed. A group of 2000 donations obtained in midwinter was assayed for antilatex and antigrass pollen IgE. A group of 5000 midsummer donations was assayed for total IgE, and antilatex IgE and the sera giving a positive reaction, assayed for antigrass pollen, antihouse dust mite and anticat IgE. The nature of the principal latex and grass pollen polypeptides reacting with IgE in the sera was assessed by immunoblotting. RESULTS: Anti-latex IgE was detected in approximately 4% of the winter and 7% of the summer donations. The prevalence of antigrass IgE in the winter donations was approximately 20% and amongst the latex-positive sera approximately 84% contained antigrass IgE. Of the summer donations of latex-positive sera, 96% contained antigrass, 48.6% antimite IgE and 34% anticat IgE. The prevalence of both antilatex and antigrass IgE was age and sex related. Inhibition studies indicated cross-reactivity of IgE with latex and grass pollen proteins. CONCLUSIONS: Whilst 4-7% of the population may have serum IgE reacting with latex, the levels are low compared with those reacting with the aeroallergens studied. The apparent cross-reactivity of some serum IgE with both latex and grass pollen taken with other evidence suggests that, in some individuals, allergy to latex may arise from an initial sensitization by grass pollen.

Adolescent↗
PubMed1996

The allergenic properties of fresh and preserved Hevea brasiliensis latex protein preparations.

The allergenic properties of the proteins of two lyophilized fractions of fresh natural rubber latex obtained by ultracentrifugation, the C serum and the sedimented bottom or lutoid fraction, have been compared with those of the serum proteins of two samples of high ammonia latex (HAL) [A]HALS obtained from HAL stored for more than 1 year, and [M]HALS derived from HAL stored for 6 weeks before ultracentrifugation and lyophilization. The most potent source of allergenic polypeptides both for skin prick testing of latex-sensitive patients and for immunoblots of their blood serum was the lutoid fraction of fresh latex. Skin prick tests and immunoblots of patients' sera showed that the allergenicity of the ammoniated latex decreased during storage. Skin prick tests using fractions of [A]HALS, C serum and lutoid proteins obtained after passage through a Sephacryl S300 column showed that the components of all three preparations which eluted in the largest volumes were almost equally effective in provoking the largest number of responses. Immunoblots of the sera of 43 latex-sensitive individuals showed that the majority (66%) of sera of the adult allergic patients reacted with a polypeptide of 19 kD. No characteristic pattern of binding latex polypeptides could be recognized in the sera from patients who were also asthmatic or from those who had an anaphylactic response to latex proteins.

Adult↗
PubMed1994

Solubilization and Reconstitution of the Mg2+/2H+ Antiporter of the Lutoid Tonoplast from Hevea brasiliensis Latex.

The Mg2+/2H+ antiporter recently described on lutoid membrane (Z. Amalou, R. Gibrat, C. Brugidou, P. Trouslot, J.d'Auzac [1992] Plant Physiol 100: 255-260) was solubilized by octylglucoside and reconstituted into soybean liposomes using the detergent dilution method. Magnesium efflux or influx experiments were used to generate a H+ influx or efflux, respectively, monitored with the fluorescent probe 9-amino-6-chloro-2-methoxyacridine. Both experiments gave saturable H+ fluxes as a function of internal or external Mg2+ concentrations with similar kinetic parameters Km and Vmax. The Km value for Mg2+ (about 2 mM) was identical to that previously found in lyophilized-resuspended lutoid (reference therein), whereas the Vmax value was 14-fold higher. Since only 10% of the initial proteins were recovered in proteoliposomes, and electrophoretic patterns of the two kinds of vesicles differed significantly, it was inferred that the increase in Vmax was due essentially to an enrichment of the protein antiporter in the reconstituted fraction, owing to a selective effect of octylglucoside at both solubilization and reconstitution steps. None of the various divalent cations used could dissipate the pH gradient of control liposomes of soybean lipids, unless the divalent/H+ exchanger A23187 was added, whereas a rapid dissipation of the pH gradient was observed with reconstituted proteoliposomes from lutoid proteins, with the cation selectivity sequence Zn2+ > Cd2+ > Mg2+ in the millimolar concentration range. The divalent ions Ca2+, Ba2+, and Mn2+ were incapable of generating a H+ efflux in reconstituted proteoliposomes, whereas both Mg2+/H+ and Ca2+/H+ exchanges were observed in lyophilized-resuspended lutoids. Therefore, the lutoid membrane seems to contain separate Mg2+/H+ and Ca2+/H transport systems, the latter being eliminated during the solubilization/reconstitution of lutoid membrane proteins.

Journal Article↗