Kristiina Turjanmaa

Incidence of immediate allergy to latex gloves in hospital personnel.

Latex surgical gloves may cause contact urticaria and serious allergic reactions in sensitized persons, but the frequency of this allergy is not known. In the present study, 512 hospital employees were screened with a latex‐glove scratch‐chamber test: 23 (4.5%) were suspected and 15 (2.9%) were proven allergic with latex prick and use tests. All of them were doctors and nurses, and 12 had had contact urticaria but no special symptoms. They could continue their routine work using cotton or vinyl undergloves or special latex surgical gloves. Atopy, hand eczema and surgical work seemed to be predisposing factors. In operating units, 7.4% of the doctors and 5.6% of the nurses were allergic; the frequency was lower in non‐operating units and among laboratory personnel. The high frequency of latex glove allergy, especially in operating units, focuses attention on the quality of surgical latex gloves

Efficacy and safety of hydrolyzed cow milk and amino acid–derived formulas in infants with cow milk allergy

OBJECTIVE To determine the antigenicity, nutritional adequacy, and growth-promoting efficacy of protein hydrolysate or amino acid-derived formulas in infants with cow milk allergy. STUDY DESIGN Several protein hydrolysate or amino acid-derived formulas were graded for beta-lactoglobulin content and skin reactivity in 74 atopic children with cow milk allergy proved by a double-blind, placebo-controlled challenge. A randomized, prospective follow-up study of 9 months included 22 infants with a mean age of 6 months (95% confidence interval, 4 to 7), who were fed an extensively hydrolyzed whey formula (group We), and 23 infants with a mean age of 17 (95% confidence interval, 4 to 7) months, who were given an amino acid-derived formula (group AA). RESULTS Both formulas were clinically and biochemically tolerated. The mean concentration of essential amino acids in plasma was lower in group We but higher in group AA compared with values for breast-fed control infants (p = 0.001). There was a different trend between the groups in weight (p = 0.09) and length (p = 0.006). Growth was promoted in group AA during the follow-up; it was constant during the first months, followed by a gradual decline in rate in group We. In both groups, atopic eczema improved significantly and progressively, and a downward trend was found in serum total and milk-specific IgE concentrations, proving the efficacy of both formulas. CONCLUSIONS Extensively hydrolyzed formulas are safe and effective for most infants; an amino acid-derived formula may be preferable for infants with multiple food allergies, especially for the maintenance of normal growth.

Cow's milk allergy: diagnostic accuracy of skin prick and patch tests and specific IgE

Background: The objective of the present study was to evaluate the relevance of skin tests and the concentration of cows milk‐specific IgE antibodies in correlation with oral cows milk challenge in infants with suspected cows milk allergy.

Prohevein from the rubber tree (Hevea brasiliensis) is a major latex allergen

Background There is general agreement that proteins eluting from different natural rubber latex products can cause immediate type hypersensitivity reactions in latexallergic patients. However, there is as yet no consensus as to what are the most important allergens in natural rubber latex.

Latex allergy diagnosis: in vivo and in vitro standardization of a natural rubber latex extract

For the diagnosis of IgE‐mediated (immediate) hypersensitivity to natural rubber latex (NRL), skin prick testing with extracts of latex gloves has been widely used, but such extracts are difficult to standardize. The present study aimed to produce on an industrial scale an NRL extract from freshly collected NRL and to evaluate, calibrate, and standardize the extract by both in vivo and in vitro testing. The source material, latex of the rubber tree, Hevea brasiliensis (clone RRIM 600), was frozen immediately after collection in Malaysia and shipped in dry ice to Stallergènes SA, France. Protein and allergen profiles were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE), immunoblotting, isoelectric focusing (IEF), crossed immunoelectrophoresis (CIE), and crossed radioimmunoelectrophoresis (CRIE). Allergen quantification was effected by RAST inhibition. The capacity of the preparation to elicit immediate hypersensitivity reactions in vivo was measured by skin prick testing in 46 latex‐allergic patients and 76 nonallergic control subjects. SDS‐PAGE and immunoblot profiles of the extract and an NRL standard (E8) provided by the US Food and Drug Administration were almost identical, disclosing several distinct IgE‐binding proteins with apparent molecular weights of 14, 20, 27, 30, and 45 kDa, conforming to reported molecular weights of several significant NRL allergens. An arbitrary index of reactivity (IR) of 100 was assigned to the extract at 1:200 dilution (w/v), having a protein content of 22 μg/ml. Skin prick testing of latex‐allergic patients and controls using the extract at 100 IR revealed 93% sensitivity, 100% specificity, 100% negative predictive value, and 96% positive predictive value. In conclusion, a skin prick test reagent for diagnosis of type I NRL allergy was successfully standardized. The reagent was demonstrated to contain most, if not all, of the currently known clinically significant NRL allergens, and it showed high sensitivity and specificity.

Hevein-like protein domains as a possible cause for allergen cross-reactivity between latex and banana

BACKGROUND Patients allergic to natural rubber latex (NRL) frequently exhibit immediate hypersensitivity reactions to banana, but the molecular basis of these putative cross-reactions is unknown. OBJECTIVE We wanted to examine whether proteins resembling hevein, a major NRL allergen, exist in banana and whether coexisting allergy to NRL and banana can be explained by IgE cross-reactivity to these proteins. METHODS Allergens in banana cross-reacting with hevein were identified by IgE immunoblot inhibition. The cross-reacting proteins were purified by reversed-phase chromatography and characterized by amino acid sequencing. Allergen cross-reactivity was further assessed by IgE ELISA, IgE ELISA inhibition, and skin prick testing. RESULTS In immunoblotting, 9 of 15 sera from patients allergic to NRL with IgE to hevein showed IgE binding to 32- and 33-kd banana proteins. These 2 protein bands were also targets to IgG from a hevein-immunized rabbit. IgE binding to both 32- and 33-kd protein bands was totally inhibited by hevein (10 ng/mL) in all 5 sera from patients allergic to NRL sera studied. N-terminal sequencing of the purified 32- and 33-kd proteins revealed 80% identity to the N-terminus of hevein. An internal peptide (19 amino acids) of the 33-kd protein gave over 90% identity to endochitinases of several plants. In ELISA all 15 sera from patients allergic to NRL had IgE to the purified 32-kd banana protein. In ELISA inhibition hevein (10 ng/mL) inhibited approximately 50% of IgE binding to the solid-phase 32-kd banana protein in a pool of sera from patients allergic to NRL. CONCLUSION These results suggest that the commonly occurring hypersensitivity to banana in patients allergic to NRL could be explained by cross-reacting IgE antibodies binding to epitopes in hevein and in a hevein-like domain of a previously undescribed endochitinase in banana.

Differences in skin‐prick and patch‐test reactivity are related to the heterogeneity of atopic eczema in infants

Current data indicate an obvious relation between food allergy and atopic eczema in infants. However, diagnostic methods for food allergy need to be supplemented. The objective was to study the relevance of food patch testing in the detection of food allergy in correlation with oral food challenge and skin prick tests in atopic infants. Infants with atopic eczema (n = 113) aged 2–24 months were studied. Each patient was subjected to double‐blind, placebo‐controlled, or open cows milk challenge, and skin prick and patch tests. Polysensitization, as judged from skin test results, was common in patients with atopic eczema (79/113). Cows milk challenge was positive in 54/113 infants; reactions were immediate in 36/54 and delayed in 18/54. Immediate‐type reactions were associated with skin prick test positivity and delayed reactions with patch test positivity. Altogether 26% of the cows milk‐allergic infants were detected by patch testing only. Patch testing improved the accuracy of skin testing in the diagnosis of food allergy in infants with atopic eczema, but it needs to be standardized. Polysensitization appears to be more common than generally believed among infants with atopic eczema.

Measurement of natural rubber latex allergen levels in medical gloves by allergen-specific IgE-ELISA inhibition, RAST inhibition, and skin prick test

Exposure to natural rubber latex (NRL) medical gloves poses risks to patients sensitized to NRL and to users of protective gloves. Previous studies have shown that extractable allergen levels of the gloves vary widely. Since most of the available laboratory methods of NRL allergen measurement lack adequate validation, we wanted to evaluate the performance of a recently developed competitive IgE‐ELISA‐inhibition method in relation to the skin prick test (SPT) and RAST inhibition, as well as to extractable protein quantification and an immunochemical latex antigen assay (LEAP). Twenty samples of surgical (n = l4) and examination gloves (n=6), covering >90% of medical gloves marketed in Finland in 1994–5. were collected by the Finnish National Research and Development Centre for Welfare and Health, coded, extracted, and analyzed by the five methods. The IgE‐ELISA inhibition correlated highly significantly with SPT (r=0.94) and RAST inhibition (r=0.96). Likewise, ELISA inhibition and RAST inhibition showed highly significant correlation (P=0.96, P<0.0001 in all three instances). Protein quantification by a modified Lowry method also correlated highly significantly with SPT (r=0.80). RAST inhibition (r=0.82), and ELISA inhibition (r=0.81. P100 AU/ml) in seven of the 20 glove brands analyzed. In conclusion, the results of a novel IgE‐ELISA‐inhibition method of measuring NRL allergen levels in medical gloves correlated highly significantly with those of SPT TTie ELISA method was found to be sensitive, reproducible, technically easy, inexpensive, and suitable for the analysis of large numbers of NRL products. The results of extensive market surveys in 1994 and 1995, communicated to the medical community in Finland, appear to have had a clear effect in moving glove purchasing policies toward the use of low‐allergen gloves.

Cross-reacting allergens in natural rubber latex and avocado ☆ ☆☆ ★ ★★

BACKGROUND An association between allergy to latex and avocado has been reported but the responsible cross-reacting allergens have not been identified or characterized. METHODS Immunoblotting, immunoblot inhibition, and RAST inhibition methods were used to study cross-reactive proteins between natural rubber latex (NRL) and avocado. Sera from 18 patients with previously verified latex allergy were used as the source of IgE antibodies, and 11 of the patients underwent skin prick testing with fresh avocado. RESULTS Fourteen of the 18 sera (78%) had IgE antibodies that bound to a total of 17 avocado proteins with apparent molecular weights ranging from 16 to 91 kd. Ten most strongly reacting sera were used for immunoblot inhibition studies. When NRL proteins were used as soluble inhibitors, binding of IgE antibodies to solid-phase avocado proteins was inhibited in a dose-dependent manner: 100 micrograms of NRL proteins inhibited IgE binding to 15 of the 17 avocado proteins, and 10 micrograms caused inhibition to 13 protein bands. Comparably, soluble avocado proteins were able to inhibit IgE binding to solid-phase NRL. Corresponding RAST inhibitions were performed with two patient sera; in both, avocado inhibited IgE binding to NRL and in one NRL proteins inhibited IgE binding to avocado. Skin prick test responses to fresh avocado were positive in seven of the 11 patients with latex allergy who were tested. CONCLUSIONS The large number of inhibitable proteins in immunoblot experiments and clinical observations from skin prick tests suggest considerable immunologic cross-reactivity between NRL and avocado. The observed cross-reacting protein components may be responsible for the recently reported type I hypersensitivity reactions to NRL and avocado in patients with a preexisting allergy to either allergen.

Identification of patatin as a novel allergen for children with positive skin prick test responses to raw potato

BACKGROUND Peeling of raw potatoes may cause allergic symptoms, such as sneezing, wheezing, and contact urticaria, for adults. For children, potatoes as food may cause various allergic reactions. However, the identity and molecular structure of the putative allergens in potato have remained unknown. OBJECTIVE The aim of our study was to identify possible major allergens in potato by using sera of atopic children suspected of having food allergy and having positive skin prick test responses to raw potato. METHODS Potato proteins were purified by standard methods of protein chemistry and characterized with amino-terminal sequencing and mass spectrometry. The IgE-binding ability of the purified proteins was verified by immunoblotting and ELISA with IgE antibodies from the sera of atopic children having positive skin prick test responses to raw potato. RESULTS Immunoblotting showed strong IgE binding to a 43-kd protein, identified as patatin, the main storage protein of potato tubers. In ELISA, 20 of 27 (74%) children with positive skin prick test responses to potato and none of the control subjects showed specific binding of IgE antibodies to purified patatin. A positive wheal-and-flare reaction was seen in 8 of 14 children prick tested with purified patatin. CONCLUSION These results show that patatin in potatoes is a significant, previously unrecognized,IgE-binding protein for children with a positive skin prick test response to raw potato. Further studies are needed to confirm the clinical importance of potatoes, and especially patatin, as a food allergen.