Soili Mäkinen-Kiljunen

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.

Rubber contact urticaria. Allergenic properties of 19 brands of latex gloves

To compare the immediate skin test reactivity of various latex (natural rubber) surgical and cleaning gloves. prick tests were performed on 40 latex‐allergic persons, 26 of whom were sensitized by surgical and 14 by cleaning latex gloves. 6/17 surgical gloves tested and 1/2 cleaning gloves caused positive reactions in almost all (over 87%) of the allergic subjects. In contrast. the frequencies of positive reactions to 4 other surgical latex gloves were us low as 8–21%, suggesting that not all surgical gloves arc equally allergenic. Control prick tests with I synthetic rubber and 1 polyvinyl chloride (PVC) glove were negative in all subjects. 2 surgical latex gloves causing either a high or low number of positive prick tests in allergic subjects were analyzed with high‐pressure liquid chromatography (HPLC). Similar allergenic protein fractions were detected, which showed protein peaks at MW 2000 5000 and 3000 daltons. Corresponding proteins were detected in I latex cleaning glove analyzed and in natural rubber. This result confirms that allergnic proteins persist in various surgical and cleaning latex gloves after manufacture from natural rubber and may cause contact, urticaria symptoms toms in sensitized people.

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.

Banana allergy in patients with immediate-type hypersensitivity to natural rubber latex : characterization of cross-reacting antibodies and allergens

BACKGROUND An association between allergy to latex and banana has been reported. Even though cross-reacting IgE antibodies have been demonstrated, in no study has the existence of structurally similar allergens been confirmed. In the present study banana allergy was studied in a large series of patients with latex allergy. Specific IgE antibodies were characterized for cross-reactivity and compared with pollen RAST results. Latex and banana extracts were investigated for common antigens and allergens. METHODS Latex-, banana-, and pollen-specific (birch, timothy, mugwort) IgE were measured in 47 sera from patients with latex allergy. Thirty-one patients were skin prick tested with banana and questioned for possible reactions after eating bananas. Several RAST inhibition and immunospot inhibition studies were used to characterize cross-reacting IgE antibodies. Structurally similar antigens and allergens were evaluated with crossed-line immunoelectrophoresis and crossed-line radioimmunoelectrophoresis, respectively. RESULTS Latex RAST results were positive in 31 (66%) and banana RAST results were positive in 26 (55%) of the 47 sera. Of the 31 latex RAST-positive sera, 25 (81%) were also banana RAST-positive. Results from latex RAST correlated significantly with results from banana RAST (p < 0.001), but not with those from pollen RAST (p > 0.05). Banana skin prick test results were positive in 11 (35%) of the 31 patients tested. Symptoms after eating bananas were reported by 16 (52%) of the 31 patients. In inhibition studies the binding of IgE antibodies to solid-phase banana and to several latex preparations was inhibited by latex and banana, respectively. In crossed-line immunoelectrophoresis at least one antigen from banana fused with an antigen from latex, which also bound IgE antibodies in autoradiography (crossed-line radioimmunoelectrophoresis). CONCLUSIONS Patients with latex allergy have symptoms caused by banana and show positive skin test and specific IgE test results. Cross-reacting IgE antibodies were confirmed by several inhibition techniques. For the first time, a structurally similar antigen/allergen was demonstrated.

β-lactoglobulin secretion in human milk varies widely after cow's milk ingestion in mothers of infants with cow's milk allergy

Abstract Background: Cows milk proteins secreted in human milk may cause cows milk allergy (CMA) even during exclusive breast-feeding. We studied β-lactoglobulin levels in human milk of mothers of infants with CMA. We also studied intestinal absorption of macromolecules in the same mothers to see whether it is related to the secretion of β-lactoglobulin in human milk. Methods: CMA was verified with oral challenge in 46 of 55 infants assessed. β-Lactoglobulin levels were assessed in human milk from 53 of 55 mothers of the infants before (basal sample) and 1 and 2 hours after an oral cows milk load, which was given after a 24-hour milk-free diet. β-Lactoglobulin was determined by an ELISA with a detection limit of 0.002 μg/L. The 6-hour urine recovery of a high-molecular-weight polyethylene glycol (PEG) 3000 was assessed afer an oral load of PEG in 45 of 55 mothers. Results: β-Lactoglobulin was found in the 1- or 2-hour samples in 75% of the mothers. β-Lactoglobulin levels were increased in the 1- or 2-hour samples as compared with the basal levels in about half of the mothers. The respective levels were decreased in one third of the mothers whose basal β-lactoglobulin levels were higher than in the others. β-Lactoglobulin was found in none of the three human milk samples in 15% of the mothers. After an oral load of a high-molecular-weight PEG 3000, the 6-hour urine recovery of PEG was similar in the mothers of the infants with CMA and the mothers of infants without CMA. Neither was the urinary recovery of PEG related to the β-lactoglobulin levels in human milk. Conclusions: The results support the view that β-lactoglobulin in human milk may contribute to, but does not alone explain, the development of CMA in breast-fed infants.

Dog allergen in indoor air and dust during dog shows

Background and methods:  Dog dander is one of the most important indoor allergens in Nordic countries. Due to the population flow into cities, the number of dogs in urban areas has increased. Dog allergens can be found practically everywhere indoors. We measured allergen content in indoor air and dust during dog shows.

Cow's milk challenge through human milk evokes immune responses in infants with cow's milk allergy

OBJECTIVES In order to measure the immune response evoked in breast-fed infants with cows milk allergy (CMA) by cows milk challenge through human milk, mothers were given increasing doses of cows milk after they had been on a cows milk elimination diet. Another objective was to study the secretion of beta-lactoglobulin (BLG) into human milk before and during milk challenge in relation to the appearance of symptoms in infants. STUDY DESIGN Seventeen asymptomatic mothers who had infants with challenge-proven CMA and 10 asymptomatic mothers who had healthy infants were recruited. Infants ranged in age from 1.8 to 9.4 months. A solid-phase enzyme-linked immunoassay (ELISPOT) was used to assess the total number of immunoglobulin-secreting and specific antibody-secreting cells. Flow cytometry was used to enumerate different lymphocyte subpopulations among peripheral blood lymphocytes primed during provocation by cows milk antigens. BLG levels were assessed in human milk before the challenge and 1, 2, 3, and 4 hours after the commencement of the challenge. RESULTS All but one of the infants with CMA showed symptoms of CMA during cows milk challenge through human milk. There was a significant rise in the total number of immunoglobulin-secreting cells in the IgA and IgG classes associated with a positive cows milk challenge response, but the proportions of peripheral blood B cells bearing CD19, CD23, CD19 and 23, CD5, or CD19 and CD5 were comparable. BLG levels were comparable in both study groups. CONCLUSIONS Most of the infants with CMA reacted to cows milk challenge through human milk. Hypersensitivity reactions to food antigens through human milk may be more common than previously thought.

A sensitive enzyme-linked immunosorbent assay for determination of bovine β-lactoglobulin in infant feeding formulas and in human milk

We developed a sensitive sandwich‐type ELISA for measuring low levels of cows milk (CM) β‐lactoglobulin. Purified anti‐β‐lactoglobulin was used as coating antibody and also as second antibody conjugated with alkaline phosphatase. Polyethylene glycol 6000 was added to the incubation buffers to improve sensitivity. The detection limit of the assay was 0.002 μg/l, which is much better than sensitivities reported for other β‐lactoglobulin assays. The sensitivity was not impaired by the presence of other CM proteins. The recovery from breast milk was 93% and from the diluting buffer 127%. The coefficient of variation within day was 5–15% and between days 10%. One hour after oral intake of milk, P‐lactoglobulin could be detected in the breast milk of three mothers at concentrations of about 1–2 μg/l. Widely different concentrations of β‐lactoglobulin were measured in two protein hydrolysates based on CM whey and casein proteins; the observed concentrations were 200 and 0.0056 μg P‐lactoglobulinμ/g dry weight, respectively.

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.