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H Oman

Publications and source records attributed to H Oman.

At least 19 recordsLinked to original sources
PubMed2006

Pholcodine stimulates a dramatic increase of IgE in IgE-sensitized individuals. A pilot study.

BACKGROUND: A previous study showed a relation between pholcodine (PHO) consumption, prevalence of IgE-sensitization to PHO, morphine (MOR) and suxamethonium (SUX) and anaphylaxis to neuromuscular blocking agents (NMBA). The purpose of this pilot study was to explore the effect on IgE production, in IgE-sensitized and nonsensitized individuals, of exposure to cough syrup and environmental chemicals containing PHO, MOR and SUX related allergenic structures. METHODS: Serum concentrations of IgE and IgE antibodies to PHO, MOR and SUX allergens measured by ImmunoCAP (Pharmacia Diagnostics, Uppsala, Sweden) were followed after intake of cough syrup, or exposure to confectionary and other household chemicals containing various amounts of substances cross-reacting with PHO, MOR and SUX. RESULTS: Cough syrup containing PHO gave, in sensitized individuals, within 1-2 weeks, an increase of IgE of 60-105 times and of IgE antibodies to PHO, MOR and SUX in the order of 30-80 times. The tested confectionary did not have any similar stimulating effect but seemed to counteract the expected decrease of IgE. No effect was seen in nonsensitized individuals. The PHO stimulated IgE showed a nonspecific binding to ImmunoCAP with common allergens and glycine background ImmunoCAP that was up to 10-fold higher than that of monomeric myeloma-IgE at twice the concentration. CONCLUSIONS: It seems as cough syrups containing PHO have a most remarkable IgE boostering effect in persons IgE-sensitized to PHO, MOR and SUX related allergens. Household chemicals containing such allergenic epitopes seem capable of some, minor, stimulation.

Adult↗
PubMed2006

Basophil allergen threshold sensitivity: a useful approach to anti-IgE treatment efficacy evaluation.

BACKGROUND: Monitoring of the allergen sensitivity of a patient is most important for optimal patient care and a basic prerequisite for immunomodulating treatment. The objective of this study was to investigate how basophil allergen sensitivity can be applied in the monitoring of anti-immunoglobulin E (IgE) treatment. METHODS: Basophils from timothy grass pollen allergic patients were, by flow cytometry, analysed for allergen threshold sensitivity (CD-sens) by measuring CD63 up-regulation on CD203c-identified basophils. The results were compared with maximal percentage CD63 up-regulation at one allergen dose (CD-max), skin prick test end-point allergen titration, (SPT-sens), nasal provocation titration tests (nasal provocation titre) and serum IgE and IgE antibody concentrations. RESULTS: There was a significant correlation (r = 0.50, P = 0.01) between CD-sens and SPT-sens, CD-sens and the IgE antibody concentration in percentage of 'total IgE' (relative IgE antibody concentration) (r = 0.72, P < 0.001) as well as between CD-sens and nasal provocation titre (r = 0.54, P < 0.05) but, in contrast, CD-max did not correlate with any of the sensitization parameters, i.e. SPT-sens, nasal provocation titre, absolute and relative IgE antibody concentration or CD-sens. CD-sens could be used to monitor omalizumab treatment efficacy while, based on CD-max, four of seven symptom-free patients on omalizumab would have been classified as having ongoing allergy. CONCLUSIONS: CD-sens seems to be very useful for the determination of a patient's allergen sensitivity and should be evaluated for the measurement and monitoring of anti-IgE treatment efficacy. CD-max, the conventional approach to basophil allergen challenge, which mirrors cell reactivity, gives incorrect information.

Allergens↗
PubMed2006

The importance of IgE antibody levels in anti-IgE treatment.

BACKGROUND: Dosages of anti-immunoglobulin (Ig)E in treatment of allergic asthma is based on total IgE body pool assuming that IgE antibodies responsible for the disease are evenly distributed among patients. This assumption was evaluated. METHODS: Median and quartile concentrations of IgE and IgE antibodies to cat and mite in 6461 sera submitted to an allergy laboratory during 2003-2005 were calculated and expressed in groups of different IgE levels. RESULTS: Of 3872 (60%) samples from adults with a serum IgE level of 30-700 kU/l, 22.2% had IgE antibodies (>or=0.35 kU(A)/l) to mite, 36.0% to cat and 8.1% to both. The relative concentration of IgE antibody of IgE decreased with increasing IgE, indicating a more specific response in patients with slightly elevated serum IgE. At a hypothetical serum IgE level of 10 kU/l, the threshold recommended for anti-IgE treatment, 25% of the originally mite- and/or cat-positive population in the <75 kU/l IgE group still would have detectable IgE antibodies. CONCLUSIONS: Sera from patients sensitized to mite and cat with moderate serum IgE levels have a high proportion of IgE antibodies; in the 30-74 kU/l group, as much as 10% of the IgE could be specific to one allergen. An increase of the anti-IgE dosage given to such patients should be considered, especially because IgE antibodies with different, relevant specificities have an additive effect in triggering inflammatory cells.

Adult↗
PubMed2006

Simultaneous exposure of several allergens has an additive effect on multisensitized basophils.

BACKGROUND: Patients immunoglobulin (Ig)E-sensitized to more than one allergen in their environment often have more symptoms than mono-sensitized individuals, which indicates that the allergens may have an additive effect. In order to study if such an effect could be detected on the inflammatory, cellular level, multisensitized basophils were challenged with various dose combinations of two relevant allergens. METHODS: Basophils from patients IgE-sensitized to timothy/cat, birch/cat, timothy/mite and cat/mite were challenged with serial dilutions of different combinations of the two allergens. The basophil response was measured as CD63 expression analysed by flow cytometry. RESULTS: The doses of each allergen in the pair had an additive effect resulting in a shift of the dose-response curve to higher CD63 percentages and higher CD-sens. CONCLUSIONS: If a patient has IgE antibodies and thus sensitized basophils to more than one allergen, to which he is simultaneously exposed, the additive effect should be considered. Even low concentrations of IgE antibodies could be of clinical relevance in such a situation.

Allergens↗
PubMed2005

IgE-sensitization to predatory mites and respiratory symptoms in Swedish greenhouse workers.

BACKGROUND: Predatory mites are used as biological pesticides worldwide for control of spider mites and other pests in greenhouses. The aim of this study was to evaluate the impact of occupational exposure to Phytoseiulus persimilis and Hypoaspis miles on IgE sensitization among a large group of Swedish greenhouse workers and to examine the relationship between exposure and allergic asthma and rhinoconjunctivitis. METHODS: A total of 96 greenhouse workers from the southern part of Sweden, who were using the predatory mites for control of pests, were investigated with a questionnaire and a medical examination including lung function test. Blood samples were taken to test for allergen-specific IgE antibodies to Phytoseiulus persimilis and Hypoaspis miles as well as to Tetranychus urticae, Dermatophagoides pteronyssinus/farinae and Tyrophagus putrescentiae. RESULTS: Seventeen of the 96 workers were positive in ImmunoCAP to predatory mites: 17 to P. persimilis (17.7%) and 14 to H. miles (14.6%). Subjects sensitized to predatory mites were significantly more often atopic (13/17), defined as a positive Phadiatop, than those who lacked IgE against these mite species (17/79) (P <0.01). IgE antibodies to the red spider mite T. urticae were present among 23 subjects. Thirty-five of the investigated subjects displayed a positive ImmunoCAP to at least one of the investigated mite species. Furthermore, sensitization to any of the mites tested was significantly associated with asthma (OR=9.3) and rhinoconjunctivitis (OR=4.3). CONCLUSIONS: IgE sensitization to predatory mites, P. persimilis and H. miles, is common among greenhouse workers. The findings stress the importance of improved allergen avoidance in greenhouse environments.

Adult↗
PubMed2005

Passive IgE-sensitization by blood transfusion.

BACKGROUND: To study the mechanisms of passive sensitization of patients receiving plasma containing IgE antibodies to a defined allergen. METHODS: When required for medical reasons, regular donor plasma with IgE antibodies to timothy grass allergen (8-205 kU(A)/l), was given. Kinetics of IgE antibodies in the recipients' serum and his/her basophil allergen threshold sensitivity, CD-sens, was monitored up to 2-3 weeks after transfusion. The IgE antibodies were quantitated by ImmunoCAP. The CD-sens in plasma recipients, determined by CD63 up-regulation, was measured by flow cytometry and compared to CD-sens of patients with allergic asthma and/or rhinitis. RESULTS: There was a significant correlation (r = 0.98; P < 0.001) between amount of IgE antibody given and recipient serum peak concentration. The T(1/2) for IgE antibody in circulation was 1.13 days (95% confidence limit 0.35-1.91 days). The recipients became CD-sens positive already 3 h after transfusion. The CD-sens peak was observed after 3.4 days and the value were correlated (r = 0.68; P < 0.02) to the amount of IgE antibody transfused and were of the same magnitude as found in allergic patients. The T(1/2) of CD-sens indicated two populations of basophils; one with a CD-sens decrease T(1/2) of 4 days and one of 10 days. CONCLUSION: Transfused IgE antibodies will sensitize mast cells and basophils to CD-sens levels similar to those of allergic patients. The recipients expressed 'slow' or 'rapid' CD-sens decline, indicating two different basophil populations. After transfusion of plasma with >10 kU(A)/l IgE antibody the recipient could have allergen reactive basophils for up to 7 weeks.

Allergens↗
PubMed2005

High prevalence of IgE antibodies among blood donors in Sweden and Norway.

BACKGROUND: Reactions after a blood transfusion could be allergic because of passive transfer of immunoglobulin E (IgE) antibodies from allergic donors. AIMS OF THE STUDY: To compare spectrum and prevalence of IgE antibodies in blood donors from Sweden and Norway. METHODS: Using the ImmunoCAP method, serum samples from 1002 blood donors from Sweden and 500 from Norway were analysed for IgE antibodies to common inhalant and food allergens and allergens common in a hospital environment, such as penicilloyl G and latex. RESULTS: As many as 23.6-27.3% of the donors had IgE antibodies to at least one of the 14 allergens tested. Of these 6.8-16.7% had extremely high concentrations, i.e. >35 kU(A)/l corresponding to 100 times the cut-off for a positive allergy test. Most donors were sensitized to pollens, dander and mite but several had very high levels of IgE antibodies to penicilloyl G, latex and peanut. The pattern of sensitizing allergens differed between Sweden and Norway. CONCLUSIONS: High serum levels of IgE antibodies to various allergens are common among blood donors and the degree of sensitization and spectrum of involved allergen varies between geographical regions. Present routines to identify IgE sensitized, potential risk, donors are not satisfactory; the sensitivity of selection procedures is about 25%.

Allergens↗
PubMed2005

Prevalence of IgE antibodies to morphine. Relation to the high and low incidences of NMBA anaphylaxis in Norway and Sweden, respectively.

BACKGROUND: Anaphylactic reactions to a neuromuscular blocking agent (NMBA) is more than six times as common in Norway as in Sweden, probably due to differences in preoperative sensitization. The prevalence of IgE-sensitization to morphine (MOR) and suxamethonium (SUX) in comparable populations in Bergen, Norway, and Stockholm, Sweden, was studied and related to possible sensitizing agents. METHODS: Three hundred sera of 'allergics' and 500 blood donors in Bergen and Stockholm were tested for IgE antibodies to MOR and SUX using Pharmacia Diagnostics ImmunoCAP(Uppsala, Sweden) assay and the results compared to those of 65 patients from Bergen with documented anaphylaxis to NMBA. In addition, 84 different household chemicals were tested, by IgE antibody inhibition, for SUX and MOR. RESULTS: In Norway 0.4% of blood donors, 3.7% of allergics and 38.5% of anaphylactics were IgE-sensitized to SUX, and 5.0, 10.0 and 66.7%, respectively, to MOR. No serum from Sweden was positive. The majority of those sensitized (69%) were women. Several household chemicals contained SUX and/or MOR activity, but the only difference between Norway and Sweden was cough mixtures containing pholcodine (PHO). IgE antibodies to PHO were present in 6.0% of blood donors from Norway and in no serum from Sweden. Of the anaphylactics, 65-68% were sensitized to MOR or PHO but only 39% to SUX. CONCLUSIONS: IgE-sensitization to SUX, MOR and PHO was detected in Norway but not in Sweden. One possible explanation is the unrestricted use of cough mixtures containing MOR derivatives in Norway.

Algorithms↗
PubMed2001

Instrumental and dermatologist evaluation of the effect of glycerine and urea on dry skin in atopic dermatitis.

BACKGROUND/AIMS: Moisturising creams are useful treatment adjuncts in inflammatory dermatoses and have beneficial effects in the treatment of dry, scaly skin. The effects on dryness and skin permeability of a new moisturising cream with 20% glycerine was compared with its placebo and with a medicinally authorised cream with 4% urea (combined with 4% sodium chloride) in the treatment of dry skin. METHODS: Patients (n=109) with atopic dermatitis were treated for 30 days with a moisturiser in a randomised, parallel and double-blind fashion. Transepidermal water loss (TEWL) and skin capacitance were assessed instrumentally, and changes in the dryness of the skin were assessed by the dermatologist. RESULTS: No difference in TEWL was found between glycerine treatment and its placebo, whereas a lower value was found in the urea-treated area compared to the glycerine-treated area. No difference in skin capacitance was found. The clinical assessment of dryness showed urea to be superior to glycerine in treating the condition. CONCLUSIONS: Moisturising creams are different, not only with respect to composition but also with respect to their influence on skin as a barrier to water in patients with atopic dermatitis.

Adult↗
PubMed1999

A case of allergy to cow's milk hydrolysate.

We here report a girl, now 3 years old, who has suffered from severe food allergy since her first year of life. She was strongly allergic to cow's milk, and had high levels of IgE antibody (AB) to casein (210 kU/I), beta-lactoglobulin (43 kU/I), and alpha-lactalbumin (23 kU/l) at 12 months of age. In addition, at the same age, she showed positive (2-4+) skin prick reactions to both unboiled and boiled formulas (Profylac, Nutramigen, and Neocate), besides being positive in RAST to Nutramigen (0.6 kU/l). During the first 3 years, IgE Ab levels against casein and Nutramigen increased to 310 and 1.6 kU/l, respectively. Furthermore, at 3 years of age, she had positive RAST to 14 of 15 tested food allergens, being negative only to codfish. Assessment of eosinophil-related markers revealed high total eosinophil count, increased eosinophil activity, and a low ratio of interferon (IFN)-gamma:IL-5, indicating enhanced IL-5 production. The food allergy was correlated to poor weight gain and increasing problems with atopic allergy in the airways.

Animals↗
PubMed1999

Peanut oil in vitamin A and D preparations: reactions to skin test and manifestation of symptoms.

The aim of this study was to establish whether there is a link between sensitisation to peanut and exposure to peanut oil in vitamin A and D preparations. Forty-one children with a positive in vivo or in vitro test towards peanut were included. Twenty-one children had consumed vitamins A and D in oil solution, 14 in water solution, and 6 both types. Refined and unrefined peanut oils were obtained and skin prick test extracts were prepared. None of the children exhibited a positive SPT in response to the refined peanut extract. In contrast, 15 children exhibited a positive SPT to the unrefined extract. There was no significant difference in the number of children reacting clinically to peanut exposure who had received vitamins A and D in oil-based or water-based formulations. However, children with clinical allergy to peanut and who had exclusively consumed vitamin A and D in peanut oil, exhibited a greater number of different allergic symptoms upon consumption of peanut compared with clinical allergic children who had consumed the vitamins in water solution or both types (p<0.01). This study indicates that sensitisation to peanut during childhood through consumption of vitamins A and D in oil-based solution seems unlikely, but its consumption may contribute to the development of a wider range of clinical symptoms due to peanut exposure.

Adolescent↗
PubMed1999

A retrospective study of seroconversion against Toxoplasma gondii during 3,000 pregnancies in Stockholm.

The incidence of Toxoplasma gondii infections in Swedish women during pregnancy is largely unknown. This retrospective pilot study was performed on consecutive sera sampled from 3,094 women at delivery during 1992-93. Specific IgG anti-toxoplasma antibodies were found in 14% (450/3,094). Serum drawn from the women during the first trimester and cord blood from their children were analysed for IgG and IgM anti-toxoplasma antibodies. A seroconversion during pregnancy was found in 4 women, whose children were followed up at 4 years of age. No signs of sequelae, either neurological or ophthalmological, were found in 3 of the children. The fourth child died at 1 year of age of a disease of different aetiology. An incidence of a primary toxoplasma infection of >1/1,000 pregnancies in this pilot study justifies a larger study.

Adolescent↗
PubMed1998

Reversible increase in tight junction permeability to macromolecules in rat ileal mucosa in vitro by sodium caprate, a constituent of milk fat.

Intestinal tight junction function is thought to be of importance in the pathogenesis of various diseases. The regulation of uptake of macromolecules via the tight junctions is largely unknown. Effects of luminal sodium caprate (10 mM), a dairy product constituent, and cytochalasin B (30 microM), were studied in rat ileum in vitro in Ussing chambers. Both agents caused a reversible fall in potential difference and increased [51Cr]EDTA permeability. In addition, sodium caprate induced increased permeability to polysucrose (15,000 daltons) and opening of the tight junctions as visualized by transmission electron microscopy. Dose-response patterns suggested mainly dose-dependent differences between the agents. Confocal laser scanning microscopy suggested paracellular permeation of polysucrose. Luminal sodium caprate, a food constituent, can increase tight junction permeability, allowing passage of macromolecules, without affecting epithelial viability. Increased permeability to medium-sized molecules does not necessarily coincide with increased paracellular uptake of protein-sized molecules.

Animals↗
PubMed1997

Influence of maternal infections with viral agents or Toxoplasma gondii during pregnancy on fetal IgE production.

The importance of maternal infections with Toxoplasma gondii, cytomegalovirus (CMV), Parvovirus B19, respiratory syncytial virus (RSV), and influenza A and B on fetal IgE synthesis was studied in 153 pregnant women. No case of specific IgM activity or viral DNA in cord blood, indicating a congenital infection, was found. From gestational week 15 to delivery, maternal IgG-Ab seroconversion to Parvovirus B19, RSV, influenza A, or influenza B occurred in 47 women. At delivery, serologic signs of past infection with T. gondii were observed in 29 (19%) women, and the corresponding figure for CMV was 117 (77%). The number of women with positive IgG seroconversion during pregnancy or positive IgG-Ab activity toward the studied infectious agents at delivery did not differ significantly among infants with an increased (> or = 1.3 kU/l; n = 51) or with an undetectable (< 0.1 kU/l; n = 102) cord-blood IgE level. These results show that genetic and other environmental factors probably have a greater influence on fetal IgE synthesis than do maternal infections during pregnancy.

Adolescent↗
PubMed1997

Permeation of polysucrose 15000 across the human nasal mucosa in vivo.

Studies of the nasal permeation of small molecules (< 1000 Da) have yielded important information about the integrity of the human airway mucosa in health and disease. In this study, we used a much larger tracer molecule, polysucrose (PS) 15,000 (approx. 14,700 Da), to predict the mucosal permeation of inhalational allergens. PS 15,000 (50 mg/ml; 15 ml), with or without a detergent type of permeation enhancer (dioctyl sodium sulfosuccinate 10 mg/ml), was maintained for 15 min in one nasal cavity of 12 healthy nonatopic subjects by employment of a nasal-pool device. Permeation as determined by the 24-h urine recovery of PS (micro-ELISA analysis assay) was expressed as percentage of nasal instillate. Mean baseline permeation was 0.044% (range 0.009-0.250%). In the presence of the detergent, permeation increased to 0.600% (range 0.007-2.260%) (P < 0.01). After oral intake of 750 mg of PS 15,000 (50 micrograms/ml; 15 ml), the 24-h urinary recovery was 0.013% (range 0.004-0.023%). Our study thus demonstrates a measurable baseline permeation of PS 15,000, an elevated permeation rate in the presence of an epithelium-damaging detergent molecule, and a negligible permeation by the oral route. These properties support the utility of PS 15,000 as a nasal airway permeation tracer. Its size further suggests that its permeation may reflect mucosal perviousness to many allergens.

Adult↗
PubMed1996

Detection of naproxen-induced intestinal permeability change may be facilitated by adding a standardized meal but not by forming marker ratios.

BACKGROUND: We recently compared the intestinal permeability markers polysucrose (PS) 15,000, 51Cr-ethylenediaminetetraacetic acid (EDTA), and 14C-mannitol in healthy humans. We have now studied the ability of these markers to show non-steroidal anti-inflammatory drug (NSAID)-induced intestinal damage, with special regard to the possibility of improving discrimination versus healthy intestine by using a hyperosmolar test solution, adding a standardized liquid meal, calculating paracellular/ transcellular marker excretion ratios, or correcting excretion values for urinary volume. METHODS: Seventeen healthy volunteers ingested a solution containing PS 15,000, 51Cr-EDTA, and 14C-mannitol before and after 1 week of naproxen intake, the solution being isosmolar, hyperosmolar, or isosmolar and followed by a standardized liquid meal. Fractional urinary excretion of the substances was measured over 0-4 h, 4-8 h, and 8-12 h. RESULTS: The excretion of the paracellular permeability markers PS 15,000 and 51Cr-EDTA increased after NSAID pretreatment, whereas that of the transcellular marker 14C-mannitol was unaffected. A standardized liquid meal reduced test variability for all markers and tended to improve differentiation between diseased and healthy intestine. A hyperosmolar test solution tended to improve differentiation for 51Cr-EDTA but not for PS 15,000. Calculating a paracellular/transcellular ratio or correcting excretion values for urinary volume did not improve the differentiation. CONCLUSIONS: A standardized liquid meal may improve the capacity of permeability tests to distinguish between healthy and NSAID-damaged intestine.

Adult↗