Erik Florvaag

Antigenic and allergenic determinants of ovalbumin. I. Peptide mapping, cleavage at the methionyl peptide bonds and enzymic hydrolysis of native and carboxymethyl OA.

The effects of enzymic cleavage and perturbing the conformation of the allergenic and antigenic determinants of hens egg white albumin (OA) were examined. Hens egg white extract of a total protein concentration 8.43 g/l was prepared. Isoelectric focusing in sodium dodecyl sulfate and polyacrylamide gel peptide maps for the crude egg white extract showed 26 spots visualized by staining with Coomassie blue. The OA was purified using a TSK-2000 gel filtration chromatography column. The specific allergenic reactivity of the purified OA as measured by RAST inhibition and direct RAST was relatively high: 3 micrograms gave an inhibition of approximately 10%. The cleavage of OA with cyanogen bromide resulted in 4 fractions, all capable of binding specific IgE with the first peak showing the highest inhibition. Thermal denaturation of OA had no direct effect on the antigenic reactivity. RAST inhibition values for the denatured protein were similar to those of the native protein. Carboxymethylation of OA gave a product with only 20% of the inhibition reactivity. Further treatment with trypsin did not abolish the allergenic and antigenic reactivities as shown by RAST inhibition and by deflection of OA line in rocket line immunoelectrophoresis. On the other hand, limited pepsin hydrolysis destroyed the antigenic structure of the molecule. The reactivity of OA is thus relatively stable and could easily be retained making it possible to identify the allergenic determinants of enzymic hydrolysates used for elucidating the antigenic structure of the molecule.

Quality of life in patients with subjective food hypersensitivity: Applicability of the 10-item short form of the Nepean Dyspepsia Index

The aim of this study was to investigate quality of life and applicability of the 10-item short form of the Nepean Dyspepsia Index (SF-NDI) in patients with subjective food hypersensitivity. Fifty-two adult patients and 120 controls were examined using three questionnaires: Quality of life Nepean Dyspepsia Index (NDI), Gastrointestinal Symptom Rating Scale (GSRS), and Ulcer Esophagitis Subjective Symptoms Scale (UESS). To document psychometric properties, 20 of the patients filled in the SF-NDI questionnaire once more 4 weeks later. Patients had poor quality of life compared with controls from health care workers or general population (P < 0.001). Scores on SF-NDI were significantly correlated with scores on the GSRS (r = 0.34, P = 0.02) and UESS (r = 0.41, P = 0.003). The SF-NDI performed very satisfactorily, with a high reliability, construct validity, and responsiveness. Patients with subjective food hypersensitivity have considerably reduced quality of life. The SF-NDI provides reliable, responsive, and clinically valid measures of quality of life in these patients.

Prevalence of airway symptoms among hairdressers in Bergen, Norway

OBJECTIVE To assess respiratory symptoms among hairdressers in Norway. METHODS The study was based on a questionnaire sent to 100 hairdressers (91% responding) and 95 office workers (84% responding). The questionnaire sought information about allergy, respiratory symptoms in the past year, and symptoms after exposures to different types of pollutants, working conditions, and smoking habits. A population based control group was established because the hairdressers and office workers differed in age and smoking habits. RESULTS The prevalence of respiratory symptoms in the past year did not differ significantly between hairdressers and office workers after adjusting for age, atopy, and smoking. The hairdressers over 40 years of age reported significantly more symptoms—such as wheezing and breathlessness—in the past year than the office workers of the same age. Compared with the population based control group, both hairdressers younger than 30 and those over 40 reported more symptoms—such as breathlessness in the past year. The oldest hairdressers reported such symptoms as wheezing and breathlessness more often than did the younger hairdressers. These differences in breathlessness were significant after adjusting for smoking and wheezing. The same trend was not found among the office workers. The hairdressers reported significantly more wheezing, breathlessness, runny eyes, and blocked or runny nose from exposure to hair dyes, permanent oils, bleaching powder, and other chemicals used in a hairdressing salon, compared with the office workers. Prevalence of symptoms during exposure to other types of generel pollutants was similar in the two groups. CONCLUSIONS Hairdressers are exposed to low levels of various irritating chemicals every day. The prevalences of acute symptoms related to the exposure of hairdressers to hairdressing chemicals are very high. Hairdressers, especially the oldest hairdressers, have more asthma-like symptoms than the control groups.

Subjective Health Complaints and Modern Health Worries in Patients with Subjective Food Hypersensitivity

Perceived food hypersensitivity is much more common than food allergy as medically verified. Unexplained symptoms and wrong attribution are typical in subjective health complaints. We hypothesize that subjective health complaints and worries are abnormally prevalent among patients with subjective food hypersensitivity. Forty-six patients with subjective food hypersensitivity and two control groups, one formed by 50 health care workers and one by 70 sex- and age-matched volunteers from the general population, were included in our study. All filled in two questionnaires: Subjective Health Complaints Inventory and Modern Health Worries Scale. None of the patients had IgE-mediated food allergy. The patients scored significantly higher than the controls on sum scores for four domains of subjective health complaints, including gastrointestinal complaints (P < 0.001), musculoskeletal complaints (P < 0.01), “pseudoneurology” (P < 0.001), and allergy (P < 0.001). Sum scores on modern health worries did not differ significantly between groups. The results support our hypothesis of an association between subjective food hypersensitivity and subjective health complaints, corroborating the view that, in the absence of food allergy, the conditions are sharing pathogenetic mechanisms.

Indications of 'atopic bowel' in patients with self-reported food hypersensitivity.

Aliment Pharmacol Ther 31, 1112–1122

Occupational rhinitis: diagnostic criteria, relation to lower airway symptoms and IgE sensitization in bakery workers

Conclusions. The use of different diagnostic criteria has considerable consequences for the prevalence estimates of occupational rhinitis. There is a strong relationship between occupational rhinitis and lower airway symptoms. Storage mites appear to be important occupational allergens in Norwegian bakeries. Objectives. To study the consequences of various diagnostic criteria on the prevalence of occupational rhinitis, assess the prevalence of IgE sensitization and explore the relationships between upper and lower airway symptoms and between symptoms and IgE sensitization. Material and methods. A total of 197 employees in 6 bakeries were interviewed and completed a questionnaire. A skin prick test was performed, total and specific IgE were determined and a histamine release test was performed for relevant allergens. The criteria for the diagnosis of occupational rhinitis were based on the 1994 International Consensus Report on Rhinitis. Results. The prevalence of occupational rhinitis varied between 23% and 50%, depending on the criteria used. The occurrence of nasal symptoms was found to precede the development of lower airway symptoms. Occupational rhinitis, both IgE- and non-IgE-mediated, was associated with asthma symptoms. The most frequent causes of sensitization (20%) were different species of storage mites. Storage mite sensitization was related to occupational rhinitis and work exposure.

Effects of industrial processing on the immunogenicity of commonly ingested fish species.

Background: Food-processing techniques may induce changes in fish protein immunogenicity. Allergens from >100 fish species have been identified, but little is known on the effects of processing on fish protein immunogenicity. Methods: IgE binding of sera of patients allergic to fresh and processed (smoked, salted/sugar-cured, canned, lye-treated and fermented) cod, haddock, salmon, trout, tuna, mackerel and herring and of hydrolysates based on salmon and whiting was investigated using immunoblot and inhibition ELISA. Results: Parvalbumin oligomers were identified using monoclonal and polyclonal antibodies. IgE binding was seen in most sera at 12–14 kDa (parvalbumin), and at 17–60 kDa for all fish except tuna. Changes in IgE binding appeared to reflect altered parvalbumin monomers and oligomers. Smoked haddock, salmon and mackerel had increased IgE binding and novel bands at 30 kDa. Chemically processed cod, salmon, trout and pickled herring had reduced or abolished IgE binding. The serum of 1 subject, however, had increased IgE binding to these products and also inhibition of binding by both fish hydrolysates to their constituent fish species. Conclusion: Process-induced changes in fish protein immunogenicity were more dependent on process rather than species, although individual responses varied. Changes in the allergenicity of a product may depend on the net effect of processing on parvalbumin oligomerization patterns, which may also vary in different species. Chemical processes generally caused loss in IgE-binding activity, though sensitization may occur to modified or degraded rather than intact peptides as shown by increased binding by chemically processed fish and hydrolysates in 1 subject. The clinical significance of these findings remains to be established.

Patients with subjective food hypersensitivity: the value of analyzing intestinal permeability and inflammation markers in gut lavage fluid.

Background/Aim: Subjective food hypersensitivity is prevalent in the general population. The aim of this study was to seek objective evidence of food hypersensitivity by analyzing intestinal permeability and inflammation markers in gut lavage fluid. Methods: Fifty-two patients with abdominal complaints self-attributed to food hypersensitivity were examined by skin prick test, serum IgE analysis, double-blind, placebo-controlled food challenge (DBPCFC), and intestinal lavage. The results were compared with those of 44 patients without food hypersensitivity. Neither the patients nor the controls had organic diseases that could explain their symptoms. Intestinal lavage was performed by administering 2 liters of isotonic polyethylene glycol (molecular weight 3,350 daltons) solution containing 50 µCi of [51Cr]EDTA through a nasoduodenal tube. The first clear fluid passed per rectum was collected and analyzed for histamine, eosinophilic cationic protein (ECP), tryptase, and calprotectin. The intestinal permeability was assessed by determining the 5-hour urinary excretion of [51Cr]EDTA. Calprotectin was also analyzed in native faecal samples. Results: The ECP concentration in gut lavage fluid was significantly higher in the patients than in the controls (p = 0.007), but the overlap between groups was large. Food hypersensitivity was confirmed by positive DBPCFC in only 4 patients. On average, histamine and ECP concentrations were high in these patients. Tryptase, intestinal permeability, and faecal and lavage calprotectin levels were normal. Conclusions: Very few patients had objective evidence of food hypersensitivity. Analyzing intestinal permeability and inflammation markers in gut lavage fluid did not contribute to the diagnosis, but further studies on histamine and ECP are warranted.

Response to intestinal provocation monitored by transabdominal ultrasound in patients with food hypersensitivity.

Objective Owing to lack of objective measures, the diagnosis of food hypersensitivity may be difficult. The aim of this study was to investigate whether the intestinal response to direct provocation in patients with food hypersensitivity could be recognized by ultrasound. Material and methods Thirty-two patients with chronic abdominal complaints, self-attributed to food hypersensitivity/allergy were included in the study. Via a nasoduodenal tube, the duodenal mucosa was challenged with the suspected food item dissolved in 10 ml water or saline. Using external ultrasound, the sonographic features (wall thickness and diameter of the duodenal bulb and jejunum, peristalsis activity and luminal fluid) were recorded before and during one hour after challenge. Results Sonographic changes were observed after challenge in 14 (44%) of the 32 patients. A positive sonographic response (increased wall thickness, diameter, peristalsis and/or luminal fluid) was significantly related to a positive skin prick test (p=0.008) and a positive double-blind placebo-controlled food challenge (p=0.03). A significant correlation was found between provocation-induced symptoms and wall thickness of the duodenal bulb (r=0.50, p=0.004) or the jejunum (r=0.42, p=0.02). Intra- and interobserver variation of the tracing procedure showed low values. Conclusions Responses of the proximal small intestines to direct provocation (swelling of the wall and exudation of fluid into the lumen) could be visualized by transabdominal ultrasound. This new provocation test could be helpful in the evaluation of patients with food hypersensitivity.

Food allergy and intolerance: response to intestinal provocation monitored by endosonography

OBJECTIVE Objective assessment of adverse reactions to food is a long-felt want. We report our preliminary experience with a new endosonographic allergen provocation test. METHODS Twenty patients were examined, seven patients having food allergy and 13 having food intolerance. The duodenal mucosa was challenged with allergen extracts via a nasoduodenal tube. The responses were recorded using a miniprobe for endosonography through the tube. Thereafter, intestinal lavage was performed by giving 2 l PEG solution containing micro Ci (51)CrEDTA. The gut lavage fluid and urine for 5 h were collected. RESULTS Increased mucosal thickness in response to provocation was recorded in 11 patients, but not more often or pronounced in the allergic than in the intolerance group. Interestingly, increased mucosal thickness associated with a new echogenic layer was seen in two patients and a sustained duodenal contraction, lasting 15-20 min associated with pain, in another two. Intestinal permeability and inflammatory mediators were not significantly different in the two groups. CONCLUSION In patients with self-reported adverse reactions to food abnormal responses to duodenal provocation may be recognised by endosonography. However, neither endosonography nor intestinal permeability or faecal calprotectin responses were able to distinguish between food allergy and intolerance. Sustained duodenal contractions in response to food might be a cause of abdominal pain.