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BACKGROUND: It is uncertain as to what extent the development of allergic disease in childhood is predictable during early infancy. A number of environmental factors have been suspected of increasing the risk of acquiring allergy, but the evidence is conflicting. OBJECTIVE: To observe the development of atopy and allergic disease in a cohort of high-risk children so as to determine the importance of certain environmental factors and to study the relationship between early and later manifestations. METHODS: A cohort of infants, all at high risk of allergy, was followed up from birth to the age of 7 years. In half, selected at random, cow's milk protein was avoided for 4 months. Skin-prick tests were performed and serum IgE measured in infancy and at 7 years, when an AlaTOP test was also performed. RESULTS: Skin sensitivity to egg in the first year of life was strongly associated with eczema, asthma, mite sensitivity and serum IgE at the age of 7 years, when mother's atopic history was associated with AlaTOP status, father's atopic history with skin sensitivity, and male sex with both. Maternal smoking during pregnancy was associated positively with IgE at 3 months and negatively with skin sensitivity at 7 years. The development of allergy was unrelated to infant feeding method or number of older siblings. CONCLUSION: Allergic disease in childhood is to a large degree determined before birth or during infancy.

Summary Background Previous studies on allergy to feathers have not adddressed whether orgatiisms living on feathers (mites. lice, moulds) are a source of allergens. Objective To investigate whether feather mites produced allergens of clinical relevance to bird keepers. Methods We examined serum IgE responses of 96 pigeon breeders to an extract of feather mites from pigeons (predominantly Diplaegidia columbae). using Western blotting, specific IgE assay using AlaSTAT EIA and RAST inhibition. Results Feather mites are a major source of soluble proteins derived from feathers, accounting for up to 10% of the total weight of the feather. Forty-three sera had a negative score (0) for anti-feather mite IgE. 27 were weakly positive (1–2) and 26 had strongly positive scores (3–4). Fewer pigeon breeders with scores ± 3 were asymptomatic than those with negative scores (12 versus 40%). more had late onset symptoms (with or without early onset symptoms; 77% versus 44%) and had IgE antibody against house dust mite (89% versus 23%). Western blotting of eight sera against the extract of Diplaegidia columbae revealed 20 IgE-binding components ranging from 22 to 200 kDa. A high diversity of components was recognized by each serum: arithmetic mean 7 (range 2 14). RAST inhibition indicated feather mites had species-specific epitopes as well as ones that cross-reacted with Dermatophagoides pteronyssinus. Conclusion Strongly-positive AlaSTAT scores to pigeon leather mite were associated with allergic symptoms of late onset in pigeon breeders. We conclude that feather mites are a major source of clinically-relevant allergens for pigeon breeders.

The location of IgE synthesis has been a longstanding controversy, with previous evidence favoring either the mucosa or lymphoid tissue in the region of allergen entry. The evidence for IgE synthesis in mucosal tissues has always been circumstantial. We have developed a novel explant culture system, using ELISA and radioactive amino acid incorporation, to measure de novo IgE protein synthesis in the nasal mucosa of hay fever patients. Surprisingly, IgE synthesis continues between seasons in the explants from grass pollen-sensitive patients and a higher proportion of this IgE compared to serum IgE is allergen specific. Persistent IgE synthesis may ensure the expression of immediate hypersensitivity in the mucosa and promote rapid amplification of the allergic response in the local lymphoid tissue on allergen provocation. Our work demonstrates definitively for the first time that the local mucosa is a site of ongoing IgE synthesis.

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.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.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.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.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.

It is uncertain as to what extent the development of allergic disease in childhood is predictable during early infancy. A number of environmental factors have been suspected of increasing the risk of acquiring allergy, but the evidence is conflicting.To observe the development of atopy and allergic disease in a cohort of high-risk children so as to determine the importance of certain environmental factors and to study the relationship between early and later manifestations.A cohort of infants, all at high risk of allergy, was followed up from birth to the age of 7 years. In half, selected at random, cow's milk protein was avoided for 4 months. Skin-prick tests were performed and serum IgE measured in infancy and at 7 years, when an AlaTOP test was also performed.Skin sensitivity to egg in the first year of life was strongly associated with eczema, asthma, mite sensitivity and serum IgE at the age of 7 years, when mother's atopic history was associated with AlaTOP status, father's atopic history with skin sensitivity, and male sex with both. Maternal smoking during pregnancy was associated positively with IgE at 3 months and negatively with skin sensitivity at 7 years. The development of allergy was unrelated to infant feeding method or number of older siblings.Allergic disease in childhood is to a large degree determined before birth or during infancy.

Summary Background Control oTdusl miles tising cxlfcniL's o[ Ictnperaturc is un alternative to the use of acaricidcs. In ihe past we have ;iltenipled control by IVcc/ing with liqtiid nitrogen. The present paper deals with the opposite exlrcnic, the use of steam. Objective To assess the leasibility inid elTeetiveness o!" a domestic steam eleaner Ibr the eontrol ol" dust tiiites. its ellecl on mile populations and eoncentrations of the allergen Der p I. Methods A domestic sleam cleaner was used to treat earpet squares Ihat had been seeded in the laboratory with known numbers of dust mites {Dcrniaiopliagoides ptcroiiy.ssintis). The number of live miles was monitored for ii period of 4 months in eight treated carpet sqtiares and eight controls. Dtisl samples were taken from 12 standardized areas of carpet in a tenement Hat in Glasgow, UK., before and after steam cleaning treatmetil. and the concentration of allergen Der p 1 was compared with 12 adjacenl. control areas. Results No live mites were foLmd at any lime in the treated carpet squares, whereas in the control squares geometric mean mite population density rose frotn 11 after 3 days to .39 after 1 month. 66 after 2. 122 after 3 and IS5 after 4 months. There was a mean reduetion o\' 86-7% in Der p I eoneentralion (3? 0-44 /jg/g.) compared with a reduction of 4-7% (2'22-2-l 16//g/g) in eontrol areas, a dilTerence that was statistically significant at the 5% level. Conclusion These data indicate thai steatii eleaning has considerable potential as an highly cITective and efficient method of killing dust tnites and reducing concentrations of Der p 1 in domestic premises. Kcywt)i

The determinants of wheezing and allergy were investigated in 453 children with a family history of allergic disease. A randomised controlled trial examined the effects of withholding cows' milk protein during the first three months of life and replacing cows' milk with soya milk. The children were followed up to the age of 7 years. Withholding cows' milk did not reduce the incidence of allergy or wheezing. Children who had ever been breast fed had a lower incidence of wheeze than those who had not (59% and 74% respectively). The effect persisted to age 7 years in the non-atopics only, the risk of wheeze being halved in the breast fed children after allowing for employment status, sex passive smoking, and overcrowding. Allergic disease was not associated with exposure to tobacco smoke, house dust mite antigen, or cats. Breast feeding may confer long term protection against respiratory infection.

Pairwise analysis of siblings from 21 families showed that house dust mite (HDM) sensitive children were exposed to higher concentrations of Der p I allergen in their mattress (P = 0.005) and bedding (P = 0.04), but not bedroom floor (P = 0.33), than their atopic sibling who was not sensitive to HDM antigens. There was no difference in the exposure to HDM numbers/100 mg of dust in the mattress (P = 0.61) or bedroom floors (P = 0.09). In contrast, pairwise analysis of siblings from 15 families showed that HDM sensitive children were not exposed to significantly different concentrations of Der p I in the mattress (P = 0.96), bedding (P = 0.11) or bedroom floor (P = 0.70) nor HDM numbers/100 mg of dust in the mattress (P = 0.12) and bedroom floor (P = 0.98) than their non-atopic siblings. These findings were identical when absolute allergen load was compared in these pairs. Genetic linkage studies in these families suggest the tendency to atopic IgE responses is conferred by a putative atopy locus on chromosome 11q. These results together suggest that differences in allergen levels in beds, among siblings with a comparable genetic tendency to atopy, play a significant role in determining the development of HDM allergy.

The effects of treating the environment of 25 dust mite-allergic patients with an acaracide are reported. Remarkable symptomatic improvements in asthma, eczema, or rhinitis were observed. Many patients could reduce or stop medication, and these benefits have persisted for up to a year after using Acarosan once only. Relapse of symptoms following exposure to untreated dusty environments was observed on many occasions confirming that the improvements were due to removal of the mite allergen.

Summary Skin test materials vary in their potency and specificity. Although 3 mm reactions are often regarded as diagnostic of a type I allergy, a study based on 100 allergy clinic patients with food intolerance showed that thirteen out of fifteen patients with a 3 mm reaction to common inhalant allergens had no RAST-detectable allergen-specific IgE. Three millimetre reactions were significant for milk and egg extracts. Food intolerance was clinically demonstrable in six out of seven patients giving a 4 mm skin reaction and in ten out of thirteen with a 3 mm reaction. There was, however, a ‘clinically false positive’ reaction of 3 mm or more in 3.8% of allergy clinic patients for milk and 2.8% for egg. In fifteen out of nineteen patients with a clinical diagnosis of fish allergy, the diagnosis was supported by a skin test reaction of 5 mm or more. However, seven patients with no history of intolerance to fish gave a 4 mm reaction to the same extract. Reactions of less than 5 mm were thus unhelpful clinically.

Longitudinal studies of hookworm infection (Necalor americanus) in two Gambian villages over a 14-month period showed that the rise in egg count began two months after the short rainy season and re...

Summary In a normal population aged over 70 years the geometric mean IgE value of 30.6 u/ml was not significantly different from that obtained previously in a similar epidemiological survey of a population aged 20–44 years. However, in the older population we have noted a significant sex difference–38.6 u/ml for males against 27.2 u/ml for females–which was only apparent in the atopic subjects of the younger population. There have been some other reports that IgE levels decrease with age, and possible reasons for these differences with our own results are discussed.

Summary Twenty-one asthmatic and twenty-two non-asthmatic children and nine asthmatic adults from two different rural areas of Tanzania, and eight asthmatic children from Dar-es-Salaam were surveyed by questionnaires, skin testing and the measurement of serum IgE. Asthma was significantly commoner in female rural children (four males, fifteen females). The rural asthmatic children apparently had less skin reactivity (in seven of nine tests) and lower specific (in two of four tests) and total serum IgE than age-, sex- and village-matched controls. This pattern of asthma in rural children in the tropics represents a different type of asthma from that found in temperate zones. In contrast, the adult rural asthmatics and the urban children seemed to have the pattern of increased skin reactivity and serum IgE found in asthmatic patients from temperate climates.

Summary Sera from 119 patients with possible food allergies were tested against a panel of thirteen food allergens by the RAST technique. The results were compared with in vivo tests. 79% of foods causing symptoms gave a positive RAST to the specific food. Symptoms were grouped according to their time of appearance after taking the food; ‘immediate’ up to 1 hr and ‘non-immediate’ more than 1 hr afterwards. Almost all those with ‘immediate’ symptoms were already aware of the foods causing them and there was a 100% correlation of the RAST result with these. Only a few of those with ‘non-immediate’ symptoms were previously aware that these foods were responsible, and 64% of these gave a positive RAST. The majority of patients with a positive RAST result had total IgE in excess of 300 u/ml, had specific IgE antibodies against one or more common inhalant allergens, were under the age of 30 years and had a combination of asthma and eczema. We found the RAST method a useful and safe guide upon which to base a clinical investigation of food allergy, especially for patients whose symptoms appeared more than 1 hr after the food and in whom the relationship between their symptoms and food was not apparent. The RAST technique was surprisingly successful in identifying the foods which caused these ‘non-immediate’ symptoms.

A survey was undertaken among adults aged 20-44 years in a South Wales town. Persons with a history of wheezing with breathlessness and in the absence of a cold were identified by postal questionnaires and seen at a clinic, together with a sample of subjects without these symptoms. The response rates for the first and second stages of the survey were 99.6% and 91.0% respectively, and 574 subjects were ultimately seen. Asthmatic patients (those receiving treatment within the previous year) had some airways obstruction at rest, which increased after exercise. They also had strong allergic tendencies, as shown by personal and family history, skin tests, and serum IgE levels. The ex-asthmatics (those not receiving treatment within the previous year) showed these tendencies to a lesser extent. A larger group gave a history of wheezing but stated that they had never had asthma; in their response to exercise and allergic traits they resembled the control group rather than the asthmatics, and appeared to have the features of chronic bronchitis. Asthma and chronic bronchitis would therefore seem to be distinct entities within the population studied.

STUDY OBJECTIVE: To identify environmental determinants of six symptoms associated with allergic disease in infancy. DESIGN: Infants were participants in a prospective randomised controlled trial of feeding practices in families with a history of atopy. SETTING: Infants were recruited in two maternity hospitals in S Wales and followed up in the community for 1 year. PARTICIPANTS: Mothers of 519 infants agreed to participate, but 36 were excluded (mainly for moving home or failing to attend for follow-up), leaving 483 in the study (253 male, 230 female). Infants were followed up and examined for evidence of allergic disease at 3, 6, and 12 months. MEASUREMENTS AND MAIN RESULTS: At each examination, mothers were questioned about episodes of illness in the infant, and the data presented relate to (reported and observed) eczema and nasal discharge, and (reported) wheeze, prolonged colds, diarrhoea and vomiting. Mothers kept a diary with details of feeding for the first 6 months. All homes were visited by a nurse who took samples of dust for dust mite antigen analysis. Extensive socio-demographic data were collected. None of the factors studied showed a convincing relationship with eczema. In a multiple logistic regression analysis breast feeding appeared to protect against wheeze, nasal discharge, colds, vomiting and diarrhoea. Having more siblings increased the likelihood of prolonged colds, and (together with overcrowding) of wheeze and nasal discharge. Maternal smoking and low social class were associated with wheeze, and house dust antigen with prolonged colds. Respiratory symptoms were associated with some aspects of housing but these could not be distinguished clearly from other social factors. Babies born in Autumn were at increased risk of wheeze, vomiting and diarrhoea. CONCLUSIONS: Environmental factors play an important part in determining risk of symptoms in potentially atopic babies. These factors are in principle open to manipulation.

One hundred and sixty women admitted for breast tumour biopsy to the King's College Hospital group have been followed sequentially for 2 years. Sixty-nine women had early operable breast cancer and 91 had benign breast disease. All these women had serum immunoglobulin IgG, IgA, IgM and IgE levels measured preoperatively and postoperatively at 3 months, 1 year and 2 years. No differences were found in any of the serum immunoglobulin levels between the two groups at any time. There was, however, a positive correlation between the extent of metastatic breast cancer and the serum level of various immunoglobulins, particularly IgA. There was no evidence that routine postoperative radiotherapy influenced the levels of serum immunoglobulins. The findings suggest a secondary defence reaction against increasing tumour load, and do not support the theory of an early immune defect in immunoglobulin metabolism which could play a part in the pathogenesis of breast cancer. Although there is no diagnostic value in measuring the levels of serum immunoglobulins in patients with breast tumours, there may be some value in following the levels in cancer patients, as a guide to subclinical spread of the disease.

Summary Four radioimmunoassay techniques, two conventional and two sandwich, have been used to measure circulating IgE levels in 100 sera. The test sera had IgE levels ranging From 1.0 to 20,000 u/ml, and each was measured at live dilutions, ranging from threefold to 400-fold. The same IgE standards were used throughout, and the optimal range for each assay was determined by assessing data for quality control sera and the WHO standard 69/204. To be of general use in the United Kingdom an IgE test must measure accurately levels as low as 20-30 u IgE/ml. The Phadebas RIST method failed to meet this criterion, and of the remaining tests the double antibody method had the most useful operating range and produced the most reliable results. However, the double antibody method is not available commercially and so, for the majority of laboratories, the Phadebas PRIST technique should be the method chosen.

SummaryThe incidence of atopy among 64 adults undergoing polypectomy was 25 per cent. Among these atopic patients it was usual for the polyp IgE level to exceed that in the serum. Similarly,D. pteronyssinus-specific IgE was more commonly identified in polyp fluid by the RAST technique than in serum. However, this was not so for grass poolen-specific IgE, where serum and polyp fluid were equally positive. We conclude that there are atopic and non-atopic polyps.

Summary Of eighty African asthmatics, sixty-three had significant levels of specific IgE against the house dust mite Dermatophagoides pteronyssinus. By contrast, grass-specific IgE was found in six patients and mould-specific IgE in none. Sixty-three patients also had symptoms predominantly during the rainy season. Positive skin tests against D. pteronyssinus correlated well with the presence of mite-specific IgE, as did the size of these skin test weals with the amount of specific IgE. For grass pollen and moulds there was no such relationship. There was no correlation between a history of sensitivity to house dust and either skin tests or specific IgE against D. pteronyssinus. The results support previous findings that it is allergy to house dust mite and not to grass pollens or moulds which is important in producing the seasonal symptoms in our patients.

The Phadiatop test, which is based on a multi-allergen allergosorbent, proved to be a test that is simple to perform in the laboratory and produces reliable results. When compared with the more conventional RAST atopy screening test for grass, mite and IgE antibodies it produced similar results, except in those rare instances of patients who were RAST-positive only for moulds where the Phadiatop test was decidedly superior. The Phadiatop test disc contains only inhalant allergens and so it could not be used for screening infants and very young children whose IgE response, if any, is probably limited to foods.

Two rural Tanzanian primary schools were surveyed to test the hypothesis that parasitic infestation prevents the development of asthma. 242 pupils were interviewed to determine the prevalence of pupils with recurrent episodes of wheezing. The nineteen pupils so discovered had more exercise-induced bronchial lability than equivalently exercised controls. More girls (12.8%) than boys (3.3%) had asthma. In one school, 77% of the controls had faecal parasites, mainly Ascaris spp., and in the other school 55% of the controls had Schistosoma haematobium in their urine. Parasites were found in similar proportions in the asthmatics. The mean serum IgE for the whole population was 3174 u/ml with no demonstrable difference between the asthmatics and controls. There was no difference in immediate cutaneous hypersensitivity to twenty-two allergens between the asthmatics and controls. These findings suggest that parasitic infestation does not prevent the development of asthma.

Fifty patients with bullous pemphigoid were investigated over periods of up to 7 years. Sequential studies of circulating basement membrane zone (BMZ) antibody titres revealed two groups of patients: 44% had a high initial titre (greater than 1:160) and 56% had a low initial titre (less than 1:160). Subjects with titres greater than 1:160 continued to have high titres, whereas in those with lower titres the BMZ antibodies usually became undetectable after 4 months. The BMZ antibody titres were of no prognostic value. High titres remained high even in patients who were in remission and off treatment, and in these subjects, there was no evidence of a change in the IgG subclass. The initial BMZ IgG antibody titres showed a highly significant correlation with total serum IgE concentrations. A significant correlation also existed between total serum IgE and IgG4 concentrations, although not between the serum IgE and the peripheral blood eosinophil count. No anti-BMZ antibody of IgE class was found, nor specific IgE against inhalants and foods identified, and the significance of the high total serum IgE remains unexplained. The majority of those followed for more than 2 years were able to stop their steroid therapy without further blistering: this confirms that pemphigoid tends to be a self-limiting disease. Nine patients had a recent history of malignant disease, and this is no more than would be expected for this age group of patients: however, 3 patients presented with pemphigoid and figurate erythema and all died of neoplastic disease, suggesting that such patients should be investigated thoroughly for neoplasia.

Summary We report the development of a detailed allergy questionnaire designed so that the answers can be typed into a mini-computer. Computer programmes have been written to file and to retrieve these answers, and to print a summary which is then ‘weighed’, so as to produce a clinical atopy score which is then further broken down into indoor and outdoor scores. In a pilot survey of ninety patients, their clinical atopy scores and immunoglobulin E (IgE) profiles have been compared, and additional computer programmes have been written which will (a) assess if a more detailed IgE investigations is warranted, and (b) suggest which allergens, if any, are likely to be responsible for the patients' symptoms.

This investigation studied 487 babies for symptoms of allergic disease during their first year of life. Because of their positive family histories all the babies are at high risk of becoming allergic. The babies were randomly divided such that cows' milk was deliberately withheld from one group; infants in this group were fed with a soya substitute where required. No benefit resulted from withholding cows' milk, indeed symptoms were more usually associated with this group. Breast feeding, even for a short period, was clearly associated with a lower incidence of wheeze, prolonged colds, diarrhoea, and vomiting. It seemed that the duration of breast feeding was less important than whether or not the child had been breast-fed at all. Wheezing was both more common among boys than girls (P less than .05) and if the mother was a smoker. Other environmental features related to wheezing were social class, month of birth, lack of breast feeding, exposure to dampness, mould and coal fires, but not to domestic pets nor to the numbers of mites found in bedding and carpets. Mite exposure was, however, associated with prolonged colds. Eczema was the only allergic symptom not positively associated with any environmental factor; moreover, it was neither associated with a lack of breast feeding nor with inclusion of cows' milk in the diet. Eczema was associated with the incidence of positive skin prick tests and IgE antibodies to egg white. IgE and IgG4 antibodies were estimated at birth (mothers' and cord bloods) and 3 and 12 months later.(ABSTRACT TRUNCATED AT 250 WORDS)

Summary A single in vitro screening test for atopic allergy is described. It uses the radioallergosorbent test (RAST) principle, and has been applied to screening sera from U.K. patients with possible atopic symptoms. When compared with the Phadebas RAST, the test sensitivity was 97% and the specificity 100%, and these results suggest that it is useful in any preliminary allergy investigation.

Precise and specific radioimmunoassays have been developed to quantify IgG4 and IgG4 antibodies. A community survey has demonstrated that men have significantly higher total serum IgG4 levels than women: geometric mean values of 0.581 mg/ml versus 0.302 mg/ml. This sex difference was extended to total IgE values. Circulating levels of IgG4 antibodies against foods, especially egg and milk, were normally higher than those against the three most common U.K. inhalant allergens--grass pollen, house dust mite and cat epithelium.

Total circulating IgE levels were measured in a carefully selected normal population, using a highly sensitive double antibody assay. The mean level of 36.3 u/ml found in this group is much lower than that reported in all previous studies. No circadian rhythm was evident, but IgE levels varied slightly from day-to-day. IgE levels in 100 serum samples were compared using the double antibody assay and the Phadebas test kit, based on a solid phase technique. A poor correlation was obtained with values below 100 u/ml, however, there was an excellent correlation for samples with IgE levels above this figure.

Summary The prevalence of atopy (assessed by prick testing and serum IgE measurement), and of symptoms associated with atopy, has been defined in 122 patients with inflammatory bowel disease (IBD) and 103 age-matched controls. History analysis for atopic symptoms, and serum IgE levels, showed no differences between controls and IBD patients, or IBD subgroups (Crohn's disease, ulcerative colitis, ulcerative proctitis). Both in controls and in IBD patients, the prevalence of positive skin tests was higher in young people (aged > 30) than in others; taking account of age distribution within the groups, there were no differences between controls and IBD patients, or subgroups, in the prevalence of positive skin tests. Our findings do not support the hypothesis that reaginic hypersensitivity plays a significant role in the pathogenesis of IBD.

It has been suggested that patients with cystic fibrosis have abnormal immune responses to foods. We have measured IgE antibodies to inhalants and foods (by RAST) in 105 patients with cystic fibrosis aged between 8 months and 28 years. Serum IgE was elevated (greater than 180 kU/l) in 21 patients. In 43, IgE antibodies were detected in serum. The majority of positive results were with house-dust mite, grass pollen or Aspergillus. Only four of the patients had a positive RAST to a food--one to milk, one to wheat and two to egg. On the basis of high serum IgE or positive RAST results, 44.8 per cent of the patients were atopic and the frequency of atopy was age-related, being higher in patients aged 4 years or more. However, the presence of food antibodies was unrelated to age. This study confirms the high prevalence of atopy in patients with cystic fibrosis but unequivocally demonstrates that the presence of IgE antibodies to foods in their serum is rare.

Summary Serum levels of total and specific immunoglobulin E (IgE) have been determined by radioimmunoassays in sixty-nine allergic subjects. The forty-one subjects with mild symptoms were the most difficult to diagnose, since nine had IgE levels less than 50 U/ml and nineteen had no detectable specific IgE antibodies. Samples of nasal secretions were collected from these nineteen subjects and five were found to have specific IgE antibodies, and in a further eight increased amounts of total IgE. The possibility of locally produced IgE antibodies should therefore be considered when using in vitro tests to diagnose mild or recently acquired allergies, especially when serum IgE levels are less than 50 U/ml.

Mite counts and tests for mite antigen were performed on samples of dust taken from the bedding of 53 children with mite-sensitive asthma. The samples from damp houses and the beds or enuretic children had markedly more mites and mite-antigen than those from dry houses. although the predominant species was usually Dermatophagoides pteronyssinus, some of the beds in the damp houses were heavily infested with another pyroglyphid mite Euroglyphus maynei, so that this was the species found in the greatest numbers. D pteronyssinus antigen was found to be correlated broadly with the total mite count, but more antigen was present for a given number of mites in the mattresses than in the blankets. The children were randomly allocated into two groups, one of which carried out rigorous anti-mite measures. The amounts of dust and mite antigen were reduced, though not the numbers of mites. Peak flow readings were monitored in the two groups for eight weeks and a final assessment made by a paediatrician who was unaware of the allocation of each patient in the trial. No significant differences emerged in the progress of the two groups, both tending to improve. Measures designed to remove mites from bedding do not greatly benefit the majority of children with mite-sensitive asthma.

A survey was undertaken to assess the importance of food allergy in asthma. Seventy-two asthmatics aged 15-60 years were identified in a general practice and compared with 72 controls matched for age and sex. A diagnostic procedure involving dietary elimination and challenge was carried out on those who thought food exacerbated their symptoms, together with those with concurrent eczema, positive skin tests to food or positive food IgE-RAST. The asthmatics more frequently had positive skin tests of IgE-RAST to food than the controls, but these tests proved to be rather non-specific in identifying provoking foods. One patient was found to be allergic to wheat and his clinical condition improved when wheat was removed from his diet. Two patients seemed to respond to other foodstuffs, but the effects were small, the foods (honey and peppermint) unimportant, and the patients' symptoms appeared to be largely due to other factors. Most cases of alleged food-induced asthma could not be confirmed by challenge testing. This survey suggests that some degree of provocation by food (excluding drink) affects at least 4 per cent of adult asthmatics, although in some of these patients it plays an unimportant part in the disease.

Total and specific IgE have been measured in serum, suction blister fluid and jejunal aspirate in patients with various atopic disorders in an attempt to increase our knowledge of the association between food allergy and adult atopic eczema. We found (a) that patients with atopic disorders, irrespective of whether the disease affects primarily the skin or airways, have raised IgE concentrations that are largely attributable to antibodies directed against inhaled allergens; (b) that IgE antibodies against food allergens account for an appreciable amount of the total IgE in patients with atopic eczema though not as much as that contributed by inhalants; and (c) that in patients with atopic eczema, most of the IgE is produced at sites other than the intestine or skin.

Highly sensitive and specific methods for assaying IgE and IgG4 for antibodies in serum have been developed in order to test a recent suggestion that food allergy is a major cause of migraine. Sera were collected from 208 adults--74 with dietary migraine, 45 with non-dietary migraine, 29 with cluster headache and 60 controls. No significant differences were identified between any of the groups with the one exception that cluster headache patients had significantly raised levels of total serum IgE: this difference may be explained by the high proportion of smokers. Mean IgG4 titres to cheese, milk and chocolate were very similar in the dietary and non-dietary migraine patients and the control subjects, though lower in the cluster headache patients. There was, therefore, no evidence that the food intolerance often associated with migraine headaches is associated with a conventional allergic mechanism.

We have measured plasma histamine, serum neutrophil chemotactic activity (NCA) and complement (C3 and C4) over a 24-hour period in patients experiencing either early- and late-phase (dual) or single early asthmatic reactions to inhaled allergens. There was a significant biphasic elevation in plasma histamine, which paralleled the fall in forced expiratory volume in 1 sec in 10 patients with dual responses, whereas in seven subjects with single early reactions, only a single early increase in histamine concentrations was observed. In general, in the individual subjects, the changes in plasma histamine paralleled both the elevations in serum NCA and the decreases in forced expiratory volume in 1 sec. By gel filtration on Sephacryl S-400, anion exchange chromatography on DEAE Sephacel, and chromatofocusing with Polybuffer Exchanger 94, the major NCA of both the early and the late reactions was associated with proteins having an estimated molecular size of 600,000 daltons, an elution from DEAE Sephacel at 0.15M to 0.30M of NaCl (pH 8.1), and a pI of approximately 6.5. There were no appreciable changes in serum C3 and C4 up to 24 hr after challenge in subjects with late-hase responses. The patterns of asthmatic response were not related to either the total or allergen-specific serum IgE or IgG 4 concentrations. These results support the view that mediators of hypersensitivity participate in late-phase as well as early asthmatic reactions.

One hundred patients who reacted adversely to one or more specific foods were studied. In 93 the food induced symptoms included asthma, eczema, angioedema, urticaria, rhinorrhoea, or a combination of one or more of these with gastrointestinal symptoms. The remaining seven had gastrointestinal symptoms only. The diagnosis of food allergy was made on the on the basis of a definite, immediate allergic reaction to specific foods or a reaction that was suggestive of allergy, supported by a corresponding positive skin prick or radioallergosorbent test. In the absence of such evidence, the less specific diagnosis of 'food intolerance' seemed preferable. Test materials appeared to differ in their diagnostic usefulness. A high proportion (c. 75 per cent) of patients who were intolerant to egg, fish or nuts had positive test results. In contrast, only 30 per cent of patients with milk intolerance had positive tests, suggesting inadequate test methods or a non-allergic cause for many patients' milk intolerance. Nevertheless, five milk intolerant patients with negative tests had milk-induced asthma.

The median serum beta 2-microglobulin value for a population aged over 70 years was 2.30 mg/l. This value increased significantly with age in both men and women--there were no sex differences.

Data are presented to show that a microcomputer can be programmed to: (1) analyse a standard allergy questionnaire, (2) reliably predict the ranked order probabilities with which IgE antibody tests will produce positive results, (3) store the IgE test results, and (4) print a comprehensive report that summarises and integrates the clinical and laboratory data. Consequently, the practitioner who refers a blood sample and a questionnaire completed by the patient to a centre where both can be analysed will obtain enough practical information to decide whether to treat or refer that patient to a specialist. The microcomputer is therefore potentially of great value in any preliminary allergy investigation.