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Biomedical subjects

M H Lessof

Publications and source records attributed to M H Lessof.

At least 73 records · Page 4Linked to original sources

The immune response to bee venom. Comparison of the antibody response to phospholipase A2 with the response to inhalant antigens.

The antibody response to phospholipase A2 (PLA2) was studied by using radiolabelled antigen-binding techniques for both IgG and IgE antibodies. The results are compared with results for antigen P1 from Dermatophagoides pteronyssinus and for rye I from rye grass pollen. The response to PLA2 differs from the response to the inhalant allergens in several ways: almost all exposed bee keepers produce IgG antibodies to PLA2; among the allergic bee keepers there was no quantitative correlation between IgG and IgE antibodies; and the antibodies to PLA2 are not produced locally in the nose. Bee keepers with hay fever did not appear to have an increased incidence of allergic reactions to bee venom. In addition, the bee keepers with hay fever and the same levels of IgG and IgE antibodies to rye I as other individuals with hay fever. However, the bee keepers who had no history of hay fever were found to have high levels of IgG antibodies to rye I. These antibodies did not cross-react with PLA2 or bee venom, and the results suggest that bee stings may act as an adjuvant for IgG antibodies to pollen antigens.

Allergens↗

Intestinal permeability in patients with eczema and food allergy.

Polyethylene glycol (PEG) was used as a probe molecule to investigate intestinal absorption in eight patients with eczema and evidence of food allergy and ten with eczema alone. In both groups absorption of molecules of larger molecular weight was greater than in normal subjects but absorption of molecules of low molecular weight was normal. There was no difference in absorption between eczema patients with or without food allergy. These results suggest that there is an intestinal mucosal defect in eczema which exists whether or not there is coexistent food allergy. Half the patients with eczema alone and two of the eight with food allergy had more of the large molecular weight PEG recovered in their urine in the second 12 h after ingestion than in the first 12 h. This could be the result of abnormal permeability in the more distal small bowel or even in the colon.

Adolescent↗

Role of bronchial irritant receptors in asthma.

Sulphur dioxide inhaled at low concentration had no detectable effect on forced expiratory volume in one second in non-asthmatic atopic controls, but it induced asthma and increased bronchial reactivity in nine symptomless atopic and non-atopic asthmatic patients. This increased reactivity was inhibited by sodium cromoglycate (SCG) and partly inhibited by atropine. This suggests that SCG, in addition to its ability to stabilise mast cells, may also act on bronchial irritant receptors or directly on smooth muscle in asthmatic patients.

Adolescent↗

Assessing the value of skin prick tests.

Skin test materials vary in their potency and specificity. Although 3 mm reactions are often regarded as diagnostic of a type 1 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.

Animals↗

IgE and IgG antibodies to bee venom as measured by a modification of the RAST method.

The radioallergosorbent test (RAST) has been widely used in studying allergy to hymenoptera stings, but with variable results. We report here a modification of the RAST method which in a total of 157 bee keepers and family members, gave a close correlation between a positive RAST, and a history of generalized (100%) or localized (95%) allergic reactions. There was no positive RAST among forty-nine non-atopic control subjects but a striking finding was that 58% of non-allergic bee keepers had significant, but usually low, levels of IgE antibody to bee venom. IgG antibodies to bee venom have also been measured by a paper disc RAST which is quick and convenient. Levels were highest in non-allergic bee keepers. In the presence of high levels of IgG antibody, IgE antibody levels may be underestimated.

Animals↗

Corticosteroid treatment, serum lipids and coronary artery disease.

Serum lipids and the cholesterol concentrations in the high density lipoprotein (HDL) fractions were measured in patients receiving long-term corticosteroid treatment for connective tissue disorders and asthma. Patients who were not receiving corticosteroid treatment had blood lipid levels which did not differ from those of healthy people. However, female (but not male) patients who had received prednisolone for a mean period of 3.1 years had a significant elevation in total cholesterol and a large decrease in HDL cholesterol. It seems possible that high levels of corticosteroids may increase the incidence of premenopausal ischaemic heart disease in females.

Adolescent↗

Food allergy and intolerance in 100 patients---local and systemic effects.

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.

Adolescent↗

Comparison of the atopic background between allergic and non-allergic beekeepers.

A study was carried out on beekeepers and their families. 34 subjects with a history of bee sting allergy and also a positive radioallergosorbent test (RAST) to honey bee venom were compared with 47 subjects with neither. 16 subjects in the bee allergy group (47%) had a history of atopic diseases as compared to 6 (13%) in the control group (p less than 0.01). 15 in the bee allergy group (44%) had at least one positive RAST to three common inhalant allergens as compared to 5 (11%) in the control group (p less than 0.01). These results suggest that, although bee sting allergy frequently affects non-atopic subjects, sensitization among beekeepers and their families occurs more readily in atopics. It is notable that a large proportion of patients injected with foreign proteins (the control group) either never develop venom-specific IgE antibodies or have suppressed their production.

Adult↗

Evaluation of bee sting allergy by skin tests and serum antibody assays.

We studied 55 subjects who had had anaphylactic reactions to bee stings within the previous 3 years. 38 out of 54 tested had IgE antibody to honey bee venom (HBV) as measured by radioallergosorbent test (RAST). On skin testing, 30 out of 34 had a positive test to HBV. Of these, 26 had a positive RAST. A positive skin test to HBV at high dilution or else a high anti-HBV RAST score appeared to identify those who, in a 6-month follow-up period, were at risk of developing further anaphylaxis following bee stings or immunotherapy. Of the two tests, RAST appeared to be the less sensitive. Measurements of IgG antibody to phospholipase A were seldom available for the period immediately preceding an anaphylactic episode and proved to be a poor means of predicting the liability to bee sting anaphylaxis in subsequent months.

Anaphylaxis↗

Prostaglandin synthetase inhibitors and food intolerance.

12 patients with adverse reactions to foods are discussed, including 1 with biopsy-proven ulcerative proctitis. 10 had predominantly gastrointestinal symptoms (diarrhoea, abdominal pain, vomiting) and two had rhinitis and headache. Skin tests (in all but two) and radioallergosorbent tests (RAST) in some patients were negative. All of the patients were challenged in hospital with the offending food, either alone or preceded by a prostaglandin synthetase-inhibiting drug (aspirin, indomethacin or Ibuprofen). In 11 of the 12 patients this premedication prevented both the gastrointestinal and the more remote symptoms. Blood and stool prostaglandin measurements (PGE2 and PGF2 alpha) showed changes which correlated with clinical symptoms and did not occur if one of the inhibiting drugs had been given prior to challenge.

Digestive System↗