IgE antibodies against penicillin as determined by Phadebas RAST.

Serum samples from eighty-one patients with suspected penicillin allergy were investigated with Phadebas RAST using the penicillin derivatives Benzylpenicilloyl-human serum albumin (PBO-HSA) and Phenoxymethylpenicilloyl-human serum albumin (PMPO-HSA) and the results were compared with skin test results and clinical data. Of the sixty-one patients who had anaphylactic shock and/or urticaria as a possible consequence of penicillin administration, reagins against PBO-HAS and PMPO-HSA could be detected in thirty-four cases (56%). Five per cent of these patients, with positive RAST results, showed negative skin tests; in the other 95% both RAST and skin tests were positive. All, except eight, of the RAST-negative patients had had their adverse reactions at least 2 years prior to the blood sampling and in some of these cases skin tests were also negative. RAST and provocation test results agreed in 80% of the cases where exposition was performed. It is concluded that the RAST technique is a valuable diagnostic tool for the detection of immediate type hypersensitivity to penicillin.     

Investigation of the response to some haptenic determinants in penicillin allergy by skin and in vitro allergy tests.

The role of three penicillin metabolites in human allergic reaction to penicillin has been assessed using sensitive in vitro tests in addition to skin testing. Conjugates of the benzylpenicilloyl (BPO), benzylpenicillenate (BPE) and penicillamine (PA) groups with human serum albumin (HSA) and bovine gamma globulin (BGG) have been made. In the passive haemagglutination test antibodies specific for all three determinants were found but there was no difference between allergic and non-allergic groups. However, the ratio IgG/IgM, specific for each determinant, was higher in normals than in allergics. In skin tests, histamine release from leucocytes and the lymphocyte transformation test, the BPO group was confirmed as the major determinant, but in some individuals the BPE or PA groups are more important.     

Reaginic allergy to Parthenium pollen: evaluation by skin test and RAST

The pollen of Parthenium hysterophorus, an alien weed growing wild in India was found to be a potential source of allergic rhinitis. A clinical survey showed that 34% of the patients suffering from rhinitis and 12% suffering from bronchial asthma gave positive skin-prick test reactions to Parthenium pollen antigen extracts. Parthenium-specific IgE was detected in the sera of sixteen out of twenty-four patients suffering from seasonal rhinitis. There was 66% correlation between skin test and RAST.     

Diagnosis and management of penicillin allergy

Among patients with a reported history of penicillin allergy, 80% to 90% have no evidence of IgE antibodies to penicillin on skin testing and thus avoid penicillin unnecessarily. Moreover, 97% to 99% of such patients with a penicillin skin test negative to the major and minor determinants can tolerate penicillin without risk of an immediate-type hypersensitivity reaction. A penicillin skin test is valuable for evaluating penicillin allergy in patients who need penicillin or cephalosporin. Assessment of sensitivities to penicillin is important to reduce the unnecessary use of antimicrobial agents such as vancomycin. We review the role of penicillin skin testing for evaluating penicillin allergy and the use of cephalosporin in patients with a history of penicillin allergy.     

改良安全皮肤试验法鉴别真假青霉素严重过敏

目的 用安全皮肤试验法鉴别真假青霉素过敏.方法 对自称有严重青霉素过敏史患者51例,以青霉素皮试液分别行斑贴、点刺及不同浓度的皮内试验.结果 51例中有17例(33.3%)确诊为严重青霉素过敏,34例(66.7%)排除了青霉素过敏.结论 安全皮肤试验法安全、可靠,适合临床推广.     

Clinical manifestations of cows' milk allergy in childhood. II. The diagnostic value of skin tests and RAST

In a study of cows' milk allergy (CMA) in infancy, 135 consecutive challenges were performed on children with a good clinical history of the disorder. Of these, only half of the patients were shown to have the disease. Highly atopic patients responded rapidly to small volumes of milk with acute urticaria, wheezing, stridor and eczema, whereas patients who were relatively non-atopic developed symptoms of eczema, bronchitis and wheezing over several hours or days. In a statistical evaluation of the diagnostic value of skin tests and RAST it was shown for the extracts used in this investigation, and for the population studied, all patients with SPT greater than or equal to 4 had CMA. The results highlight the potential diagnostic value of SPT in the identification of children with some forms of CMA if standardized cows' milk allergen extracts can be prepared.     

青霉素G迟发变态反应两例

临床资料病例 1　患者 ,男 ,2 8岁 ,因风湿性关节炎给予青霉素Ｇ钠 (哈尔滨制药总厂 ,批号 2 0 0 0 0 4 3 )抗感染治疗 ,取新鲜配制原液 ,含青霉 2 0ｕ做左前臂屈侧腕横纹上 4厘米处皮内试验 ,观察 2 0分钟 ,结果为阴性 ,遂给予生理盐水 2 50毫升、青霉素 80 0万ｕ ,2 /日静滴 ,用药5小时后始出现全身皮肤潮红 ,以颜面部为重 ,周身泛发性小米粒大小散在红色丘疹 ,伴搔痒不适 ,无寒战、头痛 ,轻度心悸 ,无胸闷及呼吸困难 ,体温、血压正常 ,诊断为青霉素Ｇ迟发变态反应 ,即给予地塞米松1 0ｍｇ ,肌注 ;葡萄糖酸钙 1 0 ,缓慢静注 ;维生素Ｃ片0…     

History of penicillin allergy and referral for skin testing: evaluation of a pediatric penicillin allergy testing program

INTRODUCTION: Penicillin allergy, commonly reported in children, leads to use of more expensive, broad-spectrum drugs. The results and effectiveness of a skin testing program for immediate hypersensitivity to penicillin in children were studied. METHODS: Children seen at the IWK Health Centre in Halifax between 1986 and 2000 with a history of suspected penicillin allergy were referred by their family physician or pediatrician. Two-stage skin testing (scratch, intradermal) of benzylpenicilloyl-polylysin and penicillin G sodium, with histamine and saline as positive and negative controls, was carried out. If the test results were negative, an oral challenge was conducted and the child observed for 60 minutes. If no adverse reaction was noted, a letter was sent to the referring physician and to Health Records at the IWK Health Centre, indicating that warning labels should be removed from the chart. RESULTS: Of 72 children tested, 32% described their past cutaneous eruption as hives and 68% had other rashes; 96% of rashes were generalized. The mean age at the time of the suspected penicillin allergy was 4.4 years; it was 7.4 years at the time of testing. There was no positive response to the scratch testing, but 4% of children had a positive response to intradermal testing. No adverse responses to oral challenge were observed. Letters confirming negative status were not received in 4% (3 of 69) cases, resulting in ongoing avoidance of penicillins and falsely labelling of the child as penicillin allergic. CONCLUSIONS: In this referral setting, true penicillin allergy was uncommon, suggesting that many children are incorrectly labelled as penicillin-allergic. Communication of test results to family and care providers and health records administration must be effective if testing is to affect prescribing behaviour.     

Value of Etest penicillin V and penicillin G strips for penicillin susceptibility testing of Neisseria meningitidis

The NCCLS agar dilution method and Etest are currently accepted methods for susceptibility testing of Neisseria meningitidis to penicillin. We determined the MIC of penicillin V and penicillin G by both the agar dilution method and Etest using 43 strains of N. meningitidis. Although results for reference strains were within the accepted quality control range of penicillin MICs for both drugs, differences of two to three dilutions were seen between the two antibiotics with both methods. Penicillin V results cannot correctly predict the susceptibility to penicillin G for N. meningitidis if penicillin G breakpoints are used for penicillin V. However, adjusting the penicillin V breakpoints two dilutions higher (i.e., S < or = 0.25 and R > or = 8 microg/ml), concordance could be achieved for susceptibility categorization by the two compounds. An agreement of 98% +/- 1 dilution was obtained between Etest and the reference method when using penicillin G strips. We conclude that Etest with penicillin G strips is a convenient and reliable alternative method for determining the MICs of penicillin for N. meningitidis.     

Results of skin test and RAST in allergy to a clinically potent allergen (castor bean)

In order to investigate once more the usefulness of the RAST procedure in the diagnosis of reaginic hypersensitivity, we studied a series of patients showing a well known sensitivity to castor bean, which is a potent antigen, and compared the results with those given by patients with no clinical allergy to this antigen as confirmed by negative skin testing. The latter group included patients with no contact, a remote contact or a close contact with castor bean. Castor bean allergy seems to be a good model in the testing of human reaginic hypersensitivity. We observed in the castor bean positive group of forty-one patients a 95% correlation between RAST positivity and skin test positivity with only two negative RAST scores, and in the castor bean negative group of ninety-four patients, a 97% correlation, with three RAST positive scores. For its specificity and its good sensibility (although lesser than skin testing), RAST can thus be recommended as a diagnostic tool as a complement to skin testing. Moreover, for potent allergens, RAST offers a risk-free diagnostic alternative.     

Specific IgE estimations by RAST in Japanese asthmatics compared with skin, passive transfer and bronchial provocation tests.

198 asthmatics and twenty healthy persons were studied by RAST and in vivo tests with four common inhalant allergens. (a) Higher RAST classes were elicited with mite (Dermatophagoides farinae) extract and lower classes with other allergens. The agreement between positive RAST and skin or P-K tests was highest with the mite extract. RAST sensitivity was dependent on the kinds of allergens and was most sensitive to mite extract. Positive RAST was most closely related to the prick test reactions. (b) RASTs to house dust and mite extract were examined in terms of the threshold dosage of house dust and also the types of bronchial response (early, dual and late) induced by a certain amount of house dust; higher RAST classes were found in subjects with bronchial response to the dual or early type, elicited by a threshold dosage of diluted extract, while lower RAST classes were found in cases of the late-type response elicited by the threshold dosage of concentrated extract. (c) Changes in IgE antibodies to house dust and mite extract were estimated in patients with positive house dust provocation. A greater increase occurred in cases of dual or early response, a smaller increase in those with a late response. Despite discordances in skin tests and RAST between house dust and mite extracts, the increases in IgE antibodies to mite extracts as well as house dust were observed in all cases, presumably caused by an allergenic identity between the allergens.     

Diagnosis of secondary antiphospholipid syndrome in children by means of screening tests

Comprehensive clinical laboratory studies were performed in 38 children with systemic lupus erythematosus. Screening tests (kaolin time, thromboplastin time with diluted thromboplastin, lebetox time) used which allowed secondary antiphospholipid syndrome to be diagnosed in 7 patients. IgG phosphatidylserine and cardiolipin antibodies were most frequently detected in the patients. Analysis of the findings has established the high sensitivity, specificity, and diagnostic value of the lebetox-echitox index, which permits this method to be recommended for the diagnosis of secondary antiphospholipid syndrome in children.     

Epithelial or dandruff allergen for the diagnosis of dog allergy by RAST?

When used for screening by the RAST technique, dog epithelium provided too few positive results (29.2%) compared with dog dandruff (58.8%), cat epithelium (53.6%) and horse dandruff (52.2%). However, dog dandruff can provide an unexpectedly high incidence of positive RAST results (45.2%) in sera from patients with an allergic history to cat or horse, but not to dog. Dog dandruff allergens were found to cross-react with some cat or horse serum proteins in about 25% of such patients. We conclude that dog dandruff is preferable to epithelium for screening by the RAST technique, but if emotional issues involving a family pet arise then confirmation by a trial separation is likely to be more convincing than a provocation test with a possibly non-specific allergenic extract.     

Diagnosis of penicillin allergy. An evaluation of the leucocyte aggregation test in man

A study was made to establish the value of the leucocyte aggregation test (LAT) in drug allergy using penicillin antigen. The antigen-induced human peripheral blood leucocyte aggregation was measured quantitatively. The results obtained have been compared with the leucocyte migration inhibition test (LMIT) in patients with or without delayed penicillin allergy. Among forty-four penicillin-allergic subjects and thirty-six control subjects, LAT was found positive in respectively 70.5 and 30.5% (P less than 0.001) whereas LMIT was found positive in respectively 56.8 and 50% of the patients. These results were confirmed by multiple correspondence analysis (MCA), using a computer. Furthermore, this method, enables a more comprehensive and reliable interpretation of the tests, by the help of various quantitative and qualitative criteria. It is concluded that LAT shows more discrimination than the LMIT in distinguishing a penicillin-allergic population from a non-allergic one. In addition, LAT offers great technical advantages over the LMIT for the diagnosis of drug allergy.     

Relationships between skin test, specific IgE and levels of cytokines in patients with penicillin allergy

The aim of this study was to investigate the relationships between skin test, specific immunoglobulin (Ig) E and cytokines in penicillin allergy. We collected the sera of 259 patients with historical positive skin test to penicillins, with immediate positive skin test and with a negative skin test results. The positive rate of specific IgE antibodies in 259 patients was 62.2% (161) by using radioallergosorbent test (RAST). Of the eight kinds of antigenic determinants, the positive rates of specific IgE to major and minor determinants were 43.63% (113) and 52.51% (136), respectively (p < 0.05). In 122 patients with immediate positive skin test, when the degrees of skin test were +, 2+, 3+ and 4+, the positive rates of specific IgE were 45.7, 57.1, 85.2 and 100%, respectively. The levels of interleukin (IL)-4, IL-13 and interferon (IFN)-gamma in the sera of patients with positive skin test were significantly increased with the degree of positive skin test (p < 0.05). The combined use of major and minor determinants in RAST offers the better test for the detection of penicillin-specific IgE antibodies. IL-4, IL-13 and IFN-gamma play important roles in penicillin allergy.     

Diagnosis of allergy in different age groups of children: use of mixed allergen RAST discs, Phadiatop and Paediatric Mix

Childhood asthma often begins in children under 3 years of age. Allergy contributes to the severity and persistence of childhood asthma so we examined the application of mixed allergen RAST discs (Paediatric Mix, a mixture of food antigens and Phadiatop, a mixture of inhalants) to the diagnosis of allergy. One hundred and nine children with a median age of 3 years, 71.6% of whom had asthma, were first assessed by one allergist who recorded their atopic status as positive, negative or questionable, on clinical grounds. Serum from each of these patients was used to determine a total IgE and 13 RAST assays. A laboratory definition of atopy was defined as a serum IgE greater than 1 standard deviation from normal, plus one or more positive RAST assays. The laboratory results influenced the assessment of atopy in 41% of cases. The use of just two mixed allergen discs (Paediatric Mix and Phadiatop) correctly assigned the presence or absence of atopy with a sensitivity of 98% and specificity of 98%, compared with the full laboratory evaluation. Very young infants were often just positive to food allergens but the Phadiatop disc could be used to suggest the onset of immunological sensitivity to inhalant antigens. Thus the application of mixed allergen RAST discs facilitated the diagnosis of atopy in young children.