Ethanol-induced urticaria: elevated tryptase levels after double-blind, placebo-controlled challenge.

We present a 48-year-old patient who complained for 1 year about urticarial reactions which appeared always when he ingested alcoholic beverages. Skin prick tests with ethanol were negative but positive with 10% acetic acid in the patient. Normal controls tested negative with acetic acid. Skin prick tests to common immediate-type allergens were negative. The patient underwent a double-blind, placebo-controlled challenge test. A few minutes after challenge with ethanol but not with placebo, the patient developed erythema and wheals on the chest and the upper arms. The tryptase serum level rose from undetectable (0.1 U/ml) before challenge to 3.8 U/ml after skin lesions had appeared. This case demonstrates that increased tryptase serum levels can help in the diagnosis of ethanol-induced urticaria.

[The problem of hidden food allergens: two cases of anaphylaxis to peanut proteins concealed in a pizza sauce]. / Le problème des allergènes alimentaires cachés: deux cas d'anaphylaxie aux protéines de la cacahuète dissimulées dans une sauce pizza.

Peanut is one of the major food allergens inducing anaphylaxis. It is increasingly consumed and often used as a hidden ingredient, thus making avoidance especially difficult for allergic patients. In Switzerland legislation stipulates that all ingredients of a processed food exceeding 2% of the total mass of the finished food product should be labelled. However, in the case of a mixture of vegetables it can be labelled as "vegetable mix" if it does not exceed 10% of the total weight. Peanut, which is a member of the legume family, can thus form up to 10% of processed foods without being mentioned on the label, thus making avoidance impossible. We report on two patients who presented severe anaphylaxis from peanut hidden in a pizza from a fast food restaurant. We were able to provide evidence for the presence of major peanut antigens in the pizza sauce by immunochemical analysis. These two cases clearly demonstrate the danger of peanut hidden in foods and point up the necessity of a change in legislation.

The frequency of pretransplant donor cytotoxic T cell precursors with anti-host specificity predicts survival of patients transplanted with bone marrow from donors other than HLA-identical siblings.

Transplantation with bone marrow from other than genotypically HLA-identical donors is associated with an increased incidence and severity of graft-versus-host disease (GvHD). The precise influence of HLA incompatibilities is not easy to analyze as even perfectly matched, HLA-identical unrelated donors might still express HLA differences that remain undetected by conventional typing. To measure T cell activity against serologically detectable and nondetectable HLA antigens, we analyzed the frequencies of CTL precursors (CTLp) between 11 unrelated HLA-matched and five related haploidentical donor/recipient pairs in graft-versus-host direction. Our results show that whenever HLA class I disparities could be identified by serology, high precursor frequencies (1/28,000-1/94,000) were measured. In contrast, in donor/recipient pairs that differed for class II only, no precursors were detected. CTLp were elevated in two out of eight fully matched donor/recipient combinations. These combinations displayed activities as high (1/21,000; 1/52,000) as the combinations that were serologically HLA class I disparate. The incompatibilities detected by the cellular assay were highly significant for the clinical results after transplantation. High CTLp frequencies before transplantation correlated with unfavorable clinical results independent of the incidence of detected HLA differences. Five out of the six patients with high (> 1/100,000) CTLp frequencies died within 120 days after transplantation. GvHD IV was the cause of death for all (3/5) patients who had received an unmanipulated bone marrow. In the group with intermediate or undetectable CTLp frequencies, eight out of 10 patients are alive, seven (CTLp frequency undetectable) without GvHD more severe than grade II, while one patient (CTLp frequency = 1/180,000) suffered from GvHD grade III. One patient rejected the graft and was rescued by an autologous BMT.