宇理須 厚雄

P>Egg allergy is one of the most frequent food allergies in children below the age of three. Common symptoms of egg allergy involve frequently the skin as well as the gut and in more severe cases result in anaphylaxis. Non-IgE-mediated symptoms such as in eosinophilic diseases of the gut or egg-induced enterocolitis might also be observed. Sensitization to egg white proteins can be found in young children in absence of clinical symptoms. The diagnosis of egg allergy is based on the history, IgE tests as well as standardized food challenges. Ovomucoid is the major allergen of egg, and recent advances in technology have improved the diagnosis and follow-up of patients with egg allergy by using single allergens or allergens with modified allergenic properties. Today, the management of egg allergy is strict avoidance. However, oral tolerance induction protocols, in particular with egg proteins with reduced allergenic properties, are promising tools for inducing an increased level of tolerance in specific patients.

Topical calcineurin inhibitor (TCI) was reported to be an effective therapeutic agent for patients with atopic dermatitis (AD), for not only improving clinical findings but also for reducing pruritus. Recently in Japan tacrolimus ointment (0.03%) as a TCI was approved for use in children aged >= 2 years. There have been no reports, however, on the impact of TCI on quality of life (QOL) in pediatric AD in Japan. The purpose of the present study was therefore to evaluate the efficacy of tacrolimus ointment (0.03%) in the short-term and the impact on patient QOL. A total of 30 pediatric patients with AD, whose skin problems were not sufficiently controlled by mid-high potency topical glucocorticosteroids, were enrolled. Efficacy was assessed on score of cutaneous findings, pruritus, sleeping disorder, and QOL. Three patients discontinued because of skin burning (n = 1), generalized herpes infection (n = 1), and feeling of lack of efficacy (n = 1), leaving a final total of 27 patients who were evaluated. Significant improvements in clinical findings, pruritus, and sleeplessness were observed within 1 week of treatment and consequently each QOL category was also improved. These improvements continued for the duration of the study. Tacrolimus ointment therapy is rapidly effective for not only clinical symptoms (cutaneous findings, pruritus and sleeplessness) but also in QOL of AD pediatric patients aged 2 years.

Oral allergy syndrome (OAS) is defined as the symptoms of IgE-mediated immediate allergy localized in the oral mucosa, and the characteristics depend on the lability of the antigen. Another term used for this syndrome is pollen-food allergy (PFS) the patient is sensitized with pollen via the airways and exhibits an allergic reaction to food antigen with a structural similarity to the pollen (class 2 food allergy). In addition to PFS, latex-fruit syndrome is also well-known as the disease exhibiting OAS. In treating the condition, it must be noted that most but not all symptoms of PFS are those of OAS. In many cases, antigens become edible by heating, but some are resistant to heating. Also, since the exacerbation of atopic dermatitis is occasionally observed after the intake of cooked antigens in asymptomatic individuals, careful inquiry of the history is important in designing the treatment. Immunotherapy against the cross-reacting pollen has also been attempted in PFS. ©2009 Japanese Society of Allergology.

Diagnosis of food allergy should be based on the observation of allergic symptoms after intake of the suspected food. The oral food challenge test (OFC) is the most reliable clinical procedure for diagnosing food allergy. The OFC is also applied for the diagnosis of tolerance of food allergy. The Japanese Society of Pediatric Allergy and Clinical Immunology issued the 'Japanese Pediatric Guideline for Oral Food Challenge Test in Food Allergy 2009' in April 2009, to provide information on a safe and standardized method for administering the OFC. This review focuses on the clinical applications and procedure for the OFC, based on the Japanese OFC guideline. ©2009 Japanese Society of Allergology.

Background: Children with allergy to raw egg white might tolerate low amounts of heated egg. Ovomucoid-specific IgE antibodies have been suggested to be predictors of whether children could tolerate heat-treated egg. Objective: The aim was to evaluate the clinical usefulness and added diagnostic value of measurements of IgE antibodies to egg white, ovalbumin, and ovomucoid in children with egg allergy. Methods: One hundred eight patients (median age, 34.5 months) with suspected egg allergy underwent double-blind, placebo-controlled food challenges with raw and heated egg. The outcomes of the challenges were related to the serum concentration of specific IgE antibodies and total IgE by using ImmunoCAP. Results: Reactions to heated egg white were observed in 38 patients (considered allergic to raw and heated egg), 29 patients reacted to only raw egg white, and 41 patients were tolerant. Correlation was observed between the serologic parameters studied. Receiver operating characteristic analysis showed that egg white ImmunoCAP was useful in the diagnosis of allergy to raw egg white. The positive decision point, based on 95% clinical specificity, was 7.4 kU(A)/L, and the negative decision point, based on 95% clinical sensitivity, was 0.6 kU(A)/L. For reaction to heated egg white, ovomucoid ImmunoCAP was superior. The positive decision point was 10.8 kU(A)/L, and the negative decision point was 1.2 kU(A)/L. Conclusions: Quantitative measurements of specific IgE antibodies to both egg white and ovomucoid and the evaluation against the suggested positive and negative decision points for specific IgE will be useful in the diagnosis of egg allergy.

Background: Phenytoin can induce diversified adverse reactions including generalized eruptions and the hypersensitivity syndrome. Delayed-type allergic mechanisms have been postulated to underlie these reactions. The tests most widely used to detect T-cell sensitization to drugs are the patch test and the lymphocyte transformation test (LTT), but their sensitivity is not sufficient. Simultaneous assessment of both the frequencies and the cytokine-producing phenotypes of allergen-specific T cells has become possible with the recently introduced carboxyfluorescein succinimidyl ester (CFSE) assay. Methods: Seven patients who presented with phenytoin-induced maculopapular exanthema with and without fever were included in this study. Peripheral blood mononuclear cells (PBMCs) were labeled with CFSE and cultured with phenytoin for seven days. The cells were stained with anti-CD4 and cytokine-specific monoclonal antibodies (MoAbs), and analyzed with FACSCalibur. Results: The phenytoin-specific proliferation of CD4+ cells in patients was significantly higher than in the four controls exposed to phenytoin, and in seven healthy children with no previous phenytoin intake. A significant difference in the percentages of CD4+ IFN-γ+ cells between patients and the seven healthy children was observed. The sensitivity and specificity of proliferation were 100% and 90.9%, and those of IFN-γ secretion were 71.4% and 100%, respectively. Conclusions: Phenytoin-specific proliferation may be detected with greater sensitivity by the CFSE dilution assay than the conventional LTT. The assay revealed that both CD4+ and CD4- T cells proliferated and produced IFN-γ and TNF-α after stimulation with phenytoin. The CFSE dilution assay might be useful for the diagnosis and understanding of drug hypersensitivity. ©2007 Japanese Society of Allergology.

Background An association between pollinosis and sensitivity to fruits and vegetables has been reported. Although Japanese cedar (Cryptomeria japonica) pollinosis is one of the most widespread diseases in Japan, there have been no reports demonstrating cross-reactivity between Japanese cedar pollen and other plant food. Objective The aim of this study was to demonstrate cross-reactivity between Japanese cedar pollen and tomato fruit (Lycopersicon esculentum) using RAST inhibition and immunoblot inhibition. Methods The RAST and immunoblot inhibition were performed using sera from patients with oral allergy syndrome (OAS) after ingesting fresh tomatoes. We identified some proteins that took part in cross-reactive IgE by the determination of N-terminal animo acid sequences and a homology search through the SWISS-PROT database. Results In the RAST inhibition. the bindings of IgE from the sera from four out of five (4/5) subjects to Japanese cedar pollen discs were inhibited by more than 50% by preincubation of the serum with tomato fruit extracts, Likewise. the IgE bindings to tomato fruit discs were inhibited more than 50% by Japanese cedar pollen extracts in 315 sera. In immunoblot inhibition, IgE binding activities of some protein bands on both membranes were decreased by heterologous inhibitors. However, the combinations of these protein bands involved in cross-reactivity were different between patients. Conclusion We have demonstrated cross-reactivity between Japanese cedar pollen and tomato fruit using RAST inhibition and immunoblot inhibition.

Human parvovirus (HPV) B19 infection has been reported to be a cause of transient erythroblastopenia in patients with hemolytic disorders (aplastic crisis). Human parvovirus B19 is directly cytotoxic for erythroid progenitor cells and inhibits erythropoiesis. Infrequently, HPV B19 inhibits hematopoiesis of three cell lineages and causes transient pancytopenia in patients with hemolytic disorders. In experimental infections with normal volunteers, reticulocytes and platelet counts in the peripheral blood decreased 10-14 days after intranasal inoculation, and these hematological abnormalities recovered spontaneously within a few weeks. We report a boy without any underlying disease who developed transient pancytopenia. A HPV B19 infection was confirmed by serological studies and DNA analysis as the causative infectious agent associated with severe pancytopenia.

筆者らが報告した加熱脱 ovomucoid 卵白は, アレルゲン性の低減化はされているが, 起泡性がなく, 溶解しにくく, 味がわるいため, 実用的でなく, 卵白の代用品として日常の食生活に用いるには困難であった. そこで, 臨床応用に足る程度に低アレルゲン化され, しかも家庭でも作製できる加熱脱 ovomucoid 卵白の簡便な作製方法を試みた.<br>今回作製した加熱脱 ovomucoid 卵白の ovomucoid は, 14%SDS-PAGEの band の比較から, 加熱卵白よりも減少していた.<br>この加熱脱 ovomucoid 卵白を米飯に混ぜて作っただんごを用い, 二重盲検法による経口負荷試験によってアレルゲン性を検討した. その結果, 加熱卵白で過敏反応陽性患者全例に, 症状の出現は認められなかった. 栄養価の検討でも, タンパク質が90%以上残存していた.<br>したがって, 鷄卵アレルギー児の食生活を豊かにすることが期待される.

筆者らが報告した加熱脱 ovomucoid 卵白は, アレルゲン性の低減化はされているが, 起泡性がなく, 溶解しにくく, 味がわるいため, 実用的でなく, 卵白の代用品として日常の食生活に用いるには困難であった. そこで, 臨床応用に足る程度に低アレルゲン化され, しかも家庭でも作製できる加熱脱 ovomucoid 卵白の簡便な作製方法を試みた.<br>今回作製した加熱脱 ovomucoid 卵白の ovomucoid は, 14%SDS-PAGEの band の比較から, 加熱卵白よりも減少していた.<br>この加熱脱 ovomucoid 卵白を米飯に混ぜて作っただんごを用い, 二重盲検法による経口負荷試験によってアレルゲン性を検討した. その結果, 加熱卵白で過敏反応陽性患者全例に, 症状の出現は認められなかった. 栄養価の検討でも, タンパク質が90%以上残存していた.<br>したがって, 鷄卵アレルギー児の食生活を豊かにすることが期待される.

Background: We occasionally see egg-allergic children who develop contact urticaria to hen's egg despite the absence of the overt symptoms on ingestion. The mechanisms remain to be elucidated. Methods: Twenty-one subjects with positive reactions to 20-min patch tests for egg-white antigens were divided into subgroups with positive (n = 10) and negative (n = 11) results to oral challenge tests by the same antigens. We measured IgE antibody for egg white and its components, and IgE-binding activities to digestive enzyme-treated ovomucoid by RAST inhibition. Results: There were no significant differences in IgE antibody titers to egg white (positive vs negative: 30.3% vs 15.3%, P = 0.130), ovomucoid (21.5% vs 10.2%, P = 0.078), ovotransferrin (9.9% vs 3.7%, P = 0.105), and lysozyme (3.4% vs 2.9%, P = 0.944), except ovalbumin (16.8% vs 5.6%, P = 0.024), between the positive and negative subjects in the provocation tests. In contrast, the concentration (1.93 mu g/ml) of pepsin-treated ovomucoid needed for 50% RAST inhibition in the challenge-positive subjects was significantly (P = 0.0003) lower than that (114.9 mu g/ml) of negative subjects. Similar but less significant differences were obtained when ovomucoid fragments treated with chymotrypsin (0.91 mu g/ml vs 6.86 mu g/ml, P = 0.014) and trypsin (0.75 mu g/ml vs 4.67 mu g/ml, P = 0.041) were used as inhibitors. Conclusions: We suggest that IgE antibodies from subjects showing contact urticaria despite the absence of reactions to the ingestion of egg white recognize the epitope(s) unstable to digestive enzymes.

我々は, トマト特異的IgE抗体 (CAP-FEIA) が少なくとも class 3以上の25例の患者血清 (このうち, 11例はトマト果実による口腔アレルギー症候群) を用いて immunoblot 法でトマト果実主要アレルゲンの同定を試みた. その結果, 46kDa, 25kDa, 22kDa, 18kDa, 14kDaのタンパク質バンドが50%以上の患者血清と反応した. これらのバンドのN末端アミノ酸配列を Edman 法で決定し, 相同性検索をしたところ, 46kDaは polygalacturonase 2A, 25と22kDaは β-fructofuranosidase, 18kDaは superoxide dismutase, 14kDaは pectinesterase であることが判明した. また, これらのタンパク質は superoxide dismutase を除いてトマトの成熟が進むにつれて増加することも明らかになった.