Serum IgE profiles in Chinese pollinosis patients with grass pollen sensitisation.

PURPOSE: Pollen from trees, grasses, and weeds is a common allergen source. The characteristics of pollen allergy in China are obviously different from Europe. Most studies have focused on tree and weed pollen, but there is a paucity of data on grass pollen sensitisation in China. Therefore, we used component-resolved diagnostics to investigate the serum-specific immunoglobulin E (sIgE) to grass pollen in Chinese patients with pollinosis. METHODS: We retrospectively analysed 547 patients with pollen allegy from an outpatient Allergy Department in Beijing, China. All the patients answered questionnaires about their clinical allergy histories. Total immunoglobulin E (IgE) and sIgE levels to grass pollen (Bermuda, Timothy grass) were quantified by ImmunoCAP using 0.35 kUA/L as a threshold for positivity. RESULTS: Of the 547 pollinosis patients, 389 (71.1%) showed a positive sIgE reaction to either grass pollen, or both. The prevalence of food allergy was significantly lower in patients with grass pollen sensitisation. Among the 389 patients with grass pollen sensitisation, the prevalence of sIgE to allergen extracts of bermuda, mugwort, ragweed, plane, hop, ash, birch, and timothy grass was 97%, 96%, 94%, 88%, 88%, 84%, 78%, and 78%, respectively. However, only 134/389 (34%) were positive for Cyn d 1, 29/389 (7%) for Phl p 1, and 8/389 (2%) for Phl p 5b. For pollinosis patients, 62/547 (11%) were sIgE-positive for cross-reactive carbohydrate determinants (CCDs), and their grass pollen-sIgE was also positive. CONCLUSIONS: The prevalence of in vitro IgE sensitisation to grass pollen extract is high in Chinese patients with pollinosis. But mostly spurious and characterized by IgE sensitisation to profilins and CCD, induced by other pollen. Component-resolved diagnostics is an extremely useful tool precise diagnostics of pollen allergy in China.

Retrospective analysis of epidemic thunderstorm asthma in children in Yulin, northwest China.

BACKGROUND: An epidemic of thunderstorm asthma in pediatric patients occurred in Yulin, a northwest city of China, on 11 September 2018. We described the epidemic and retrospectively analyzed the demographic and clinical aspects of the involved children. METHODS: The caseload data of patients were collected from the hospital information system in Yulin Pediatric Hospital. The detailed document of hospitalized children with thunderstorm asthma was sourced from the medical records. RESULTS: The mean number of daily visits to emergency/outpatient department and the daily admission to hospital were 2.7 and 16 times, respectively, than on the other days of September. A gender prominence of males was observed in both emergency/outpatient and inpatient department. Among the 51 hospitalized children with detailed medical records, 56% of them had never experienced or were diagnosed with asthma and 25% had confirmed diagnosis of asthma. Sixty-seven percent had a history of allergic rhinitis during August and September. Seventy-six percent of the hospitalized children presented as moderate asthma. Ninety-four percent of the pediatric patients had positive IgE against mugwort pollen and 78% were monosensitized to pollen. CONCLUSION: Thunderstorm asthma can affect children, especially who has allergic rhinitis or asthma without preventive management. Mugwort is also an aeroallergen in thunderstorm asthma attacks. IMPACT: Thunderstorm can induce asthma attacks in children with allergic rhinitis owing to mugwort and aggravate symptoms in children with confirmed diagnosis of asthma. Children with mugwort allergy are susceptible to thunderstorm asthma and a preponderance of boys was observed. Better identification of allergic children to mugwort, giving suitable protective measures during thunderstorm and standard therapy to existing allergic situation could be a benefit for children at risk of thunderstorm asthma.

A Case of Anaphylaxis Caused by Major Royal Jelly Protein 3 of Royal Jelly and Its Cross-Reactivity with Honeycomb.

PURPOSE: Royal jelly and honeycomb are commonly consumed in China, and anaphylaxis caused by ingestion of royal jelly is rare. To date, there is no report of anaphylaxis after ingestion of royal jelly in China. Its cross-reactivity with honeycomb is still unclear. CASE REPORT: A 56-year-old Chinese female experienced two episodes of anaphylaxis within 1 hour after ingestion of royal jelly within one month. After avoiding royal jelly and other bee products, no anaphylactic reaction occurred again. The skin prick test and basophil activation test showed positive reactivity to royal jelly and honeycomb. In immunoblotting and immunoblotting inhibition tests, a 60 kDa protein was recognized in royal jelly and cross-reactivity with honeycomb. The mass spectrometry data revealed that the 62kDa protein belongs to major royal jelly protein 3. CONCLUSION: Our data suggest that major royal jelly protein 3 of royal jelly is a main allergen that induces anaphylaxis and cross-reactivity with honeycomb. Therefore, the patient was allergic to royal jelly to avoid other bee products.

Hereditary angioedema caused by a premature stop codon mutation in the SERPING1 gene.

BACKGROUND: Hereditary angioedema with deficient and dysfunctional C1 inhibitor (C1-INH-HAE) is a rare genetic disorder. The majority of the cases with this disease are caused by mutations in the C1-inbitor gene SERPING1 and are classified as type 1 and type 2. We aimed to detect mutations in the SERPING1 gene and evaluate its expression in nine probands with hereditary angioedema from nine different families. METHODS: Nine probands with hereditary angioedema from nine different families and 53 healthy controls were recruited in this study. All eight exons and intron-exon boundaries in the SERPING1 gene were amplified by PCR and then sequenced. Mutations were identified by alignment with reference sequences. mRNA expression was measured by real-time PCR. RESULTS: All probands were diagnosed with HAE type 1. Nine mutations were found in nine patients: c.44delT, c.289C

Characteristics of pollen-related food allergy based on individual pollen allergy profiles in the Chinese population.

BACKGROUND: Patients with pollinosis are often multi-sensitized to diverse pollen allergens. However, little is known about pollen allergy types among Chinese pollinosis patients. This study is aimed to characterize clinical manifestations of food allergy among patients with different types of pollen allergy. METHODS: We retrospectively analyzed 402 pollinosis patients from an outpatient allergy department of the Peking Union Medical College Hospital who had been diagnosed by experienced allergists. All included patients who answered a questionnaire regarding seasonal pollinosis and clinical symptoms after ingestion of food and underwent intradermal skin tests. Total IgE and specific IgE levels were quantified by ImmunoCAP, using 0.35 kUA/L as a threshold for positivity. RESULTS: The patients were divided into 3 groups, based on the season during which they experienced symptoms and the 2 peaks of Chinese airborne pollen: spring-tree pollen symptoms group (SG), autumn-weed pollen symptoms group (AG), and a combined spring and autumn pollen symptoms group (CG). Birch pollen (83%) and ash pollen (74%) were common allergens among patients with spring symptoms, while mugwort pollen (87%) was a common allergen among patients with autumn symptoms. In total, 30% of the study population experienced pollen-related food allergy. Pollen-related food allergies were more prevalent among the single-season symptom groups (68% and 50% for the SG and AG, respectively) than among the CG (20%). All patients with pollen-related food-induced anaphylaxis exhibited autumn weed pollen symptoms. Except for 2 patients, all patients with food-induced anaphylaxis were allergic to mugwort pollen. In the SG, all patients with food allergy were sensitive to birch pollen, with birch and Bet v 1-specific IgE levels higher in this group than in the group without food allergy (p < 0.001). In the AG, Art v 3 was more prevalent among patients with pollen-related food allergy than without food allergy (79% vs. 33%, p < 0.001), a proportion similar to the one in the CG (67% vs. 48%, p = 0.01). Meanwhile, the Art v 3-specific IgE levels among patients with pollen-related food allergy were higher than among tolerant patients in the AG (p < 0.001) and CG (p = 0.02). Unexpectedly, the Art v 3-specific IgE levels were higher in patients with food-induced anaphylaxis than with oral allergy syndrome only in the CG. CONCLUSIONS: Bet v 1 (a Pathogenesis-related 10 protein) and Art v 3 (a non-specific lipid transfer protein; nsLTP) are candidate molecular biomarkers for the diagnosis of food allergies in patients with season-specific pollen-related allergies. Measuring pollen allergen component-specific IgE levels might be an effective tool for the management of pollinosis in clinical practice in China.

Stinging Insect Allergens.

Hymenoptera venom allergy is one of the common causes of anaphylaxis. However, when physicians make the diagnosis of Hymenoptera venom allergy, the history of being stung is not always consistent with the results of venom-specific IgE. With the development of component-resolved diagnosis, it is possible to accurately localize an allergic reaction to certain sensitized proteins. This paper reviewed the studies that have addressed the identified allergenicity and cross-reactivity of Hymenoptera venom allergens accepted by the WHO/IUIS Nomenclature Sub-committee, the componentresolved diagnosis of Hymenoptera venom allergy and its predictive values for the efficacy and safety of venom immunotherapy. Also special attention was paid to the spread of Hymenoptera venom allergy in Asian countries.

Wheat allergy in patients with recurrent urticaria.

BACKGROUND: Clinical observation revealed that most of wheat-induced anaphylaxis (WIA)/wheat-dependent exercise-induced anaphylaxis (WDEIA) patients showed a history of recurrent urticaria. We aim to determine the association between recurrent urticaria and anaphylaxis in wheat allergy. METHODS: Population-based cohort study involved patients with WIA (n = 193, including WDEIA n = 104), recurrent urticaria (n = 177), non-wheat-related anaphylaxis (n = 584), atopic disease (excluding anaphylaxis, n = 221) and healthy control (n = 95) from 2009 to 2016. Detailed course of urticaria and anaphylaxis were obtained from medical records and following-up questionnaire. Serum IgE specific to wheat, gluten and ω-5 gliadin and skin prick test to wheat were examined. Clinical and laboratory data were statistically analyzed. RESULTS: In recurrent urticaria patients, wheat allergy was not rare, and 6.8% (n = 12) was diagnosed as wheat-induced urticaria. Patients with WIA/WDEIA had higher prevalence of recurrent urticaria history than those with non-wheat-related anaphylaxis (164/193, 84.9% vs 85/584, 14.5%), and 70.4% of them (136/193) had recurrent urticaria prior to their first anaphylactic attack. Among patients with WIA/WDEIA and previous urticaria, 46.3% experienced an exacerbation of urticaria. The value of serum specific IgE to ω-5 gliadin was significantly higher in patients with WIA/WDEIA than those with wheat-induced urticaria. CONCLUSIONS: We recommend screening wheat allergy in recurrent urticaria to identify patients who have a potential risk to develop severe reactions earlier.

Identification of a thermal stable allergen in yam (Dioscorea opposita) to cause anaphylaxis.

Yam (Dioscorea opposita) is commonly consumed in East Asia, but allergic reaction to this plant food is rare. To date, there is no report of anaphylactic reaction after ingestion of cooked yam. We described 3 cases with anaphylaxis after eating boiled yam and 1 present with oral allergy syndrome as well. Basophil activation test in patients showed positive reactivity to boiled yam extract. In immunoblotting, a 30-kDa protein was recognized by all patients' sera and a 17-kDa band was detected by 1 patient. N-terminal amino acid revealed the 30-kDa IgE reacted band was DB3S, dioscorin in Dioscorea tuber. It promoted us that DB3S was a thermal stable oral allergen to trigger anaphylactic reaction and oral allergy syndrome in cooked yam (D. opposita) allergy. Patients with this plant food allergy should avoid both raw and well-cooked yam.

Upper airway edema in 43 patients with hereditary angioedema.

BACKGROUND: Upper airway edema (UAE) occurs infrequently in hereditary angioedema (HAE), but still results in significant morbidity and mortality. OBJECTIVE: To assess patients with HAE and UAE to determine whether unique features exist that can predict the risk of UAE. METHODS: Clinical, laboratory, and genetic data were compared between 43 patients with HAE and 743 UAE attacks and those without UAE and normal controls after ethics committee approval. RESULTS: Most patients had their first episode of UAE in the second (25.6%), third (27.9%), and fourth (23.3%) decades of life, and the mean age at onset was 27.3 years. Evolution of UAE from initial to maximum symptoms was 4.6 hours on average, and most cases (69.8%) progressed within 4 hours. Dyspnea was the most frequent manifestation in per-episode (92.2%) and per-patient (97.7%) analyses. Men developed more asphyxiation attacks (19 vs 2) and underwent more tracheotomies (12 vs 2) than did women. UAE was associated with facial edema in half the studied patients. Patients with a positive family history of UAE had a high risk of UAE attacks. CONCLUSION: Symptoms limited to the upper airway should be taken seriously. Dyspnea may be the only manifestation of UAE. UAE attacks most commonly start spontaneously and usually progress rapidly, as quickly as 30 minutes, from awareness of symptoms to maximum airway involvement. Patients with a positive UAE family history are predisposed to UAE attacks, and men appear to be more apt to develop asphyxiation than women.

Clinical features of hereditary angioedema in Chinese patients: new findings and differences from other populations.

BACKGROUND: Hereditary angioedema (HAE), caused by C1 inhibitor deficiency, is characterized by recurrent subcutaneous or submucosal swelling. Because it is rare, data on clinical features, especially in Chinese patients, are not comprehensive. OBJECTIVE: Our aim was to identify the characteristics of HAE in a Chinese population and enhance clinical knowledge of this disease. METHODS: One hundred and fifty-eight symptomatic patients were studied retrospectively. Data were obtained from medical records. Statistical analyses were performed using statistical software package: R version 2.14.0. RESULTS: The majority of patients first experienced attacks during the second (42%) and third (32%) decades: the mean onset of symptoms was at the age of 21.25 years. The percentage of patients having experienced a swelling at least once for the following sites were: extremities (83.54%); pharyngolarynx (58.86%); face (55.06%); gastrointestinal tract (34.17%); trunk (18.35%) and genitalia (15.33%). Rare manifestations included melaena, swollen gastric mucosa inverting into the oesophagus, pleural effusion, dysuria and syncope. For patients who first experienced swelling in pre-adolescence, 41.67% noted intensified attack rates when they entered puberty. In pregnancy, 61.70% did not note a change in HAE attack frequency. CONCLUSION: Compared with previous studies, the mean age of symptom onset is older. The frequencies of abdominal attacks occurring in patients on the Chinese Mainland, as well as in Taiwan and Japan, appears much lower than in western countries. Ethnic or environmental differences may contribute to this finding. Melaena and gastric mucosa inverting into the oesophagus secondary to edema are first reported here.

Recent advances in the management of hereditary angioedema.

Hereditary angioedema (HAE) is a rare genetic condition that manifests as painful and potentially life-threatening episodic attacks of cutaneous and submucosal swelling. It results from functional deficiency of C1 inhibitor (C1 INH), which is a regulator of the complement, fibrinolytic, kinin (contact), and coagulation systems. In patients with HAE, the low plasma concentration of functional C1 INH leads to overactivation of the kinin cascade and local release of bradykinin. Bradykinin is responsible for the pain, vascular permeability changes, and edema associated with HAE. Until recently, therapeutic options for HAE have been very limited. Many new therapies have emerged, however, such as C1 INH replacement drugs and medications aimed at components of the contact system (eg, plasma kallikrein inhibitor and bradykinin B2 receptor antagonist). The authors review current and novel treatments for patients with HAE.