Real-World Sensitization and Tolerance Pattern to Seafood in Fish-Allergic Individuals.

BACKGROUND: Seafood is a common cause of food allergy and anaphylaxis, but there are limited published real-world data describing the clinical presentation of fish and shellfish allergies. OBJECTIVE: This study aimed to examine the clinical characteristics, immunological profile, and tolerance pattern to fish, crustaceans, and mollusks in fish-allergic individuals. METHODS: Patients presenting with IgE-mediated fish allergy between 2016 and 2021 were recruited. A comprehensive sensitization profile including specific IgE and skin prick test to various fish and shellfish species and a detailed clinical history including individuals' recent seafood consumption were evaluated. RESULTS: A total of 249 fish-allergic individuals (aged 4.2 ± 5.8 years) were recruited from 6 allergy clinics in Hong Kong, and they had experienced their fish-allergic reaction 2.2 ± 3.4 years before enrollment. Seventy-five subjects (30%) reacted to either grass carp, salmon, grouper, or cod in oral food challenges. We identified an IgE sensitization gradient that corresponded to the level of ß-parvalbumin in fish. In total, 40% of fish-allergic individuals reported tolerance to 1 or more types of fish, more commonly to fish with a lower ß-parvalbumin level such as tuna and salmon, compared with ß-parvalbumin-rich fish such as catfish and grass carp. Despite fish and shellfish cosensitization, 41% of individuals reported tolerance to crustaceans, mollusks, or both, whereas shellfish avoidance occurred in half of the fish-allergic individuals, of whom 33% lacked shellfish sensitization. CONCLUSIONS: Fish allergy commonly presents in early childhood. A considerable proportion of fish-allergic patients are selectively tolerant to certain fish, typically those with lower levels of ß-parvalbumin. There is an unmet need to promote precision medicine for seafood allergies.

Differential patterns of fish sensitization in Asian populations: Implication for precision diagnosis.

BACKGROUND: The current diagnostics of fish allergy lack sufficient accuracy such that more reliable tests such as component-resolved diagnosis (CRD) are urgently needed. This study aimed at identifying fish allergens of salmon and grass carp and evaluating the sensitization pattern in fish allergic subjects from two distinct populations in Asia. METHODS: One hundred and three fish allergic subjects were recruited from Hong Kong (67 subjects) and Japan (46 subjects). Western blot and mass spectrometry were used to identify allergens from salmon and grass carp. Fish allergens were purified and tested against 96 sera on ELISA to analyze patients' sensitization pattern. The protein profiles of salmon meat prepared under different cooking methods until core temperature reached 80 °C were evaluated by SDS-PAGE and mass spectrometry. RESULTS: Three common allergens between salmon and grass carp, namely enolase, glycerldehyde-3-phosphate dehydrogenase (GAPDH) and parvalbumin, and two salmon-specific allergens collagen and aldolase were identified. Parvalbumin was the major allergen for both fishes showing an overall sensitization rate of 74.7%, followed by collagen (38.9%), aldolase (38.5%) and enolase (17.8%). Japanese subjects showed more diverse allergen sensitization pattern and more frequent IgE-binding to heat-labile salmon allergens. Compared with steaming and boiling, cooking by baking and frying retained more fish proteins inclusive of heat-labile allergens. CONCLUSIONS: Fish allergic patients from different Asian populations show varying fish allergen sensitization profiles. The relevant extracts and components for diagnosis are population-dependent but parvalbumin and collagen are important biomarkers. Cooking methods modify allergen composition of salmon and appear to influence patients' allergic manifestations.

Comprehending the allergen repertoire of shrimp for precision molecular diagnosis of shrimp allergy.

BACKGROUND: Clinical management of shrimp allergy is hampered by the lack of accurate tests. Molecular diagnosis has been shown to more accurately reflect the clinical reactivity but the full spectrum of shrimp allergens and their clinical relevance are yet to be established. We therefore sought to comprehend the allergen repertoire of shrimp, investigate and compare the sensitization pattern and diagnostic value of the allergens in allergic subjects of two distinct populations. METHODS: Sera were collected from 85 subjects with challenge-proven or doctor-diagnosed shrimp allergy in Hong Kong and Thailand. The IgE-binding proteins of Penaeus monodon were probed by Western blotting and identified by mass spectrometry. Recombinant shrimp allergens were synthesized and analyzed for IgE sensitization by ELISA. RESULTS: Ten IgE-binding proteins were identified, and a comprehensive panel of 11 recombinant shrimp allergens was generated. The major shrimp allergens among Hong Kong subjects were troponin C (Pen m 6) and glycogen phosphorylase (Pen m 14, 47.1%), tropomyosin (Pen m 1, 41.2%) and sarcoplasmic-calcium binding protein (Pen m 4, 35.3%), while those among Thai subjects were Pen m 1 (68.8%), Pen m 6 (50.0%) and fatty acid-binding protein (Pen m 13, 37.5%). Component-based tests yielded significantly higher area under curve values (0.77-0.96) than shrimp extract-IgE test (0.70-0.75). Yet the best component test differed between populations; Pen m 1-IgE test added diagnostic value only in the Thai cohort, whereas sensitizations to other components were better predictors of shrimp allergy in Hong Kong patients. CONCLUSION: Pen m 14 was identified as a novel shrimp allergen predictive of challenge outcome. Molecular diagnosis better predicts shrimp allergy than conventional tests, but the relevant component is population dependent.

Changing pattern of pediatric anaphylaxis in Hong Kong, 2010-2019.

BACKGROUND: Anaphylaxis is a significant health burden in most Western countries, but there are little published data on the incidence and pattern of anaphylaxis in Asia. We aim to determine the incidence rate and pattern of anaphylaxis over the past decade among the pediatric population in Hong Kong. METHODS: Medical records of patients presenting with allergy-related symptoms during the period 2010 to 2019 were examined. Pediatric patients aged below 18 years who fulfilled the diagnostic criteria for anaphylaxis laid out by the NIAID/FAAN were analyzed. Incidence rates were calculated using population statistics as the denominator. All information pertaining to the anaphylaxis events and patients' characteristics was retrieved using standardized data collection forms. RESULTS: The overall 10-year estimated incidence of anaphylaxis was 9.76 per 100,000 person-years, with a rising trend of anaphylaxis incidence across time. Food-induced anaphylaxis accounted for the majority of hospital presentations, of which peanut and shellfish were the top food triggers in our population. Majority of anaphylaxis episodes were of Grade 4 severity, and young age was a significant predictor of severe allergic reactions. Half of the anaphylaxis episodes were misdiagnosed and adrenaline was only utilized in 42.2% of cases, of which 9.4% were administered adrenaline prior to hospital arrival. CONCLUSIONS: An increasing trend of anaphylaxis incidence over the past decade is evident in Hong Kong children, with a discrepantly low accuracy in diagnosis and suboptimal management of anaphylaxis. There is a pressing need to heighten public and physicians' awareness of the distinctive features of anaphylaxis in the pediatric age-group.

Dendritic Cell Migration and Antigen Presentation Are Coordinated by the Opposing Functions of the Tetraspanins CD82 and CD37.

This study supports a new concept where the opposing functions of the tetraspanins CD37 and CD82 may coordinate changes in migration and Ag presentation during dendritic cell (DC) activation. We have previously published that CD37 is downregulated upon monocyte-derived DC activation, promotes migration of both skin and bone marrow-derived dendritic cells (BMDCs), and restrains Ag presentation in splenic and BMDCs. In this article, we show that CD82, the closest phylogenetic relative to CD37, appears to have opposing functions. CD82 is upregulated upon activation of BMDCs and monocyte-derived DCs, restrains migration of skin and BMDCs, supports MHC class II maturation, and promotes stable interactions between T cells and splenic DCs or BMDCs. The underlying mechanism involves the rearrangement of the cytoskeleton via a differential activation of small GTPases. Both CD37(-/-) and CD82(-/-) BMDCs lack cellular projections, but where CD37(-/-) BMDCs spread poorly on fibronectin, CD82(-/-) BMDCs are large and spread to a greater extent than wild-type BMDCs. At the molecular level, CD82 is a negative regulator of RhoA, whereas CD37 promotes activation of Rac-1; both tetraspanins negatively regulate Cdc42. Thus, this study identifies a key aspect of DC biology: an unactivated BMDC is CD37(hi)CD82(lo), resulting in a highly motile cell with a limited ability to activate naive T cells. By contrast, a late activated BMDC is CD37(lo)CD82(hi), and thus has modified its migratory, cytoskeletal, and Ag presentation machinery to become a cell superbly adapted to activating naive T cells.

Three-dimensional mechanical dyssynchrony and myocardial deformation of the left ventricle in patients with tricuspid atresia after Fontan procedure.

BACKGROUND: The aim of this study was to test the hypothesis that dyssynchronous contraction of functional single ventricles occurs in Fontan patients and is related to indices of myocardial deformation and global ventricular function. METHODS: Twenty patients with tricuspid atresia (mean age, 23.5 ± 7.1 years) were studied 17.8 ± 3.8 years after undergoing the Fontan procedure. Three-dimensional echocardiographic data were acquired for determination of left ventricular (LV) volumes and systolic dyssynchrony indices. LV myocardial deformation was determined using speckle-tracking echocardiography. Calibrated integrated backscatter intensity was measured as an index of myocardial fibrosis. The results were compared with those in 20 controls. RESULTS: Compared with controls, patients had significantly greater systolic dyssynchrony indices (6.13 ± 1.32% vs 4.06 ± 0.84%, P < .001). The prevalence of LV mechanical dyssynchrony (systolic dyssynchrony index > 5.74%) in patients was 55% (95% confidence interval, 32%-77%). LV global systolic longitudinal, radial, and circumferential strain (P < .001 for all), longitudinal systolic (P < .001) and early diastolic (P < .001) strain rate, and circumferential systolic (P < .001) and early diastolic (P = .009) strain rate were significantly lower in patients than in controls, while the average calibrated integrated backscatter was higher (P < .001). Patients with LV dyssynchrony (n = 11) had lower global LV longitudinal strain (P = .02), reduced LV ejection fractions (P = .002), and higher average calibrated integrated backscatter (P = .03) compared with those without LV dyssynchrony (n = 9). CONCLUSIONS: A high proportion of patients with tricuspid atresia after the Fontan operation exhibit LV mechanical dyssynchrony, which may in part be related to myocardial fibrosis and has implications for myocardial deformation and global ventricular function.

Mammalian initiator apoptotic caspases.

Caspases are a conserved family of cysteine proteases. They play diverse roles in inflammatory responses and apoptotic pathways. Among the caspases is a subgroup whose primary function is to initiate apoptosis. Within their long prodomains, caspases-2, -9 and -12 contain a caspase activation and recruitment domain while caspases-8 and -10 bear death effector domains. Activation follows the recruitment of the procaspase molecule via the prodomain to a high molecular mass complex. Despite sharing some common features, other aspects of the biochemistry, substrate specificity, regulation and signaling mechanisms differ between initiator apoptotic caspases. Defects in expression or activity of these caspases are related to certain pathological conditions including neurodegenerative disorders, autoimmune diseases and cancer.

Association between body mass index and risk of formation of breast cancer in Chinese women.

OBJECTIVE: To analyse the association between body mass index (BMI) and breast cancer risk among Chinese women in Hong Kong. METHODS: We conducted a population-based case control study of breast cancer in June 2002. Standardized questionnaires concerning BMI and other anthropometric data were completed by patients at the Queen Mary Hospital (QMH). The cases were 198 women aged 24-85 years who had documented breast cancer in 1995-2000 by triple assessment criteria, and the controls were 353 women who were followed up at QMH for benign breast disease after breast cancer had been excluded by triple assessment. The controls were frequency-matched to the cases by age. RESULTS: BMI at diagnosis was positively correlated with the risk of breast cancer among postmenopausal women (p < 0.001 for trend). Also, when compared with women with a low BMI (< 19), women with a BMI of 23-27 and 27-31 had a 1.73-fold (95% confidence interval, CI, 1.04-2.86) and 2.06-fold (95% CI, 1.08-3.93) increased risk of breast cancer, respectively, after adjustment for non-anthropometric risk factors. BMI at diagnosis, however, was not related to the risk of breast cancer among premenopausal women. The odds ratios for premenopausal women with a BMI of 23-27 and 27-31 were 1.5 (95% CI, 0.82-2.71) and 1.32 (95% CI, 0.39-4.43), respectively. Furthermore, present BMI and BMI 5 years before diagnosis were poorly associated with breast cancer risk among both pre- and postmenopausal women. CONCLUSION: Weight control in obese women may be an effective measure for breast cancer prevention in postmenopausal women.

Caspase-2 is resistant to inhibition by inhibitor of apoptosis proteins (IAPs) and can activate caspase-7.

Caspases are a family of cysteine proteases with roles in cytokine maturation or apoptosis. Caspase-2 was the first pro-apoptotic caspase identified, but its functions in apoptotic signal transduction are still being elucidated. This study examined the regulation of the activity of caspase-2 using recombinant proteins and a yeast-based system. Our data suggest that for human caspase-2 to be active its large and small subunits must be separated. For maximal activity its prodomain must also be removed. Consistent with its proposed identity as an upstream caspase, caspase-2 could provoke the activation of caspase-7. Caspase-2 was not subject to inhibition by members of the IAP family of apoptosis inhibitors.

A modified screening tool for autism (Checklist for Autism in Toddlers [CHAT-23]) for Chinese children.

BACKGROUND: There is a recent trend of a worldwide increase in the incidence of autistic spectrum disorder. Early identification and intervention have proved to be beneficial. The original version of the Checklist for Autism in Toddlers (CHAT) was a simple screening tool for identification of autistic children at 18 months of age in the United Kingdom. Children with an absence of joint attention (including protodeclarative pointing and gaze monitoring) and pretend play at 18 months were at high risk of autism. Section A of the CHAT was a self-administered questionnaire for parents, with 9 yes/no questions addressing the following areas of child development: rough and tumble play, social interest, motor development, social play, pretend play, protoimperative pointing (pointing to ask for something), protodeclarative pointing, functional play, and showing. Section B of the CHAT consisted of 5 items, which were recorded with observation of the children by general practitioners or health visitors. The 5 items addressed the child's eye contact, ability to follow a point (gaze monitoring), pretend (pretend play), produce a point (protodeclarative pointing), and make a tower of blocks. A 6-year follow-up study of >16,000 children screened with the CHAT at 18 months in the United Kingdom showed a sensitivity of only 0.40 and a specificity of 0.98, with a positive predictive value (PPV) of 0.26. Rescreening using the same instrument at 19 months for those who failed the 18-month screening yielded a higher PPV of 0.75. Therefore, children were likely to have autism if they failed the CHAT at 18 months and failed again at 19 months. It was estimated that consistent failure in 3 key questions (ie, protodeclarative pointing, gaze monitoring, and pretend play) at 18 months indicated an 83.3% risk of having autism. Because of the poor sensitivity of the original CHAT for autism, a Modified Checklist for Autism in Toddlers (M-CHAT), consisting of 23 questions, with 9 questions from the original CHAT and an additional 14 questions addressing core symptoms present among young autistic children, was designed in the United States. The original observational part (ie, section B) was omitted. The M-CHAT was designed as a simple, self-administered, parental questionnaire for use during regular pediatric visits. The more questions children failed, the higher their risk of having autism. Two criteria were used to measure the sensitivity and specificity of M-CHAT. Criterion 1 used any 3 of the 23 questions, and criterion 2 used 2 of the 6 best questions that could be used to discriminate autism from other groups. The sensitivity and specificity for criterion 1 were 0.97 and 0.95 and those for criterion 2 were 0.95 and 0.99, respectively. M-CHAT had a better sensitivity than the original CHAT, because children up to 24 months of age were screened, with the aim of identifying those who might regress between 18 and 24 months. The 6 best questions of the M-CHAT addressed areas of social relatedness (interest in other children and imitation), joint attention (protodeclarative pointing and gaze monitoring), bringing objects to show parents, and responses to calling. Joint attention was addressed in the original CHAT, whereas the other areas were addressed only in the M-CHAT. To date, there has been no study of the application of either the original CHAT or the M-CHAT for Chinese populations. OBJECTIVES: CHAT-23 is a new checklist translated into Chinese, combining the M-CHAT (23 questions) with graded scores and section B (observational section) of the CHAT. We aimed to determine whether CHAT-23 could discriminate autism at mental ages of 18 to 24 months for Chinese children and to determine the best combination of questions to identify autism. METHODS: A cross-sectional cohort study was performed with 212 children with mental ages of 18 to 24 months. The children were categorized into 2 groups, ie, group 1 (N = 87) (autistic disorder: N = 53; pervasive developmental disorder: N = 33) and group 2 (N = 125) (nonautistic). The checklist included self-ad25) (nonautistic). The checklist included self-administered questionnaires with 23 questions (part A) and direct observations of 5 items by trained investigators (part B). We performed discriminant function analysis to We found that 7 key questions, addressing areas of joint attention, pretend play, social relatedness, and social referencing, were identified as discriminative for autism. For part A, failing any 2 of 7 key questions, ie, question 13 (does your child imitate you? [eg, you make a face; will your child imitate it?]), question 5 (does your child ever pretend, for example, to talk on the phone or take care of dolls, or pretend other things?), question 7 (does your child ever use his/her index finger to point, to indicate interest in something?), question 23 (does your child look at your face to check your reaction when faced with something unfamiliar?), question 9 (does your child ever bring objects over to you [parent] to show you something?), question 15 (if you point at a toy across the room, does your child look at it?), and question 2 (does your child take an interest in other children?), yielded sensitivity of 0.931 and specificity of 0.768. Failing any 6 of all 23 questions produced sensitivity of 0.839 and specificity of 0.848. For part B, failing any 2 of 4 items produced sensitivity of 0.736, specificity of 0.912, and PPV of 0.853. The 4 observational items were as follows: item B1: during the appointment, has the child made eye contact with you? item B2: does the child look across to see what you are pointing at? item B3: does the child pretend to pour out tea, drink it, etc?; item B4: does the child point with his/her index finger at the light? CONCLUSION: We found that integrating the screening questions of the M-CHAT (from the United States) and observational section B of the original CHAT (from the United Kingdom) yielded high sensitivity and specificity in discriminating autism at 18 to 24 months of age for our Chinese cohort. This new screening instrument (CHAT-23) is simple to administer. We found that a 2-stage screening program for autism can offer a cost-effective method for early detection of autism at 18 to 24 months. For CHAT-23, use of both the parental questionnaire and direct observation and use of the criterion of failing any 2 of 7 key questions yielded the highest sensitivity but a relatively lower specificity, whereas use of part B yielded the highest specificity but a lower sensitivity. We recommend identifying the possible positive cases with part A (parental questionnaire) and then proceeding to part B (observation) with trained assessors. The proposed algorithm for screening for autism is as follows. 1) The parents or chief caretakers complete a 23-item questionnaire when their children are 18 to 24 months of age. 2) The parents mail, fax, or hand this 23-item questionnaire to the local child health agency. 3) Clerical staff members check for and score failure, with the criteria of failing any 2 of 7 key questions or failing any 6 of 23 questions; if either criterion is met, then the staff members highlight the medical records of the suspicious cases. 4) Trained child health care professionals observe the children who failed any 2 of 7 key questions or any 6 of 23 questions. These identified patients are observed for 5 minutes for part B of the CHAT-23. 5) Any child who fails any 2 of 4 items requires direct referral to a comprehensive autism evaluation team, for early diagnostic evaluation and early intervention. The high sensitivity and specificity of the criteria observed in our study suggested that CHAT-23 might be used to differentiate children with autism. Additional international collaboration with the use of the CHAT, M-CHAT, and CHAT-23 could provide more prospective epidemiologic data, to establish whether there is a genuine increase in the worldwide incidence of autism.

Preparation of biologically active recombinant human progastrin(1-80).

The bacterial expression of human progastrin(6-80) has been reported previously [Baldwin, G.S. et al. (2001) J. Biol. Chem. 276: 7791-7796]. The aims of the present study were to prepare full-length recombinant human progastrin(1-80) and to compare its biological activity with that of progastrin(6-80) in vitro, to determine whether or not the N-terminal five amino acids contributed to activity. A fusion protein of glutathione-S-transferase and human progastrin(1-80) was expressed in Escherichia coli, collected on glutathione-agarose beads, and cleaved with enterokinase. Progastrin(1-80) was purified by reversed-phase and anion exchange HPLC and characterized by radioimmunoassay, amino acid sequencing, and mass spectrometry. No differences were detected in the extent of stimulation by progastrin(1-80) and progastrin(6-80) in proliferation and migration assays with the mouse gastric cell line IMGE-5. We conclude that residues 1-5 of progastrin(1-80) are not essential for biological activity.