Association of vitamin D-binding protein polymorphisms and serum 25(OH)D concentration varies among Chinese healthy infants of different VDR-FokI genotypes: A multi-centre cross-sectional study

Hypovitaminosis D during infancy is associated with the development of chronic diseases and poor health later in life. While the effect of environmental factors on vitamin D concentration has been extensively explored, this study aimed to explore the effect of genetic factors on vitamin D concentration among Chinese infants. We conducted a multi-centre cross-sectional study in Hong Kong from July 2019 to May 2021. A candidate genetic approach was adopted to study four selected genetic variants of the vitamin D-binding protein (DBP) and vitamin D receptor (VDR) (rs4588, rs7041, rs2282679 and rs2228570) to examine their associations with measured serum 25(OH)D concentration. A total of 378 Chinese infants aged 2-12 months were recruited in this study. Peripheral blood samples were collected from the infants to measure serum 25(OH)D concentration and extract DNA. Results showed that rs7041T and rs2282679C were significantly associated with lower serum 25(OH)D concentration. Further analysis of the DBP variants revealed that the GC1F allele was significantly associated with lower 25(OH)D concentration and identified as the risk DBP isoform in infants. While our results revealed that there is no direct association between VDR-FokI genotype and serum 25(OH)D concentration, a VDR-FokI genotype-specific pattern was observed in the association between DBP isoforms and serum 25(OH)D concentration. Specifically, significant associations were observed in the DBP genotypes GC1F/F, GC1F/2 and GC1S/2 among VDR-FokI TT/TC carriers, but not in VDR-FokI CC carriers. Our findings lay down the basis for the potential of genetic screening to identify high risk of hypovitaminosis D in Chinese infants.

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 β-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 β-parvalbumin level such as tuna and salmon, compared with β-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 β-parvalbumin. There is an unmet need to promote precision medicine for seafood allergies.

Hong Kong-Macau Severe Hives and Angioedema Referral Pathway

Background

Urticaria (defined as the presence of hives, angioedema, or both) can be caused by a variety of etiologies ranging from more common conditions such as chronic spontaneous urticaria (CSU) to rarer conditions such as hereditary angioedema (HAE). Specialist referral may be necessary in cases of severe urticaria or HAE, but access to specialist services remains limited in certain regions, such as the Greater Bay Area (GBA) of China. To address this, the Hong Kong-Macau Severe Hives and Angioedema Referral Pathway (SHARP) was initiated by the Hong Kong Institute of Allergy and Macau Society of Dermatology to promote multidisciplinary collaboration and regional exchange of expertise in the diagnosis and management of severe urticaria.

Methods

A nominated task force of dermatologists and immunologists who manage patients with severe urticaria formulated the consensus statements (CS) using the Delphi method. The consensus was defined a priori as an agreement of ≥80%.

Results

A total of 24 CS were formulated, including four statements on classifications and definitions, seven statements on diagnosis, and 13 statements on management and referral. The definitions for acute/chronic urticaria and severe CSU were stated. Unnecessary investigations and inappropriate medications were discouraged. The characteristics and recommended approach to suspected bradykinergic angioedema were specified. Stepwise treatment options using second-generation antihistamines, omalizumab, or cyclosporin for patients with CSU were addressed, and the importance of access to HAE-specific medications was emphasized. Furthermore, an integrated referral pathway for patients with severe hives and angioedema was constructed.

Conclusion

The SHARP provides guidance for the management and specialist referral of patients with severe hives and angioedema in Hong Kong and Macau.

Safety and immunogenicity of 3 doses of BNT162b2 and CoronaVac in children and adults with inborn errors of immunity

Our study (NCT04800133) aimed to determine the safety and immunogenicity in patients with IEIs receiving a 3-dose primary series of mRNA vaccine BNT162b2 (age 12+) or inactivated whole-virion vaccine CoronaVac (age 3+) in Hong Kong, including Omicron BA.1 neutralization, in a nonrandomized manner. Intradermal vaccination was also studied. Thirty-nine patients were vaccinated, including 16 with homologous intramuscular 0.3ml BNT162b2 and 17 with homologous intramuscular 0.5ml CoronaVac. Two patients received 3 doses of intradermal 0.5ml CoronaVac, and 4 patients received 2 doses of intramuscular BNT162b2 and the third dose with intradermal BNT162b2. No safety concerns were identified. Inadequate S-RBD IgG and surrogate virus neutralization responses were found after 2 doses in patients with humoral immunodeficiencies and especially so against BA.1. Dose 3 of either vaccine increased S-RBD IgG response. T cell responses against SARS-CoV-2 antigens were detected in vaccinated IEI patients by intracellular cytokine staining on flow cytometry. Intradermal third dose vaccine led to high antibody response in 4 patients. The primary vaccination series of BNT162b2 and CoronaVac in adults and children with IEIs should include 3 doses for optimal immunogenicity.

Vulnerability and resilience in children during the COVID-19 pandemic

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic is having a profound impact on the health and development of children worldwide. There is limited evidence on the impact of COVID-19 and its related school closures and disease-containment measures on the psychosocial wellbeing of children; little research has been done on the characteristics of vulnerable groups and factors that promote resilience.

METHODS

We conducted a large-scale cross-sectional population study of Hong Kong families with children aged 2-12 years. Parents completed an online survey on family demographics, child psychosocial wellbeing, functioning and lifestyle habits, parent-child interactions, and parental stress during school closures due to COVID-19. We used simple and multiple linear regression analyses to explore factors associated with child psychosocial problems and parental stress during the pandemic.

RESULTS

The study included 29,202 individual families; of which 12,163 had children aged 2-5 years and 17,029 had children aged 6-12 years. The risk of child psychosocial problems was higher in children with special educational needs, and/or acute or chronic disease, mothers with mental illness, single-parent families, and low-income families. Delayed bedtime and/or inadequate sleep or exercise duration, extended use of electronic devices were associated with significantly higher parental stress and more psychosocial problems among pre-schoolers.

CONCLUSIONS

This study identifies vulnerable groups of children and highlights the importance of strengthening family coherence, adequate sleep and exercise, and responsible use of electronic devices in promoting psychosocial wellbeing during the COVID-19 pandemic.

Multilevel Factors Affecting Healthcare Workers' Perceived Stress and Risk of Infection During COVID-19 Pandemic

Objectives: This study aimed to identify key factors affecting Healthcare workers (HCWs) perceived stress and risk of contracting COVID-19 among themselves and their family members during the pandemic. Methods: A cross-sectional online questionnaire study was conducted between 19 March and April 5, 2020 in Hong Kong. HCWs from public hospitals and private dentists, and their family members participated. Results: A total of 747 HCWs and 245 family members participated. Higher perceived stress in HCWs was associated with more negative changes in family relationship (p = 0.025). The HCWs' perceived stress, however, was positively associated with family cohesion (p = 0.033) and stress levels of family members (p < 0.001). The level of HCWs' satisfaction toward the hospital policies in response to the COVID-19 outbreak was associated with lower levels of perceived stress and risk of themselves or their family members contracting COVID-19. HCWs' previous frontline experience of SARS was significantly associated with less perceived risk of themselves or their family members contracting COVID-19. Conclusion: Hospital policies addressing HCWs' needs, frontline experience of SARS, and family relationship influenced psychological wellbeing of HCWs during the COVID-19 outbreak.

Consensus Statements on the Approach to COVID-19 Vaccine Allergy Safety in Hong Kong

Background: Mass coronavirus disease 2019 (COVID-19) vaccination to achieve herd immunity is an effective means to mitigate the current COVID-19 pandemic. Reports of COVID-19 vaccine-associated allergic reactions and lack of clear local guidance are contributing factors leading to a low vaccine acceptance rate in the community. A task force of experts from the Hong Kong Institute of Allergy (HKIA) has been formed to address current needs.

Objective: To formulate a set of consensus statements (CS) on COVID-19 vaccine allergy safety (VAS) in Hong Kong.

Methods: A nominated task force of experts managing patients with drug and vaccine allergies in Hong Kong formulated the CS by the Delphi method. An agreement was a priori defined as ≥80% consensus.

Results: A total of 11 statements met the criteria for consensus with good overall agreement among task force members, including seven statements on pre-vaccination recommendations and four statements on vaccination and post-vaccination guidance. Individuals with a history of suspected allergic reaction to prior COVID-19 vaccination should not receive further COVID-19 vaccination, and other groups at risk of COVID-19 vaccine-associated allergic reactions have been identified. The importance of pre-vaccination and post-vaccination assessment by frontline healthcare workers and evaluation by allergists are highlighted.

Conclusion: The CS provides pragmatic and timely guidance for local frontline healthcare providers on decisions regarding COVID-19 VAS.

Impact of COVID-19 Pandemic on Serum Vitamin D Level among Infants and Toddlers: An Interrupted Time Series Analysis and before-and-after Comparison

Background: During the coronavirus disease 2019 (COVID-19) pandemic, the implementation of social distancing and home confinement measures may elevate the risk of vitamin D deficiency particularly for infants. This study aimed to quantify changes in vitamin D level among infants and toddlers in Hong Kong after the COVID-19 outbreak. Methods: We recruited 303 infants and toddlers aged 2–24 months by stratified random sampling from 1 June 2019 to November 30, 2020. Regression models were used to estimate the effect of time on infants’ serum 25-hydroxyvitamin D (25(OH)D) level overall and by age groups before and after the outbreak. Interrupted time series (ITS) analysis was performed to examine the sustained effect of COVID-19 on their serum 25(OH)D level. Results: The ITS results showed no immediate reduction in serum 25(OH)D level among infants, but a decreasing trend was observed in the subsequent months post-outbreak at a monthly decline rate of −6.32 nmol/L. When analyzed by age group, the magnitude of post-outbreak reduction in 25(OH)D was stronger among younger infants (aged 2–6 months). Conclusion: Guidelines and recommendations should be given to pregnant women and mothers to ensure sufficient vitamin D level in their infants during the COVID-19 period.

An Assessment of Risk Factors for Insufficient Levels of Vitamin D during Early Infancy

Recent evidence suggests that breastfeeding may increase the risk of vitamin D deficiency in offspring. However, it is unclear whether increased risk results from breastfeeding alone, or whether it is associated together with other risk factors. This study surveyed 208 infant–mother dyads recruited by stratified random sampling in different districts of Hong Kong. Mothers were asked to complete a questionnaire on their demographics, history of risk behavior, and feeding practices. Peripheral blood samples were collected from infants to determine their vitamin D status. Among all infant participants, 70 were vitamin D insufficient or deficient. Being breastfed, being a girl, having a multiparous mother, and the use of sun cream were found to be the strongest risk factors for vitamin D insufficiency during infancy (all p < 0.05), after mutual adjustment. The cumulative risk model displayed a dose–response pattern between the number of risk factors and the risk of vitamin D insufficiency during this period. Our findings indicate the risk profile of infants with insufficient vitamin D. Guidelines and recommendations on healthy diet and lifestyle should be provided to mothers during the early stage of pregnancy to increase the likelihood of adequate levels of vitamin D in their offspring.

Saliva viral load better correlates with clinical and immunological profiles in children with coronavirus disease 2019

Background

Pediatric COVID-19 studies exploring the relationships between NPS and saliva viral loads, clinical and immunological profiles are lacking.

Methods

Demographics, immunological profiles, nasopharyngeal swab (NPS), and saliva samples collected on admission, and hospital length of stay (LOS) were assessed in children below 18 years with COVID-19.

Findings

91 patients were included between March and August 20 20. NPS and saliva viral loads were correlated (r = 0.315, p = 0.01). Symptomatic patients had significantly higher NPS and saliva viral loads than asymptomatic patients. Serial NPS and saliva viral load measurements showed that the log₁₀ NPS (r = −0.532, p < 0.001) and saliva (r = −0.417, p < 0.001) viral loads for all patients were inversely correlated with the days from symptom onset with statistical significance. Patients with cough, sputum, and headache had significantly higher saliva, but not NPS, viral loads. Higher saliva, but not NPS, viral loads were associated with total lymphopenia, CD3 and CD4 lymphopenia (all p < 0.05), and were inversely correlated with total lymphocyte (r = −0.43), CD3 (r = −0.55), CD4 (r = −0.60), CD8 (r = −0.41), B (r = −0.482), and NK (r = −0.416) lymphocyte counts (all p < 0.05).

Interpretation

Saliva viral loads on admission in children correlated better with clinical and immunological profiles than NPS.

Hong Kong Anaphylaxis Consortium Consensus Statements on prescription of adrenaline autoinjectors in the acute care setting

Background

Adrenaline autoinjectors (AAInj) facilitates early administration of adrenaline and remains the first-line treatment for anaphylaxis. However, only a minority of anaphylaxis survivors in Hong Kong are prescribed AAInj and formal guidance do not exist. International anaphylaxis guidelines have been largely based on Western studies, which may not be as relevant for non-Western populations.

Objective

To formulate a set of consensus statements on the prescription of AAInj in Hong Kong.

Methods

Consensus statements were formulated by the Hong Kong Anaphylaxis Consortium by the Delphi method. Agreement was defined as greater than or equal to 80% consensus. Subgroup analysis was performed to investigate differences between allergy and emergency medicine physicians.

Results

A total of 7 statements met criteria for consensus with good overall agreement between allergy and emergency medicine physicians. AAInj should be used as first-line treatment and prescribed for all patients at risk of anaphylaxis. This should be prescribed prior to discharge from the Accident and Emergency Department together with an immediate referral to an allergy center. The decision for prescribing AAInj should be based on the severity of previous reactions; including objective signs of respiratory involvement, objective signs of cardiovascular involvement and multiorgan involvement (regardless of severity). Patient demographics and comorbidities, specifically history of asthma or chronic obstructive pulmonary disease, should also be considered. Patients deemed eligible for AAInj should be offered avoidance advice and prescribed one AAInj while awaiting review by allergists. AAInj technique should be demonstrated by a healthcare professional or instruction video, and a return demonstration by the patient is required. The patient should also be counseled that the decision on the continued need of AAInj prescription in the long-term should be reviewed by an allergist.

Conclusion

Consensus statements support the prescription of AAInj by front-line physicians with subsequent allergist review when treating patients at risk of anaphylaxis in Hong Kong.

A Comparison Between Chinese Children Infected with Coronavirus Disease-2019 and with Severe Acute Respiratory Syndrome 2003

OBJECTIVES

To compare the clinical and laboratory features of severe acute respiratory syndrome 2003 (SARS) and coronavirus disease 2019 (COVID-19) in 2 Chinese pediatric cohorts, given that the causative pathogens and are biologically similar.

STUDY DESIGN

This is a cross-sectional study reviewing pediatric patients with SARS (n = 43) and COVID-19 (n = 244) who were admitted to the Princess Margaret Hospital in Hong Kong and Wuhan Children's Hospital in Wuhan, respectively. Demographics, hospital length of stay, and clinical and laboratory features were compared.

RESULTS

Overall, 97.7% of patients with SARS and 85.2% of patients with COVID-19 had epidemiologic associations with known cases. Significantly more patients with SARS developed fever, chills, myalgia, malaise, coryza, sore throat, sputum production, nausea, headache, and dizziness than patients with COVID-19. No patients with SARS were asymptomatic at the time of admission, whereas 29.1% and 20.9% of patients with COVID-19 were asymptomatic on admission and throughout their hospital stay, respectively. More patients with SARS required oxygen supplementation than patients with COVID-19 (18.6 vs 4.7%; P = .004). Only 1.6% of patients with COVID-19 and 2.3% of patients with SARS required mechanical ventilation. Leukopenia (37.2% vs 18.6%; P = .008), lymphopenia (95.4% vs 32.6%; P < .01), and thrombocytopenia (41.9% vs 3.8%; P < .001) were significantly more common in patients with SARS than in patients with COVID-19. The duration between positive and negative nasopharyngeal aspirate and the length in hospital stay were similar in patients with COVID-19, regardless of whether they were asymptomatic or symptomatic, suggesting a similar duration of viral shedding.

CONCLUSIONS

Children with COVID-19 were less symptomatic and had more favorable hematologic findings than children with SARS.

Haematological and immunological data of Chinese children infected with coronavirus disease 2019

Haematological and immunological data of children with COVID-19 infection is lacking. Between 21st January and 20th March 2020, 244 children who were confirmed to have COVID-19 infection and admitted to the Wuhan Children's Hospital, China were retrospectively reviewed. 193 children were considered as symptomatic, which was defined as having either the presence of clinical symptoms or the presence of CT thorax abnormalities. Their haematological and immunological profiles, including complete blood counts, lymphocyte subsets (T, B and NK cell counts), immunoglobulin (Ig) profiles (IgG, IgA and IgM) and cytokine profiles were analysed and compared between the symptomatic and asymptomatic groups. The median values and the interquartile ranges were calculated. Comparison was made using the Mann–Whitney U test. Children with symptomatic COVID-19 infection had significantly lower haemoglobin levels, but higher absolute lymphocyte and monocyte counts, IgG and IgA levels, as well as interleukin 6 (IL-6), IL-10, tumour necrosis factor alpha and interferon gamma levels. The obtained data will be utilized for further studies in comparing children and adults with COVID-19 infections in other parts of the world and with different severity .

Paediatric case series of drug reaction with eosinophilia and systemic symptoms (DRESS): 12-year experience at a single referral centre in Hong Kong and the first reported use of infliximab

Summary

DRESS (drug reaction with eosinophilia and systemic symptoms) is a rare but potentially life-threatening disorder characterized by fever, skin eruption, haematological abnormalities and multi-organ dysfunction after drug exposure. The pathophysiology is thought to be related to interactions between culprit drugs, viral reactivation and T-lymphocytes activation. We report 4 paediatric patients with DRESS who were treated at our centre over the past 12 years. Most cases improved after corticosteroids. Other immunosuppressive medications were attempted in refractory cases with varied outcomes. Patient 3 was the first reported case that involved the use of infliximab, a TNF-α inhibitor, for DRESS. Although clinical efficacy was not observed for this one patient, a previous study demonstrated that patients with DRESS, disease progression and HHV-6 reactivation had elevated pre-treatment TNF- α and IL-6 levels. Further research is needed to explore the role of these cytokines in DRESS.

Prevalence of self-reported food allergy in Hong Kong children and teens--a population survey

BACKGROUND

There is a paucity of data on the prevalence, natural history and management of food allergy in most of the populous Asian countries, including China.

OBJECTIVE

To determine the point prevalence of self-reported food allergy in Chinese children and teenagers in Hong Kong.

METHODS

A cross-sectional population-based questionnaire survey targeted at children aged 0-14y was conducted by use of face-to-face interviews and self-administered questionnaires. Information was obtained from the parent as proxy respondent for children aged 10 and below and from both parent and child for children aged 11 to 14. Households were drawn from the Register of Quarters maintained by the Census and Statistics Department by systematic replicated sampling.

RESULTS

A total of 7,393 land-based noninstitutionalized children aged 14 and below in Hong Kong were recruited, excluding those with non-Cantonese speaking parents and those living in non-built-up areas. The sample was representative of the 884,300 children in the target population. 352 reported having adverse reactions to foods and the estimated prevalence was 4.8% (95% CI 4.3-5.3%). The estimated prevalence of peanut allergy was 0.3-0.5% (95%CI 0.1 to 0.7%). In terms of relative frequency, shellfish, which was the top allergen, accounted for more than a third of all reactions. The second most common was hen's egg (14.5%), the third cow's milk and dairy products (10.8%) and co-fourth were peanut and combined fruits (8.5%). Out of 352 subjects who reported adverse reactions, 127 (36.1%) had urticaria and or angioedema and 79 (22.4%) had eczema exacerbations. Combined gastrointestinal symptoms accounted for 20.8 % (diarrhoea 12.8%; vomiting 5.4%; abdominal pain 2.6%). Fifty-five (15.6%) had anaphylaxis, and 7 (2%) had respiratory difficulties.

CONCLUSION

This survey has provided the first population based epidemiological information related to food allergy amongst children and younger teenagers in Hong Kong. The prevalence of food allergy, including that from more common subtypes, like shellfish and peanut, is highly comparable to that of most of the developed nations.

Association of CD247 with systemic lupus erythematosus in Asian populations

OBJECTIVE

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease with complex genetic inheritance. CD247 (CD3Z, TCRZ) plays a vital role in antigen recognition and signal transduction in antigen-specific immune responses, and is known to be involved in SLE pathogenesis. Weak disease association was reported for genetic variants in this gene in Caucasian studies for SLE, Crohn's disease and systemic sclerosis, but its role as a genetic risk factor was never firmly established.

METHODS

In this study, using a collection of 612 SLE patients and 2193 controls of Chinese ethnicity living in Hong Kong in a genome-wide study, single nucleotide polymorphisms (SNPs) in and around CD247 were identified as being associated with SLE. The two most significant SNPs in this locus were selected for further replication using TaqMan genotyping assay in 3339 Asian patients from Hong Kong, Mainland China, and Thailand, as well as 4737 ethnically and geographically matched controls.

RESULTS

The association of CD247 with SLE in Asian populations was confirmed (rs704853: odds ratio [OR] = 0. 81, p = 2.47 × 10(-7); rs858543: OR = 1.10, p = 0.0048). Patient-only analysis suggested that rs704853 is also linked to oral ulcers, hematologic disorders and anti-double-stranded DNA (dsDNA) antibody production.

CONCLUSION

A significant association between variants in CD247 and SLE was demonstrated in Asian populations. Understanding the involvement of CD247 in SLE may shed new light on disease mechanisms and development of new treatment paradigms.

The prevalence of food allergy in infants in Chongqing, China

BACKGROUND

Over the past three decades, the prevalence of allergic diseases has markedly increased in developed countries. There has been a paucity of data on food allergy (FA) in developing countries such as China. We aimed to estimate the prevalence and the clinical features of FA in Chinese infants attending a routine well-baby clinic in Chongqing, China.

METHODS

From January 1st to February 28th, 2009, consecutive infants and young children aged 0-12 months attending routine well-baby checks at the Department of Primary Child Care, Children's Hospital of Chongqing Medical University, were invited to participate in the study. Parents completed questionnaires, and children were skin prick tested (SPT) to a panel of 10 foods (egg white, egg yolk, cow's milk, soybean, peanut, wheat, fish, shrimp, orange, and carrot) together of histamine and saline controls. Subjects with either a positive SPT or a positive medical history were invited to undergo an oral food challenge.

RESULTS

Of 497 children who consented to participate, 477 (96%) participated fully in the study. Of these, 56 subjects had a positive SPT (11.3%), with 45 positive to egg, 13 to cow's milk, 2 to peanut, 1 to fish, shrimp, and orange respectively. Eighty subjects (16.1%, 80/497) participated in food challenges.

CONCLUSION

  The overall prevalence of challenge-proven FA in 0- to 1-yr-old children in Chongqing, China, was 3.8% (18/477, 95% CI, 2.5-5.9%) with 2.5% (12/477) egg allergic and 1.3% (6/477) cow's milk allergic.

Molecular diagnosis of severe combined immunodeficiency--identification of IL2RG, JAK3, IL7R, DCLRE1C, RAG1, and RAG2 mutations in a cohort of Chinese and Southeast Asian children

Severe combined immunodeficiencies (SCID) are a group of rare inherited disorders with profound defects in T cell and B cell immunity. From 2005 to 2010, our unit performed testing for IL2RG, JAK3, IL7R, RAG1, RAG2, DCLRE1C, LIG4, AK2, and ZAP70 mutations in 42 Chinese and Southeast Asian infants with SCID adopting a candidate gene approach, based on patient's gender, immune phenotype, and inheritance pattern. Mutations were identified in 26 patients, including IL2RG (n = 19), IL7R (n = 2), JAK3 (n = 2), RAG1 (n = 1), RAG2 (n = 1), and DCLRE1C (n = 1). Among 12 patients who underwent hematopoietic stem cell transplantation, eight patients survived. Complications and morbidities during transplant period were significant, especially disseminated bacillus Calmette-Guérin disease which was often difficult to control. This is the first cohort study on SCID in the Chinese and Southeast Asian population, based on a multi-centered collaborative research network. The foremost issue is service provision for early detection, diagnosis, management, and definitive treatment for patients with SCID. National management guidelines for SCID should be established, and research into an efficient platform for genetic diagnosis is needed.

Association of BANK1 and TNFSF4 with systemic lupus erythematosus in Hong Kong Chinese

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease with complex genetic inheritance. Recently, single nucleotide polymorphisms (SNPs) in BANK1 and TNFSF4 have been shown to be associated with SLE in Caucasian populations, but it is not known whether they are also involved in the disease in other ethnic groups. Recent data from our genome-wide association study (GWAS) for 314 SLE cases and 920 controls collected in Hong Kong identified SNPs in and around BANK1 and TNFSF4 to be associated with SLE risk. On the basis of the results of the reported studies and our GWAS, SNPs were selected for further genotyping in 949 SLE patients (overlapping with the 314 cases in our GWAS) and non-overlapping 1042 healthy controls. We confirmed the associations of BANK1 and TNFSF4 with SLE in Chinese (BANK1, rs3733197, odds ratio (OR)=0.84, P=0.021; BANK1, rs17266594, OR=0.61, P=4.67 x 10(-9); TNFSF4, rs844648, OR=1.22, P=2.47 x 10(-3); TNFSF4, rs2205960, OR=1.30, P=2.41 x 10(-4)). Another SNP located in intron 1 of BANK1, rs4522865, was separately replicated by Sequenom in 360 cases and 360 controls and was also confirmed to be associated with SLE (OR=0.725, P=2.93 x 10(-3)). Logistic regression analysis showed that rs3733197 (A383T in ankyrin domain) and rs17266594 (a branch point-site SNP) from BANK1 had independent contributions towards the disease association (P=0.037 and 6.63 x 10(-8), respectively). In TNFSF4, rs2205960 was associated with SLE independently from the effect of rs844648 (P=6.26 x 10(-3)), but not vice versa (P=0.55). These findings suggest that multiple independent genetic variants may be present within the gene locus, which exert their effects on SLE pathogenesis through different mechanisms.

Relationship between carotid intima-media thickness and arterial stiffness in children after Kawasaki disease

BACKGROUND

Evidence of premature atherosclerosis and systemic arterial stiffening in patients after Kawasaki disease is accumulating.

AIM

To test the hypothesis that carotid intima-media thickness (IMT), a surrogate marker of atherosclerosis, is associated with systemic arterial stiffness in children after Kawasaki disease.

METHODS

A cohort of 72 patients was studied, comprising 26 patients with Kawasaki disease and coronary aneurysms (group I), 24 patients with Kawasaki disease and normal coronary arteries (group II) and 22 healthy age-matched children (group III). The carotid IMT, carotid artery stiffness index, brachioradial pulse wave velocity (PWV), fasting total cholesterol, high-density lipoprotein (HDL) cholesterol and low-density lipoprotein (LDL) cholesterol were determined and compared among the three groups.

RESULTS

The carotid IMT was related to indices of arterial stiffness, and significant determinants of carotid IMT were identified by multivariate analysis. The mean (standard deviation (SD)) carotid IMT of both group I (0.41 (0.04) mm) and group II (0.39 (0.04) mm) was significantly greater than that of group III (0.36 (0.04) mm; p<0.001 and p = 0.008, respectively). For the entire cohort, carotid IMT correlated positively with LDL cholesterol (r = 0.31, p = 0.009), carotid artery stiffness index (r = 0.40, p = 0.001) and brachioradial PWV (r = 0.28, p = 0.016), but not with age, body mass index, systemic blood pressure, and HDL and total cholesterol. Multiple linear regression analysis identified carotid artery stiffness index (beta = 0.25, p = 0.028) and subject grouping (beta = -0.39, p = 0.001; model R(2) = 0.29) as significant correlates of carotid IMT.

CONCLUSION

The increased carotid IMT in children after Kawasaki disease is associated with systemic arterial stiffening.

White button mushroom food hypersensitivity in a child

We reported a child with anaphylaxis to edible white button mushroom, a disorder not previously described.

Lack of association of cervical lymphadenopathy and coronary artery complications in Kawasaki disease

BACKGROUND

Cervical lymphadenopathy is a typical feature in some children with Kawasaki disease, but whether its presence or absence delays diagnosis, thereby increasing the risk of coronary artery abnormalities, has remained uncertain.

AIM

: The aim of this study is to review the clinical features of Kawasaki disease with particular reference to investigating the relationship of cervical lymphadenopathy to the development of coronary artery lesions.

METHODS

Demographic and clinical data from all the patients entered into the Hong Kong Kawasaki disease registry during 1994 to 2000 were reviewed. The presenting clinical features, echocardiographically monitored coronary artery lesions and influence of cervical lymphadenopathy (> or = 1 nodes > or = 1.5 cm diameter) on clinical onset-to-diagnosis time and response to immunoglobulin therapy are reported.

RESULTS

We studied 696 patients (99% Chinese, male/female ratio 1.7:1). Their distribution was inversely related to age. Twenty-four percent of the patients presented with cervical lymphadenopathy, the relative incidence of which was directly related to age. Five percent of patients had demonstrable coronary artery aneurysms at 8 weeks after disease onset. A slightly higher percentage of patients with absence of lymphadenopathy had late diagnosis. No significant positive or negative overall association between cervical lymphadenopathy and coronary artery lesions was observed. Time to resolution of fever after immunoglobulin administration did not differ between those with and without cervical lymphadenopathy.

CONCLUSIONS

Cervical lymphadenopathy was present in only 24% of the patients with Kawasaki disease, correlating directly with age. Its absence may delay the timing of diagnosis. There was, however, no overall association between lymphadenopathy and coronary lesions.

Kawasaki disease in Hong Kong, 1994 to 2000

OBJECTIVE

To describe the epidemiology, clinical characteristics, and management of Kawasaki disease in children in Hong Kong.

DESIGN

Retrospective survey of medical records from July 1994 to June 1997, and prospective data collection from July 1997 to June 2000.

SETTING

Hospitals with a paediatric unit in Hong Kong.

PATIENTS

Patients diagnosed with Kawasaki disease between July 1994 and June 2000 in public hospitals in Hong Kong.

MAIN OUTCOME MEASURES

Incidence of Kawasaki disease and coronary artery aneurysm rates.

RESULTS

A total of 696 cases of Kawasaki disease were reported. There were 435 (62.5%) boys and 261 (37.5%) girls giving a male to female ratio of 1.7:1. The age ranged from 1 month to 15 years 5 months with a median of 1.7 years. Infants (<1 year) constituted the largest group of patients (223, 32.0%) and overall, 638 (91.7%) were younger than 5 years. Skin rash, conjunctivitis, and oral signs were among the principal clinical features present in over 80% of cases. Prominent cervical lymph nodes larger than 1.5 cm were less commonly found (24%). Coronary artery aneurysms or ectasia were present in 15.7% (109/696), 8.5% (59/696), and 5.0% (35/696) of patients at 2, 4, and 8 weeks, respectively. The incidence of Kawasaki disease per 100,000 children under 5 years was significantly higher in the prospective study period than in the retrospective period (39 vs 26, P<0.001).

CONCLUSION

The incidence of Kawasaki disease is high in Hong Kong and is 39 per 100,000 children below 5 years of age. The coronary artery aneurysm prevalence is 5%. Intravenous gamma-globulin and high-dose aspirin is the mainstay of treatment.

Increased high sensitivity C reactive protein concentrations and increased arterial stiffness in children with a history of Kawasaki disease

OBJECTIVES

To test the hypothesis that low grade inflammation persists after the acute phase and affects arterial stiffness in children with a history of Kawasaki disease.

DESIGN AND PATIENTS

A cohort of 106 children was studied, which comprised 43 patients with Kawasaki disease with coronary aneurysms (group I), 28 patients with Kawasaki disease with normal coronary arteries (group II), and 35 healthy age matched children (group III). Their systemic blood pressure, fasting cholesterol concentrations, serum high sensitivity C reactive protein (hs-CRP) concentrations, and carotid artery stiffness index were compared. Significant determinants of serum hs-CRP concentration and carotid artery stiffness were identified and the relation between hs-CRP concentration and arterial stiffness was investigated.

SETTING

Tertiary paediatric cardiac centre.

RESULTS

Serum hs-CRP concentration of group I patients (median 0.39 mg/l, interquartile range 0.28-0.65 mg/l) was significantly greater than that of group II (median 0.24 mg/l, interquartile range 0.17-0.29 mg/l, p < 0.001) and of group III patients (median 0.25 mg/l, interquartile range 0.18-0.40 mg/l, p < 0.01). Likewise, carotid artery stiffness index of group I patients (mean (SD) 5.07 (1.11)) was significantly greater than that of group II (4.27 (0.83), p = 0.002), and of group III patients (4.24 (0.86), p = 0.001). For the entire cohort, the carotid artery stiffness index correlated positively with log serum hs-CRP concentration (r = 0.24, p = 0.013). In multiple linear regression analysis, age (standardised beta = 0.22, p = 0.02), systolic blood pressure (standardised beta = 0.28, p = 0.01), log serum hs-CRP concentration (standardised beta = 0.21, p = 0.017), and patient grouping (standardised beta = -0.36, p < 0.001) were all independently associated with the carotid artery stiffness index.

CONCLUSIONS

These findings support the possibility of ongoing low grade inflammation late after the acute phase of Kawasaki disease in patients with coronary aneurysms. Furthermore, this low grade inflammation may have a role in increasing systemic arterial stiffness.

Modulating effects of mannose binding lectin genotype on arterial stiffness in children after Kawasaki disease

Systemic arterial stiffness is increased in patients after Kawasaki disease (KD). Recently, associations between mannose-binding lectin (MBL) gene mutation and coronary complications in infants with KD and atherosclerosis in adults have been reported. We tested the hypothesis that MBL genotype modulates arterial stiffness in children after KD. Seventy-one KD patients (42 with and 29 without coronary aneurysms), aged 9.5 +/- 3.7 y, and 41 age-matched controls were studied. We determined and compared their blood pressure, brachioradial arterial stiffness as determined by pulse wave velocity (PWV), fasting total cholesterol, serum MBL level, and MBL genotype. Additionally, the modulating effects of different MBL expression genotypes [high level (HL) versus intermediate or low level (IL/LL)] on arterial stiffness in different groups were assessed. The MBL genotype distributions did not differ between patients and controls (p = 0.41) or between patients with and without coronary aneurysms (p = 0.42). Patients with IL/LL expression genotypes had significantly faster PWV than those with HL expression genotypes (7.93 +/- 1.38 m/s versus 6.67 +/- 2.28 m/s, p = 0.027). This genotype-modulating effect is more pronounced in patients without (HL 8.86 +/- 0.77 m/s versus IL/LL 6.48 +/- 2.32 m/s, p = 0.02) than those with (HL 7.50 +/- 1.41 m/s versus IL/LL 6.80 +/- 2.28 m/s, p = 0.32) coronary aneurysms. Multiple linear regression analysis identified age (beta = 0.26, p = 0.012), being a Kawasaki patient (beta = 0.22, p = 0.015), and MBL IL/LL genotype subgroup (beta = 0.20, p = 0.03) as significant determinants of arterial stiffness in the entire cohort. In conclusion, MBL genotype modulates arterial stiffness, an important cardiovascular risk factor, in children after KD.

Novel and traditional cardiovascular risk factors in children after Kawasaki disease

OBJECTIVES

We determined the profile of cardiovascular risk factors in children late after Kawasaki disease (KD) and compared it with that of age-matched healthy children.

BACKGROUND

Concerns have been raised regarding the possibility of a predisposition of KD to premature atherosclerosis later in life.

METHODS

A cohort of 102 subjects were studied: 37 KD patients with coronary aneurysms (group I), 29 KD patients with normal coronary arteries (group II), and 36 healthy age-matched children (group III). The fasting total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, apolipoprotein (apo) A-I, apoB, and homocysteine levels were compared among the three groups. In addition, blood pressure and brachioradial arterial stiffness, as determined by pulse wave velocity (PWV), were measured and compared.

RESULTS

Group I subjects had lower HDL cholesterol (p = 0.016) and apoA-I levels (p = 0.044) and higher apoB levels (p = 0.029) and PWV (p = 0.001) than group III control subjects. Likewise, the apoB levels (p = 0.007) and PWV (p = 0.042) were higher in group II than in III subjects, although their HDL cholesterol (p = 0.54) and apoA-I (p = 0.52) levels were similar. The LDL cholesterol levels were higher in group I and II patients than in controls, although not statistically significant (p = 0.17). Blood pressure and homocysteine levels did not differ among the groups.

CONCLUSIONS

An adverse cardiovascular risk profile, as characterized by a proatherogenic alteration of the lipid profile and increased arterial stiffness, occurs in children after KD. The profile is worse in those with than in those without coronary aneurysms.

Mesenteric blood flow response to feeding after systemic-to-pulmonary arterial shunt palliation

BACKGROUND

We hypothesized that the splanchnic circulation protects against diastolic steal through a systemic-to-pulmonary arterial shunt by reducing its resistance. To test the hypothesis we compared the basal and postprandial mesenteric blood flow velocities and vascular resistance in infants after shunt palliation for their underlying cyanotic heart disease with those in nonshunted infants.

METHODS

The basal and postprandial superior mesenteric arterial (SMA) time-average flow velocity (TAMV), end-diastolic flow velocity (EDFV), and relative resistance were assessed in 23 infants with congenital heart disease. The findings in the 9 shunted infants (group I) were compared with those in 14 nonshunted ones (group II).

RESULTS

In group II, TAMV (0.25 +/- 0.07 versus 0.33 +/- 0.09 m/s, p < 0.001) and EDFV (0.08 +/- 0.04 versus 0.11 +/- 0.04 m/s, p = 0.003) increased, while SMA relative resistance decreased (297 +/- 121 versus 198 +/- 73 mm Hg/ms(-1), p < 0.001) postprandially. Similarly, in group I, TAMV (0.35 +/- 0.13 versus 0.48 +/- 0.19 m/s, p = 0.008) increased, while SMA relative resistance decreased (182 +/- 61 versus 116 +/- 38 mm Hg/ms(-1), p = 0.005) after feeding. However, whereas basal and postprandial diastolic flow was antegrade in group II, absent or retrograde diastolic flow was characteristic of group I (preprandial, -0.10 +/- 0.07 m/s; postprandial, -0.13 +/- 0.06 m/s). Furthermore, group I had significantly lower SMA relative resistance both before (p = 0.02) and after (p = 0.006) feeding.

CONCLUSIONS

Profound disturbance of splanchnic perfusion occurs in infants palliated with a systemic-to-pulmonary arterial shunt. Their basal and postprandial SMA diastolic blood flow is either absent or reversed. The lowering of basal and postprandial resistance of the splanchnic circulation probably represents an adaptive mechanism to counteract such diastolic steal.