Female adiposity and time-to-pregnancy: a multiethnic prospective cohort

STUDY QUESTION

Are higher overall and central adiposity associated with reduced fecundability, measured by time-to-pregnancy (TTP), in Asian women?

SUMMARY ANSWER

Higher overall adiposity, but not central adiposity, was associated with longer TTP in Asian women.

WHAT IS KNOWN ALREADY

High body mass index (BMI) has been associated with a longer TTP, although the associations of body composition and distribution with TTP are less clear. There are no previous studies of TTP in Asian women, who have a relatively higher percentage of body fat and abdominal fat at relatively lower BMI.

STUDY DESIGN, SIZE, DURATION

Prospective preconception cohort using data from 477 Asian (Chinese, Malay and Indian) women who were planning to conceive and enrolled in the Singapore PREconception Study of long-Term maternal and child Outcomes (S-PRESTO) study, 2015-2017.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women's mean age was 30.7 years. Overall adiposity was assessed by BMI, sum of 4-site skinfold thicknesses (SFT) and total body fat percentage (TBF%, measured using air displacement plethysmography); central adiposity was assessed by waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR) and A body Shape Index (ABSI). Pregnancy occurring within one year from recruitment was ascertained by ultrasonography. Those who did not conceive within one year of recruitment, were lost to follow-up, or initiated fertility treatment were censored. TTP was measured in cycles. Discrete-time proportional hazards models were used to estimate the fecundability ratio (FR) and 95% confidence interval (CI) for each anthropometric measure in association with fecundability, adjusting for confounders.

MAIN RESULTS AND THE ROLE OF CHANCE

Compared to women with a normal BMI of 18.5-22.9 kg/m2, women with higher BMI of 23-27.4 and ≥27.5 kg/m2 showed lower FR of 0.66 (95% CI 0.45, 0.97) and 0.53 (0.31, 0.89), respectively. Compared to women in the lowest quartile of SFT (25-52.9 mm), those in the highest quartile of ≥90.1 mm showed lower FR of 0.58 (95% CI 0.36, 0.95). Compared to women in the lowest quartile of TBF% (13.6-27.2%), those in the upper two quartiles of 33.0-39.7% and ≥39.8% showed lower FR of 0.56 (95% CI 0.32, 0.98) and 0.43 (0.24, 0.80), respectively. Association of high BMI with reduced fecundability was particularly evident among nulliparous women. Measures of central adiposity (WC, WHR, WHtR, ABSI) were not associated with fecundability.

LIMITATIONS REASONS FOR CAUTION

Small sample size could restrict power of analysis.The analysis was confined to planned pregnancies, which could limit generalizability of findings to non-planned pregnancies, estimated at around 44% in Singapore. Information on the date of last menstrual period for each month was not available, hence the accuracy of self-reported menstrual cycle length could not be validated, potentially introducing error into TTP estimation. Measures of exposures and covariates such as cycle length were not performed repeatedly over time; cycle length might have changed during the period before getting pregnant.

WIDER IMPLICATIONS OF THE FINDINGS

Other than using BMI as the surrogate measure of body fat, we provide additional evidence showing that higher amounts of subcutaneous fat that based on the measure of SFT at the sites of biceps, triceps, suprailiac and subscapular, and TBF% are associated with longer TTP. Achieving optimal weight and reducing total percentage body fat may be a potential intervention target to improve female fertility. The null results observed between central adiposity and TTP requires confirmation in further studies.

STUDY FUNDING/COMPETING INTEREST(S)

This research is supported by Singapore National Research Foundation under its Translational and Clinical Research Flagship Programme and administered by the Singapore Ministry of Health's National Medical Research Council, (NMRC/TCR/004-NUS/2008; NMRC/TCR/012-NUHS/2014). Additional funding is provided by the Singapore Institute for Clinical Sciences, Agency for Science Technology and Research (A*STAR), Singapore. Y.S.C., K.M.G., F.Y. and Y.S.L. have received reimbursement to speak at conferences sponsored by companies selling nutritional products. Y.S.C., K.M.G. and S.Y.C. are part of an academic consortium that has received research funding from Abbott, Nutrition, Nestle and Danone. Other authors declared no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Ratio of Klebsiella/Bifidobacterium in early life correlates with later development of paediatric allergy

Several studies have reported that intestinal microbial colonisation patterns differ between non-allergic and allergic infants. However, the microbial signature underlying the pathogenesis of allergies remains unclear. We aim to gain insight into the development of the intestinal microbiota of healthy infants and infants who develop allergy in early life, and identify potential microbiota biomarkers of later allergic disease. Using a case-control design in a Chinese sub-cohort of a Singaporean birth cohort (GUSTO), we utilised 16S rRNA gene sequencing to assess intestinal microbial composition and diversity of 21 allergic and 18 healthy infants at 3 weeks, 3 months and 6 months of age, and correlated the microbiota with allergy at ages 18 and 36 months. Pronounced differences in intestinal microbiota composition between allergic and healthy infants were observed at 3 months of age. The intestine of healthy infants was colonised with higher abundance of commensal Bifidobacterium. Conversely, Klebsiella, an opportunistic pathogen, was significantly enriched in the allergic infants. Interestingly, infants with a high Klebsiella/Bifidobacterium (K/B) ratio (above the population median K/B ratio) at age 3 months had an odds ratio of developing allergy by 3 years of age of 9.00 (95% confidence interval 1.46-55.50) compared to those with low K/B ratio. This study demonstrated a relationship between the ratio of genera Klebsiella and Bifidobacterium during early infancy and development of paediatric allergy in childhood. Our study postulates that an elevated K/B ratio in early infancy could be a potential indicator of an increased risk of allergy development. This line of research might enable future intervention strategies in early life to prevent or treat allergy. Our study provides new insights into microbial signatures associated with childhood allergy, in particular, suggests that an elevated K/B ratio could be a potential early-life microbiota biomarker of allergic disease.

Influences of prenatal and postnatal maternal depression on amygdala volume and microstructure in young children

Maternal depressive symptoms influence neurodevelopment in the offspring. Such effects may appear to be gender-dependent. The present study examined contributions of prenatal and postnatal maternal depressive symptoms to the volume and microstructure of the amygdala in 4.5-year-old boys and girls. Prenatal maternal depressive symptoms were measured using the Edinburgh Postnatal Depression Scale (EPDS) at 26 weeks of gestation. Postnatal maternal depression was assessed at 3 months using the EPDS and at 1, 2, 3 and 4.5 years using the Beck's Depression Inventory-II. Structural magnetic resonance imaging and diffusion tensor imaging were performed with 4.5-year-old children to extract the volume and fractional anisotropy (FA) values of the amygdala. Our results showed that greater prenatal maternal depressive symptoms were associated with larger right amygdala volume in girls, but not in boys. Increased postnatal maternal depressive symptoms were associated with higher right amygdala FA in the overall sample and girls, but not in boys. These results support the role of variation in right amygdala structure in transmission of maternal depression to the offspring, particularly to girls. The differential effects of prenatal and postnatal maternal depressive symptoms on the volume and FA of the right amygdala suggest the importance of the timing of exposure to maternal depressive symptoms in brain development of girls. This further underscores the need for intervention targeting both prenatal and postnatal maternal depression to girls in preventing adverse child outcomes.

Clinical and immunochemical profiles of food challenge proven or anaphylactic shrimp allergy in tropical Singapore

BACKGROUND

Shellfish allergy in Singapore is highly prevalent, and shrimp allergy is the most common.

OBJECTIVE

This study aims to evaluate the clinical characteristics and immunological phenotype of shellfish allergy in this population.

METHODS

Patients with self-reported shellfish allergy were recruited from outpatient clinics of three large hospitals and from a population survey. Open oral food challenges (OFC) to glass prawn (Litopenaeus vannamei) and tiger prawn (Penaeus monodon) were carried out on all patients except for those who had a history of severe anaphylaxis. Skin prick tests (SPT) and specific IgE to crude and recombinant allergens were carried out to evaluate shrimp and dust mite sensitization. Immunoblots were used to assess IgE-binding proteins.

RESULTS

The 104 patients recruited were categorized into shellfish allergic (SA) when OFC was positive or had a history of severe anaphylaxis (n = 39), shellfish tolerant (ST) when OFC was negative (n = 27), and house dust mite positive controls (HDM(+) ) who were ST (n = 38). Oral symptoms (87.1%) were the predominant clinical manifestation. Positive challenge doses ranged from 2 to 80 g of cooked shrimp, with 25/52 patients reacting to either one or both shrimps challenged. The presence of specific IgE to shrimp either by SPT and/or ImmunoCAP(®) assay provided diagnostic test sensitivity of 82% and specificity of 22.2%. The inclusion of specific IgE to shrimp tropomyosin and IgE immunoblots with shrimp extracts did not improve the diagnostic proficiency substantially.

CONCLUSIONS AND CLINICAL RELEVANCE

This study highlights the predominance of oral symptoms in shrimp allergy in tropical Asia and that a high provocation dose may be necessary to reveal shrimp allergy. Furthermore, specific IgE diagnostic tests and immunoblots were of limited use in this population.

Academy of medicine, Singapore-Ministry of Health clinical practice guidelines: management of food allergy

The Academy of Medicine, Singapore (AMS) and the Ministry of Health (MOH) publish clinical practice guidelines to provide doctors and patients in Singapore with evidence-based guidance on managing important medical conditions. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the AMS-MOH clinical practice guidelines on the Management of Food Allergy, for the information of readers of the Singapore Medical Journal. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Academy of Medicine website: http://www.ams.edu.sg/guidelines.asp#foodallergy. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

Severe Kikuchi's disease responsive to immune modulation

Kikuchi's disease, although an uncommon entity, has been increasingly reported since it was first discovered in 1972. The most common manifestation of Kikuchi's disease, cervical lymphadenopathy, has no clinically distinguishable features. Therefore, a diagnosis of Kikuchi's disease has largely been based on clinical suspicion and histopathological confirmation. We present a 15-year-old Chinese girl with severe Kikuchi's disease, whose relapsing course was only responsive to highdose steroid and intravenous immunoglobulin therapy.

An association between floor vacuuming and dust-mite and serum eosinophil cationic protein in young asthmatics

Although vacuum cleaning is recommended to reduce allergen levels and improve asthma and allergic rhinitis symptoms, some studies suggest it may increase allergen load in homes. We conducted a cross-sectional study to determine if home floor vacuuming was associated with sensitization to dust-mites and cockroaches, and serum eosinophil cationic protein (ECP), a biomarker for atopy, in 102 physician-diagnosed spirometry-confirmed asthmatics. We collected data on floor type, floor cleaning method and frequency, asthma severity, allergy medications used, serum ECP and skin prick tests (SPT) to three dust-mites [Dermatophagoides pteronyssisinus (Der p), Dermatophagoides farinae (Der f) and Blomia tropicalis (Blo t)] and two cockroaches [Periplanata americana (Per a) and Blatella germanica (Bla g)]. Those who vacuumed had increased sensitization to three dust-mites [adjusted ORs (95%CI) = Der p: 26.6 (1.8-405.2); Der f: 44.8 (3.2-620.9); Blo t: 14.1 (1.8-108.1)] but not to cockroaches, adjusted for cleaning frequency and other methods of floor cleaning. Subjects who vacuumed their floor had higher levels of serum ECP than those who did not [adjusted median difference (95%CI): 9.4 (1.1-17.7)], adjusted for use of nasal corticosteroids among those with allergic rhinitis. Vacuuming is associated with increased sensitization to dust-mite allergens and higher serum ECP.

PRACTICAL IMPLICATIONS

We found an association between floor vacuuming and increased sensitization to dust-mite allergens and higher levels of an atopy biomarker. Current recommendations to use vacuuming to control allergen exposure and allergic conditions may need to be reconsidered until further studies are performed.

Endotoxin Levels in Rural Thai and Urban Singaporean Homes

BACKGROUND

Exposure to dust endotoxin and allergens in early childhood may influence the development of allergic diseases.

AIMS

This study aimed to evaluate dust endotoxin and dust mite allergens in urban Singapore and rural Thai homes of young children and study potential environmental influences.

METHODS

Mattress dust endotoxin and Der p 1, Der f 1, group 2 (Der f 2 and Der p 2) and Blo t 5 allergen levels were quantified in 101 infant mattress dust samples, 51 from urban Singapore and 50 from rural Thailand. Comprehensive questionnaires on the home environment and cleaning practices were completed.

RESULTS

Endotoxin levels in rural Thailand were significantly higher than in urban Singapore (geometric mean 26,334.12 +/- 4.60 and 18,377.85 +/- 2.52 endotoxin units/g, respectively; p = 0.032). In contrast, higher levels of Der f 1 (p = 0.02), group 2 (p < 0.01) and Blo t 5 (p < 0.01) allergens were found in Singapore homes compared with rural Thai homes. Multiple logistic regression analysis showed that the use of detergents (p = 0.001) and disinfectants (p = 0.024) to clean floors and mattress protectors (p = 0.021) were independently associated with lower endotoxin levels.

CONCLUSION

Endotoxin levels are higher in rural compared with urban homes in South East Asia. The reverse was true for dust mite allergen levels. Certain identifiable home environmental conditions and practices accounted for the differences in endotoxin levels.

Distinct Pattern of Commensal Gut Microbiota in Toddlers with Eczema

BACKGROUND

Recent studies have demonstrated differences in the composition of gut microbiota in infants with and without allergic diseases, particularly eczema.

METHODS

A case-control study involving 21 toddlers (age 3.0 +/- 0.5 years) with and 28 age-matched toddlers without eczema was conducted. Four groups of aerobic gut microbiota were identified and quantitated in stool samples grown on selective media. Three groups of anaerobes were enumerated by fluorescent in situ hybridization followed by quantitative flow cytometry. We also performed molecular typing of lactic-acid-producing bacteria (LAB) and enterococcal isolates to facilitate detailed analysis at species level by bacterial 16S rDNA sequencing.

RESULTS

Toddlers with eczema harbored significantly lower counts of Bifidobacterium [(median 0.14 (25th and 75th percentile: 0.04 and 0.47) vs. 0.71% (0.16, 1.79) of cells acquired, p = 0.003)] and Clostridium [(0.28 (0.09, 0.78) vs. 0.83% (0.35, 1.82) of cells acquired, p = 0.012)] but significantly higher counts of total LAB [7.3 (6.1, 8.5) vs. 5.7 (4.4, 7.3) log CFU/g, p = 0.006] in particular enterococci [6.3 (4.8, 7.4) vs. 5.0 (3.4, 6.4) log CFU/g, p = 0.018]. There was no significant correlation between eczema severity score and bifidobacterial counts.

CONCLUSION

The results further confirm previous reports that the gut microecosystem differs between children with and without eczema and extend them beyond infancy.

Immunoglobulin E reactivity of native Blo t 5, a major allergen of Blomia tropicalis

BACKGROUND

Blo t 5 is a major allergen of Blomia tropicalis and its complementary DNA (cDNA) has been expressed in both prokaryotic and eukaryotic expression systems. Although the recombinant Blo t 5 has been well characterized, relatively less is known about its native counterparts and the allergenicity comparison of the native and recombinant Blo t 5 allergens has not been reported.

OBJECTIVE

The aims of this study are to characterize the native counterpart of Blo t 5, and compare the allergenicity of native and recombinant Blo t 5 by in vivo and in vitro assays.

METHODS

Native Blo t 5 were purified by immuno-affinity chromatography and characterized by proteomic means. The allergenicity of the allergen was evaluated by skin prick tests, human IgE ELISA, ELISA inhibition and histamine release assays.

RESULTS

Native Blo t 5 consists of at least five distinct isoforms, ranging from pI 3 to 5.5. Allergenicity assessment of recombinant and native Blo t 5 based on skin reaction, IgE-binding capacity and histamine release in allergic individuals indicated that there was a good correlation between both forms of Blo t 5 in general. However, data from IgE ELISA inhibition assay revealed the presence of additional unique IgE epitopes in native Blo t 5.

CONCLUSIONS

At least five distinct isoforms of Blo t 5 have been identified. Comparative assessment of native and recombinant Blo t 5 revealed that the allergenicity of these two forms was similar but not completely identical suggesting that the various isoforms of native Blo t 5 may exhibit additional unique IgE epitopes.

Identification of shared and unique immunoglobulin E epitopes of the highly conserved tropomyosins in Blomia tropicalis and Dermatophagoides pteronyssinus

BACKGROUND

Tropomyosin belongs to a class of highly conserved proteins in invertebrates and vertebrates. The invertebrate tropomyosins are allergenic in man with high IgE cross-reactivity and have been therefore referred to as pan-allergens.

OBJECTIVES

This study aimed to clone and identify the IgE epitopes of tropomyosin from Blomia tropicalis (Blo t 10) mite. Cross-reactivity between the IgE epitopes of Blo t 10 and Der p 10 was also evaluated.

METHODS

Blo t 10 was isolated using mouse anti-Der p 10 antibodies. Allergenicity of the cloned Blo t 10 was confirmed by skin prick test (SPT) and enzyme-linked immunosorbent assay (ELISA). Dose-dependent inhibition assay was performed to determine the degree of IgE cross-reactivity between Blo t 10 and Der p 10. Overlapping polymerase chain reaction-derived cDNA were generated and expressed as glutathione-S-transferase (GST) recombinant proteins in Escherichia coli and used to identify shared and unique IgE epitopes of Blo t 10 and Der p 10.

RESULTS

The cloned Blo t 10 shared up to 96% amino acid identity to tropomyosin of other mites. SPT and ELISA IgE-immunoassay showed recombinant Blo t 10 sensitization rates of between 20% and 29% in atopic subjects. Results of SPT and dose-dependent inhibition assays showed that some allergic individuals had unique IgE epitopes for Blo t 10. IgE epitope mapping of Blo t 10 revealed that the epitopes were mainly located at N- and C-termini of the molecule. The results of ELISA inhibition assays of overlapping recombinant fragments indicated that the unique IgE epitopes of Blo t 10 were located at the C-terminal.

CONCLUSION

Although Blo t 10 and Der p 10 are highly conserved (shared 95% amino acids identity) and significantly cross-reactive, unique IgE epitopes do exist. The results suggest the potential deficiency of using only one of these highly conserved allergens as diagnostic or therapeutic reagents.

Pattern of sensitization to common environmental allergens amongst atopic Singapore children in the first 3 years of life

This study was aimed to investigate the sensitization pattern to a range of common allergens in young Singaporean children. A cross-sectional study involving 75 children aged below 3 years was carried out. They presented between December 1995 and April 2000 with symptoms of asthma, rhinitis, eczema, or food allergy. Their levels of allergen-specific serum IgE to a panel of foods (egg white, milk, soy protein, shrimp, wheat and peanut), pet dander, dust mites and cockroaches were measured with Pharmacia CAP System radioallergosorbent test kits. Serum IgE levels greater than 0.35 kU/l represented a positive result. Four children could not be tested with the complete panel because of insufficient serum. The prevalence of sensitization was highest for cow's milk (45.9%) followed by egg white (38.7%), dust mites Dermatophagoides pteronyssinus (31.4%) and Blomia tropicalis (25.5%). Sensitization to ingested allergens was significantly more prevalent in children aged 1 year or younger than in the older children (70.4% of those below 1 year, and 50% of those aged 1-3 years; p < 0.02). Sensitization to inhaled allergens, such as dust mites, was more likely to manifest as respiratory symptoms (allergic rhinitis and asthma), while ingested allergens were associated with gastrointestinal symptoms and eczema (p < 0.001). It was concluded that infants and young children are at high risk of sensitization to common environmental substances. Allergen avoidance is therefore important even in the very young. The prevalence of sensitization to food allergens is higher compared to inhalant allergens in young children.

Genetic susceptibility to asthma and atopy among Chinese in Singapore--linkage to markers on chromosome 5q31-33

BACKGROUND

Asthma and atopy are complex genetic traits, influenced by the interaction of multiple genes and environmental factors. Linkage of these traits to chromosome 5q31-33 has been shown in other populations, but has not been well studied in the Chinese. We studied linkage between asthma and atopy with markers on chromosome 5q31-33 in the Singapore Chinese. This region contains many candidate genes, including the cytokine gene cluster.

METHODS

We recruited 88 Chinese families with at least two affected offspring, totaling 373 subjects, with 125 and 119 sib-pairs for atopy and asthma, respectively. All individuals were genotyped with 19 polymorphic microsatellite markers spanning a distance of 41 cM along chromosome 5q31-33. Affected sib-pair and multipoint linkage analysis was performed.

RESULTS

There was evidence for linkage of the asthma and atopy phenotypes with three markers, D5S2110, D5S2011, and D5S412 (P values of 0.001 to 0.00001). Multipoint analysis further substantiated this (nonparametric linkage scores of 1.8-2.9). These findings suggest that susceptibility genes for asthma and atopy are found in this region in the Chinese.

CONCLUSION

This study has shown linkage of atopy and asthma to chromosome 5q31-33 in a heterogeneous Chinese population. These findings further substantiate the notion that chromosome 5q31-33 contains "universally" important susceptibility genes for these traits.

Ethnic differences in genetic susceptibility to atopy and asthma in Singapore

INTRODUCTION

Asthma and atopy are complex traits, the phenotypes being influenced by the interaction of both genetic and environmental factors. In view of the growing evidence for inter-ethnic differences in genetic susceptibility to complex diseases such as asthma and atopy, we have assessed genetic factors for these diseases in the local population.

METHODS

The genetic analysis of asthma and atopy is being approached by candidate gene analysis as well as linkage studies for mapping of susceptibility loci. We reviewed published studies, which include data from our population on some candidate genes, as well as our preliminary data on susceptibility locus mapping for linkage to chromosome 5q31-33.

RESULTS

In local studies of the interleukin-4 receptor and tumour necrosis factor polymorphisms, we failed to find associations with genetic variants previously implicated to be associated with asthma and atopy. Evaluation of markers on chromosome 5q31-32 identified novel loci for susceptibility to asthma and atopy in addition to loci already described by others.

CONCLUSION

Both the published literature and our own findings indicate that there are inter-ethnic differences in genetic susceptibility to asthma and atopy.

Pediatric asthma quality of life questionnaire: validation in children from Singapore

"Quality of Life" is a multidimensional measure encompassing the physical, emotional and social functioning of the child. The asthma specific questionnaire contains 23 questions (items) in three areas (domains) of activity, symptoms and emotions. The objective of the present study was to validate the Paediatric Asthma Quality of Life Questionnaire "PAQLQ"(copyright 1991 McMaster University). If the questionnaire is valid, a change in the child's asthma will be accompanied by a change in the "Quality of Life" questionnaire score. The questionnaire was administered twice over four weeks and the child's asthma status was assessed concurrently. Two groups were thus identified; Group A = unchanged asthma, Group B = changed asthma. Forty-seven children, aged 7 to 14 years, completed the study. Reliability of the questionnaire shows an intraclass-correlation coefficient of only 0.71. Cross-sectional construct validity was demonstrated by a significant correlation between the whole questionnaire and the clinical asthma score (p<0.001) but not in the separate domains. Longitudinal construct validity was also demonstrated by the significant correlation between change in the total questionnaire score, but not separate domains, with change in the child's asthma score (p<0.05). Responsiveness was shown by a significant difference in the magnitude of the change in the questionnaire score between the two groups (p<0.001), but again not in the separate domains. It was concluded that the questionnaire was validated as a whole but not in as convincing a manner, as has been done by others, and we are therefore in a position to advise caution in its application in our population.

Sensitization to Blomia tropicalis and dermatophagoides pteronyssinus-a comparative study between Singapore and Taiwan

Blomia tropicalis (Bt) and Dermatophagoides pteronyssinus (Dp) are the predominant domestic mites species in Singapore and Taiwan. This study aims to characterize and compare the mite sensitization profiles in both countries. Skin prick tests were performed on 203 Singaporeans with Dp and Bt crude extracts. In vitro IgE and IgG4 reactivity to extracts and specific allergens (Der p 1, Der p 2 Der p 5 and Blo t 5) were determined by immunoassays. Approximately 91% of the tested Singaporeans were skin test positive for both Bt and Dp. Both populations share similar frequencies of in vitro IgE reactivity to all the allergens tested, but they differ in the pattern and magnitude of allergen sensitization. Although Der p 1, Der p 2 and Blo t5 are major sensitizing allergens in both countries, Blo t 5 is a more potent one in Singapore, probably reflecting the high level of exposure to Bt. The unique major Bt and Dp allergens should be included for precise diagnosis and effective immuno-therapeutic treatment of mite allergy in both countries.

Food allergy in children-the Singapore story

The study of food allergy in Singaporean children is still in its infancy. Confusion and misunderstanding is common among the public. Even so, we have found certain unique features regarding food allergy among Singaporean children. "Bird's nest" has been shown to be the most common cause of anaphylaxis requiring medical attention. This allergen has not been described before. Peanuts and tree nuts are extremely uncommon causes of anaphylaxis, unlike the West. However, the pattern of sensitization to foods in children as shown by skin prick test is similar to other Western populations. The reasons for the difference between the profile foods responsible for anaphylactic reactions in our population and those of the western population, despite the similarity in sensitization profiles, are still unclear.

Ethnic differences in genetic susceptibility to atopy and asthma

The genetics of asthma and atopy is complex, but can be approached by studies of both candidate genes and mapping of susceptibility loci. Genetic factors conferring susceptibility to disease may vary among ethnic groups. We present our experience with some candidate gene studies for asthma and atopy and susceptibility locus mapping for linkage to chromosome 5q.

Thalidomide responsiveness in an infant with Behçet's syndrome

BACKGROUND

Behçet's syndrome is a chronic relapsing vasculitis characterized by aphthous stomatitis, genital ulcerations, and uveitis. The disease is a multisystem illness, which may involve the skin, joints, gastrointestinal tract, blood vessels, central nervous system, and other organs.

CASE STUDY

We report a case of an infant with features of Behçet's syndrome who did not respond to conventional immunosuppression with high-dose corticosteroids and cytotoxic agents. Thalidomide, a potent immune response-modifying drug, was used with marked improvement and resolution of symptoms.

CONCLUSION

This finding supports a trial of thalidomide treatment in patients with Behçet's syndrome who are unresponsive to other forms of immunosuppressive therapy or develop undesirable side effects.