Biomedical subjects

L P C Shek

Publications and source records attributed to L P C Shek.

5 recordsLinked to original sources

PubMed2005

Humoral and cellular responses to cow milk proteins in patients with milk-induced IgE-mediated and non-IgE-mediated disorders.

BACKGROUND: Cow milk allergy (CMA) is one of the most common food allergies in childhood. Patients with CMA present with a wide range of immunoglobulin (Ig)E- and non-IgE-mediated clinical syndromes. Limited information is known about the specific humoral and cellular responses to cow milk proteins in these various forms of CMA. OBJECTIVE: The aim of the study was to determine IgE, IgA, IgG1 and IgG4 antibody levels and lymphocyte proliferative responses to the major cow milk allergens in patients with IgE- and non-IgE-mediated CMA. METHODS: One hundred and forty cow milk allergic patients, 6 months to 22 years of age, were included in the study. One hundred and thirteen patients had IgE-mediated CMA, 11 had milk protein-induced enterocolitis syndrome and 16 had allergic eosinophilic gastroenteritis. Twenty-one patients without food allergy, 8 months to 18 years of age, served as controls. Serum IgE, IgA, IgG1 and IgG4 antibodies to alpha-, beta-, and kappa-casein, alpha-lactalbumin and beta-lactoglobulin were measured using enzyme-linked immunosorbent assays. For a subset of these patients, we performed lymphocyte proliferation assays to the various milk allergens. RESULTS: Patients with IgE-mediated CMA had higher specific IgE concentrations to casein compared with whey proteins (P < 0.001). In this group of patients, there was a positive correlation between IgE levels and levels of the other isotypes for all four milk proteins (P < 0.001). In general, the caseins were the more allergenic and antigenic proteins in all groups of patients. Patients with enterocolitis syndrome produced less milk protein-specific IgG4 (P < 0.05) and had a trend for higher IgA antibody levels when compared to the control group. Lymphocyte proliferative responses in all groups with CMA were significantly higher than controls (P < 0.05), although this response was similar in patients with IgE- and non-IgE-mediated CMA. CONCLUSION: There is a distinct pattern of humoral antibody response in the different forms of CMA. Patients with IgE-mediated CMA have an elevated polyisotypic response to cow milk protein. The relative lack of specific IgG4 production in patients with enterocolitis syndrome may be involved in the pathogenesis of the disease. In general, caseins appear to be the predominant allergen in patients with CMA.

Adolescent↗

PubMed2004

The prevalence of asthma and allergies in Singapore; data from two ISAAC surveys seven years apart.

BACKGROUND AND AIMS: Over the past few decades, the prevalence of asthma has been increasing in the industrialised world. Despite the suggestion of a similar increase in Singapore, the 12 month prevalence of wheeze among schoolchildren in 1994 was 2.5-fold less than that reported in western populations. It was hypothesised that with increasing affluence in Singapore, the asthma prevalence would further increase and approach Western figures. A second ISAAC survey was carried out seven years later to evaluate this hypothesis. METHODS: The cross-sectional data from two ISAAC questionnaire based surveys conducted in 1994 (n = 6238) and in 2001 (n = 9363) on two groups of schoolchildren aged 6-7 and 12-15 years were compared. The instruments used were identical and the procedures standardised in both surveys. RESULTS: Comparing data from both studies, the change in the prevalence of current wheeze occurred in opposing directions in both age groups--decreasing in the 6-7 year age group (16.6% to 10.2%) but increasing to a small extent in the 12-15 year age group (9.9% to 11.9%). The 12 month prevalence of rhinitis did not change; there was an increase in the current eczema symptoms in both age groups. CONCLUSION: The prevalence of current wheeze, a surrogate measure of asthma prevalence, has decreased significantly in the 6-7 year age group. Eczema was the only allergic disease that showed a modest increase in prevalence in both age groups.

Adolescent↗

PubMed2003

Primary immunodeficiency diseases in Singapore--the last 11 years.

OBJECTIVES: To describe the clinical features, disease complications, treatment modalities and overall outcome of 39 local patients with Primary Immunodeficiency Diseases (PID) in Singapore over the last 11 years. METHODS: Paediatric and adult patients who presented to the The Children's Medical Institute, National University Hospital, Tan Tock Seng Hospital and KK Women's and Children's Hospital between January 1990 and December 2000 were identified. Their diagnoses were categorised into six groups according to the IUIS (International Union of Immunological Societies, affiliated to World Health Organisation) classification: antibody deficiencies, combined immunodeficiencies, immunodeficiencies associated with other major defects, congenital phagocytic defects, complement deficiencies and other well-defined immunodeficiency syndromes. Patients were selected from screening of inpatients with discharge diagnoses associated with primary immunodeficiency and of patients undergoing tests for immunodeficiency. Patient data were collated from case files and compiled using a standard questionnaire. RESULTS: There were 39 Singaporean patients diagnosed and treated for PID during the study period. The age at diagnosis ranged from three weeks to 69 years. Antibody deficiency (41%) was the most common form of PID. Seven patients had a family history of PID. Recurrent bacterial respiratory tract infections were the most common clinical manifestation. Associated conditions included autoimmune diseases, allergies and malignancies. Infection was the commonest cause of mortality. Eighteen patients (46.2%) with antibody or combined deficiencies received regular intravenous immunoglobulin (IVIG) as the primary treatment modality. Two children successfully received sibling-matched haematopoietic stem cell transplantation (HSCT). CONCLUSIONS: Antibody deficiencies are the most common form of PID in Singapore. Treatment with antibiotics, IVIG and HSCT are the main therapeutic modalities currently available. Early referral to an immunologist is needed to achieve good outcomes.

Adolescent↗

PubMed2002

Thalidomide in Behçet's disease.

Behçet's disease is a chronic relapsing multisystem disease of unknown aetiology. It has a relapsing cyclical course, and is characterized by the triad of aphthous stomatitis, genital ulcerations and uveitis. There is familial and geographical clustering of cases, especially around the Mediterranean, the Middle East and East Asia. The condition is uncommon, but lesions sometimes are recalcitrant and can be debilitating to the affected individual. The treatment of Behçet's currently involves the use of steroids, immunomodulaters and immunosuppressives. Thalidomide has been used in cases of Behçet's disease with some success. This review will discuss Behçet's disease and the current information we have about using thalidomide for its treatment.

Abnormalities, Drug-Induced↗

PubMed2002

Use of hypoallergenic formula in the prevention of atopic disease among Asian children.

OBJECTIVE: To determine the effect of a partially hydrolysed formula on genetically predisposed children, with respect to the development of atopic clinical manifestations and in vitro testing of serum IgE levels (total and milk-specific). METHODS: One hundred and ten infants were randomly assigned to receive either partially hydrolysed formula or standard infant formula, and were prospectively monitored from birth for clinical atopic symptoms and serum IgE levels. RESULTS: Eczema occurred less frequently in infants receiving partially hydrolysed formula. This was significant (P < 0.05) at 3, 6, 9, 12, 18 and 24 months. However, the significance decreased with time, although it almost reached statistical significance at 30 months by the Kaplan-Meier survival function (log-rank statistic, 3.46; P = 0.063). Although wheezing occurred less frequently in infants receiving partially hydrolysed formula, compared to those receiving standard infant formula, the difference did not reach statistical significance (P > 0.05). CONCLUSIONS: Exclusive feeding of hypoallergenic milk formula in the first 4 months of life has a protective effect in terms of the development of atopic dermatitis in the first 2 years of life, compared to feeding with cow's milk formula.

Child↗