Eugene Weinberg

Reduced interferon-γ but normal IL-4 and IL-5 release by peripheral blood mononuclear cells from Xhosa children with atopic asthma

BACKGROUNDnAllergic asthma is increasing in black South Africans, a cohort with inherently high basal IgE levels. Atopy has been linked to an excess of the T helper 2 cytokines IL-4 and IL-5 relative to the T helper 1 cytokine interferon-gamma (IFN-gamma); however, most studies have utilized T cell clones. Studies on peripheral blood mononuclear cells (PBMC) have shown decreased IFN-gamma release in patients with atopic dermatitis. It is uncertain whether this finding extends to atopic asthma.nnnOBJECTIVESnTo characterize cytokine release by mitogen-activated PBMC from Xhosa children and to investigate whether reduced IFN-gamma release is a feature of atopic asthma and whether there is a relationship between cytokine profiles and asthma severity.nnnMETHODSnCytokine release and proliferation of phytohemagglutinin-stimulated PBMC from 10 patients with severe asthma and 14 patients with moderate asthma (highly allergic to house dust mites) and 17 healthy controls was assessed. Total serum, allergen-specific, and Ascaris-specific IgE was measured.nnnRESULTSnProliferation did not differ between the groups. The release of IFN-gamma was progressively decreased (and the IL-4/IFN-gamma ratio increased) in the groups with moderate or severe asthma. Tumor necrosis factor-alpha release was reduced, but IL-4, IL-5, and granulocyte-macrophage-colony stimulating factor release was unchanged. The presence of Ascaris-specific IgE did not influence the cytokine profiles.nnnCONCLUSIONnOur study extends the findings observed for other atopic disorders and suggests that defective IFN-gamma release is a generalized feature of atopic diseases. This study-the first to investigate both severe and moderate asthma, with the groups having similar atopic profiles-indicates that the extent of the defect in IFN-gamma release might be related to asthma severity.

Treatment preferences of adolescent patients with asthma

The study objective was to assess whether asthmatic adolescents who were regular users of inhaled corticosteroids preferred treatment with zafirlukast tablets or inhaled beclomethasone dipropionate (BDP), and, secondarily, to assess adolescents’ inhaler technique and their opinions about treatment. An open‐label, randomized, two‐period, cross‐over study was conducted in 18 centres (primary care to specialist asthma centres) in South Africa, the UK, Finland and the Czech Republic. One hundred and thirty‐two adolescents aged 12–17u2003years with asthma for at least 1u2003year and FEV1u2003≥u200375% of predicted, treated with short‐acting bronchodilators and inhaled corticosteroids, entered the study. Patients received oral zafirlukast tablets (Accolate™) 20u2003mg bd or inhaled BDP 100 or 200u2003µg bd, provided by a standard pressurized metered‐dose inhaler, for 4u2003weeks each. One questionnaire was used to determine preference (the primary outcome measure) and a second questionnaire was used to determine patients’ likes and dislikes of treatment. Investigators also scored inhaler technique. Of 113 adolescents, 79 (70%) preferred zafirlukast compared with 31 (27%) who preferred the BDP inhaler (p <u20030.001); three had no preference. Only 35 (29%) of 122 adolescents could use their inhaler correctly at study entry. Seventy‐six patients (65%) rated zafirlukast tablets as ‘very easy’ to use, compared with 35 (30%) for the BDP inhaler. Both treatments were well tolerated. This study shows that asthmatic adolescents prefer zafirlukast tablets by a ratio of 2.6:1 over inhaled BDP, and these results may have implications for improving adolescent patient compliance with asthma therapy.

Low prevalence of latex sensitivity in South African spina bifida children in Cape Town.

Spina bifida children have a high prevalence of latex allergy in studies reported from Europe and the USA. This study investigated the prevalence of latex allergy in a cohort of 24 spina bifida children at the Red Cross Childrens Hospital from Cape Town, South Africa. The children were investigated using a detailed questionnaire, skin prick tests (ALK‐Abello), ImmunoCap RASTs, Western blotting and ELISA, using the purified latex proteins Hev b1 and Hev b3 and whole latex preparation. A low overall prevalence of latex sensitization of 16.7% was found in the children. Children who were sensitive reacted to water insoluble to Hev b1 and Hev b3 proteins. The low prevalence of latex sensitization in the South African children may not be entirely explained by stringent latex avoidance. The children were from a low socioeconomic social status and ‘hygiene’ and other factors should be considered.

Incorrect use of a homemade spacer for treatment of recurrent wheezing in children - a cause for concern

Inhaled bronchodilators, particularly β2-agonists, are one of the most effective therapies for rapid reversal of airway narrowing in acute asthma. In children bronchodilators are best given using a metered dose inhaler (MDI) with attached spacer; this is as effective as nebulised therapy, with fewer side-effects. 1,2 However, a spacer must be used with a MDI as children are unable to synchronise inspiration with actuation of the MDI nor can they breath hold at the end of inspiration, particularly when there is lower airways obstruction as occurs during an acute asthma attack. A modified 500 ml plastic bottle spacer has been found to be as effective as a conventional smallvolume spacer for delivery of bronchodilators in children with acute wheezing. In contrast, a cup has been shown to be a very poor spacer, with poor efficacy when used for giving bronchodilators in the treatment of acute asthma.