Infection by Ascaris lumbricoides and bronchial hyper reactivity: an outstanding association in Venezuelan school children from endemic areas.

Asthma and other respiratory diseases have increased in the last years among Venezuelan children from helminthic endemic areas where the infection by Ascaris lumbricoides has been associated to bronchial airway inflammation in parasitized individuals. The aim of this work was to investigate the possible associations between the development of bronchial hyper reactivity and the immune response against A. lumbricoides in urban and rural children.

[Influence of helminthic infections and nutritional status on immune response in Venezuelan children].

We investigated the influence of nutritional status, as determined from anthropometric measurement, and of helminthic infections on the immune response of children of low socioeconomic status in two rural communities in Venezuela: El Cardón in the state of Nueva Esparta and San Daniel in the state of Miranda. A total of 125 boys and girls between 2 and 15 years old participated in the study. Their socioeconomic stratum was determined by a modified Graffar method.

Immunological changes associated with clinical improvement of asthmatic children subjected to psychosocial intervention.

In the present study we evaluated the impact of a program of psychosocial intervention (PSI) on the immunological status and the clinical management of a group of asthmatic children of an island population in Venezuela. We studied a total of 35 asthmatic children who belonged to either a PSI group (19 patients) or a control group (16 patients), both of which received conventional antiasthmatic treatment. The PSI group received, in addition, a 6-month psychosocial intervention program which included relaxation, guided imagery, and self-esteem workshops.

Association of polymorphisms in the beta2-adrenoreceptor gene with higher levels of parasitic infection.

The diminishing incidence of parasitic infection in westernised societies has been suggested to result in an increased prevalance of asthma. Asthma is a polygenic disease and genome screens have shown that genes on chromosome 5q31-33 are strongly linked to the disease. The gene for the beta2-adrenoreceptor is located in this region and two polymorphisms have been identified that result in amino acid changes at positions 16 (ArgGly) and 27 (GlnGlu).

Relationship between helminthic infection and IgE response in atopic and nonatopic children in a tropical environment.

Background: Although IgE antibody is clearly involved in allergic reactions to environmental allergens, this immunoglobulin is an important component of host-protective immune responses against the helminthic parasites that are endemic in the majority of the world population. However, these infections not only stimulate the production of antiparasite IgE antibody but can nonspecifically induce polyclonal IgE synthesis that results in highly elevated total serum IgE levels. Such polyclonal stimulation can diminish specific IgE antibody responses and cause saturation of mast cell Fc epsilon receptors, thus inhibiting allergic reactivity.

Mutation screening of interferon-gamma (IFNgamma) as a candidate gene for asthma.

Background: Reduced levels of interferon gamma (IFNgamma) mRNA and protein have been detected in the bronchoalveolar lavage fluid of atopic asthmatics. IFNgamma is secreted by TH1 cells while IL-4 and IL-5 are secreted by TH2 cells and an imbalance in the TH1/TH2 response may be responsible for atopic asthma. The gene for IFNgamma is located on chromosome 12; a region of the genome which has been shown in linkage studies to be associated with asthma.

Clinical improvement of asthma after anthelminthic treatment in a tropical situation.

Intestinal helminths are among the most common infectious organisms of humans, particularly in tropical regions, and can induce the production of large quantities of IgE antibody. Part of this response is directed against the helminths own antigens, but a polyclonal stimulation also occurs that may increase the allergic reactivity toward environmental allergens. The importance of this in the symptomatology of asthma in these regions is, however, uncertain.