Biomedical subjects

I Hagel

Publications and source records attributed to I Hagel.

22 records · Page 2Linked to original sources

PubMed1987

Allergic reactivity and socio-economic level in a tropical environment.

As some factors associated with the tropical environment can modify the expression of atopic disease, various indicators of allergic reactivity were compared between allergic and non-allergic subjects of different socio-economic level in Caracas, Venezuela (Lat. 10 degrees N). The socio-economic levels considered were high (HSEL), medium-high (MSEL) or low (LSEL). As generally found in temperature climates, in the HSEL the total serum IgE levels of allergic patients were significantly greater than those of non-allergic individuals (geometric means of 274 vs 126 IU/ml, respectively), as were also the specific serum IgE antibody levels (55.6 vs 23.8% positive, respectively, for house dust). These results correlated closely with the skin-test reactivity of these subjects (60.3 vs 17.5% positive for house dust). In this group, the degree of intestinal helminthic infection was low (5.6% positive for Ascaris). In contrast, for the MSEL where the degree of parasitic infection was higher (13.0%), the total serum IgE levels were elevated in both allergic and non-allergic subjects (602 vs 363 IU/ml). Similarly, positivity for specific IgE antibody was high, and comparable between allergics and non-allergics of this group (61.5 vs 54.2%), as was also the case for skin-test reactivity (71.9 vs 60.4%). In the LSEL, parasitic infection was prevalent (47.6%), and the total serum IgE levels were markedly elevated, with little difference occurring between allergic and non-allergic individuals (2269 vs 1981 IU/ml). The positivity for specific IgE antibody was high, and effectively independent of the allergic state (75.6 vs 53.7%), but in contrast the skin test reactivity was relatively low (22.0 vs 9.8%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMedDate not supplied

Relationship between the degree of poverty and the IgE response to Ascaris infection in slum children.

We examined a group of urban slum children in Caracas, Venezuela, and demonstrated the relationship that exists between poverty, conditions of hygiene and the prevalence of helminth infection. Concordant with the high prevalence of helminth infection in these children, the total serum levels of immunoglobulin E (IgE) and blood eosinophilia were elevated and were directly related to the degree of poverty and lack of sanitary facilities. However, in contrast, the reverse pattern was observed for the specific allergic response to these parasites. Thus, the immediate hypersensitivity skin test reactivity to Ascaris antigens, and the serum levels of specific anti-Ascaris IgE antibody, were lowest in the poorest children, who had the highest prevalence of helminth infection and the highest total IgE levels. As allergic-type reactions may participate in protective mechanisms against helminths, these results suggest that poverty and poor sanitary conditions may, by influencing the IgE response, compromise the resistance of such children to parasitic infections.

Animals↗

PubMedDate not supplied

Nutritional status and the IgE response against Ascaris lumbricoides in children from a tropical slum.

Helminthic infection can stimulate the interleukin-4 (IL-4)-dependent polyclonal synthesis of immunoglobulin E (IgE) in children endemically exposed to these parasites. As such children are also frequently at nutritional risk, in this study we considered the possible influence of malnutrition on serum IL-4 levels and the IgE response in helminthic infection. We evaluated 85 Ascaris-infected children living in an urban slum area of Caracas, Venezuela, and found that the serum levels of IL-4 and total IgE were significantly higher in malnourished children than in their well nourished counterparts. In contrast, the specific anti-Ascaris IgE antibody response was significantly lower in the malnourished group. After anthelmintic treatment of the children, the total serum IgE and IL-4 levels decreased significantly in the well nourished group, while the specific anti-Ascaris IgE antibody response increased. No significant change was detected, however, in the malnourished group. Our results suggested that malnutrition potentiates the polyclonal stimulation of IgE synthesis induced by helminths. As specific IgE antibody has been implicated in the resistance to helminthic infection, and the polyclonal stimulus diminishes this response, these factors may increase the susceptibility of malnourished children to such parasites.

Animals↗

PubMedDate not supplied

Effect of age and helminthic infection on IgE levels in slum children.

Helminthic infections can cause an IL-4-dependent polyclonal synthesis of IgE, which is the major cause of the elevated serum levels of this immunoglobulin in tropical populations. In the present study, we measured the IgE levels in the serum of children of different ages in slum areas of Caracas, Venezuela, where intestinal helminths are endemic. As would be expected, in children over 5 years of age, the IgE levels were highly elevated, and in addition, the cord blood serum levels were higher than those reported for populations where parasitic infections are uncommon. However, the IgE levels measured in the sera of children under 5 years of age were relatively low, and within the generally accepted normal ranges. This was surprising because the latter children were infected by parasites and had high IgG antibody levels against helminths. We found, however, that whereas older children had detectable IL-4 levels in their sera, the younger children did not. These results suggest that, despite infection of these slum children by common intestinal helminths, a polyclonal stimulation of IgE synthesis did not occur, possibly due to a lack of IL-4 production by an immature immune system.

Adolescent↗