Serum levels of immunoglobulins (IgG, IgA, IgM) in a general adult population and their relationship with alcohol consumption, smoking and common metabolic abnormalities.

The present study investigated serum immunoglobulin (Ig) concentrations in relation to demographic factors, common habits (alcohol consumption and smoking) and metabolic abnormalities in an adult population-based survey including 460 individuals. Serum levels of interleukin (IL)-6, a marker of inflammation, were also determined. After adjusting for confounders, male sex was associated positively with IgA levels and negatively with IgM levels. Age was associated positively with IgA and IgG levels. Smoking was associated negatively with IgG levels. Heavy drinking was associated positively with IgA levels. Metabolic abnormalities (obesity and metabolic syndrome) were associated positively with IgA levels. Abdominal obesity and hypertriglyceridaemia were the components of metabolic syndrome associated most strongly with serum IgA. Heavy drinkers with metabolic syndrome showed particularly high serum IgA levels. Serum IL-6 levels were correlated positively with IgA and IgG concentrations. It is concluded that sex, age, alcohol consumption, smoking and common metabolic abnormalities should be taken into account when interpreting serum levels of IgA, IgG and IgM.

Toxocara infection seroprevalence and its relationship with atopic features in a general adult population.

BACKGROUND: The relationship of helminth infection with atopy is controversial. Toxocariasis is the most common helminth infection in industrialized countries. The study aimed to investigate the association between Toxocara exposure and atopic features. METHODS: The study is based on a cross-sectional survey of 463 subjects, randomly selected (stratified by decades of age) from a general adult population. Toxocara exposure was defined by the presence of serum Toxocara antibodies. Main outcome measures included total serum IgE levels, skin prick tests (SPT) to a panel of 13 relevant aeroallergens, specific IgE to aeroallergens (Phadiatop test), and respiratory symptoms evaluated by means of a questionnaire. RESULTS: A total of 134 subjects (weighted proportion 28.6%, 95% CI 26.5-30.7%) showed Toxocara exposure. Pet ownership, rural habitat, farming, and low educational level were associated with Toxocara exposure. Toxocara exposure was associated with both positive SPT (particularly to mites) and positive specific IgE (Phadiatop test) after adjusting for potential confounders. The effect of Toxocara exposure on total serum IgE levels and blood eosinophil count was different in SPT-positive subjects and SPT-negative individuals. In SPT-negative individuals, Toxocara exposure was associated with an increase in both serum IgE levels and eosinophil counts, whereas an opposite trend was observed in SPT-positive individuals. Toxocara exposure was not associated with respiratory symptoms. CONCLUSIONS: In this adult population, Toxocara exposure is associated with allergic sensitization, particularly to mites. There is evidence of an intriguing interaction between Toxocara exposure and allergic sensitization for both total serum IgE levels and blood eosinophil counts.

Evaluation of the phadiatop test in the diagnosis of allergic sensitization in a general adult population.

BACKGROUND: Phadiatop is a commercially available qualitative serological test employed for screening of allergic sensitization in patients with suspected allergic diseases. AIM: The study evaluated the diagnostic accuracy of Phadiatop for the diagnosis of allergic sensitization in a general adult population. METHODS: A total of 469 subjects from the population of A-Estrada (Spain) were selected by age-stratified random sampling (age range, 18-92 years). Phadiatop test (Uni-CAP method) was performed in serum samples from 465 of these subjects. Skin prick tests to a panel of 13 relevant aeroallergens in the studied area (including mites, pollens, moulds, and animal dander) were employed as the reference diagnostic procedure. Subjects with at least a positive skin prick test (> or =4 mm, n= 120) were considered to have allergic sensitization. RESULTS: Phadiatop sensitivity was 70.8% (95% CI 61.7-78.6%), specificity 90.7% (95% CI 87.0-93.5%), positive predictive value 72.6% (95% CI 63.5-80.3%), negative predictive value 89.9% (95% CI 86.2-92.8%), global accuracy 85.6% (95% CI 82.0-88.6%), negative likelihood ratio 0.3 (95% CI 0.2-0.4), and positive likelihood ratio 7.6 (95% CI 5.4-10.8). A high proportion of false-positive Phadiatop cases showed (a) increased total serum IgE levels, (b) significant alcohol consumption, and (c) small-sized (below the diagnostic cut-off) wheal reactions on SPT. A high proportion of false-negative Phadiatop cases showed exclusive storage mite sensitization. Sensitivity and positive predictive value of Phadiatop were somewhat higher among individuals with a history of nasal or bronchial symptoms. CONCLUSIONS: Phadiatop is a valuable tool for the diagnosis of allergic sensitization in a general adult population. However, limitations of the test should be taken into account in similar surveys.

Association of hepatitis A virus infection with allergic sensitization in a population with high prevalence of hepatitis A virus exposure.

BACKGROUND: An inverse association between allergic sensitization and markers of exposure to food-borne and orofecal infections (particularly hepatitis A virus, HAV) has been reported. The prevalence of HAV exposure and allergic sensitization vary widely in different areas, and vary along with age within a given area. AIM: To investigate the association between HAV exposure and allergic sensitization in adults from a mostly rural area of Spain. METHODS: An age-stratified random sample of 720 subjects was drawn from the population older than 18 years of A-Estrada, Spain. From 697 eligible subjects, 469 (67.2%, median age 54 years, range: 18-92) participated in the study. Positive skin prick tests to a panel of aeroallergens defined allergic sensitization. Positive serum HAV antibodies (assayed in 465 subjects) defined HAV exposure. RESULTS: The prevalence of HAV exposure was 83.6% (95% CI: 80.7-86.5). The prevalence of allergic sensitization was lower in subjects with HAV exposure than in patients without it (25.0%vs 40.0%, OR 0.44, 95% CI: 0.25-0.77, P=0.004), but this association became substantially altered after adjusting for age, which was closely linked to both allergic sensitization and HAV exposure (adjusted OR 1.15, 95% CI: 0.60-2.19, P=0.66). CONCLUSIONS: In a population with high prevalence of HAV exposure, no significant association between HAV exposure and allergic sensitization is observed after controlling for the confounding effect of age.

High prevalence of storage mite sensitization in a general adult population.

BACKGROUND AND AIM: Occupational and nonoccupational storage mite (SM) allergy has received considerable attention in recent years. The study aimed to evaluate both the prevalence and factors associated with sensitization to SMs in a general adult population from a warm and humid area where mites are the predominant allergens. PATIENTS AND METHODS: An age-stratified random sample of 720 subjects was drawn from the population older than 18 years of A-Estrada (Galicia, Spain). From 697 eligible subjects, 469 (67%, median age 54 years, range 18-92 years, 44% males, 75% of cases from a rural environment) agreed to participate. Skin prick tests to SMs (Lepidoglyphus destructor and Tyrophagus putrescentiae), house dust mite (Dermatophagoides pteronyssinus), pollens, moulds and animal danders were performed in all cases. Wheals >or= 4 mm were considered positive. Epidemiological data were assessed by questionnaire. A design-based analysis was performed and all calculations were weighted to give unbiased estimates. RESULTS: Tyrophagus putrescentiae and L. destructor were the leading causes of allergic sensitization throughout all ages. SM sensitization was found in 104 cases (weighted value 24.4%, 95% CI 20.6-28.2). SM sensitization was inversely associated with age. Multivariate analysis showed that SM sensitization was not significantly associated with sex, smoking, educational level, farming profession, rural environment, indoor humidity, presence of pets, livestock or grain storage facilities near home. CONCLUSIONS: SMs (T. putrescentiae and L. destructor) are major aeroallergens in adults in the region studied, even in subjects without occupational exposure.

Association of alcohol consumption with total serum immunoglobulin E levels and allergic sensitization in an adult population-based survey.

BACKGROUND: Chronic alcoholism is associated with increased total serum IgE levels. OBJECTIVE: The study aimed to investigate the relationship between alcohol intake and both total serum IgE levels and allergic sensitization in a general adult population. MATERIALS AND METHODS: A total of 720 subjects was randomly selected (stratified by age) from the population older than 18 years of A-Estrada (Spain) and invited to participate in the study. From 697 eligible subjects, 469 (67%, median age 54 years, range 18 to 92 years, 44% males, 75% of cases from a rural environment) agreed to participate. A battery of 13 skin prick tests to common aeroallergens was performed in all subjects. Cases with at least one positive test (n = 121, 26%) were considered to have allergic sensitization. The most frequent sensitisers were mites and pollens (24% and 10% of subjects, respectively). Total serum IgE was measured in 465 subjects (99%). Alcohol consumption was registered as the number of standard (approximately 10 g) drinking units habitually consumed per week. A total of 244 subjects (52%) were alcohol consumers (median intake, 14 units/week, range 1 to 147 units/week). Abstainers (n = 225, 48%) constituted the reference category. RESULTS: Alcohol consumption of more than 14 units/week was associated with an increase in serum IgE levels after adjusting for age, gender, allergic sensitization and smoking (P = 0.02). Alcohol consumption was not significantly associated with either overall allergic sensitization or mite sensitization after adjusting for age, gender and smoking. However, alcohol consumption of more than 14 units/week was associated with an increased prevalence of pollen sensitization (adjusted OR 3.15, 95% CI 1.19 to 8.34, P = 0.02). CONCLUSION: Alcohol consumption above a certain threshold is associated with an increase in total serum IgE levels. Alcohol consumption may also be associated with an increased prevalence of pollen sensitization.