Low Allergen Levels Research Articles

House dust mite allergen levels in two cities in Canada: effects of season, humidity, city and home characteristics

The homes of 120 patients with asthma, 57 in Vancouver and 63 in Winnipeg, were studied. The characteristics of the homes were assessed by a questionnaire. Dust samples were collected and the indoor relative humidity was measured four times during the year covering all four seasons in both cities. Mite allergen levels were determined using monoclonal antibodies against Der p I and Der f I by the ELISA method. The mean levels of both mite allergens in mattress and floor samples in the homes in Vancouver and in Winnipeg were relatively low for all seasons. Mite allergen levels were found to be associated with city, season and individual home differences. They were significantly higher in Vancouver than in Winnipeg. Der p I and Der f I in mattress samples in both cities and Der f I in floor samples in Vancouver, varied by season. The indoor relative humidity level in the homes in Vancouver were also significantly higher than those in Winnipeg. There was, however, no significant association between the levels of indoor relative humidity and the levels of mite allergens after adjusting for variations in city, season and individual home. Although individual home differences were highly associated with mite allergen levels, only a few home characteristics were found to be related to mite allergen levels such as the type and the age of the home, the type of heating, the use of feather pillows and the number of occupants in the homes. Whether low levels of mite allergens are partially responsible for the relatively low prevalence of childhood asthma in Canada remains to be investigated.

Extractable latex allergens and proteins in disposable medical gloves and other rubber products

Background: IgE-mediated sensitization to rubber proteins is being reported with increasing frequency in health care workers. To explore the relative importance of various sources of allergen exposure, we measured the total rubber allergen and protein levels in extracts of disposable rubber gloves and compared the allergen levels with those in extracts of other medical and consumer rubber products. Methods: Rubber allergens were measured by inhibition immunoassay with a rubber glove extract as the solid-phase allergen and pooled plasma from five rubber-sensitized health care workers as the IgE antibody source. Proteins were measured by Ninhydrin assay. Results: Among 71 lots of gloves tested, the extractable allergen and protein levels were significantly correlated and were appreciably higher in powdered gloves than in powder-free gloves. Allergen levels varied 3000-fold among gloves from different manufacturers and were higher in examination gloves than in surgical or chemotherapy gloves. Measurable allergen was found in 11 of 24 lots of “hypoallergenic” gloves tested. Allergen levels in toy balloons were comparable to those in powdered gloves; much lower allergen levels were measured in condoms and anesthesia rebreathing bags. Conclusions: The allergen content of disposable rubber gloves varies widely and is higher in powdered gloves than in powder-free gloves and higher in examination gloves than in surgical gloves. Hypoallergenic gloves may contain substantial amounts of IgE-binding proteins. Gloves and toy balloons appear to be more important sources of rubber allergens than the other rubber products tested.

Prevalence of dust-mite allergens in homes and workplaces of the Upper Connecticut River Valley of New England.

This study sought to determine the relative abundance and seasonal variation of Dermatophagoides farinae and D pteronyssinus allergens in homes and workplaces of the Upper Connecticut River Valley of New England. Dust samples were obtained from 15 homes and 23 carpeted workplaces in public buildings. Half the samples were collected in June 1990 and half in September 1990. D pteronyssinus and D farinae content of the samples were determined by enzyme-linked immunosorbent assay (ELISA). This observational study of homes and workplaces found a predominance of D pteronyssinus allergens in both homes and workplaces; a marked seasonal increase in total Dermatophagoides group I allergens from June to September; and only very low levels of allergens in workplaces. Workplaces seem an unlikely source of significant dust-mite allergen exposure, and workplace exposure does not negate efforts at home dust control by affected patients in this region.