Influence of residential fungal contamination on peripheral blood lymphocyte populations in children.
Reported residential fungal contamination has been associated consistently with increased symptoms among occupants; however, an objective measure of a health effect is lacking, and a pathophysiologic mechanism has not been established. Our objective was to determine if exposure to indoor fungal contamination influenced T-cell differentiation. In this study, we contrasted lymphocyte populations, measured by flow cytometry, between a group of children who lived in homes with considerable fungal contamination (n = 39) and a group in less-contaminated homes (n = 20). Indicators of fungal biomass were viable fungi in house dust and air ergosterol in the child's bedroom. Living in a more-contaminated home versus a less-contaminated home was associated with a larger number of CD3+ T cells expressing CD45RO (1.5 x 10(9)/I versus 1.1 x 10(9)/I, respectively; p = .05, two-tailed t testing) and a reduced CD4/CD8 ratio (1.6 versus 1.8, respectively; p = .04). The differences persisted over a 12-mo period, and they were not explained by the child's age or total serum IgE, dust mite antigens, and the presence of furry or feathered pets or a humidifier. The results suggest that residential fungal contamination leads to chronic stimulation of children's lymphocytes.
Dales
R
R
Health Effects Research Section, Environmental and Occupational Toxicology, Health Canada, Ottawa.
Miller
D
D
White
J
J
Dulberg
C
C
Lazarovits
A I
AI
D000391:Air Microbiology; D016902:Air Pollution, Indoor / Q000009:adverse effects*; D016516:CD4-CD8 Ratio; D002648:Child; D005260:Female; D005434:Flow Cytometry; D005658:Fungi / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D008213:Lymphocyte Activation / Q000276:immunology; D018655:Lymphocyte Count; D008297:Male; D009864:Ontario; D016176:T-Lymphocyte Subsets / Q000276:immunology*
D007073:Immunoglobulin E