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Updated: Jun 24, 2026
A Method for Generating Pulmonary Neutrophilia Using Aerosolized Lipopolysaccharide
Published on: December 15, 2014
Low tumor necrosis factor alpha levels and neutrophil counts in nasal lavage after mold exposure
Ulla-Maija Hellgren1, Marina Leino, Antti A Aarnisalo
1Finnish Institute of Occupational Health, Helsinki, Finland. ulla-maija.hellgren@ttl.fi
Background:
The results of allergy tests against molds usually remain negative in patients with upper respiratory tract and conjunctival symptoms after microbial exposure in a water-damaged building. Most mold-exposed persons report nasal irritation. Immune mechanisms of the nasal symptoms have not been fully elucidated.
Objective:
To investigate local inflammatory responses after mold exposure in the upper respiratory tract and the feasibility of nasal lavage in diagnosing work-related exposure.
Methods:
Altogether, 26 mold-exposed and 20 nonexposed workers from the same hospital were selected for the present study. The work premises of the exposed workers had detectable moisture and microbial problems. All exposed workers and their nonexposed controls underwent clinical examination, laboratory tests to detect allergy to molds, and nasal lavage. Inflammatory cells and proinflammatory cytokines were measured in the nasal lavage fluid. Nasal lavages were performed again 6 months after a thorough renovation of the building.
Results:
In the nasal lavage, the neutrophil count and the level of tumor necrosis factor alpha in the exposed employees were lower, whereas the macrophage and epithelial cell counts were higher than in the control group. After the renovation, no difference was found in inflammatory response between the study group and the control group. The mean concentration of serum IgG to Stachybotrys chartarum was higher in the exposed workers.
Conclusions:
These results suggest that exposure to toxin-producing microbial growth in a water-damaged building caused immunosuppression in nasal mucosa, leading to a decrease in neutrophil counts and tumor necrosis factor alpha levels. Nasal lavage is a suitable method for examining inflammatory responses in work-related mold exposure.
Insights
Mold exposure in water-damaged buildings may suppress the immune response in the nasal passages, indicated by lower neutrophil and tumor necrosis factor alpha levels. Nasal lavage effectively assesses these inflammatory changes in workers.
Area of Science:
- Environmental Health
- Occupational Medicine
- Immunology
Background:
- Allergy tests for molds are often negative despite symptoms in water-damaged buildings.
- Nasal irritation is common after mold exposure, but underlying immune mechanisms are unclear.
- Investigating local inflammatory responses is crucial for understanding mold-related health effects.
Purpose of the Study:
- To examine upper respiratory tract inflammatory responses following mold exposure.
- To evaluate the effectiveness of nasal lavage for diagnosing work-related mold exposure.
Main Methods:
- Compared 26 mold-exposed workers with 20 non-exposed controls from a hospital.
- Assessed clinical, allergic, and nasal lavage parameters, including inflammatory cells and cytokines.
- Repeated nasal lavages 6 months post-renovation to observe changes.
Main Results:
- Exposed workers showed lower neutrophil and tumor necrosis factor alpha but higher macrophage and epithelial cell counts in nasal lavage.
- Serum IgG levels to Stachybotrys chartarum were elevated in exposed individuals.
- Post-renovation, inflammatory responses normalized, showing no difference between groups.
Conclusions:
- Exposure to toxin-producing mold in water-damaged buildings may induce nasal mucosal immunosuppression.
- Nasal lavage is a viable diagnostic tool for assessing inflammatory responses to occupational mold exposure.
- Building renovation effectively resolved the observed inflammatory effects.
