13 October 2021

Press release 
Finnish Institute of Occupational Health, University of Helsinki and Helsinki University Hospital

The study included 88 non-smoking women with adult-onset asthma or idiopathic environmental intolerance (IEI), as well as healthy controls. Some of the asthma cases were associated with damp and mouldy buildings. The study compared the gene profiles (RNA biomarker profiles) of the groups with each other. Biomarker profiles were identified from nasal mucosa and white blood cells using modern biomedical methods.

IEI individuals were included in the study because they may show the same type of prolonged indoor-air-related symptoms as asthma patients and because there is more environmental sensitivity in asthma patients than the general population. IEI individuals experience a variety of symptoms in environments that do not cause symptoms for most people. These symptoms are not explained by known biomedical mechanisms.

No specific gene profile was found for asthma associated with damp buildings, but one was found for idiopathic environmental intolerance (IEI)

 Asthma patients whose asthma was associated with damp and mould did not have a specific biomarker profile that would differentiate it from other groups.

“A surprising finding in the study was that the biomarker profile of IEI patients differed from the other groups,” says Professor Harri Alenius from the University of Helsinki.

“Changes in the function of white blood cell genes in IEI patients were clearly different from healthy controls. It is possible that these changes in immune response are associated with chronic stress and psychosocial workload.”

Some similarity found in gene profiles of individuals with asthma associated with damp buildings and individuals with IEI

Although no specific gene profile was found in people with asthma associated with damp and mould, identical characteristics were however discovered when comparing the gene profiles of individuals with damp-related asthma and individuals with IEI.

“The similarity in the gene profiles of individuals with damp-related asthma and individuals with IEI suggests that there may be common mechanisms behind the symptoms,” says FIOH Chief Physician Hille Suojalehto.
“This finding provides further understanding of the mechanisms of prolonged indoor-air-related symptoms. As prolonged symptoms can significantly impair an individual’s ability to work and their functional capacity, it is important to identify the origin and mechanisms of the symptoms in order to develop treatments,” Suojalehto explains.

The study ”Transcriptomic Profiling of Adult-Onset Asthma Related to Damp and Moldy Buildings and Idiopathic Environmental Intolerance” by FIOH, the University of Helsinki and HUS:

  • The aim of the study was to identify RNA biomarker profiles of asthma associated with damp and mould in buildings on the one hand and idiopathic environmental intolerance (IEI) on the other hand from nasal mucosa and white blood cells using modern biomedical methods based on high-throughput screening of thousands of biomolecules.
  • The study included 88 non-smoking women with adult-onset asthma or IEI, as well as healthy controls.
  • Asthma patients were divided into three groups based on symptoms and results of technical surveys of buildings: individuals whose asthma and symptoms were known to be associated with damp and mouldy buildings; individuals who had no association with such buildings; and individuals for whom such an association was possible but not proven.
  • No specific biomarker profile related to damp buildings was found, but the biomarker profile of patients with IEI differed from the other groups.
  • The study received funding from the Finnish Work Environment Fund.

The results of the study were published in the International Journal of Molecular Sciences (IJMS) in October 2021. Article: Transcriptomic Profiling of Adult-Onset Asthma Related to Damp and Moldy Buildings and Idiopathic Environmental Intolerance

For more information, please contact:

Hille Suojalehto, Chief Physician, FIOH, hille.suojalehto@ttl.fi, tel. +358 43 820 0363

Harri Alenius, Professor, University of Helsinki, harri.alenius@helsinki.fi, tel. +358 50 448 9526