Persons with high (G-high) and low (G-low) airborne levels of (1->3)-b-D-glucan in their homes, as an indicator of mold exposure, were examined regarding baseline values for cytokine secretion from blood mononuclear cells (BMNC). All persons were then exposed during three hours to airborne, pure (1->3)-b-D-glucan (grifolan) and cytokines were again determined 24 hours after exposure. Exposure to saline was used as a reference.

The atopics in the G-high group had a larger secretion of TNF in both unstimulated and in vitro LPS-stimulated BMNC, compared to the G-low groups. Non-atopic persons in the G-high group had a significantly higher baseline ratio IFN /IL-4, compared to the G-low group.

After exposure to (1->3)-b-D-glucan, the LPS induced TNF secretion from BMNC was significantly lower among the atopics in the G-high group compared to the other groups. The exposure to (1->3)-b-D-glucan resulted in a further increased ratio IFN /IL-4 among the non-atopic in the G-high group but also the atopics in the G-high group showed a higher ratio compared to before exposure. The data suggest that mold exposure at home induces an inflammatory response and an altered reaction to (1->3)-b-D-glucan.