IgE-reactive proteins from Stachybotrys chartarum.
BACKGROUND
Stachybotrys chartarum has been associated with idiopathic pulmonary hemorrhage in infants. This is thought to be mycotoxin-related. There are increasing numbers of reports linking this fungus to the indoor environment of patients with other pulmonary problems, including allergies and asthma.


OBJECTIVE
Given the potential significance of this fungus as a pulmonary pathogen, this work evaluates the antigenic proteins of S. chartarum as to their molecular size and the prevalence of immunoglobulin (Ig)E and IgG directed against them in the general population.


METHODS
S. chartarum was isolated from a local home. S. chartarum for extract production was grown on minimum salts and glucose. Plasma from 132 healthy individuals was evaluated for IgE and IgG directed against S. chartarum using direct and inhibition enzyme immunoassay. The number and molecular size of those proteins that were bound by IgE from pooled sera known to contain IgE to S. chartarum were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis immunoblotting.


RESULTS
Enzyme immunoassay indicated 65 of 132 (49.2%) sera tested contained IgG against S. chartarum and 13 of 139 (9.4%) sera tested contained IgE against S. chartarum. Pooled sera identified two IgE-binding proteins from extracts of S. chartarum spores and mycelia. These proteins are 34 and 52 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis immunoblot.


CONCLUSIONS
We conclude sensitivity to S. chartarum is potentially much more widespread than previously appreciated. This fungus may impact the asthmatic and allergic population through both immunologic and toxic mechanisms. Its significance in the milieu of allergenic fungi may need to be re-evaluated.
Barnes
Charles
C
Section of Allergy/Immunology, The Children's Mercy Hospital, Kansas City, Missouri 64108, USA.
Buckley
Steve
S
Pacheco
Freddy
F
Portnoy
Jay
J
D005656:Fungal Proteins / Q000276:immunology*; D006801:Humans; D015151:Immunoblotting; D007124:Immunoenzyme Techniques; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology*; D007074:Immunoglobulin G / Q000097:blood; D008970:Molecular Weight; D013191:Stachybotrys / Q000276:immunology*
D005656:Fungal Proteins; D007074:Immunoglobulin G; D007073:Immunoglobulin E