Immunoglobulin classes of antibodies to Aspergillus fumigatus in patients with pulmonary aspergillosis.

An indirect immunofluorescence test was used to determine the titre and immunoglobulin classes of antibodies to Aspergillus fumigatus in human serum. In 15 patients with aspergillosis, significant titres of IgG but not IgA or IgM antibodies were found. The IgG, IgA and IgM fractions of serum from 2 patients with aspergillosis were separated. This confirmed that antibodies to A. fumigatus reside in highest titre in the IgG fraction. Precipitating antibodies to A. fumigatus in these patients also belonged to the IgG class of immunoglobulin.