Immunofluorescence test with antigen-loaded erythrocytes: detection of influenza virus specific IgG, IgA, and IgM antibodies.

An immunofluorescence test (IFT) for the detection of influenza virus antibodies was established to supplement the standard serological diagnostical complement fixation test (CFT). Current strains (A/Philippines/2/82, A/Brazil/11/78, B/Singapore/222/79) were loaded on formalinized chicken erythrocytes. In contrast to CFT, we can distinguish specific immunoglobulin classes against influenza virus. Unlike CFT, IFT is subtype-specific. A recent infection can be distinguished from a past infection by the differentiation of specific immunoglobulin classes. Anticomplementary factors and hemolytic sera do not influence the result of the IFT. IFT does not require cell cultures and is easy to read.