[Rapid serodiagnosis of influenza by a modified radial haemolysis test: immune response (author's transl)].

A modification of the single radial haemolysis test by treatment with Cl3Cr of the virus coated red blood cells is proposed for a rapid, more sensitive and reproducible serodiagnosis of Influenza infections. The reagents "red blood cells-virus-Cl3Cr" is stable at 4 degrees C for at least 1 month: the modified test gives results within 3 hours, in measuring the H-anti-H specific reactions. The anti-influenza A immune response was studied in patients of different age, bled at different time after exposure. The IgM do not diffuse in the agarose and do not haemolyse. A clear haemolytic area is produced by IgG, partially haemolysed areas occur when there is a competition between specific IgM and IgG and in the case of reactions involving cross-reacting antigenic determinants.