Anti-B. pertussis Toxin IgG
The detection of specific IgM and IgA antibodies is used in the diagnosis of acute infection. IgA antibodies in combination with the corresponding symptoms indicate an active infection. The detection of IgM antibodies is particularly useful for diagnosis in young children, in whom the IgA response is often reduced or absent. According to WHO definitions, the increase in levels and IgG and / or IgA antibodies to one or more Bordetella pertussis antigens in unvaccinated children confirms the presence of whooping cough. For optimal laboratory diagnosis of whooping cough in children, two methods of investigation should be used simultaneously: sowing of material from the nasopharynx and determining the level of specific antibodies of class G, A and M to two toxins (CT and PHA) by means of an enzyme immunoassay (ELISA). In the presence of typical clinical manifestations, ELISA confirms the diagnosis, and with erased and atypical forms of infection, this method may be crucial.
IgG antibodies are evidence of an acute infection or vaccination, appear 2-3 weeks after infection, are strictly specific for the pathogen, persist for life, the level does not reflect the activity of the process