Case Study, continued: IgA, IgM and IgG Antibody Testing

How to Subscribe
MLS & MLT Comprehensive CE Package
Includes 175 CE courses, most popular
$109Add to cart
Pick Your Courses
Up to 8 CE hours
$55Add to cart
Individual course$25Add to cart
Need multiple seats for your university or lab? Get a quote
The page below is a sample from the LabCE course Respiratory Case Study: Possible Pertussis Infection. Access the complete course and earn ASCLS P.A.C.E.-approved continuing education credits by subscribing online.

Learn more about Respiratory Case Study: Possible Pertussis Infection (online CE course)
Case Study, continued: IgA, IgM and IgG Antibody Testing

If the patient presented late in the course of her illness, both NAAT and culture may be negative. In this case, serologic tests that measure antibodies may be useful. Infection with pertussis produces IgA (except in infants), IgM, and IgG antibodies.
The problem is that the presence of antibodies could indicate a current/past exposure to B. pertussis or immunization. Vaccination can produce both IgA and IgM antibodies in addition to IgG, so serologic antibody testing cannot differentiate vaccine response from infection.
A common testing protocol is to first use an enzyme-linked immunosorbent assay (ELISA). Positive results may then be confirmed using an immunoblot assay. Some testing laboratories may also recommend paired sera when testing for IgG antibodies, with a convalescent specimen following the acute specimen within 30 days.