Antibody tests Antibody tests are mainly intended to detect specific antibodies against Borrelia burgdorferi sl in serum but they can also be used in CSF or joint fluid. Briefly, Borrelia organisms are inactivated and fixed on glass slides. The slides are incubated with the patient's serum. Borrelia specific antibodies, if present, bind to the slides. After washing, Borrelia-antibody complexes are visualized by incubation with a fluorescent antiserum directed against human immunoglobulins.
Final reading is done by UV microscopy.
The technique is simple and inexpensive to perform, considered as reasonably sensitive but not very specific. The lack of specificity is mainly due to the fact that the target for antibody detection consists of whole Borrelia organisms. False positive have to be expected and are observed with samples containing antibodies against similar bacteria such as samples from syphilitic patients. This may or may not be viewed as a problem, depending upon syphilis incidence in the local population. However, the major problems with IFA are practical.