CPT® Code 86684

The CPT® Code 86684 refers to a laboratory test that measures the presence of antibodies against Haemophilus influenzae type B (HIB) in a patient's blood. This test specifically evaluates the IgG antibodies, which are crucial for determining the immune response to the HIB vaccine. The assessment of these antibodies is particularly important in understanding a patient's immune status, especially after vaccination, and can be instrumental in diagnosing immunodeficiency response syndromes. Haemophilus influenzae is a significant encapsulated bacterium known for its potential to cause severe infections, particularly in vulnerable populations such as children under five years of age. Among the six identified types of this bacterium (A-F), type B is the most prevalent and is associated with serious health conditions, including meningitis, bacteremia, cellulitis, epiglottitis, pneumonia, and septic arthritis. The test is performed by obtaining a blood sample through venipuncture, which is a separately reportable procedure. The serum obtained from the blood sample is then analyzed using an enzyme-linked immunosorbent assay (ELISA), a common laboratory technique used to detect and quantify proteins, such as antibodies, in the serum.