Western blot had been the gold standard for HIV confirmation for many years; however, it is no longer part of the Centers for Disease Control and Prevention (CDC) recommended algorithm for confirmation of reactive initial immunoassay results. Western blot can produce false-negative results in late infection (as antibody titers diminish) or indeterminate results early in the course of HIV infection. An indeterminate result is frustrating to a patient and clinician as there is much anxiety around the confirmation of an HIV diagnosis.
