CPT® Code 85705

The CPT® Code 85705 refers to the thromboplastin inhibition test, specifically designed to qualitatively assess the presence of lupus anticoagulants (LA) in a blood specimen. This test is crucial for identifying LA, which are a group of antibodies that can lead to various clinical and laboratory effects. The detection of these antibodies is often incidental, typically revealed when a prolonged activated partial thromboplastin time (APTT) is noted during routine testing. The presence of lupus anticoagulants is frequently associated with autoimmune conditions, particularly systemic lupus erythematosus (SLE), but can also arise from other medical issues such as inflammatory bowel disease, infections, or malignancies. Additionally, certain medications may contribute to the presence of LA. Clinically, lupus anticoagulants can lead to serious complications, including recurrent thromboses, multiple spontaneous miscarriages, migraine headaches, strokes, and bleeding disorders. However, it is important to note that many individuals with LA may remain asymptomatic. The primary purpose of the TTI test is to elucidate the underlying cause of increased clotting times attributed to these antibodies. The testing process involves diluting the blood specimen to enhance sensitivity to the inhibitors present, and the methodology employed can be either photometric or an automated enzyme immunoassay (EIA).