VDRL and TPHA

VDRL and TPHA are two tests used for the diagnosis of syphilis. As this is a screening test, it must be accompanied by further tests to confirm the diagnosis.
VDRL and TPHA are often performed together and have different clinical significance.
TPHA is positive only at around week 10 of infection and is therefore of little use in the early stages of the disease. It remains positive throughout the patient’s life, even after treatment.
VDRL is positive between the eighth and fifteenth day after the initial stage (primary syphiloma), which presents itself after about three weeks of incubation with a small, painless wound in the area where the infection occurred. It becomes negative after treatment and is therefore used to assess the effectiveness of treatment.

VDRL, although a fairly sensitive test, is insufficiently specific: high values are found even in the absence of syphilis, in the case of autoimmune diseases (rheumatoid arthritis, lupus), pregnancy, drug addiction and other viral infectious diseases (acute hepatitis, measles, varicella, Epstein-Barr) or chronic bacterial diseases (malaria, leprosy, tuberculosis).