What does tppa mean?

Tppa refers to the agglutination test of Treponema pallidum gelatin particles.

The simple gel agglutination test of Treponema pallidum is based on the ultrasonic lysis of Treponema pallidum as antigen, and the sensitized red gelatin particles combine with the antibody of Treponema pallidum in human serum or plasma to produce a red agglutination reaction visible to the naked eye.

TPPA test has high sensitivity and specificity, and it is a good test for the diagnosis of syphilis. Patients with positive TPPA test can not be used as an index to observe the therapeutic effect even after anti-syphilis treatment because of their strong replication ability of memory cell antibody and high sensitivity of specific test.

However, according to clinical observation, the serum of early syphilis patients, such as TPPA test, is weakly positive and may turn negative with time. Specific detection of primary syphilis can appear one week earlier than non-specific detection. IgM bodies first appeared in the process of syphilis, and can be detected from serum in the second week after syphilis infection, while IgG antibodies can only be detected in the fourth week after infection.

Syphilis confirmatory test, generally positive qualitative test, can be used as the basis for syphilis diagnosis, and quantitative test should be done if necessary. After effective treatment, the titer of specific antibody can also be reduced to varying degrees, but the chance of negative conversion is rare. This test has strong specificity and few false positives. However, according to statistics, there may be 1% biological false positive.

Abnormal results Primary syphilis. That is, hard chancre, the incubation period is 2-4 weeks, and dark red lumps, superficial ulcers, chondroid hardness and lymphadenopathy appear in the external genitals.

Secondary syphilis. After one-stage syphilis 1-2 months, symmetrical generalized rashes, maculae, papules and pustules appeared on the skin and mucosa of the whole body. Mucosal plaque and verruca plana can appear, which is highly contagious.

Tertiary syphilis. It occurs 2-3 years or even 10 years after infection, and the skin is gelatinous swelling, which can also involve bones, joints, heart and blood vessels. The main manifestations are arteritis, aortic insufficiency and aortic aneurysm. The invaded nerves include spinal tuberculosis, general paralysis (paralytic dementia) and so on.