Blood Test Showing VDRL Is Non Reactive. Does It Indicate Any Abnormality?

Posted on Fri, 8 Nov 2013

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Fri, 8 Nov 2013 Answered on

Fri, 29 Nov 2013 Last reviewed on

Question : Hi, I just had my blood test last week and i just received the blood test result just now, can i know why my VDRL is NONREACTIVE but my TPHA is positive? I have syphilis last year and already done treatment and completed.

Answered by Dr. Roopa Hiremath (1 hour later)

Brief Answer: VDRL and TPHA Detailed Answer: Hi Mr. XXXXXXX Welcome to health care magic. I have gone through your query and I want to elaborate a little on VDRL and TPHA. VDRL is Venereal Diseases Research Laboratory test and it is a standard test used for diagnosis of syphillis. This is reported as reactive if positive and non reactive if negative. This test detects a specific antibody called "Reagin" which starts appearing 7-10 days after first chancre of syphilis and the titres go on rising as the disease progresses. These tests become non reactive 6-18 months after effective treatment. Hence in your case the test came up non reactive. Now coming to TPHA, this is one of the specific tests used to diagnose syphilis. It is called Treponema Pallidum Hemagglutunation test. This test detects antibodies specific against treponema (causative organism of syphilis) and is very useful to detect active infection. However, the test may show positive even if effective treatment is given as it detects even low titres of antibodies. Here titre of antibodies is important. If TPHA test is showing more 1:80 titre of antibodies then only it is significant. TPHA can also be positive in Lymes disease with VDRL negative. Please check the titre levels in the TPHA test and if significant, I would suggest you get in touch with your treating doctor for further examination. I hope I have cleared your doubts. Please get back if any more clarifications. Thanks.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Roopa Hiremath (29 minutes later)

Thank you Dr XXXXXXX for the advice, For the TPHA test result that i received today, there's no titre level. It just stated there VDRL : NONREACTIVE, TPHA : Positive. So do i need to make blood test again for this TPHA? One more thing, If once that person had syphilis in his past life, TPHA will always remain Positive although that person is healthy and no active syphilis? is there any possibility that the TPHA will become Negative?

Answered by Dr. Roopa Hiremath (49 minutes later)

Brief Answer: TPHA Detailed Answer: Hi Mr. XXXXXXX Welcome back. This is a very good question. Tests like TPHA are useful in monitoring the patients response to treatment, they also help to indicate the stage of disease and they can identify reinfection. But the problem with these tests as I told you in my previous answer is that they can remain positive in low titres for life even after effective treatment. So in such cases the VDRL test is preferred for diagnosis. If VDRL is negative then it indicates effective treatment and the status is taken as negative. There is no requirement for a repeat test of TPHA. Yes, there is a possibility of TPHA becoming negative after 18 months to up to 5 years after treatment. I hope I have answered your question satisfactorily. Thanks.

Above answer was peer-reviewed by : Dr. Vaishalee Punj