Teat results concern

[beagle825]

I an a guy who recently took a 10 panel STD test all results were negative except for the syphillis. ON the T pallidum Screening Casade T pallidum Antibodies test the result was positive abnormal so the lab ran an RPR confirmatory test ant the result was non reactive. The test overall result was indeterminate with low levels of antibody dected but insufficent to conculde syphillis ( either past or present) and reccomended I retest in one month in infection is suspected. I am not very sexually active and have had only one questionable partner recently. I have never shown any symptoms. The only possible symptom I might have is a sore on my upper gum but since I have not engaged in any giving of oral sex or seen any sores on any of  the girls lips or mouths that I have kissed I do not see how it would come from sex and when I let my primary doctor look at it she said she was not too worried about it and said the she reccommend I follow the labs reccomendation and retest in one month and that it maybe just a false positive. The test did not appear to be clear as to the exact type of antibody tested for so my doctor said the results were contradicting as well. How likely is it that the test was a false positive and should I be worried? I want to know if I need treatment and what knid of treatment would be needed?  Thanks for any insight you can provide.

[Edward W Hook, MD]

Welcome to our Forum. I suspect you are a victim of a recent change in the way syphilis is tested for.  Until recently laboratories used to perform the RPR test first and then to test to see if treponemal antibodies are present. If both tests (the RPR and treponemal test) are positive, this is considered to be indicative of either having syphilis or having been infected in the past.  Persons who had positive RPR tests an negative treponemal antibody tests were considered to have falsely positive tests.

More recently, laboratories have changed their approaches to testing so that they test for treponemal tests first.  With new tests this new approach is cheaper for the laboratory.  Studies of this approach now indicate that in low risk persons, over 50% and sometimes as many as 70% of these tests are falsely positive.  I suspect you fall into this group.  The alternative is that you have recently acquired syphilis and your tests are just beginning to become positive (treponemal tests become positive 2-4 days before the RPR test).  

I agree with your doctor.  I am confident that a repeat test will be negative. Both in the interim an when your follow-up test is negative, I would be confident that there is very, very little chance you have syphilis and would not worry.

I hope this comment is helpful to you. EWH

[Edward W Hook, MD]

The only symptoms or relevance would be a lesion at a site of sexual exposure. From your post, I don't think that is an issue.

As far as the f/u test is concerned, you can do that at any point more than a week following your last test- the development of a positve RPR only lags a few days beyond development of a positive treponemal test.  EWH

[beagle825]

Thanks for your input and providing me with the information on the testing procedures and the likely hood of it being a false positive. I believe my chances are good that I do not have syphillis as well after hearing my doctor's opinon and your opinion. If you have a chance could you please answer these two questions? Just in case the alternative you mentioned is possible are there any symptoms I should keep an eye out for over the next month until my follow-up test? Also are there any procauations I should take over the time to my follow-up test as well?  Thanks for you help.

[beagle825]

I forget to mention in the above post that I have never engaged in unprotected sex which I fel might be important information.