Will the positive reference value of Treponema pallidum increase if the immunity is improved?

First of all, let me say clearly, no. The reference value for Treponema pallidum positivity is a fixed judgment threshold set by the laboratory based on the characteristics of the test kit and combined with large sample population data, and has nothing to do with the level of personal immunity.

Last week, I met a 27-year-old boy at the dermatology follow-up clinic. After he was found to be positive for syphilis, he was afraid that he would not be cured. He went to the gym for 3 hours every day and took protein supplements and vitamins in order to maximize his immunity. This time he came to me with the reexamination report and asked, saying that his immunity is so good now. If the reference value for positive is raised, his result will be considered negative? I'm really amused. This is actually a cognitive misunderstanding that many patients confuse - confusing the reference values ​​fixed by the laboratory with the actual test results in their own bodies.

To put it bluntly, the reference value is like the passing mark of 90 points for subject one of the driver's license test. It is a standard set in advance. The passing mark will not rise to 95 points just because you study more questions and review well. There are currently two types of syphilis tests commonly used in clinical practice. One is for testing Treponema pallidum-specific antibodies, such as TPPA and chemiluminescence TP tests. Most of the reference values ​​for this type of test are COI value <1 to determine negative, or titer <1:40 negative. This threshold is set when the kit manufacturer produces it. Different laboratories may fine-tune it according to their own detection systems, but it will never change because of changes in a person's immunity.

Of course, everyone will ask this question. Essentially, they want to know whether a high immunity will be beneficial to the detection and recovery of syphilis. This is true. For example, if the immune status of patients who have received regular anti-tuberculosis treatment is good, the non-specific antibodies (also known as RPR and TRUST titers) will decline significantly faster than those of people with poor immunity. It will also be easier for them to fall below the reference value during the follow-up period and achieve serological cure. I have met two patients who were diagnosed with primary syphilis at about the same time. One young man had a regular schedule and did not drink or stay up late during treatment. His RPR turned negative in the 8th month of reexamination. The other was a designer who worked overtime until early in the morning every day and had to drink with clients every now and then. It took a full 2 ​​years of follow-up before the titer dropped to negative.

However, there are currently a few different observations in the academic community. Some infectious disease scholars have found that after being exposed to Treponema pallidum, a very small group of people with extremely strong immunity may be cleared by their own immune system before the pathogen reproduces in large numbers. The antibody may not even appear positive throughout the process, and will not reach the positive standard above the reference value. However, this situation is extremely rare and must not be regarded as a general situation. I would also like to remind you that there is no problem in improving immunity through exercise and regular work and rest. However, if you randomly take some unknown supplements that claim to "boost immunity", it may disrupt your own immune status. In rare cases, it may cause false positives in the test, which will cause trouble.

Don’t think that just because you have a good immune system, you can survive syphilis without treatment. There was a patient who had chancre and refused to take medication. He ran every day and drank VC effervescent tablets. The chancre did go away on its own, but within half a month, a secondary syphilis rash appeared all over his body, which made it worse. Immunity is always an auxiliary in the treatment of syphilis, and regular medication is the core.