The lymphocyte transformation test for borrelia (LTT borrelia)
Diagnosing borreliosis at an early state should be based mainly on clinical criteria. Antibodies are not detectable until up to 8 weeks after the infection. However, it is to be noted that a not too small amount of clinically symptomatic cases in all stages cannot be clearly assessed which is why the clinical diagnosis is of the greatest significance.
Furthermore, positive proof of borrelia-specific antibodies only demonstrates that a borrelia infection took place in the past without stating whether it is still active at the time of the examination or whether the pathogen has been eliminated by the immune system or therapy. It cannot be decided using serological methods only. Establishing a borreliosis diagnosis in stage II or III can thereby become difficult. In addition, the serological test methods are not yet standardised enough due to the polymorphism of the specific borrelia antigens and because evaluating immunoblot results requires a lot of experience by the executing laboratory.
After extensive preliminary testing and trials in which more than 3,000 patients participated, the lymphocyte transformation test with borrelia test antigens (LTT borrelia) can serve as an additional diagnostic criterion in identifying a currently active borrelia infection. In the process, the cellular immune response of the lymphocytes circulating in the blood are tested for borrelia proteins. The test is positive when the borrelia-specific T-lymphocyte in the patient's blood is identified. This indicates that the immune system at the time of the blood sampling was in a state of immunological confrontation with the pathogen. If as a result an effective antibiotic treatment takes places, then the presence of LTT borrelia will prove to be predominantly negative or it will at least show a significant decrease in the stimulation quotient (SI values). The result of the LTT borrelia test thereby gives the treating physician an indication of the effectiveness of the antibiotic therapy in the relevant patient.
The tests conducted by us in line with the LTT validation at the Institute for Medical Diagnostics show a sensitivity of the method in antibiotic treatment of 89.4%. The specificity amounted to 98.7% in seronegative patients/trial participants and 91.6% in seropositive patients.
by Baehr et al. The lymphocyte transformation test for borrelia detects active Lyme borreliosis and verifies effective antibiotic treatment. Open Neurol J. 2012;6:104-12.
The results show that the LTT does not reach 100% specificity even when lege artis methodology was implemented, which in evaluating the entirety of laboratory findings needs to be considered.
Negative findings in the LTT borrelia test cannot exclude an infection with certainty. The most important basis for diagnosing borreliosis and the resulting therapy indication should therefore always include the evaluation of the clinical picture.
Fig. 1: Recombinant OspC indicates clearly positive stimulation indices (SI's) for all 3 species-specific lysate antigens. This finding leads to the suspicion of a currently active borreliosis.
Fig. 2: The LTT borrelia shown is negative (SI < 2). This result speaks against a currently active borrelia infection. Findings of this type are seen:
- in trial participants without a borrelia infection
- In clinically healthy, seropositive trial participants
- Approx. 4 to 6 weeks following antibiotic therapy of an active borreliosis
(baseline status corresponds to Illustration 1)
Material and requirements
20 ml new heparin blood + 5 ml full blood (do not cool and submit on the same day)
The materials for drawing blood and packaging are provided by the laboratory free of charge. Tel. (030) 77001-220 or LTT@imd-berlin.de
The laboratory requirement is: LTT borrelia
Payment
It is possible to bill patients who are covered by private medical insurance according to the German schedule of medical fees (GOÄ). The examination costs €156.19 for self-pay patients (voluntary examination).
