Mity w diagnostyce i leczeniu boreliozy. Cz. 2. Jak oceni się skuteczność leczenia?

This video presents educational content. It does not replace medical advice. Lyme disease diagnosis is a two-step process: NOTE! Below, I refer to diagnostic sensitivity and diagnostic specificity, unless otherwise noted. This has nothing to do with analytical sensitivity or analytical specificity (for example, a test may have high analytical sensitivity but low diagnostic sensitivity). Step 1: ELISA (optional: ELFA, ECLIA) in blood (if neuroborreliosis or joint involvement is suspected, also in cerebrospinal fluid and joint fluid) – high sensitivity, lower specificity. High false-positive rate (FP), for example, in autoimmune diseases. Step 2: Western blot (immunoblot, line blot) in blood – high specificity, lower sensitivity. False-positive results are rare, usually after infection or a previous illness, but there may be differences between tests from different manufacturers. NOTE! It is not recommended to replace the Western blot test with the highly specific C6 ELISA test. When does a positive result qualify for treatment? When three conditions are met: 1. Clinical symptoms (joint, neurological, skin, etc.) 2. Positive ELISA IgM/IgG test 3. Positive Western blot. or when pathognomonic symptoms (erythema migrans) occur despite the absence of antibodies in the blood, which usually occurs at the onset of the disease. Serological tests are not performed in this case. When is Lyme disease not diagnosed? 1. Positive ELISA test, positive Western blot, no symptoms (past infection, previous illness). 2. The patient has only performed an ELISA test, which is positive (additional Western blot should be ordered if clinical symptoms are present). 3. The patient has only performed a Western blot test, which is positive (additional ELISA should be ordered if clinical symptoms are present). What tests should not be performed? 1. KKI (circulating immune complexes) - if KKI is positive (+) and ELISA is negative (-), Lyme disease cannot be diagnosed unless a pathognomonic symptom (erythema migrans) is present. 2. LTT (lymphocyte transformation test) - if LTT is positive (+), KKI is positive (+), and ELISA is negative (-), Lyme disease cannot be diagnosed unless a pathognomonic symptom (erythema migrans) is present. 3. Assessment of the CD57+/CD3+ subpopulation. 4. Searching for cysts or L-form bacteria. 5. PCR in skin, blood, or other tissue samples, as the test has very high analytical sensitivity but low diagnostic sensitivity and specificity. Biopsy samples taken from the center of the lesion often yield negative results in erythema migrans samples. How can treatment efficacy be confirmed? Only based on resolution of clinical symptoms. There is no reliable laboratory test (Lyme disease is a clinical diagnosis). ELISA and Western blot tests are not used to assess the effectiveness of therapy. Repeating these tests after treatment and observing the dynamics of antibody titer changes is pointless – antibody levels may paradoxically increase further after treatment, which does not indicate ineffectiveness of the therapy. Convalescence after recovery can take months, especially in advanced disease, which is mistakenly perceived by patients as ineffective therapy and leads to unnecessary, long-term antibiotic therapy. Borrelia spp. spirochetes are sensitive to tetracycline derivatives – resistance is not observed, and there is no need for culture or individualized antibiotic therapy. NOTE! Seronegative Lyme disease – occurs at the beginning of treatment. The claim that a negative ELISA but positive KKI or LTT indicates Lyme disease is false. A cutoff point is required for diagnosis, for example, for an ELISA test above 18 (16) RU/ml. Low antibody concentrations in the presence of KKI usually indicate only immunization after previous contact with the spirochetes, not active infection or current illness. References: 1. Lyme disease. NICE guidelines, 2018. 2. Diagnosis and treatment of Lyme borreliosis. MP, 2010. 3. Andrzej Szczeklik (ed.): Internal diseases. Kraków: Wydawnictwo Medycyna Praktyczna, 2010. 4. Patrick R. Murray, Ken S. Rosenthal, Michale A. Pfaller: Microbiology. Wrocław: Elsevier Urban & Partner, 2011. 5. Laboratory Diagnostics with Elements of Clinical Biochemistry - Dembińska-Kieć A., Naskalski J.W., Solnica B. 2017, publisher: Edra Urban & Partner. 6. Żaneta Smoleńska et al.: Borreliosis — the Latest Recommendations on Diagnosis and Treatment. Forum Reumatol. 2016, vol. 2, no. 2: 58–64. The video thumbnail was downloaded under the CC0 license from the PIXABAY domain and does not require attribution.