Characteristics of seroconversion and implications for diagnosis of post-treatment Lyme disease syndrome: acute and convalescent serology among a prospective cohort of early Lyme disease patients
Abstract
Two-tier serology is often used to confirm a diagnosis of Lyme disease. One hundred and four patients with physician diagnosed erythema migrans rashes had blood samples taken before and after 3 weeks of doxycycline treatment for early Lyme disease. Acute and convalescent serologies for Borrelia burgdorferi were interpreted according to the 2-tier antibody testing criteria proposed by the Centers for Disease Control and Prevention. Serostatus was compared across several clinical and demographic variables both pre- and post-treatment. Forty-one patients (39.4 %) were seronegative both before and after treatment. The majority of seropositive individuals on both acute and convalescent serology had a positive IgM western blot and a negative IgG western blot. IgG seroconversion on western blot was infrequent. Among the baseline variables included in the analysis, disseminated lesions (p < 0.0001), a longer duration of illness (p < 0.0001), and a higher number of reported symptoms (p = 0.004) were highly significantly associated with positive final serostatus, while male sex (p = 0.05) was borderline significant. This variability, and the lack of seroconversion in a subset of patients, highlights the limitations of using serology alone in identifying early Lyme disease. Furthermore, these findings underline the difficulty for rheumatologists in identifying a prior exposure to Lyme disease in caring for patients with medically unexplained symptoms or fibromyalgia-like syndromes.
I removed a tick from my back on May 15. It appeared to be there quite a while as I was bleeding after its removal. I went to the emergency at my local hospital and brought the tick for analysis. It came back positive for lyme. I was given a treatment of one day which constituted 2 capsules of doxycycline as a treatment on May 15th by the emergency doctor on staff. This is what we are doing in Canada. I am not sure it is working.
Just to de-code the scientific speak here:
seroconversion means that some people who originally test negative for Lyme, will test positive after treatment with antibiotics. This happens because the treatments strengthens the immune system enough so that it registers an immune response. In many people, the immune system is too crippled
to give a reaction before treatment. This is why the usual blood tests are so inaccurate.