CLINICAL DIAGNOSIS - SAY MAKERS OF LYME DISEASE TEST KITS
Posted Nov 10 2010 1:08am
Trinity Biotech make the test kits for Lyme Disease used here in the UK.
It is interesting to read their recently updated website here
Lyme disease is a multisystem disease caused by the spirochete Borrelia burgdorferi (1). The disease has been documented in Europe since early this century. It was documented in the United States during an epidemic in 1975 among children in Old Lyme Connecticut who demonstrated arthritic symptoms. Steere, et al. recognized the disease as a unique clinical entity (2,3). The symptoms of Lyme disease have been mistaken with many diseases including: juvenile rheumatoid arthritis, lupus erythematosis, multiple sclerosis, Bell’s palsy, rheumatic fever, Reiter's Syndrome, myocarditis and viral meningitis (4).
The spirochete is transmitted by ticks of the genus Ixodes from animal reservoirs such as deer, mice, dogs, horses and birds. The ticks are commonly found on vegetation in endemic regions especially in wooded areas common to the animal reservoir. The incidence of human infection coincides with the tick season from May through September (3,5).
Although the symptoms of Lyme Disease are varied and sometimes unclear, three distinct phases of the disease are recognized. Early manifestations include a single or multiple rash called erythema migrans (EM), a meningitis stage during the next weeks to months is often seen. Late manifestations are recognized to include arthritis or neurologic signs and symptoms. In asymptomatic or subclinical cases, symptoms of infection may not be evident until the later stages of disease (5).
Isolation of B. burgdorferi in culture is definitive evidence of active infection, but is not practical. Detection of specific antibodies is practical but an indirect marker of exposure. Patients produce IgM antibodies within a few weeks of the appearance of EM. Although only IgM antibodies may be detectable during the first month, IgG antibodies increase in most patients after approximately one month. Detectable levels of both IgG and IgM may persist for years (5,6).
B. burgdorferi strains exhibit considerable antigenic variation. Patients often develop early antibodies to the flagellar antigen which can be cross reactive. Patients in the early stage of disease and a portion of patients with late manifestations may not have detectable antibodies. Early antimicrobial treatment, after appearance of EM may lead to diminished antibody concentrations. Serologic tests have been shown to have low sensitivity and specificity and, therefore, cannot be relied upon for establishing a diagnosis of Lyme disease (6,7,8).
The Second National Conference on Serological Diagnosis of Lyme disease (1994) recommended the use of a two-tier test system for Lyme serology in which positive and equivocal samples from a sensitive first-tier test must be further tested by a more specific method such as Western blot (second tier). Positive results in the second tier test provide supportive evidence of exposure to B. burgdorferi which could support a clinical diagnosis of Lyme disease but should not be used as a criterion for diagnosis (9). *********************************************************** I don't think this could be put much clearer - negative tests can not be used to rule out the patient having Lyme Disease.
Why then are there so many doctors and consultants still telling patients here in the UK you don't have Lyme Disease your test result was negative?
Well I think the answer is that they are told this incorrect information from the 'expert' or certainly that was the case for me when I consulted a Rheumatologist who was taking an interest in Lyme Disease, he quoted this expert.
Thankfully for me I had a GP who had seen my amazing recovery on antibiotics, from being severely incapacitated with arthritis and muscle weakness and so continued to treat me on long term antibiotics despite the advice issued by our Health Protection Agency 'expert' who said she should stop giving me antibiotics. I continued to recover and can enjoy a normal life once more.
We need more doctors and consultants to be allowed to think for themselves and not be dictated to by a narrow definition which has insufficient basis to be used to restrict diagnosis and treatment of this emerging complex illness.
Whilst the science continues to emerge over this complex illness it is important to do our own research so that we can discuss with our doctors the best treatments for us, bearing in mind our doctors are often too busy to spend the time needed to read the abundant scientific research that shows that for some of us a short course of antibiotics is just not adequate.