[Luna]

9th Annual International Scientific Conference on Lyme Disease & Other Tick-Borne Disorders

Chronic Lyme Disease: An Evolving Syndrome
Benjamin J. Luft, M.D. Professor

Chair (acting) Department of Medicine, State University of New York at Stony Brook

Abstract:
Lyme disease, initially described as an arthritic disease, has unfolded over the past 15 years as a multistage, multisymptom disease of great complexity and variability. Several key factors are involved in the development of Lyme disease; the spirochetal agent, the tick and the host. The spirochete shows strain heterogeneity with at least three major genospecies: Borrelia burgdorferi, B. garinii and B. afzelii. Different genospecies appear to be associated with distinct clinical manifestations. Multiple strains of B. burgdorferi can infect the same tick and human infection can include single or multiple spirochete strains. In the case of the ticks, environmental factors such as temperature, humidity and source of blood meal may alter the major outer surface proteins (Osp) of the spirochete within the tick vector. This can affect the spirochete infectivity. Ticks can be co-infected with multiple organisms, including Babesia and Ehrlichia species. The immune response plays a definite role in the infectivity and pathogenesis of B. burgdorferi. Osp A, a major outer surface protein with relative molecular mass of 31,000, stimulates B cells and cytokine production. Humans with chronic arthritis are more likely to show an immune response to Osp A.

Chronic Lyme disease has become an increasing concern for health care providers. Retrospective studies confirm that a proportion of patients treated for Lyme disease experience prolonged post treatment problems. Persistent complaints are generally non-specific and include arthralgias, myalgias, cognitive difficulties, fatigue, malaise, dizziness, stiff neck and photophobia.

Chronic Lyme disease patients may be seropositive or seronegative with or without a documented history of Lyme disease.

Since Lyme disease is a clinical diagnosis, research must continue to improve diagnostic assays using recombinant proteins which are more sensitive and specific than the whole organism sonicate used for both ELISA and Western blots. Possible biological markers of chronic Lyme disease, such as positive Borrelial antigen, Borrelial DNA and pleocytosis in the CSF or synovial fluid, need to be assessed and validated. Elimination of biological markers in combination with sensitive indices of neuropsychological symptoms will be useful for the evaluation of treatment modalities.
Source: Tick Talk Ireland