Alphabet Soup - CRPS (RSD) FMS & WBC's

Immunological Changes in Fibromyalgia & Other Chronic Pain Conditions?

The newest issue of the medical journal Neuroimmunomodulation [2008 Feb 1;14(5):272-280] includes the results of a study conducted by Department of Anesthesiology of Ludwig Maximilians University, Munich, Germany.

The study address immunological changes in chronic pain patients, specifically complex regional pain syndrome (CRPS) and fibromyalgia (FMS), both of which the researchers describe as "chronic pain syndromes occurring in highly stressed individuals.

"Despite the known connection between the nervous system and immune cells, information on distribution of lymphocyte subsets under stress and pain conditions is limited. Lymphocytes are white blood cells that play a critical role in the body's defenses. They include T cells, B cells, and natural killer cells. They also modulate the activities of other cells.

The researchers performed a comparative study of 15 patients with CRPS, 22 patients with FMS and 37 age- and sex-matched healthy controls. Their aim was to investigate the influence of pain and stress on lymphocyte number, subpopulations and the Th1/Th2 cytokine ratio in T lymphocytes.

Lymphocyte numbers did not differ between the groups studied. However, when the subtypes of lymphocytes were studied using quantitative analyses, it became evident that there was "a significant reduction of cytotoxic CD8+ lymphocytes in both CRPS... and [fibromyalgia]... patients as compared with healthy controls. Additionally, CRPS patients were characterized by a lower percentage of IL-2-producing T cell subpopulations reflecting a diminished Th1 response in contrast to no changes in the Th2 cytokine profile."

The article concludes that future studies are necessary in order to answer "whether such immunological changes play a pathogenetic role in CRPS and [FMS] or merely reflect the consequences of a pain-induced neurohumoral stress response, and whether they contribute to immunosuppression in stressed chronic pain patients."

Monday, February 04, 2008