Lymphocyte subsets and the role of TH1/TH2 balance in stressed chronic pain patients.
BACKGROUND
The complex regional pain syndrome (CRPS) and fibromyalgia (FM) are 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.


METHODS
We performed a comparative study in 15 patients with CRPS type I, 22 patients with FM and 37 age- and sex-matched healthy controls and investigated the influence of pain and stress on lymphocyte number, subpopulations and the Th1/Th2 cytokine ratio in T lymphocytes.


RESULTS
Lymphocyte numbers did not differ between groups. Quantitative analyses of lymphocyte subpopulations showed a significant reduction of cytotoxic CD8+ lymphocytes in both CRPS (p < 0.01) and FM (p < 0.05) 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.


CONCLUSIONS
Future studies are warranted to answer whether such immunological changes play a pathogenetic role in CRPS and FM or merely reflect the consequences of a pain-induced neurohumoral stress response, and whether they contribute to immunosuppression in stressed chronic pain patients.
Kaufmann
Ines
I
Department of Anesthesiology, Klinikum Grosshadern, Ludwig Maximilians University, Munich, Germany.
Eisner
Christoph
C
Richter
Peter
P
Huge
Volker
V
Beyer
Antje
A
Chouker
Alexander
A
Schelling
Gustav
G
Thiel
Manfred
M
D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002908:Chronic Disease / Q000523:psychology; D015536:Down-Regulation / Q000276:immunology; D005260:Female; D005356:Fibromyalgia / Q000276:immunology* / Q000503:physiopathology / Q000523:psychology; D006801:Humans; D007376:Interleukin-2 / Q000097:blood / Q000276:immunology; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D015213:Neuroimmunomodulation / Q000276:immunology; D012019:Reflex Sympathetic Dystrophy / Q000276:immunology* / Q000503:physiopathology / Q000523:psychology; D013315:Stress, Psychological / Q000150:complications* / Q000276:immunology* / Q000503:physiopathology; D018417:Th1 Cells / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology*
D007376:Interleukin-2