Study of Humoral Immunity Indicators for Evaluation of Chronic Pain State.

Variation of natural antibody (nAb) levels to the pain bioregulators (β-endorphin, orphanin, serotonin, dopamine, histamine, and angiotensin) in blood serum at chronic low back pain (LBP) was studied for 21 days. We revealed gender features of immuno-profiles: more elevated nAb levels in women at 1st day and equal levels in gender groups at 21st day. In addition, nAb levels remained above normal up to day 21 in most of patients despite a threefold decrease in pain intensity, measured using a differential visual analogue scale. A significant decrease in nAb levels was found in 4-20% of patients depending on the bioregulator. These observations support the hypothesis that antibodies can be a factor in the prolongation of pain. Therefore, the analysis of the dynamics of nAbs can be recommended for patients with LBP, from which it is possible to predict the further course of the disease.