Dynamics of Pain Tolerance Thresholds and Humoral Immunity Factors at Dorsalgy
Objective: Our aim was to study the possible markers of pain syndrome - indicators of pain sensitivity - pain pressure tolerance thresholds (PPTT), and immuno-indicators - natural antibodies against pain processing mediators (eAb) for evaluation the possibility of its using for a objective pain assessment at chronic low back pain. Methods: Pain sensitivity was assessed daily and nightly, by measuring the PPTT. The natural antibody levels (eAb), were determined in serum by ELISA. Measurement of all parameters were performed at 1 <sup>st</sup>, 10 <sup>h</sup> and 21 <sup>th</sup> days. Results: 173 patients (93 women and 80 men) with chronic low back pain were included in the study. At 1 <sup>st</sup> day most patients had lowered PPTT: 55% of men and 74% during the day, 72% of men and 89% of women at night. Dynamic study has shown a tendency of PPTT normalization in men. The study of diurnal PPTT variations have shown that night PPTT lower than day PPTT on 15-17%. We found gender PPTT differences: PPTT values in women 17-26% lower than in men. Analysis of individual eAb profiles has showed that elevated and high levels of eAb to β-endorphin, orphanin and histamine have 84%, 78%, 84% women and 82% 85 and 95% men, respectively. These indicators higher than those for serotonin, dopamine and angiotensin (55%, 65%, 70% in women and 65%, 66%, 66% in men, respectively; p <0.05). Dynamic study of eAb levels have shown a significant anti-histamine eAbs decrease (23%; p =0.015) only. Conclusion: The pathological changes in pain sensitivity and levels of eAbs to pain-processing mediatos are evidenced. Further investigations are necessary to clarify to role of these variations in pain processing and for use these indicators for objective pain assessment.