PERT Program

Tip of the Month: February 2004


IMPACT OF PAIN ON NATURAL KILLER CELL ACTIVITY

This month's tip comes from PERT Faculty member, Anna Du Pen, ARNP.



New research indicates that uncontrolled pain can have a negative effect on the body's ability to fight off infection. The field of psychoneuroimmunology explores the impact of a variety of factors, including pain, on the performance of the immune system. This is an area of research that has some very important implications — pain can have a suppressive impact on the cytotoxicity of natural killer cells.

Several animals studies have demonstrated that systemic or spinal analgesics administered for control of post-surgical pain can enhance natural killer cell (NKC) activity compared to control animals that do not receive pain treatment.1,2 This NKC enhancement helped to decrease the metastatic spread of tumor in experimental animals.

Human studies have been conducted in which patients were followed after dental procedures, examining serum markers for natural killer cell cytotoxicity as well as evidence of illness over one month following the event.3 Results indicated a drop in natural killer cell activity associated with post-operative pain and an increase in infectious symptoms/events in the month that followed.

These studies underscore the complex nature of pain and its impact on other body systems. It is particularly important in a population at high risk for infection such as elderly patients in nursing home settings, demonstrating yet another reason that the control of pain should be a top priority.



References

  1. Gayle Giboney Page, Wendy P. Blakely, Shamgar Ben-Eliyahu. Evidence that post-operative pain is a mediator of the tumor promoting effects of surgery in the rat. Pain. 90, 2001, 191-199.
  2. Shahar Bar-Yosef, Rivka Melamed, Gayle G. Page, Guy Shakhar, Karen Shakhar, Shamgar Ben Eliyahu. Attenuation of the Tumor-Promoting Effect of Surgery by Spinal Blockade in Rats. Anesthesiology, 94:(6), 2001, 1066-73.
  3. Henrietta L. Logan, Susan Lutgendorf, H. Lester Kirchner, Eric M. Rivera, and David Lubaroff. Pain and Immunologic Response to Root Canal Treatment and Subsequent Health Outcomes. Psychosomatic Medicine, 63:(3), 2001, 453-462.