Decreased Immune Reactivity and Neuroendocrine Alterations Related to Chronic Stress in Spinal Cord Injury and Stroke Patients

Abstract

Both natural and adaptive immune responses were found to be strikingly decreased 2 weeks after injury in 54 spinal cord injury and stroke patients, i.e., 28 quadriplegics, 21 paraplegics and 5 stroke patients, compared with those of age-matched controls. All values are expressed as means. Natural-killer (NK)-cell function decreased to 21.0% 2 weeks after spinal cord injury compared with 48.6% in controls. At 2 weeks, plasma ACTH values increased to 17.0 pg/ ml in patients compared with 11.2 pg/ml in controls, and urine free cortisol levels were elevated to 162.4 µg/24 h in patients compared with 53.6 µg/24 h in controls. T-cell function decreased to 40.2% of normal (lymphocyte transformation) by 3 months after injury. T-cell activation (IL-2R) was diminished, i.e., 183.4 µg/ml compared with 328.2 µg/ml in controls. With rehabilitation therapy, NK-cell function increased to 41.6% by 7 months after injury. NK-cell-mediated lysis diminished sharply between 7 and 9 months, decreasing to 22.8% at 10 months and ultimately returning to the level seen 2 weeks after injury. Rehabilitation therapy contributed to the restoration of T-cell function to 92.0% of normal by 6 months after injury where it remained for 6+ months. IL·2R values improved in parallel with lymphocyte transformation. Whereas NK-cell-induced lysis remained depressed, i.e., 11.8% at 6 months and 11.4% at 12+ months in patients not receiving therapy, the restoration of NK-cell function at 6 months to 40.6% in rehabilitated patients decreased to 23.0% with cessation of treatment. NK-cell-mediated lysis values in cervical injury patients were significantly less than those in the thoracic injury group. Functional independence measurement (FIM) scores of the two paralleled their NK-cell function. With rehabilitation therapy, NK-cell-mediated lysis in the cervical group increased from 15.2 to 28.4%, whereas it improved in the thoracic group with therapy from 26.8 to 43.7%. With rehabilitation therapy, lymphocyte transformation in the cervical group increased from 37.3 to 85.6% and improved in the thoracic group from 48.4 to 88.9%. With rehabilitation therapy, FIM scores improved from 49.7 to 74.0 in the cervical group and from 79.8 to 97.3 in thoracic patients compared with 126 in controls. NK-cell-mediated lysis was depressed to 28.9% in 5 stroke patients and improved to 38.0% following rehabilitation therapy.

NK Cells in Central Nervous System Disorders

“…It is thought that CNS injuries break the delicate interplay between the immune system and CNS, resulting in secondary immunosuppression (60). Many studies have shown a reduced NKCA of blood NK cells of patients with spinal cord injury and TBI (61)(62)(63). Although the CD56 bright population stayed unchanged, the CD56 dim subtype was decreased, and this correlated with the occurrence of infections after TBI (64).…”

Bladder cancer in individuals with spinal cord injuries

“…4,[14][15][16][17][18] Other theories as to why SCI patients may be more prone to developing bladder cancer include an increased urine contact time, due to less frequent voiding, altered growth factor expression, and hormonal and immune system changes (see Table 3 for a summary of risk factors). 34 It is also possible that denervation of the bladder leads to the development of urothelial dysplasia.…”

Impaired antibody synthesis after spinal cord injury is level dependent and is due to sympathetic nervous system dysregulation

“…Clinical data show that human spinal cord injury (SCI) is accompanied by profound immunological impairment (Cruse et al, 1993;Nash, 2000). Undoubtedly, immune dysfunction after SCI contributes to the significant increase in mortality caused by septicemia, diseases of the lung (e.g., pneumonia), gastrointestinal tract or urinary system (DeVivo et al, 1989).…”