Enhanced Cellular Immune Response in Women With PTSD Related

BRIEF REPORTS 4. Koopman C, Classen C, Spiegel D: Predictors of posttraumatic stress symptoms among survivors of the Oakland/Berkeley, Calif, firestorm. Am J Psychiatry 1994; 151:888–894 5. Brunet A, Weiss DS, Metzler TJ, Best SR, Neylan TC, Rogers C, Fagan J, Marmar CR: The Peritraumatic Distress Inventory: a proposed measure of PTSD criterion A2. Am J Psychiatry 2001; 158:1480–1485 6. Weiss D, Marmar CR: The Impact of Event Scale—Revised, in Assessing Psychological Trauma and PTSD: A Practitioner’s Hand-

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Brief Report

Enhanced Cellular Immune Response in Women With PTSD Related to Childhood Abuse Margaret Altemus, M.D. Marylene Cloitre, Ph.D. Firdaus S. Dhabhar, Ph.D. Objective: Disturbed regulation of both the hypothalamic-pituitary-adrenal (HPA) axis and the sympathoadrenomedullary system in posttraumatic stress disorder (PTSD) suggests that immune function, which is modulated by these systems, also may be dysregulated in individuals with PTSD.

Method: Delayed-type hypersensitivity skin test responses were measured in 16 women with PTSD due to childhood sexual or physical abuse and 15 women who did not have a history of abuse, other trauma, or psychiatric disorders. HPA axis activity was assessed by examination of circadian salivary cortisol levels and a single time point measurement of plasma cortisol. Results: Delayed-type hypersensitivity was enhanced in women with PTSD. Cortisol measures did not differ between PTSD and healthy comparison subjects. Conclusions: These results suggest that cell-mediated inflammatory reactions are greater in individuals with PTSD. (Am J Psychiatry 2003; 160:1705–1707)

I

ndividuals with posttraumatic stress disorder (PTSD) have disturbances of both of the major stress-response systems in the body: the hypothalamic-pituitary-adrenal (HPA) axis and the sympathoadrenomedullary system. Both of these stress-response systems have well-described effects on immune function, suggesting that regulation of the immune system may be disturbed in individuals with PTSD. Most, but not all, studies of adults with longstanding PTSD have found low basal levels of urinary or plasma cortisol and greater baseline sympathoadrenomedullary activity (1). In addition, PTSD has been associated with greater HPA axis and sympathoadrenomedullary reactivity to stress (1, 2). There are at least two ways that these disturbances of stress-response systems in individuals with PTSD could exacerbate cell-mediated immune system reactivity. First, low basal levels of glucocorticoids could predispose subjects with PTSD to enhanced immune activation. Chronic elevations of glucocorticoid levels globally suppress immune system reactivity (3, 4), and conversely, a number of chronic inflammatory disorders Am J Psychiatry 160:9, September 2003

have been associated with lower basal HPA axis activity (5). Second, enhanced sympathoadrenomedullary and HPA axis reactivity to stress could also enhance cell-mediated immune function since there is preclinical evidence that acute stress and acute administration of catecholamine and glucocorticoid hormones can enhance cell-mediated immunity (4). This study was designed to determine whether delayedtype hypersensitivity, an integrated, in vivo skin test measure of cell-mediated immunity, is enhanced in subjects with chronic PTSD and whether the delayed-type hypersensitivity response is related to basal cortisol levels. Because the reaction develops over several days in vivo, it provides an opportunity to integrate the influences of basal activity of both the HPA axis and the autonomic nervous system, as well as the influence of periodic activation of these systems by environmental stressors.

Method Subjects with PTSD were recruited from a group of individuals who were evaluated for participation in a psychotherapy treathttp://ajp.psychiatryonline.org

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BRIEF REPORTS ment study for women with PTSD due to childhood physical and/ or sexual abuse. Diagnosis of PTSD was determined with the Structured Clinical Interview for DSM-IV (SCID) and the Clinician-Administered PTSD Scale (6). Nine subjects with PTSD had comorbid major depression, seven had comorbid panic disorder, and nine had comorbid social phobia. The subjects with PTSD had a mean score of 74 (SD=16) on the Clinician-Administered PTSD Scale, indicating moderate to severe symptom severity. All of 15 comparison subjects were free of current or past psychiatric disorders, as determined by the SCID, and reported no history of physical or sexual abuse or other major trauma. The PTSD and normal comparison groups were matched for age (mean=34 years, SD=8, versus mean=35 years, SD=9, respectively), race, time of day of skin testing, and menstrual cycle phase or menopausal status. Exclusion criteria included regular use of alcohol or tobacco, current medical illness and history of psoriasis, atopic dermatitis, or any autoimmune disease. Three subjects with PTSD were taking psychotropic medications at the time of the study; two were using venlafaxine, and one was taking fluoxetine. All subjects gave written informed consent before participation. Three recall antigens were given to the subjects intradermally (0.1 ml) at three sites on the flexor surface of one forearm. Candida and trichophyton (both at 1000 pnu/ml, Bayer Corp, Elkhart, Ind.) and tetanus toxoid (1 lfu/ml, Connaught Laboratories, Stillwater, Pa.) were used because there is a high probability that all subjects had previous exposure to these antigens. Forty-eight hours later, the size of the erythema response to each skin test was scored as the mean of its diameters in two perpendicular directions, and the three scores were averaged to produce a single delayed-type hypersensitivity measure. Blood samples for serum cortisol measurements were drawn immediately before placement of the skin test. A circadian cortisol profile was determined on the day before the skin testing by collection of six salivary cortisol samples every 3 hours, from 8:00 a.m. to 11:00 p.m. Two-tailed t tests were used to compare single time point variables between groups of subjects. Repeated-measures analysis of variance was used to examine salivary cortisol measures. Data are presented as means and standard deviations.

Results In relation to the comparison subjects, the subjects with PTSD had significantly higher mean delayed-type hypersensitivity reactions: mean=5.9 mm (SD=4.4) versus mean=2.9 mm (SD=3.0) (t=2.1, df=29, p