Androstenetriol Immunomodulation Improves Survival in a Severe Trauma Hemorrhage Shock Model Andreea C. Marcu, MD, Kristin E. Paccione, MS, R. Wayne Barbee, PhD, Robert F. Diegelmann, PhD, Rao R. Ivatury, MD, Kevin R. Ward, MD, and Roger M. Loria, PhD Background: Traumatic shock acti- vates the hypothalamic-pituitary-adrenal axis (HPA) to mediate a cascade of defen- sive mechanisms that often include over- whelming inflammatory response and immunosuppression, which may lead to multiple organ failure. Androstenetriol (5 androstene, 3,7, 17 triol-AET) is a me- tabolite of dehydroepiandrosterone that markedly up regulates host immune re- sponse, prevents immune suppression, modulates inflammation and improves survival after lethal infections by patho- gens and lethal radiation. Hypothesis: AET-induced immune modulation will improve survival in a con- scious rodent model of traumatic shock. Methods: A relevant traumatic shock rodent model that applies to both combat and civilian sectors was used. After cre- ation of a midline laparotomy (soft tissue trauma), animals were hemorrhaged to a mean arterial pressure of 35– 40 mm Hg. Resuscitation was initiated sixty minutes later with crystalloid fluid and packed red blood cells and animals were observed for two days. In a randomized and blinded fashion, AET or vehicle was adminis- tered subcutaneously at the beginning of resuscitation. Results: In the vehicle group 5 out of 16 animals survived, (31%). In contrast, 9 out of 13 animals who received AET sur- vived (69%), (Fisher Exact Test p < 0.05). Survival in the AET treatment group was associated with reduced levels of IL-6, IL- 10, and IL-18, and enhanced IFN- and IL-2 levels. Conclusion: The results indicate that AET provides a significant protective ef- fect and improves survival in a clinically relevant model of traumatic hemorrhagic shock. AET protective effects are associ- ated with an elevation of Th1 and reduc- tion of Th2 cytokines. Key Words: Androstenetriol, trauma- hemorrhage, shock, survival, cytokines, immunomodulation. J Trauma. 2007;63:662– 669. T raumatic shock (tissue injury and hemorrhage) induces a generalized inflammatory response, characterized by substantial metabolic, inflammatory, and immunologic alterations of the whole organism. 1 Characteristic of the in- teraction between stress and the immune system is the alter- ation of reciprocal and bidirectional communication existing among the nervous, endocrine, and immune system. 2 Among other actions, the immune system signals the brain via cyto- kines, leading to a feedback response, in part, through the action of the hypothalamic-pituitary-adrenal axis with result- ant release of glucocorticoids. 3 The period immediately after acute injury is character- ized by upregulation of proinflammatory cytokine expression leading to a later period of generalized immunosuppression. Among the neuroendocrine mechanisms involved in restoring homeostasis, the sympathetic nervous system plays a role in mediating acute counter-regulatory stress responses to injury. Using hemorrhagic shock as a model of acute stress, the sym- pathetic nervous system has been clearly identified for its role as a key component of the neuroendocrine response to stress. 4 This laboratory has previously reported that several na- tive steroid hormones possess the ability to regulate the im- mune response, and thus, may offer a potential therapy against conditions associated with immune suppression and dysregulation resulting from trauma, hemorrhage, and sepsis. In vivo dehydroepiandrosterone (5-androstene-3-ol-17-one, DHEA) and its downstream more potent metabolites, andro- stenediol (5-androstene-3,17-diol, AED) and androstenet- riol (5-androstene-3,7,17-triol, AET), decrease markedly the morbidity and mortality associated with infections from several diverse pathogens. 5–8 AET is the first known hor- mone that exerts an anti-inflammatory effect but also upregu- lates host resistance and counteracts the immunosuppressive effects of hydrocortisone. 6 Previous findings from this laboratory showed that AET provided significant survival effect in a 40%-volume hemor- rhage trauma model. 9 In view of this, experiments were undertaken to determine the effectiveness of AET in a more severe model of traumatic shock. Submitted for publication May 30, 2006. Accepted for publication November 8, 2006. Copyright © 2007 by Lippincott Williams & Wilkins From the Virginia Commonwealth University Reanimation Engineer- ing Shock Center (VCURES) (A.C.M., K.E.P., R.W.B., R.F.D., R.R.I., K.R.W., R.M.L.), Departments of Microbiology and Immunology (A.C.M., R.M.L.), Emergency Medicine (R.W.B., R.F.D., R.R.I., K.R.W., R.M.L.), Physiology (R.W.B., K.R.W.), Division of Trauma Surgery, Surgical Critical Care and Emergency Surgery, Department of Surgery (R.R.I.), and Depart- ment of Biochemistry (K.E.P, R.F.D.), Virginia Commonwealth University, Richmond, Virginia. Supported by Office of Naval Research Grant N000140310362. Dr. Loria licensed Androstenetriol to Hollis-Eden Pharmaceutical Inc. Address for reprints: Roger Loria, PhD, Department of Microbiology and Immunology, Virginia Commonwealth University, VCURES, P.O. Box 980678, Richmond, VA 23298-0678; email: loria@vcu.edu. DOI: 10.1097/TA.0b013e31802e70d9 The Journal of TRAUMA  Injury, Infection, and Critical Care 662 September 2007