Posttraumatic stress disorder (PTSD) is associated with poor health, high health care utilization, and an increased risk for a variety of somatic, inflammatory and autoimmune diseases. Research, including our own findings, indicates immunological alterations in PTSD patients. The aim of this study is to investigate whether alterations in the immune system of PTSD patients are reversible through a trauma-specific short-term therapy (Narrative Exposure Therapy).