Phenotype of blood lymphocytes in PTSD suggests chronic immune activation.

Patients with posttraumatic stress disorder (PTSD) have a past history of extremely stressful experience and often present with somatic complaints. Peripheral blood lymphocytes (PBL) of patients with PTSD associated with a history of childhood sexual abuse were examined for changes in immune phenotype. The ratio of CD45RO-positive to CD45RA-positive lymphocytes (CD45RO/CD45RA), an index of lymphocyte activation, was higher (P = 0.04) in the PTSD subjects than in the normal subjects. No differences were observed for the number of PBL or the representation of major T, B, or NK lymphocyte subsets. These findings suggest the presence of increased lymphocyte activation in the PBL of patients with PTSD.