Panic disorder and immunity: few effects on circulating lymphocytes, mitogen response, and NK cell activity.

Altered immune measures are commonly found in major depression (MD), however, less is known about the immune system in anxiety disorders. We examined quantitative and functional in vitro immune measures in patients with panic disorder (PD), which is often comorbid with MD. Fourteen otherwise healthy medication-free adults (ages 23-49; 11 female) meeting SCID-UP DSM-IIIR criteria for PD with agoraphobia and without current MD, were compared with 14 subjects free of PD, MD, or other major psychiatric disorders, matched by gender, age, and racial background. PD was associated with decreased percentage (p<.03) and total (p<.03) circulating CD19+ B lymphocytes, but no differences in other enumerative lymphocyte measures. Mitogen responses (Con A, PHA, PWM) did not differ except for possibly decreased PHA in PD (p<.06). NK cell activity did not differ between PD and control subjects. The few immune measure changes in PD contrast with those found in MD, providing further evidence for the specificity of immune changes in psychiatric disorders.