Levels of adenosine deaminase and dipeptidyl peptidase IV in patients with panic disorder

Objective: Adenosine deaminase and dipeptidyl peptidase IV are enzymes connected to T cells that play an important role in immune system functioning. In this study, in order to understand the immune processes in panic disorder, we determined the serum levels of adenosine deaminase and dipeptidyl peptidase IV in medication-free panic disorder patients and compared them to those of healthy controls. Method. Enzymes levels were determined in blood samples of 24 healthy controls and 33 panic disorder patients diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders-IV that were medication free during the previous month and medically healthy. Results: Levels of both enzymes were significantly higher in panic disorder patients than in the controls (P < 0.001 for adenosine deaminase and P < 0.05 for dipeptidyl peptidase IV). The levels of the enzymes did not correlate with sociodemographic variables, duration of the disorder presence of agoraphobia, presence of stressors, number of panic attack symptoms, and Hamilton depression and anxiety rating scale scores. In addition, the 2 enzymes' levels did not correlate with each other. There was a correlation between Hamilton anxiety rating scale score and the number of panic attack symptoms (P < 0.001); however Hamilton anxiety rating scale scores were not correlated with the other variables. Conclusion; Our results suggest that there may be a primary or secondary impaired immune state in the course of panic disorder as there is in many other psychiatric disorders, such as major depression. Future studies with larger samples are needed to clarify the relationship between the immune system and panic disorder.