Plasma anti-serotonin and serotonin anti-idiotypic antibodies are elevatedin panic disorder

The psychoneuroimmunology of panic disorder is relatively unexplored. Alter ations within brain stress systems that secondarily influence the immune sy stem have been documented. A recent report indicated elevations of serotoni n (5-HT) and ganglioside antibodies in patients with primary fibromyalgia, a condition with documented associations with panic disorder. In line with our interest in dysregulated 5-HT systems in panic disorder (PD), we wished to assess if antibodies directed at the 5-HT system were elevated in patie nts with PD in comparison to healthy volunteers. Sixty-three patients with panic disorder and 26 healthy volunteers were diagnosed by the SCID. Employ ing ELISA, we measured anti-5-HT and 5-HT anti-idiotypic antibodies (which are directed at 5-HT receptors). To include all subjects in one experiment, three different batches were ulm during the ELISA. Plasma serotonin antiid iotypic antibodies: there was a significant group effect [patients > contro ls (p = .007)] and batch effect but no interaction. The mean effect size fo r the three batches was .76. Following Z-score transformation of each separ ate batch and then combining all scores, patients demonstrated significantl y elevated levels of plasma serotonin antiidiotypic antibodies. Neither sex nor age as covariates affected the significance of the results. There was a strong correlation between anti-seratonin antibody and serotonin anti-idi otypic antibody measures. Plasma anti-serotonin antibodies: there was a sig nificant diagnosis effect [patients > controls (p = .037)]. Mean effect siz e for the three batches was .52. Upon Z-score transformation, there was a d iagnosis effect with antibody elevations in patients. Covaried for sex and age, the result falls below significance to trend levels. The data raise th e possibility that psycho-immune dysfunction, specifically related to the 5 -HT system, may be present in PD. Potential interruption of 5-HT neurotrans mission through autoimmune mechanisms may be of pathophysiologic significan ce in certain patients with panic disorder. It remains to be demonstrated i f the peripheral autoimmunity is representative of CNS 5-HT neuronal altera tions. Replication appears warranted. [Neuropsychopharmacology 20:386-391, 1999] (C) 1999 American College of Neuropsychopharmacology. Published by El sevier Science Inc.