Autoantibodies against voltage ‐gated potassium channel (VGKC) and glutamic acid decarboxylase (GAD) in psychosis: A systematic review, meta‐analysis and case series

Abstract Antibodies to the voltage‐gated potassium channel (VGKC) complex and glutamic acid decarboxylase (GAD) have been reported in some cases of psychosis. We conducted the first systematic review and meta‐analysis to investigate their prevalence in people with psychosis and report a case series of VGKC‐complex antibodies in refractory psychosis. Only five studies presenting prevalence rates of VGKC seropositivity in psychosis were identified, in addition to our case series, with an overall prevalence of 1.5% (25/1720) compared to 0.7% in healthy controls (12/1753). Meta‐analysis established the pooled prevalence of GAD65 autoantibodies was 5.8%(95%CI:2.0‐15.6%;I2=91%;9 studies) in psychotic disorders,with a prevalence of 4.6%(95%CI:1.2‐15.9%;9 studies;I2=89%%) and 6.2% (95%CI:1.2‐27.0%;2 studies;I2=69%) in schizophrenia and bipolar disorder respectively. People with psychosis were more likely to have GAD65 antibodies than controls (OR 2.24;95%CI:1.28‐ 3.92%;p = 0.005;8 studies;I2=0%).Among 21 participants with treatment‐resistant psychosis, none had VGKC antibodies. The prevalence of VGKC antibodies is low in psychosis. Our preliminary meta‐analysis suggests GAD autoantibodies are more common in people with psychosis than in controls, although few studies accounted for the possibility of co‐existing type 1 diabetes mellitus and the clinical significance of reported GAD titres remains unclear. The paucity of studies reporting thresholds for defini...
Source: Psychiatry and Clinical Neurosciences - Category: Neuroscience Authors: Tags: Review Article Source Type: research