Serum calcium-independent phospholipase A2 activity in bipolar affective disorder


  • The authors of this paper do not have any commercial associations that might pose a conflict of interest in connection with this manuscript.

Dr Brian M Ross, Division of Medical Sciences, Northern Ontario School of Medicine, MS-3002, Lakehead University, 955 Oliver Road, Thunder Bay, ON, Canada P7B 5E1. Fax: +1-807-766-7300; e-mail:


Objective:  Phospholipases A2 (PLA2) are a family of enzymes involved in membrane phospholipid metabolism and cell signalling. The gene encoding one form, type VI calcium-independent phospholipase A2, is located in a region of DNA that may contain a gene important in the aetiology of psychosis. Moreover, the activity of calcium-independent PLA2 is reported to be elevated in the blood and brain of patients with schizophrenia. In this study we determined whether a similar change takes place in patients with bipolar disorder with and without a history of psychosis.

Methods:  Serum calcium-independent and -dependent PLA2 activities were determined in 24 patients with bipolar I disorder.

Results:  Serum calcium-independent and -dependent PLA2 activities in bipolar cases did not differ significantly from that in healthy volunteers (HVs). However, calcium-independent PLA2 activity was significantly (p < 0.05) higher in patients with a history of psychosis compared with those with no history of psychosis (by 55%) or to HVs (by 31%).

Conclusions:  Our data suggest that a subset of bipolar I disorder patients with a history of psychosis have elevated calcium-independent PLA2 activity. Given that this enzyme activity is also increased in schizophrenia, elevated rates of phospholipid turnover mediated by the enzyme could represent a common biochemical feature of psychotic illness.