Variable levels of cytokines were observed in patients with schizophrenia and bipolar disorder, and an especially high level of interleukin-1 (IL-1) was detected in schizophrenia patients. It is known that IL-1 receptor antagonist (IL-1RA) binds to IL-1 receptors and inhibits the receptor binding of IL-1α and IL-1β.
In this study, the association between the variable number of tandem repeats polymorphism of the IL-1RA gene and schizophrenia (n=269) and bipolar disorder (n=83) was investigated.
The genotype distribution and allele frequency were significantly different between schizophrenic patients and the control group (P<0.05); however, there were no prominent differences between bipolar patients and the control group. The carriage rate for the IL1RN*2 allele was associated with higher risk of schizophrenia (odds ratio=2.24).
This study indicates that IL-1RA could be a candidate gene for susceptibility to schizophrenia.
aSchool of Life Sciences and Biotechnology, Korea University, Seoul, Korea
bKohwang Medical Research Institute
cDepartment of Neuropsychiatry, College of Medicine
dSeoul National Mental Hospital, Seoul, Korea
eDepartment of Preventive Medicine, School of Medicine, Keimyung University, Daegu, Korea
fCollege of Pharmacy, Kyung Hee University, Seoul, Korea
Sponsorship: This work was supported by a grant of the Biomedical Brain Research Center Grant, Ministry of Health & Welfare, Republic of Korea (01-PJ8-PG6-01 NE01-0003).
Address correspondence and requests for reprints to J.-H. Chung, Kohwang Medical Research Institute, Department of Pharmacology, College of Medicine, Kyung Hee University, 1 Hoegi-dong, Dongdaemoon-Ku, Seoul 130-701, Republic of Korea
Tel: +82 2 961 0281; fax: +82 2 968 0560;
Received 21 September 2003 Revised 27 October 2003 Accepted 17 February 2004