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Functional characterization of the complement receptor type 1 and its circulating ligands in patients with schizophrenia

Arsen Arakelyan1, Roksana Zakharyan12, Aren Khoyetsyan1, David Poghosyan1, Rouben Aroutiounian13, Frantisek Mrazek2, Martin Petrek2 and Anna Boyajyan1*

Author affiliations

1 Institute of Molecular Biology, National Academy of Sciences of the Republic of Armenia, 7 Hasratyan St., 0014, Yerevan, Armenia

2 Faculty of Medicine and Dentistry, Palacky University, 6 I. P. Pavlova St., 775 20, Olomouc, Czech Republic

3 Biological Faculty of Yerevan State University, 1 Al. Manoogian St., 0025, Yerevan, Armenia

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Citation and License

BMC Clinical Pathology 2011, 11:10  doi:10.1186/1472-6890-11-10

Published: 25 August 2011



Whereas the complement system alterations contribute to schizophrenia, complement receptors and regulators are little studied. We investigated complement receptor type 1 (CR1) expression on blood cells, the levels of circulating immune complexes (CIC) containing ligands of CR1, C1q complement protein and fragments of C3 complement protein (C1q-CIC, C3d-CIC), and CR1 C5507G functional polymorphism in schizophrenia patients and controls.


We found an increased C1q-CIC level and CR1 expression on blood cells, elevated number of CR1 positive erythrocytes and reduced number of CR1 positive lymphocytes and monocytes in patients compared to controls. No difference in the levels of C3d-CIC between groups was observed. Higher CR1 expression on erythrocytes in CC genotype versus CG+GG for both groups was detected, whereas no difference was observed for other cell populations. Our results indicated that schizophrenia is associated with the increased CR1 expression and C1q-CIC level.


Our study for the first time indicated that schizophrenia is associated with the increased CR1 expression and C1q-CIC level. Further studies in other ethnic groups are needed to replicate these findings.