Is the dopamine D3 receptor mRNA on blood lymphocytes help to for identification and subtyping of schizophrenia?

Schizophrenia is one of the neuropathological disorders, which are associated with dopamine and its receptors. In recent years, it has been shown that mRNA of D3, D4 and D5 dopamine receptor (DRD3, DRD4, DRD5) subtypes is expressed in human peripheral blood lymphocytes (PBL). A total 55 schizophrenic patients and 51 healthy subjects were included in the study to investigate the levels of DRD3 mRNA in PBL of schizophrenic patients and whether DRD3 mRNA level in PBL can serve as peripheral marker for schizophrenia. RNA was isolated from lymphocytes of both groups and reverse transcriptase polymerase chain reaction (RT-PCR) was performed for DRD3 mRNA. We found a significant difference in PBL DRD3 mRNA levels among schizophrenia subtypes (P = 0.030) while no difference was detected between control subjects and schizophrenics. We concluded that the levels of DRD3 mRNA can help understanding and severity of clinical manifestations in schizophrenia.