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Disturbances of Kynurenine Pathway of Trytophan Metabolism in Schizophrenia: A Quantitative Reverse Transcription Polymerase Chain Reaction (RT-PCR) Study

Disturbances of Kynurenine Pathway of Trytophan Metabolism in Schizophrenia: A Quantitative RT-PCR Study

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT00573300
Enrollment
60
Registered
2007-12-14
Start date
2006-01-31
Completion date
2009-05-31
Last updated
2009-08-12

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Schizophrenia

Keywords

Schizophrenia, Immune System, Kynurenate, tryptophan metabolism, NMDA receptor, indolamine 2,3-deoxygenase (IDO)

Brief summary

In this pilot study, the investigators propose to characterize the pattern of activation of the kynurenine pathway of tryptophan metabolism in peripheral macrophages of patients with schizophrenia. To do this, the investigators will measure the gene expression of several major enzymes in this pathway in macrophages, including the key enzyme involved in tryptophan to kynurenine metabolism, IDO, by means of quantitative reverse-transcription polymerase chain reaction (RT-PCR). The focus on enzyme mRNA expression as opposed to serum or cerebrospinal fluid levels of metabolites provides a possibly more sensitive characterization of the activation of this metabolic pathway.

Detailed description

In this pilot study, we propose to characterize the pattern of activation of the kynurenine pathway of tryptophan metabolism in peripheral macrophages of patients with schizophrenia. To do this, we will measure the gene expression of several major enzymes in this pathway in macrophages, including the key enzyme involved in tryptophan to kynurenine metabolism, IDO, by means of quantitative reverse-transcription polymerase chain reaction (RT-PCR). The focus on enzyme mRNA expression as opposed to serum or cerebrospinal fluid levels of metabolites provides a possibly more sensitive characterization of the activation of this metabolic pathway. Primary hypotheses: We hypothesize that patients with schizophrenia will differ in their expression of macrophage IDO mRNA, reflecting activation of this pathway compared to normals. We further hypothesize that patients with deficit syndrome will have higher degrees of enzyme activation. Secondary hypotheses: Serum tryptophan levels will be lower in patients with schizophrenia compared to controls, and they will correlate with measures of dysphoria. Serum kynurenine levels will be elevated in patients with schizophrenia, particularly in deficit syndrome patients. mRNA expression levels of enzymes downstream from IDO will differ between patients and controls. Measures of immune activation will be influenced by medical disease burden (medical comorbidities).

Interventions

PROCEDUREPhlebotomy

Single blood draw

Sponsors

North Suffolk Mental Health Association
Lead SponsorOTHER

Study design

Observational model
CASE_ONLY
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes

Inclusion criteria

1. Diagnosis of Schizophrenia, any subtype or schizoaffective disorder 2. Ages 18-65 years 3. Males or females 4. English speaking with ability to complete symptom ratings 5. Ability to provide informed consent

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026