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

August 11, 2009 updated by: North Suffolk Mental Health Association

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

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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

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).

Study Type

Observational

Enrollment (Anticipated)

60

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Massachusetts
      • Boston, Massachusetts, United States, 02114
        • Freedom Trail Clinic

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 65 years (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Schizophrenia patients

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Healthy Controls
Procedure: Phlebotomy
Single blood draw
Schizophrenia
Schizophrenia Patients
Procedure: Phlebotomy
Single blood draw

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

North Suffolk Mental Health Association

Investigators

  • Principal Investigator: Oliver Freudenreich, M.D., North Suffolk Mental Health Association

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

January 1, 2006

Primary Completion (ACTUAL)

May 1, 2009

Study Completion (ACTUAL)

May 1, 2009

Study Registration Dates

First Submitted

December 13, 2007

First Submitted That Met QC Criteria

December 13, 2007

First Posted (ESTIMATE)

December 14, 2007

Study Record Updates

Last Update Posted (ESTIMATE)

August 12, 2009

Last Update Submitted That Met QC Criteria

August 11, 2009

Last Verified

August 1, 2009

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • CORRC#10-2005

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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