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Peripheral Immune System in Individuals With Schizophrenia

Peripheral Immune System in Individuals With Schizophrenia

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT05109065
Enrollment
63
Registered
2021-11-05
Start date
2021-03-01
Completion date
2024-05-23
Last updated
2025-06-06

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

Conditions

Schizophrenia, Schizo Affective Disorder, Schizophreniform Disorders

Keywords

psychosis, psychiatry, complement immune system

Brief summary

The investigators are seeking healthy volunteers and people with schizophrenia or schizoaffective disorder for a clinical study of the immune system in psychotic disorders. This is an observational study, to understand the ways in which the immune system may be contributing to the disease process.

Detailed description

Genetic studies have linked the number of copies coding for C4 protein to risk for schizophrenia. Studies examining the amount of mRNA, the molecules that point to how much C4 protein is likely being made, found more C4 mRNA in the brains from individuals with schizophrenia. Studies in mice have suggested that expressing more C4 protein in the brain, specifically the A-type of C4, can result in abnormalities in behavior. However, researchers have also found that pathways that involve this protein in the blood to be abnormal in individuals even before they develop schizophrenia and hypothesize these abnormalities change the blood brain barrier. In this work, the researchers are hoping to understand the ways in which C4 protein is abnormal in the peripheral blood and how this may be contributing to the disease process in hopes of finding new ways of helping individuals with schizophrenia and possibly other mental health disorders. A major goal of this study is to collect blood tissue for ongoing translational study of pathophysiological mechanisms of schizophrenia. Interested participants will be asked a series of questions about their medical and mental health history, be able to provide informed consent, undergo a urine toxicology screen and be willing to provide a blood sample.

Interventions

DIAGNOSTIC_TESTSCID (Standardized Clinical Interview for DSM-V)

The Structured Clinical Interview for DSM-5 (SCID-5) is a semistructured interview guide for a clinician or trained mental health professional to diagnose major mental illnesses.

DIAGNOSTIC_TESTPSS (Perceived Stress Score)

The Perceived Stress Scale (PSS) is the most widely used psychological instrument for measuring the perception of stress. It is a measure of the degree to which situations in one's life are appraised as stressful. Items were designed to tap how unpredictable, uncontrollable, and overloaded respondents find their lives. Demographic information will also be collected.

Participants will be asked to provide a urine sample. Evidence of active substance abuse (marijuana, opioids, other non-prescription drugs) by the urine toxicology screen will disqualify participants from the study.

DIAGNOSTIC_TESTVitals

Height and weight will be measured in order to calculate BMI.

DIAGNOSTIC_TESTBlood Work

A venipuncture will be performed for the purpose of collecting blood tissue for study.

DIAGNOSTIC_TESTPQ-B

The Prodromal Questionnaire - Brief Version (PQ-B) is a self-report measure designed to identify people who may be experiencing psychotic symptoms when they do not have a schizophrenia diagnosis.

DIAGNOSTIC_TESTCOVID Screening

Questionnaire to assess risk of transmission of COVID-19.

DIAGNOSTIC_TESTPositive and Negative Syndrome Scale (PANSS)

Instrument that is completed by clinical interviewer to measure symptom severity in individuals with psychotic disorders.

Sponsors

Stanford University
Lead SponsorOTHER

Study design

Observational model
CASE_CONTROL
Time perspective
CROSS_SECTIONAL

Eligibility

Sex/Gender
ALL
Age
18 Years to 40 Years
Healthy volunteers
Yes

Inclusion criteria

for Subjects with schizophrenia and schizoaffective disorders: * Schizophrenia or schizoaffective disorder diagnosis verified by interview * Diagnosis or initiation of antipsychotic medication was within last 5 years Inclusion Criteria for Healthy Controls: * No known diagnosis of schizophrenia or schizoaffective disorder * No history of depression, anxiety, bipolar disorder, PTSD, agoraphobia, panic disorder, or generalized anxiety disorder * Negative assessment for psychotic symptoms on day of interview

Exclusion criteria

(for both groups): * Participants have a history of bleeding disorders or are taking blood thinners. * Participants have a history of epilepsy, known genetic disorders * Immunocompromised state (eg., receiving immunosuppressive therapy, transplant). * History of brain-related disease (eg., stroke) * Any uncontrolled medical disorder such as cancer. * History of substance abuse or positive urine toxicology screen (including test for marijuana) on the day of the blood draw

Design outcomes

Primary

MeasureTime frameDescription
Group comparison of C4 protein in immune cellsDay 1Measure the concentration of complement 4 protein in immune cells.

Secondary

MeasureTime frameDescription
Body Mass Index and its relationship to C4 protein concentrationDay 1The relationship between body mass index, calculated from the measured height and weight of participants, and the primary outcome (C4 protein concentration) will be determined.
C4 Gene Copy NumberDay 1Determine the C4 Gene Copy Number its relationship to C4 protein concentration in immune cells.
C4 ActivationDay 1Measure activity of C4 protein and its relationship to the primary outcome.
Relationship to symptom presentationDay 1Explore the relationship between clinical severity scores (PANSS) and the primary outcome.
Relationship to stressDay 1Explore the relationship between perceived stress (PSS) and the primary outcome.

Countries

United States

Outcome results

None listed

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