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PET-CT Scan Method to Monitor Pancreatic B-Cell Loss in Diabetes Mellitus

27. maj 2009 opdateret af: University of California, Irvine

The pancreas is an organ that plays major roles in the digestion of food. A part of the pancreas called islet beta-cells produces insulin, which regulates the amount of glucose (a sugar) present in the blood at all times. Type-1 Diabetes Mellitus (T1DM), an autoimmune disorder characterized by destruction of pancreatic islet beta-cells (the cells that produce insulin), affects at least a million individuals in the US alone. In T1DM, a type of white blood cells called T lymphocytes attacks and destroys the pancreatic islet beta-cells, leading to a loss of insulin, an increase in blood glucose, and a dependence on insulin injections for survival. Despite rigorous control of blood sugar, the majority of diabetic patients develop serious complications including retinopathy, nephropathy, neuropathy, microangiopathy and strokes.

Non-invasive methods to monitor pancreatic beta-cell loss associated with type-1 diabetes mellitus (T1DM) could improve early diagnosis, provide tools to measure responsiveness to new therapies, and evaluate the efficiency of pancreatic transplantation and graft survival.

Our goal is to develop a non-invasive PET-CT imaging method based on binding of a molecule (18F-fallypride) for tracking beta-cell loss during the progression of T1DM. In preliminary studies we demonstrated specific binding of 18F-fallypride to D2 receptors in rat pancreatic sections and we demonstrated that the loss of pancreatic beta cells in streptozotocin-treated rats was associated with a corresponding decrease in 18F-fallypride binding to pancreatic sections. A preliminary 18F-fallypride PET-CT study done by a collaborator in Ohio on a healthy volunteer, revealed 18F-fallypride-uptake by the pancreas that was distinguishable from surrounding tissues. Aim-1 of our project will measure the variability of 18F-fallypride PET-scanning of the pancreas in six healthy volunteers scanned twice with an interval of 4-6 weeks. In Aim-2 of our project, we will compare fallypride PET-CT scans of 12 patients with long-standing T1DM (nearly all beta cells destroyed) with 12 age- and sex-matched healthy volunteers. If we are able to distinguish between the two groups, we will in future (a) optimize the method so as to be able to detect a 20-30% loss of beta cells, and (b) perform PET-CT studies in new-onset T1DM patients and in at-risk first degree relatives of T1DM patients.

Studieoversigt

Status

Afsluttet

Betingelser

Intervention / Behandling

Undersøgelsestype

Observationel

Tilmelding (Forventet)

30

Kontakter og lokationer

Dette afsnit indeholder kontaktoplysninger for dem, der udfører undersøgelsen, og oplysninger om, hvor denne undersøgelse udføres.

Studiesteder

  • Forenede Stater
    • California
      • Orange, California, Forenede Stater, 92868
        • University of California Irvine Medical Center

Deltagelseskriterier

Forskere leder efter personer, der passer til en bestemt beskrivelse, kaldet berettigelseskriterier. Nogle eksempler på disse kriterier er en persons generelle helbredstilstand eller tidligere behandlinger.

Berettigelseskriterier

Aldre berettiget til at studere

18 år og ældre (Voksen, Ældre voksen)

Tager imod sunde frivillige

Ingen

Køn, der er berettiget til at studere

Alle

Prøveudtagningsmetode

Ikke-sandsynlighedsprøve

Studiebefolkning

Joslin Diabetes Clinic at the University of California Irvine, age-matched controls will be obtained from Orange County California.

Beskrivelse

Inclusion Criteria:

  • T1DM patients that are over 18 years of age, have had T1DM for greater than 5 years and show a greater than 80% reduction in C-peptide blood levels following intravenous glucagon injection are eligible to participate in this study.
  • Healthy controls that are over 18 years of age, show normal C-peptide blood levels following intravenous glucagon injection, and are age- and sex-matched with one of the T1DM patients included in the study, are eligible to participate in this study.

Exclusion Criteria:

  • T1DM patients or healthy controls that are not over 18 years of age are not eligible to participate in this study.
  • Pregnant females are not eligible to participate in this study because there is a chance PET/CT scans might be risky for the developing baby. Females physically capable of getting pregnant will be required to get a urine pregnancy test at no cost before each of the PET/CT scans. If the pregnancy test is positive, the T1DM patient or healthy control will be excluded from the study. The consent form describes the risks in detail and the need for women of childbearing age to undergo a pregnancy test.
  • Subjects with a history of psychiatric illness, substance abuse history, clinically significant head trauma, active neurological disease, cardiovascular disease, liver disease or renal impairment, claustrophobia ((very upset and afraid of being in a small space) are not eligible for the study. Dr. Ping Wang will use the subjects history, blood chemistry, to identify individuals with cardiovascular disease, liver disease, or renal impairment.
  • T1DM patients with C-peptide levels following intravenous glucagon injection that are not reduced greater than 80% are not eligible for the study.
  • Healthy volunteers with C-peptide levels following intravenous glucagon injection that are reduced greater than 20% compared to established control values are not eligible for the study.
  • To determine if it is safe to do the procedure, T1DM patients and healthy volunteers will be expected to tell the researchers about any radiation exposure the individual may have had (including diagnostic or treatment x-rays), and any history of head injury, kidney or bladder disease, or any other serious medical conditions.
  • T1DM patients and healthy volunteers will be expected to tell the researchers if they have surgical clips or metallic prostheses (i.e., replacement body parts, such as a hip joint) or a pacemaker or other pieces of metal in the body (shrapnel, metal filings, etc.).
  • Patients with history of alcoholism or significant alcohol consumption will be excluded from the study.
  • The consent form will be English, and non-English speakers will therefore be excluded from the study.
  • Pregnant women are excluded because 18F-fallypride is a radioactive substance , which will be injected into the patient and could be hazardous to the fetus.

Studieplan

Dette afsnit indeholder detaljer om studieplanen, herunder hvordan undersøgelsen er designet, og hvad undersøgelsen måler.

Hvordan er undersøgelsen tilrettelagt?

Design detaljer

  • Observationsmodeller: Case-Control
  • Tidsperspektiver: Fremadrettet

Kohorter og interventioner

Gruppe / kohorte
Intervention / Behandling
1
Healthy individuals with normal C-peptide levels following i.v. glucagon challenge. These individuals will be administered 18F-fallypride and then subjected to PET-CT scanning of the pancreas and brain. The subject will be positioned in the PET/CT scanner and a low-dose CT (15-20 secs) of the abdomen carried out (with subjects breathing normally). A 30-min PET acquisition will then be started (three 10 min static frames or one 30 min static frame). The subject will then be repositioned for a low-dose CT scan of the head (15-20 secs) following which a 20-min PET acquisition will then be started (two 10 min static frames or one 20 min static frame).
Medicin: 18F-fallypride
Single bolus i.v. injection 60 minutes before PET-CT scanning. Maximum activity per single administration 5 mCi; maximum amount of drug per administration <10 micrograms.
Medicin: 18F-fallypride
I.v. bolus maximum activity per single administration 5 mCi; maximum amount of drug per administration <10 micrograms.
2
Patients with longstanding T1DM and <20% C-peptide levels following i.v. glucagon challenge will be consented. 18F-Fallypride injected intravenously and subjects allowed to wait for approx 1 hr for the uptake.(b) Subject positioned in the PET/CT scanner and a low-dose CT (15-20 secs) of the abdomen (pancreas) carried out (with subjects breathing normally).(c) A 30-min PET acquisition will then be started (three 10 min static frames or one 30 min static frame).(d) Subject repositioned for a low-dose CT scan of the head (15-20 secs).(e) A 20-min PET acquisition will then be started (two 10 min static frames or one 20 min static frame).(f) End of PET/CT scanning procedures. Subject taken out of the scanner.
Medicin: 18F-fallypride
Single bolus i.v. injection 60 minutes before PET-CT scanning. Maximum activity per single administration 5 mCi; maximum amount of drug per administration <10 micrograms.
Medicin: 18F-fallypride
I.v. bolus maximum activity per single administration 5 mCi; maximum amount of drug per administration <10 micrograms.

Hvad måler undersøgelsen?

Primære resultatmål

Resultatmål
Tidsramme
Difference in fallypride binding in the pancreas of long-standing T1DM patients versus healthy controls
Tidsramme: At the end of the study when 12 controls and 12 patients have been studied.
At the end of the study when 12 controls and 12 patients have been studied.

Samarbejdspartnere og efterforskere

Det er her, du vil finde personer og organisationer, der er involveret i denne undersøgelse.

Sponsor

University of California, Irvine

Samarbejdspartnere

Juvenile Diabetes Research Foundation

Efterforskere

  • Ledende efterforsker: George K Chandy, MD, PhD, University of California, Irvine

Datoer for undersøgelser

Disse datoer sporer fremskridtene for indsendelser af undersøgelsesrekord og resumeresultater til ClinicalTrials.gov. Studieregistreringer og rapporterede resultater gennemgås af National Library of Medicine (NLM) for at sikre, at de opfylder specifikke kvalitetskontrolstandarder, før de offentliggøres på den offentlige hjemmeside.

Studer store datoer

Studiestart

1. februar 2008

Primær færdiggørelse (Faktiske)

1. juli 2008

Studieafslutning (Faktiske)

1. juli 2008

Datoer for studieregistrering

Først indsendt

4. marts 2008

Først indsendt, der opfyldte QC-kriterier

11. marts 2008

Først opslået (Skøn)

12. marts 2008

Opdateringer af undersøgelsesjournaler

Sidste opdatering sendt (Skøn)

29. maj 2009

Sidste opdatering indsendt, der opfyldte kvalitetskontrolkriterier

27. maj 2009

Sidst verificeret

1. maj 2009

Mere information

Begreber relateret til denne undersøgelse

Nøgleord

Yderligere relevante MeSH-vilkår

Andre undersøgelses-id-numre

  • 2007-5785

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Kliniske forsøg med Type 1 diabetes mellitus

Kliniske forsøg med 18F-fallypride

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