Study of the Pathogenesis of Porphyria Cutanea Tarda
|First Received Date ICMJE||April 6, 2000|
|Last Updated Date||June 23, 2005|
|Start Date ICMJE||November 2000|
|Primary Completion Date||Not Provided|
|Current Primary Outcome Measures ICMJE||Not Provided|
|Original Primary Outcome Measures ICMJE||Not Provided|
|Change History||No Changes Posted|
|Current Secondary Outcome Measures ICMJE||Not Provided|
|Original Secondary Outcome Measures ICMJE||Not Provided|
|Current Other Outcome Measures ICMJE||Not Provided|
|Original Other Outcome Measures ICMJE||Not Provided|
|Brief Title ICMJE||Study of the Pathogenesis of Porphyria Cutanea Tarda|
|Official Title ICMJE||Not Provided|
OBJECTIVES: I. Determine the effect of standard treatments on various predisposing factors in patients with porphyria cutanea tarda (PCT).
II. Investigate alcohol history, smoking, liver dysfunction and its etiology, estrogen use, and family history of PCT in these patients.
III. Study the relationships of excess iron and the hemochromatosis gene to PCT, including clinical features and risk of recurrence in these patients.
IV. Assess hepatitis C virus infections in these patients. V. Assess vitamin C levels in these patients before and after treatment. VI. Assess dietary habits in these patients. VII. Assess activity of cytochrome P450 enzymes (CYP) in vivo in these patients.
VIII. Study polymorphic genes for enzymes that metabolize foreign chemicals, including CYP enzymes and glutathione transferases in these patients.
PROTOCOL OUTLINE: Patients undergo a complete medical evaluation and documentation of porphyria cutanea tarda (PCT) including history, physical examination, standard clinical laboratory tests and porphyrin studies. Alcohol history, smoking, liver dysfunction and its etiology, estrogen use, and family history of PCT are investigated and recorded. Patients complete a questionnaire to assess intake of vitamin C and other nutrients.
Iron status is assessed by serum ferritin, Fe and Fe binding capacity, and by the number of phlebotomies needed to reduce ferritin to the target level. A blood sample is tested for the hemochromatosis (HC) gene to determine whether each patient has 0, 1, or 2 copies of the HC mutation.
Serum hepatitis C virus (HCV) antibody and HCV RNA are measured. Standard liver function tests and liver biopsy are done if clinically indicated.
A fasting blood level of ascorbic acid is obtained. Blood clearance of caffeine and antipyrine, and urinary excretion of caffeine and chlorzoxazone metabolites are determined by breath tests or measurements in blood or saliva.
Genotyping for polymorphic genes for enzymes that metabolize foreign chemicals, including cytochrome P450 enzymes (CYP) and glutathione transferases are completed.
Following completion of the above studies, patients undergo individualized standard treatment either by serial phlebotomies or low dose chloroquine. Patients with HCV are also treated with interferon alfa-2b.
Patients are followed after treatment, at which time initial studies are repeated.
|Study Type ICMJE||Observational|
|Study Design ICMJE||Primary Purpose: Screening|
|Target Follow-Up Duration||Not Provided|
|Sampling Method||Not Provided|
|Study Population||Not Provided|
|Condition ICMJE||Porphyria Cutanea Tarda|
|Intervention ICMJE||Not Provided|
|Study Group/Cohort (s)||Not Provided|
|Publications *||Not Provided|
* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
|Recruitment Status ICMJE||Completed|
|Completion Date||Not Provided|
|Primary Completion Date||Not Provided|
|Eligibility Criteria ICMJE||
|Ages||Child, Adult, Senior|
|Accepts Healthy Volunteers||No|
|Contacts ICMJE||Contact information is only displayed when the study is recruiting subjects|
|Listed Location Countries ICMJE||United States|
|Removed Location Countries|
|NCT Number ICMJE||NCT00005103|
|Other Study ID Numbers ICMJE||199/14875, UTMB-433, UTMB-95-173|
|Has Data Monitoring Committee||Not Provided|
|Plan to Share Data||Not Provided|
|IPD Description||Not Provided|
|Responsible Party||Not Provided|
|Study Sponsor ICMJE||National Center for Research Resources (NCRR)|
|Collaborators ICMJE||University of Texas|
|Information Provided By||National Center for Research Resources (NCRR)|
|Verification Date||December 2003|
ICMJE Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP