Galveston, Texas 77555

  • Porphyria Cutanea Tarda

Purpose:

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.


Study summary:

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.


Criteria:

- Well documented sporadic (Type I) or familial (Type II) porphyria cutanea tarda: Increased plasma porphyrins (fluorescence maximum at neutral pH near 617 nm) Increased urinary porphyrins (consisting mostly of uroporphyrin and heptacarboxylporphyrin) Increased isocoproporphyrins in feces - No other type of porphyria


Study is Available At:


Original ID:

199/14875


NCT ID:

NCT00005103


Secondary ID:

UTMB-433


Study Acronym:


Brief Title:

Study of the Pathogenesis of Porphyria Cutanea Tarda


Official Title:


Overall Status:

Completed


Study Phase:

N/A


Genders:

Both


Minimum Age:

N/A


Maximum Age:

N/A


Quick Facts

Healthy Volunteers
Oversight Has DMC
Study Is FDA Regulated
Study Is Section 801
Has Expanded Access

Study Source:

National Center for Research Resources (NCRR)


Oversight Authority:

United States: Federal Government


Reasons Why Stopped:


Study Type:

Observational


Study Design:

Primary Purpose: Screening


Number of Arms:

0


Number of Groups:

0


Total Enrollment:

120


Enrollment Type:


Overall Contact Information

Official Name:Karl Elmo Anderson
Study Chair
University of Texas

Study Dates

Start Date:November 2000
Verification Date:December 2003
Last Changed Date:June 23, 2005
First Received Date:April 6, 2000

Study Outcomes

There are no available Study Outcomes

Study Interventions

There are no available Study Interventions

Study Arms

There are no available Study Arms

Study Agencies

Agency Class:NIH
Agency Type:Lead Sponsor
Agency Name:National Center for Research Resources (NCRR)
Agency Class:Other
Agency Type:Collaborator
Agency Name:University of Texas

Sample and Retention Information

There are no available Sample and Retention Information

Study References

There are no available Study References

Data Source: ClinicalTrials.gov

Date Processed: July 27, 2021

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