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Study of the Pathogenesis of Porphyria Cutanea Tarda

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00005103
Recruitment Status : Completed
First Posted : April 7, 2000
Last Update Posted : June 24, 2005
University of Texas
Information provided by:
National Center for Research Resources (NCRR)

Brief Summary:

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.

Condition or disease
Porphyria Cutanea Tarda

Detailed Description:

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.

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Study Type : Observational
Enrollment : 120 participants
Primary Purpose: Screening
Study Start Date : November 2000

Information from the National Library of Medicine

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Ages Eligible for Study:   Child, Adult, Older Adult
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
  • 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

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00005103

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United States, Texas
University of Texas Medical Branch
Galveston, Texas, United States, 77555-0209
Sponsors and Collaborators
National Center for Research Resources (NCRR)
University of Texas
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Study Chair: Karl Elmo Anderson University of Texas

Layout table for additonal information Identifier: NCT00005103     History of Changes
Other Study ID Numbers: 199/14875
First Posted: April 7, 2000    Key Record Dates
Last Update Posted: June 24, 2005
Last Verified: December 2003
Keywords provided by National Center for Research Resources (NCRR):
inborn errors of metabolism
porphyria cutanea tarda
rare disease
Additional relevant MeSH terms:
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Porphyria Cutanea Tarda
Porphyrias, Hepatic
Porphyria, Erythropoietic
Metabolic Diseases
Skin Diseases, Genetic
Genetic Diseases, Inborn
Skin Diseases
Liver Diseases
Digestive System Diseases