Trial record 12 of 31 for:    "Congenital porphyria"

Study of the Pathogenesis of Porphyria Cutanea Tarda

This study has been completed.
Sponsor:
Collaborator:
University of Texas
Information provided by:
National Center for Research Resources (NCRR)
ClinicalTrials.gov Identifier:
NCT00005103
First received: April 6, 2000
Last updated: June 23, 2005
Last verified: December 2003
  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.


Condition
Porphyria Cutanea Tarda

Study Type: Observational
Study Design: Primary Purpose: Screening

Resource links provided by NLM:


Further study details as provided by National Center for Research Resources (NCRR):

Estimated Enrollment: 120
Study Start Date: November 2000
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.

  Eligibility

Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
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
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00005103

Locations
United States, Texas
University of Texas Medical Branch
Galveston, Texas, United States, 77555-0209
Sponsors and Collaborators
University of Texas
Investigators
Study Chair: Karl Elmo Anderson University of Texas
  More Information

No publications provided

ClinicalTrials.gov Identifier: NCT00005103     History of Changes
Other Study ID Numbers: 199/14875, UTMB-433, UTMB-95-173
Study First Received: April 6, 2000
Last Updated: June 23, 2005
Health Authority: United States: Federal Government

Keywords provided by National Center for Research Resources (NCRR):
inborn errors of metabolism
porphyria
porphyria cutanea tarda
rare disease

Additional relevant MeSH terms:
Porphyria Cutanea Tarda
Porphyria, Erythropoietic
Porphyrias
Porphyrias, Hepatic
Digestive System Diseases
Genetic Diseases, Inborn
Liver Diseases
Metabolic Diseases
Metabolism, Inborn Errors
Skin Diseases
Skin Diseases, Genetic
Skin Diseases, Metabolic

ClinicalTrials.gov processed this record on October 23, 2014