title: Associations among behavior-related susceptibility factors in porphyria cutanea tarda.
abstract: OBJECTIVE
  Porphyria cutanea tarda (PCT) is the most common of the human porphyrias and results from an acquired deficiency of hepatic uroporphyrinogen decarboxylase (UROD). Some susceptibility factors have been identified; we examined associations among multiple factors in a large cohort of patients.
  
  
  METHODS
  Multiple known or suspected susceptibility factors and demographic and clinical features of 143 patients (mean age 52 years, 66% male, 88% Caucasian) with documented PCT (mean onset at 41 +/- 8.8 years) were tabulated; associations were examined by contingency tables, classification and regression tree (CART) analysis, and logistic regression.
  
  
  RESULTS
  The most common susceptibility factors for PCT were ethanol use (87%), smoking (81%), chronic hepatitis C virus (HCV) infection (69%), and HFE mutations (53%; 6% C282Y/C282Y and 8% C282Y/H63D). Of those who underwent hepatic biopsy or ultrasound, 56% had evidence of hepatic steatosis. Of those with PCT, 66% of females took estrogen, 8% were diabetic, 13% had human immunodeficiency virus (HIV) infection, and 17% had inherited uroporphyrinogen decarboxylase (UROD) deficiency (determined by low erythrocyte UROD activity). Three or more susceptibility factors were identified in 70% of patients. HCV infection in patients with PCT was significantly associated with other behavior-related factors such as ethanol use (odds ratio [OR], 6.3) and smoking (OR, 11.9).
  
  
  CONCLUSIONS
  Susceptibility factors for PCT were similar to previous studies; most patients had 3 or more susceptibility factors. Associations between PCT and HCV, ethanol or smoking could be accounted for by a history of multiple substance abuse; other factors are distributed more randomly among patients.
authors: Division of Human Nutrition, Department of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston, Texas, USA.
authors: Sajid
authors: S
authors: Jalil
authors: James J
authors: JJ
authors: Grady
authors: Chul
authors: C
authors: Lee
authors: Karl E
authors: KE
authors: Anderson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000437:Alcoholism / Q000150:complications; D001519:Behavior; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017119:Porphyria Cutanea Tarda / Q000209:etiology*; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D019966:Substance-Related Disorders / Q000150:complications; D055815:Young Adult