title: Pulmonary arterial hypertension associated with interferon therapy: a population-based study.
abstract: BACKGROUND
  Isolated cases of pulmonary arterial hypertension (PAH) with interferon α or β therapy have been reported, but no population-based estimates of the incidence of the disease after interferon exposure are available. The aim of this study was to determine the incidence of PAH after initiation of interferon therapy, using a large commercial insurance database.
  
  
  METHODS
  Using National Drug Codes (NDCs) and Healthcare Common Procedure Coding System (HCPCS) codes, we utilized the Clinformatics™ Data Mart (CDM) database to identify subjects between 20 and 65 years old who received α or β interferon therapy between April 2001 and December 2012. Patients were followed from one year prior to the first medication claim for interferon to the first diagnosis of pulmonary hypertension using ICD-9-CM codes 416.0 and 416.8, or disenrollment. In those subjects diagnosed with pulmonary hypertension, a prescription for PAH-specific medications was used as a surrogate endpoint.
  
  
  RESULTS
  We identified 20,113 subjects who received interferon therapy during the study period. The median follow-up was 20 months. Pulmonary hypertension occurred in 71 subjects, and PAH-specific medications were prescribed to 7 of these subjects.
  
  
  CONCLUSIONS
  Although our analysis showed that the development of PAH is a rare event with interferon therapy, the risk of developing the disease is several fold higher than that for the general population.
authors.affiliation: Division of Pulmonary, Critical Care and Sleep Medicine, University of Texas Medical Branch, John Sealy Annex 5.140, 301 University Boulevard, Galveston, TX 77555 USA.
authors.forename: Ravikanth
authors.identifier: 0000-0002-5384-9150
authors.initials: R
authors.lastname: Papani
authors.affiliation: Division of Pulmonary, Critical Care and Sleep Medicine, University of Texas Medical Branch, John Sealy Annex 5.140, 301 University Boulevard, Galveston, TX 77555 USA.
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Duarte
authors.affiliation: Office of Biostatistics, Department of Preventive Medicine and Community Health, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX USA.
authors.forename: Yu-Li
authors.initials: YL
authors.lastname: Lin
authors.affiliation: Office of Biostatistics, Department of Preventive Medicine and Community Health, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX USA.
authors.forename: Yong-Fang
authors.initials: YF
authors.lastname: Kuo
authors.affiliation: Division of Pulmonary, Critical Care and Sleep Medicine, University of Texas Medical Branch, John Sealy Annex 5.140, 301 University Boulevard, Galveston, TX 77555 USA.
authors.forename: Gulshan
authors.initials: G
authors.lastname: Sharma
keywords: Drug toxicity; Interferons; Pulmonary arterial hypertension