title: Regional Variation in Analytical Techniques used in the Diagnosis and Monitoring of Porphyria: a Case for Harmonisation?
abstract: BACKGROUND
  The Royal College of Pathologists of Australasia (RCPA) Porphyrin Quality Assurance Program assesses the measurement of urine, faecal, plasma and whole blood porphyrins and their components plus urinary porphobilinogen and delta aminolaevulinic acid and has laboratories enrolled from around the world. It was observed that there was a wide scatter in results submitted to some subsections of the program.
  
  
  METHODS
  A detailed questionnaire covering the analytical techniques used in the diagnosis of porphyria was sent to all laboratories enrolled in the RCPA Porphyrin Quality Assurance Program. Additionally, self-enrolment data over a five year period was examined for trends/changes in standardisation, reagent sources and analytical technique.
  
  
  RESULTS
  Twenty of the 45 laboratories enrolled in the Porphyrin Quality Assurance Program completed the survey, providing a snapshot of the analytical techniques used world-wide. Post survey self enrolment data indicated only little or no noticeable changes to analytical standardisation of techniques despite the continual lack of agreement of results in subsections of the External Quality Assurance program.
  
  
  CONCLUSIONS
  While some aspects of porphyria testing are relatively consistent between laboratories, other diagnostic techniques vary widely. A wide variety of individualised reference intervals and reporting techniques is currently in use world-wide. While most of the participants in the survey are regional reference centres specialising in the diagnosis of porphyria and, as such, their diagnostic capability is not in question, international guidelines or global harmonisation of analytical techniques should allow better inter-laboratory comparisons to be made, ultimately improving diagnostic accuracy.
authors.affiliation: Clinical Biochemistry, Canterbury Health Laboratories, Christchurch, New Zealand;
authors.forename: Christiaan W
authors.initials: CW
authors.lastname: Sies
authors.affiliation: Biochemistry Department, Royal Melbourne Hospital, Melbourne, Australia;
authors.forename: Virginia
authors.initials: V
authors.lastname: Cronin
authors.affiliation: Clinical Biochemistry, Canterbury Health Laboratories, Christchurch, New Zealand;
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Florkowski
authors.affiliation: Royal College of Pathologists of Australasia (RCPA) Quality Assurance Programs Pty Ltd. Adelaide, Australia;
authors.forename: Jan
authors.initials: J
authors.lastname: Gill
authors.affiliation: Biochemistry Department, Royal Melbourne Hospital, Melbourne, Australia;
authors.forename: Janine
authors.initials: J
authors.lastname: Grant
authors.affiliation: Biochemistry Department, Royal Prince Alfred Hospital, Camperdown, Australia;
authors.forename: Victor
authors.initials: V
authors.lastname: Poulos
authors.affiliation: SA Pathology, Adelaide, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Zoanetti