Biomaterial Database

Measurement of urinary porphyrins and porphyrin precursors in Dutch hospital laboratories: a review of quality control over 5 years. 2003

Floris M J Zuijderhoudt, and Cas W Weykamp, and Hans L Willems

Department of Clinical Chemistry, Deventer Hospital, 7400 GC Deventer, The Netherlands. zuijderf@wanadoo.nl

BACKGROUND We evaluated a quality control scheme for the measurement of urinary uroporphyrin, coproporphyrin, total urinary porphyrins and precursors of urinary porphyrins, delta-aminolevulinic acid and porphobilinogen that was performed in The Netherlands during a period of 5 years. METHODS Six quality control samples were distributed each year to the participating laboratories. Mean concentrations and the corresponding coefficients of variation were calculated. RESULTS Coefficients of variation varied widely and were very high in the concentration ranges that can be found in patients with low-grade porphyria. CONCLUSIONS Commutable calibrators are needed to improve the laboratory diagnosis of porphyria.

UI	MeSH Term	Description	Entries
D007755	Laboratories, Hospital	Hospital facilities equipped to carry out investigative procedures.	Hospital Laboratories,Hospital Laboratory,Laboratory, Hospital
D009426	Netherlands	Country located in EUROPE. It is bordered by the NORTH SEA, BELGIUM, and GERMANY. Constituent areas are Aruba, Curacao, and Sint Maarten, formerly included in the NETHERLANDS ANTILLES.	Holland,Kingdom of the Netherlands
D011162	Porphobilinogen
D011166	Porphyrins	A group of compounds containing the porphin structure, four pyrrole rings connected by methine bridges in a cyclic configuration to which a variety of side chains are attached. The nature of the side chain is indicated by a prefix, as uroporphyrin, hematoporphyrin, etc. The porphyrins, in combination with iron, form the heme component in biologically significant compounds such as hemoglobin and myoglobin.	Porphyrin
D011786	Quality Control	A system for verifying and maintaining a desired level of quality in a product or process by careful planning, use of proper equipment, continued inspection, and corrective action as required. (Random House Unabridged Dictionary, 2d ed)	Control, Quality,Controls, Quality,Quality Controls
D003306	Coproporphyrins	Porphyrins with four methyl and four propionic acid side chains attached to the pyrrole rings. Elevated levels of Coproporphyrin III in the urine and feces are major findings in patients with HEREDITARY COPROPORPHYRIA.
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000622	Aminolevulinic Acid	A compound produced from succinyl-CoA and GLYCINE as an intermediate in heme synthesis. It is used as a PHOTOCHEMOTHERAPY for actinic KERATOSIS.	5-Amino Levulinic Acid,5-Aminolaevulinate,5-Aminolevulinate,Aminolevulinic Acid Hydrochloride,Delta-Aminolevulinic Acid,Levulan,5 Amino Levulinic Acid,5 Aminolaevulinate,5 Aminolevulinate,Acid Hydrochloride, Aminolevulinic,Acid, 5-Amino Levulinic,Acid, Aminolevulinic,Acid, Delta-Aminolevulinic,Delta Aminolevulinic Acid,Hydrochloride, Aminolevulinic Acid,Levulinic Acid, 5-Amino
D012680	Sensitivity and Specificity	Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)	Specificity,Sensitivity,Specificity and Sensitivity
D014578	Uroporphyrins	Porphyrins with four acetic acid and four propionic acid side chains attached to the pyrrole rings.