{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,19]],"date-time":"2026-02-19T11:31:29Z","timestamp":1771500689622,"version":"3.50.1"},"reference-count":13,"publisher":"BMJ","issue":"3","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["J Clin Pathol"],"accepted":{"date-parts":[[2025,10,11]]},"published-print":{"date-parts":[[2026,3]]},"abstract":"<jats:p>Diagnosing and identifying the type of porphyria in a patient requires specialist analysis of porphyrins and\/or precursors in blood, urine and faeces. Correct sample storage and handling prior to analysis is essential to minimise preanalytical error.<\/jats:p>\n                  <jats:p>We evaluated the impact of light exposure, time and temperature on erythrocyte and plasma porphyrins in samples from patients with erythropoietic protoporphyria (EPP) and porphyria cutanea tarda (PCT) stored as whole blood for up to 96\u2009hours, and in addition, the effect of freeze-thaw on plasma porphyrins in EPP, PCT and hereditary coproporphyria patient samples.<\/jats:p>\n                  <jats:p>Plasma porphyrins in the EPP patient samples decreased on average by 19% after 6\u2009hours despite light protection and fridge storage, 36% by 24\u2009hours stored light protected at room temperature, 67% within 1\u2009hour when light exposed and 33% after one freeze-thaw cycle. In contrast, plasma porphyrin in PCT samples demonstrated greater stability compared to the EPP samples when stored light protected or exposed at room temperature and during freeze-thaw. Erythrocyte porphyrins in EPP samples were stable for 96\u2009hours under all three storage conditions examined.<\/jats:p>\n                  <jats:p>Erythrocyte protoporphyrin analysis should be undertaken as an additional first-line investigation alongside plasma porphyrin analysis whenever protoporphyria needs to be excluded, due to the significant instability of plasma protoporphyrin.<\/jats:p>","DOI":"10.1136\/jcp-2025-210393","type":"journal-article","created":{"date-parts":[[2025,10,29]],"date-time":"2025-10-29T17:25:50Z","timestamp":1761758750000},"page":"206-211","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["Stability of plasma and erythrocyte porphyrins: implications for diagnosis and monitoring of erythropoietic protoporphyria"],"prefix":"10.1136","volume":"79","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2494-428X","authenticated-orcid":false,"given":"Danja","family":"Schulenburg-Brand","sequence":"first","affiliation":[{"name":"Cardiff Porphyria Service, University Hospital of Wales, Cardiff, UK"},{"name":"Department of Haematology, Immunology and Metabolic Medicine, Cardiff and Vale University Health Board, Cardiff, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Katie","family":"Maw","sequence":"additional","affiliation":[{"name":"Cardiff Porphyria Service, University Hospital of Wales, Cardiff, UK"},{"name":"Department of Haematology, Immunology and Metabolic Medicine, Cardiff and Vale University Health Board, Cardiff, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lucy-Anne","family":"Bentley","sequence":"additional","affiliation":[{"name":"Cardiff Porphyria Service, University Hospital of Wales, Cardiff, UK"},{"name":"Department of Medical Biochemistry, Immunology and Toxicology, Cardiff and Vale University Health Board, Cardiff, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rhiannon","family":"Challenger","sequence":"additional","affiliation":[{"name":"Cardiff Porphyria Service, University Hospital of Wales, Cardiff, UK"},{"name":"Department of Medical Biochemistry, Immunology and Toxicology, Cardiff and Vale University Health Board, Cardiff, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Martyn","family":"Jones","sequence":"additional","affiliation":[{"name":"Cardiff Porphyria Service, University Hospital of Wales, Cardiff, UK"},{"name":"Department of Medical Biochemistry, Immunology and Toxicology, Cardiff and Vale University Health Board, Cardiff, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-3938-5441","authenticated-orcid":false,"given":"Claire Joanne","family":"Gallagher","sequence":"additional","affiliation":[{"name":"Cardiff Porphyria Service, University Hospital of Wales, Cardiff, UK"},{"name":"Department of Medical Biochemistry, Immunology and Toxicology, Cardiff and Vale University Health Board, Cardiff, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2025,10,29]]},"reference":[{"key":"2026021902550846000_79.3.206.1","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(09)61925-5"},{"key":"2026021902550846000_79.3.206.2","doi-asserted-by":"crossref","DOI":"10.1111\/liv.16012","article-title":"Practical recommendations for biochemical and genetic diagnosis of the porphyrias","volume":"45","author":"Aarsand","year":"2025","journal-title":"Liver Int"},{"key":"2026021902550846000_79.3.206.3","doi-asserted-by":"crossref","first-page":"356","DOI":"10.1016\/0304-4165(71)90330-8","article-title":"Porphyrin stability as a function of the number of carboxylic acid side chains","volume":"237","author":"Doss","year":"1971","journal-title":"Biochimica et Biophysica Acta (BBA) - General Subjects"},{"key":"2026021902550846000_79.3.206.4","doi-asserted-by":"crossref","first-page":"753","DOI":"10.1093\/clinchem\/20.7.753","article-title":"Comparison of four methods for determination of delta-aminolevulinic acid in urine, and evaluation of critical factors","volume":"20","author":"Roels","year":"1974","journal-title":"Clin Chem"},{"key":"2026021902550846000_79.3.206.5","doi-asserted-by":"crossref","first-page":"612","DOI":"10.1093\/clinchem\/16.7.612","article-title":"The preservation of urine specimens for delta-aminolevulinic acid determination","volume":"16","author":"Vincent","year":"1970","journal-title":"Clin Chem"},{"key":"2026021902550846000_79.3.206.6","doi-asserted-by":"publisher","DOI":"10.1111\/1523-1747.ep12687961"},{"key":"2026021902550846000_79.3.206.7","doi-asserted-by":"publisher","DOI":"10.1111\/1523-1747.ep12674138"},{"key":"2026021902550846000_79.3.206.8","doi-asserted-by":"publisher","DOI":"10.1016\/0009-8981(83)90010-4"},{"key":"2026021902550846000_79.3.206.9","doi-asserted-by":"publisher","DOI":"10.1136\/jcp-2024-209443"},{"key":"2026021902550846000_79.3.206.10","doi-asserted-by":"publisher","DOI":"10.1001\/archderm.1980.01640290053010"},{"key":"2026021902550846000_79.3.206.11","doi-asserted-by":"crossref","first-page":"264","DOI":"10.1093\/clinchem\/23.2.264","article-title":"Free erythrocyte porphyrins in the detection of undue absorption of Pb and of Fe deficiency","volume":"23","author":"Piomelli","year":"1977","journal-title":"Clin Chem"},{"key":"2026021902550846000_79.3.206.12","doi-asserted-by":"crossref","first-page":"1585","DOI":"10.1093\/clinchem\/23.9.1585","article-title":"Improved ethanol extraction procedure for determining zinc protoporphyrin in whole blood","volume":"23","author":"Garden","year":"1977","journal-title":"Clin Chem"},{"key":"2026021902550846000_79.3.206.13","doi-asserted-by":"publisher","DOI":"10.1515\/CCLM.2011.733"}],"container-title":["Journal of Clinical Pathology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/jcp-2025-210393","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,2,19]],"date-time":"2026-02-19T10:55:38Z","timestamp":1771498538000},"score":1,"resource":{"primary":{"URL":"https:\/\/jcp.bmj.com\/lookup\/doi\/10.1136\/jcp-2025-210393"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,10,29]]},"references-count":13,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2026,2,19]]},"published-print":{"date-parts":[[2026,3]]}},"alternative-id":["10.1136\/jcp-2025-210393"],"URL":"https:\/\/doi.org\/10.1136\/jcp-2025-210393","relation":{},"ISSN":["0021-9746","1472-4146"],"issn-type":[{"value":"0021-9746","type":"print"},{"value":"1472-4146","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,10,29]]}}}