{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,16]],"date-time":"2026-04-16T13:55:17Z","timestamp":1776347717660,"version":"3.51.2"},"reference-count":11,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2020,2,10]],"date-time":"2020-02-10T00:00:00Z","timestamp":1581292800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>Sulfhemoglobinemia is a rare entity caused by irreversible sulfation of the heme moiety in haemoglobin to form sulfated haemoglobin (SulfHb) and has been caused by H2S arising from certain metabolites of drugs and bacterial infection. Clinical presentation is similar to that of methemoglobin (MetHb). Furthermore, it is often difficult to distinguish between the diagnosis of SulfHb from MetHb in arterial blood gas analysers due to the broad overlap in the optical density (OD) absorption spectra\u2014that of SulfHb swamping the more distinct OD absorption shift seen with MetHb. The presence of SulfHb was suspected in a 73-year-old lady with low oxygen saturation (SaO2 ~75%), central cyanosis, and normal arterial oxygen partial pressure (pO2 ~12 kPa). Repeated arterial blood gas analysis on different systems returned error messages for MetHb quantification. There was an improvement in oxygen saturation and cyanosis after an exchange transfusion. A full OD spectrophotometry (500\u2013700 nm) of the patient\u2019s whole blood was suggestive of the presence of SulfHb, with a minor peak absorption at 620 nm. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-ToF MS) was undertaken on whole blood samples from the patient pre- and post-transfusion, alongside normal controls. These demonstrated the presence of SulfHb in the patient\u2019s blood, identifying sulfur, sulfur monoxide, and sulfur dioxide bound to the heme moiety. This gave vital identification as to the cause of Hb sulfation, which was distinct from that previously reported. Levels fell after the exchange transfusion and were completely eradicated after the correct source, an Epsom Salts constipation tonic, was identified. MALDI-ToF mass spectrometry is a new, rapid, specific, and sensitive diagnostic test for rare hematological syndromes such as SulfHb. In addition, it can identify the specific compounds bound to heme. Here, we provide useful diagnostic evidence as to the source of SulfHb, which was via SO2 rather than the previously described H2S.<\/jats:p>","DOI":"10.3390\/diagnostics10020094","type":"journal-article","created":{"date-parts":[[2020,2,11]],"date-time":"2020-02-11T09:25:21Z","timestamp":1581413121000},"page":"94","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["The Diagnosis of Sulfated Hemoglobin (SulfHb) Secondary to Sulfur Dioxide Poisoning Using Matrix-Assisted Laser Desorption Time-of-Flight Mass Spectrometry (MALDI-ToF MS)\u2014A Novel Approach to an Unusual Clinical Problem"],"prefix":"10.3390","volume":"10","author":[{"given":"Suzanne","family":"Docherty","sequence":"first","affiliation":[{"name":"Department of Haematology, Norfolk &amp; Norwich University Hospital Foundation NHS Trust UK, Norwich NR4 7UY, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Raminta","family":"Zmuidinaite","sequence":"additional","affiliation":[{"name":"MAP Sciences, Bedford UK, Bedford MK44 3RZ, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"James","family":"Coulson","sequence":"additional","affiliation":[{"name":"School of Medicine, Cardiff University UK, Cardiff CF10 3AT, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Martin","family":"Besser","sequence":"additional","affiliation":[{"name":"Department of Haematology, Cambridge University Hospitals NHS Trust UK, Cambridge CB2 0QQ, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0573-9739","authenticated-orcid":false,"given":"Ray","family":"Iles","sequence":"additional","affiliation":[{"name":"MAP Sciences, Bedford UK, Bedford MK44 3RZ, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,2,10]]},"reference":[{"key":"ref_1","unstructured":"Shelton, D., Dashi, G., Cheung, M., and Sindall, T. (2019). Case Report of Methemoglobinemia: An Illustration That It Is Time to Report all Results with Arterial and Venous Blood Gas Result Reporting. J. Emerg. Med., pii: S0736-4679(19)30807-30808."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"392","DOI":"10.1097\/PAT.0000000000000258","article-title":"Co-oximetry interference","volume":"47","author":"Chan","year":"2015","journal-title":"Pathology"},{"key":"ref_3","unstructured":"Iles, R.K., Iles, J.K., Abban, T., Docherty, S.M., and Nasse, M. (2019). Method for Detecting Abnormalities in Hemoglobin. (2016\/030688), WO Patent."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Pais, R.J., Jardine, C., Zmuidinaite, R., Lacey, J., Butler, S., and Iles, R. (2019). Rapid, Affordable and Efficient Screening of Multiple Blood Abnormalities Made Possible Using an Automated Tool for MALDI-ToF Spectrometry Analysis. Appl. Sci., 9.","DOI":"10.3390\/app9234999"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"803","DOI":"10.1001\/archpedi.152.8.803","article-title":"Pseudomethaemoglobinemia: A Case Report and Review of Sulphaemoglobinemia","volume":"152","author":"Lu","year":"1998","journal-title":"Arch. Pediatr. Adolesc. Med."},{"key":"ref_6","first-page":"21","article-title":"A case of sulfhemoglobinemia in a child with chronic constipation","volume":"21","author":"George","year":"2017","journal-title":"Respir. Med. Case Rep."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"e1641","DOI":"10.1542\/peds.2015-0996","article-title":"Neonatal Sulfhemoglobinemia and Hemolytic Anemia Associated with Intestinal Morganella morganii","volume":"136","author":"Murphy","year":"2015","journal-title":"Pediatrics"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1098","DOI":"10.1093\/clinchem\/43.6.1098","article-title":"Pitfalls in Discriminating Sulphaemoglobin from Methemglobin","volume":"43","author":"Demedts","year":"1997","journal-title":"Clin. Chem."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1693","DOI":"10.1093\/clinchem\/39.8.1693","article-title":"Measurement of carboxyhaemoglobin and total haemoglobin by five specialized spectrophotometers (CO-oximeters) in comparison with reference methods","volume":"39","author":"Mahoney","year":"1993","journal-title":"Clin. Chem."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1579","DOI":"10.1056\/NEJM198406143102407","article-title":"Sulphaemoglobinemia\u2014Clinical and molecular aspects","volume":"310","author":"Park","year":"1984","journal-title":"N. Engl. J. Med."},{"key":"ref_11","first-page":"433","article-title":"Einwirkung des Schwefelwasserstoffgases auf das Blut","volume":"28","year":"1863","journal-title":"Centr. Med. Wiss."}],"container-title":["Diagnostics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-4418\/10\/2\/94\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T08:56:31Z","timestamp":1760172991000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-4418\/10\/2\/94"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,2,10]]},"references-count":11,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2020,2]]}},"alternative-id":["diagnostics10020094"],"URL":"https:\/\/doi.org\/10.3390\/diagnostics10020094","relation":{},"ISSN":["2075-4418"],"issn-type":[{"value":"2075-4418","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,2,10]]}}}