{"id":"https://openalex.org/W7223867097","doi":"https://doi.org/10.20944/preprints202610.2574.v1","title":"Evidence for the Causal Involvement of Homocysteine in Long COVID and ME/CFS","display_name":"Evidence for the Causal Involvement of Homocysteine in Long COVID and ME/CFS","publication_year":2026,"publication_date":"2026-10-27","ids":{"openalex":"https://openalex.org/W7223867097","doi":"https://doi.org/10.20944/preprints202610.2574.v1"},"language":"en","primary_location":{"id":"doi:10.20944/preprints202610.2574.v1","doi":"https://doi.org/10.20944/preprints202610.2574.v1","is_oa":true,"landing_page_url":"https://doi.org/10.20944/preprints202610.2574.v1","pdf_url":null,"source":{"id":"https://openalex.org/S6309402219","display_name":"Preprints.org","issn_l":null,"issn":null,"is_oa":true,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":null,"host_organization_name":null,"host_organization_lineage":["https://openalex.org/P4310310987"],"host_organization_lineage_names":["Multidisciplinary Digital Publishing Institute"],"type":"repository"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"acceptedVersion","is_accepted":true,"is_published":false,"raw_source_name":null,"raw_type":"posted-content"},"volume":null,"type":"preprint","is_traditional":true,"indexed_in":["crossref"],"open_access":{"is_oa":true,"oa_status":"green","oa_url":"https://doi.org/10.20944/preprints202610.2574.v1","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5077370611","display_name":"Douglas Bruce Kell","orcid":"https://orcid.org/0000-0001-5838-7963","observed_orcids":["https://orcid.org/0000-0001-5838-7963"]},"institutions":[],"countries":[],"is_corresponding":true,"raw_author_name":"Douglas B. Kell","raw_affiliation_strings":[],"raw_orcid":"https://orcid.org/0000-0001-5838-7963","affiliations":[]},{"author_position":"last","author":{"id":"https://openalex.org/A5015696712","display_name":"Etheresia Pretorius","orcid":"https://orcid.org/0000-0002-9108-2384","observed_orcids":["https://orcid.org/0000-0002-9108-2384"]},"institutions":[],"countries":[],"is_corresponding":false,"raw_author_name":"Etheresia Pretorius","raw_affiliation_strings":[],"raw_orcid":"https://orcid.org/0000-0002-9108-2384","affiliations":[]}],"institutions":[],"countries_distinct_count":0,"institutions_distinct_count":0,"corresponding_author_ids":["https://openalex.org/A5077370611"],"corresponding_institution_ids":[],"apc_list":null,"apc_paid":null,"fwci":null,"has_fulltext":false,"cited_by_count":0,"citation_normalized_percentile":null,"cited_by_percentile_year":null,"biblio":{"volume":null,"issue":null,"first_page":null,"last_page":null},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T11368","display_name":"Long-Term Effects of COVID-19","score":0.9922000169754028,"subfield":{"id":"https://openalex.org/subfields/2728","display_name":"Clinical Neurology"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}},"topics":[{"id":"https://openalex.org/T11368","display_name":"Long-Term Effects of COVID-19","score":0.9922000169754028,"subfield":{"id":"https://openalex.org/subfields/2728","display_name":"Clinical Neurology"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}},{"id":"https://openalex.org/T10499","display_name":"Folate and B Vitamins Research","score":0.004900000058114529,"subfield":{"id":"https://openalex.org/subfields/2916","display_name":"Nutrition and Dietetics"},"field":{"id":"https://openalex.org/fields/29","display_name":"Nursing"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}},{"id":"https://openalex.org/T11282","display_name":"Fibromyalgia and Chronic Fatigue Syndrome Research","score":0.0010000000474974513,"subfield":{"id":"https://openalex.org/subfields/2738","display_name":"Psychiatry and Mental health"},"field":{"id":"https://openalex.org/fields/27","display_name":"Medicine"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/homocysteine","display_name":"homocysteine","score":0.9419999718666077},{"id":"https://openalex.org/keywords/long-covid","display_name":"long COVID","score":0.8199999928474426},{"id":"https://openalex.org/keywords/chronic-fatigue-syndrome","display_name":"chronic fatigue syndrome","score":0.9829999804496765},{"id":"https://openalex.org/keywords/hyperhomocysteinemia","display_name":"hyperhomocysteinemia","score":0.9639999866485596},{"id":"https://openalex.org/keywords/homocysteine-thiolactone","display_name":"homocysteine thiolactone","score":0.9909999966621399},{"id":"https://openalex.org/keywords/n-homocysteinylation","display_name":"N-homocysteinylation","score":0.8920000195503235},{"id":"https://openalex.org/keywords/methionine-metabolism","display_name":"methionine metabolism","score":0.9660000205039978},{"id":"https://openalex.org/keywords/b-vitamins","display_name":"B vitamins","score":0.9169999957084656},{"id":"https://openalex.org/keywords/post-exertional-malaise","display_name":"post-exertional malaise","score":0.8809999823570251},{"id":"https://openalex.org/keywords/fatigue","display_name":"fatigue","score":0.5920000076293945},{"id":"https://openalex.org/keywords/endothelial-dysfunction","display_name":"endothelial dysfunction","score":0.7850000262260437},{"id":"https://openalex.org/keywords/microvascular-dysfunction","display_name":"microvascular dysfunction","score":0.578000009059906},{"id":"https://openalex.org/keywords/brain-fog","display_name":"brain fog","score":0.4880000054836273},{"id":"https://openalex.org/keywords/postural-orthostatic-tachycardia-syndrome","display_name":"postural orthostatic tachycardia syndrome","score":0.8849999904632568},{"id":"https://openalex.org/keywords/small-fiber-neuropathy","display_name":"small fiber neuropathy","score":0.7889999747276306},{"id":"https://openalex.org/keywords/fibromyalgia","display_name":"fibromyalgia","score":0.8019999861717224},{"id":"https://openalex.org/keywords/sleep-disturbance","display_name":"sleep disorders","score":0.6039999723434448},{"id":"https://openalex.org/keywords/dyspnea","display_name":"dyspnea","score":0.8080000281333923}],"concepts":[{"id":"https://openalex.org/C2777090595","wikidata":"https://www.wikidata.org/wiki/Q192466","display_name":"Homocysteine","level":2,"score":0.8741999864578247},{"id":"https://openalex.org/C71924100","wikidata":"https://www.wikidata.org/wiki/Q11190","display_name":"Medicine","level":0,"score":0.6521999835968018},{"id":"https://openalex.org/C2780912031","wikidata":"https://www.wikidata.org/wiki/Q180341","display_name":"Methionine","level":3,"score":0.5022000074386597},{"id":"https://openalex.org/C2778322612","wikidata":"https://www.wikidata.org/wiki/Q907001","display_name":"Thiolactone","level":2,"score":0.38989999890327454},{"id":"https://openalex.org/C2780972559","wikidata":"https://www.wikidata.org/wiki/Q550061","display_name":"Endothelial dysfunction","level":2,"score":0.3772999942302704},{"id":"https://openalex.org/C3008058167","wikidata":"https://www.wikidata.org/wiki/Q84263196","display_name":"Coronavirus disease 2019 (COVID-19)","level":4,"score":0.3698999881744385},{"id":"https://openalex.org/C60644358","wikidata":"https://www.wikidata.org/wiki/Q128570","display_name":"Bioinformatics","level":1,"score":0.3472999930381775},{"id":"https://openalex.org/C126322002","wikidata":"https://www.wikidata.org/wiki/Q11180","display_name":"Internal medicine","level":1,"score":0.325300008058548},{"id":"https://openalex.org/C2779483572","wikidata":"https://www.wikidata.org/wiki/Q83030","display_name":"Dementia","level":3,"score":0.32350000739097595},{"id":"https://openalex.org/C2776035688","wikidata":"https://www.wikidata.org/wiki/Q1606558","display_name":"Affect (linguistics)","level":2,"score":0.3208000063896179},{"id":"https://openalex.org/C2779624417","wikidata":"https://www.wikidata.org/wiki/Q7104932","display_name":"Orthostatic intolerance","level":4,"score":0.3179999887943268},{"id":"https://openalex.org/C2994227525","wikidata":"https://www.wikidata.org/wiki/Q456026","display_name":"Vascular tone","level":3,"score":0.31779998540878296},{"id":"https://openalex.org/C3007834351","wikidata":"https://www.wikidata.org/wiki/Q82069695","display_name":"Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)","level":5,"score":0.30640000104904175},{"id":"https://openalex.org/C50440223","wikidata":"https://www.wikidata.org/wiki/Q1475848","display_name":"Risk factor","level":2,"score":0.2930999994277954},{"id":"https://openalex.org/C3006700255","wikidata":"https://www.wikidata.org/wiki/Q81068910","display_name":"2019-20 coronavirus outbreak","level":3,"score":0.2786000072956085},{"id":"https://openalex.org/C203014093","wikidata":"https://www.wikidata.org/wiki/Q101929","display_name":"Immunology","level":1,"score":0.2784000039100647},{"id":"https://openalex.org/C177713679","wikidata":"https://www.wikidata.org/wiki/Q679690","display_name":"Intensive care medicine","level":1,"score":0.27070000767707825},{"id":"https://openalex.org/C2779753318","wikidata":"https://www.wikidata.org/wiki/Q160796","display_name":"Delirium","level":2,"score":0.25619998574256897},{"id":"https://openalex.org/C134018914","wikidata":"https://www.wikidata.org/wiki/Q162606","display_name":"Endocrinology","level":1,"score":0.2547000050544739},{"id":"https://openalex.org/C169760540","wikidata":"https://www.wikidata.org/wiki/Q207011","display_name":"Neuroscience","level":1,"score":0.25360000133514404},{"id":"https://openalex.org/C2779134260","wikidata":"https://www.wikidata.org/wiki/Q12136","display_name":"Disease","level":2,"score":0.2531000077724457},{"id":"https://openalex.org/C2779901536","wikidata":"https://www.wikidata.org/wiki/Q945238","display_name":"Peripheral neuropathy","level":3,"score":0.25040000677108765}],"mesh":[],"locations_count":1,"locations":[{"id":"doi:10.20944/preprints202610.2574.v1","doi":"https://doi.org/10.20944/preprints202610.2574.v1","is_oa":true,"landing_page_url":"https://doi.org/10.20944/preprints202610.2574.v1","pdf_url":null,"source":{"id":"https://openalex.org/S6309402219","display_name":"Preprints.org","issn_l":null,"issn":null,"is_oa":true,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":null,"host_organization_name":null,"host_organization_lineage":["https://openalex.org/P4310310987"],"host_organization_lineage_names":["Multidisciplinary Digital Publishing Institute"],"type":"repository"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"acceptedVersion","is_accepted":true,"is_published":false,"raw_source_name":null,"raw_type":"posted-content"}],"best_oa_location":{"id":"doi:10.20944/preprints202610.2574.v1","doi":"https://doi.org/10.20944/preprints202610.2574.v1","is_oa":true,"landing_page_url":"https://doi.org/10.20944/preprints202610.2574.v1","pdf_url":null,"source":{"id":"https://openalex.org/S6309402219","display_name":"Preprints.org","issn_l":null,"issn":null,"is_oa":true,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":null,"host_organization_name":null,"host_organization_lineage":["https://openalex.org/P4310310987"],"host_organization_lineage_names":["Multidisciplinary Digital Publishing Institute"],"type":"repository"},"license":"cc-by","license_id":"https://openalex.org/licenses/cc-by","version":"acceptedVersion","is_accepted":true,"is_published":false,"raw_source_name":null,"raw_type":"posted-content"},"sustainable_development_goals":[{"id":"https://metadata.un.org/sdg/3","score":1.0,"display_name":"Good health and well-being"}],"study_designs":[],"awards":[],"funders":[],"has_content":{"grobid_xml":false,"pdf":false},"content_urls":null,"referenced_works_count":0,"referenced_works":[],"related_works":["https://openalex.org/W4366245962","https://openalex.org/W4386728197","https://openalex.org/W4360602954","https://openalex.org/W4380901838","https://openalex.org/W4407418070","https://openalex.org/W4379233222","https://openalex.org/W4396675411","https://openalex.org/W1940298872","https://openalex.org/W7125473135","https://openalex.org/W4214880569"],"abstract_inverted_index":{"Long":[0],"COVID":[1],"(LC)":[2],"and":[3,25,40,51,53,106,120,137,144],"ME/CFS":[4],"affect":[5],"many":[6],"millions":[7],"of":[8,15,82,99,124,132,135],"individuals,":[9],"yet":[10],"a":[11,59,73,130],"satisfactory":[12],"mechanistic":[13],"explanation":[14],"their":[16],"diverse":[17],"manifestations":[18,134],"remains":[19],"elusive.":[20],"Common":[21],"symptoms":[22],"are":[23],"wide-ranging":[24],"include":[26],"fatigue,":[27],"post-exertional":[28],"malaise,":[29],"cognitive":[30],"impairment":[31],"(\u2018brain":[32],"fog\u2019),":[33],"Postural":[34],"Orthostatic":[35],"Tachycardia":[36],"Syndrome":[37],"(POTS),":[38],"microvascular":[39],"endothelial":[41],"dysfunction,":[42],"exercise":[43],"intolerance,":[44],"sleep":[45],"disturbances,":[46],"fibromyalgia,":[47],"dyspnoea,":[48],"small-fibre":[49],"neuropathy":[50],"hearing":[52],"olfactory":[54],"disorders.":[55],"Homocysteine":[56],"(Hcy)":[57],"is":[58],"non-proteinogenic,":[60],"sulphur-containing":[61],"amino":[62],"acid":[63],"generated":[64],"during":[65],"methionine":[66],"metabolism,":[67],"that":[68,75,110],"can":[69,90],"be":[70],"converted":[71],"to":[72,116,127],"thiolactone":[74,118],"will":[76],"react":[77],"with":[78],"the":[79,108,121,133],"e-amino":[80],"groups":[81],"protein":[83],"lysine":[84],"residues":[85],"causing":[86],"widespread":[87],"dysfunction.":[88],"Hyperhomocysteinaemia":[89],"arise":[91],"from":[92],"genetic":[93],"causes":[94],"or":[95],"through":[96],"an":[97],"inadequacy":[98],"certain":[100],"B":[101],"vitamins.":[102],"We":[103],"here":[104],"develop":[105],"evidence":[107],"hypothesis":[109],"raised":[111],"homocysteine":[112,117],"(Hcy),":[113],"its":[114],"conversion":[115],"(HTL),":[119],"consequent":[122],"N-homocysteinylation":[123],"proteins":[125],"contribute":[126],"at":[128],"least":[129],"subset":[131],"LC":[136],"ME/CFS.":[138],"This":[139],"has":[140],"both":[141],"testable":[142],"predictions":[143],"therapeutic":[145],"consequences.":[146]},"counts_by_year":[],"updated_date":"2026-11-04T10:54:05.112534","created_date":"2026-10-28T00:00:00"}
