{"id":7800,"date":"2021-12-15T10:00:00","date_gmt":"2021-12-15T15:00:00","guid":{"rendered":"https:\/\/transfusionontario.org\/?p=7800"},"modified":"2024-07-17T10:54:11","modified_gmt":"2024-07-17T14:54:11","slug":"decembre-2021","status":"publish","type":"post","link":"https:\/\/transfusionontario.org\/fr\/decembre-2021\/","title":{"rendered":"Qu\u2019en est-il du traitement par plasma convalescent?"},"content":{"rendered":"\n

Dana V. Devine, PhD, scientifique principale, Soci\u00e9t\u00e9 canadienne du sang, et directrice, UBC Centre for Blood Research\r\n\r\nLe recours au plasma d\u2019une personne ayant gu\u00e9ri d\u2019une maladie pour traiter des patients aux premiers stades de la m\u00eame maladie n\u2019est pas un nouveau concept. Notre compr\u00e9hension du syst\u00e8me immunitaire a men\u00e9 au d\u00e9veloppement de cette approche au d\u00e9but des ann\u00e9es 1900; l\u2019emploi de plasma convalescent pour traiter des patients atteints de la grippe pendant la pand\u00e9mie de 1918 \u00e9tait assez courant [1]. De nombreux essais cliniques ont \u00e9t\u00e9 organis\u00e9s autour du monde, notamment au Canada, pour tenter de d\u00e9terminer si cette approche pouvait servir \u00e0 traiter la COVID-19. L\u2019essai CONCOR-1 visait \u00e0 comparer l\u2019efficacit\u00e9 du plasma de patients ayant gu\u00e9ri de la COVID (plasma convalescent) \u00e0 celle de traitements usuels [2]. Cet essai a \u00e9t\u00e9 interrompu pr\u00e9matur\u00e9ment et qualifi\u00e9 de futile, quand les chercheurs ont constat\u00e9 que l\u2019\u00e9tude ne parviendrait pas \u00e0 atteindre son seuil statistique [3]. L\u2019\u00e9tude internationale REMAP CAP qui recrutait des patients aux soins intensifs a \u00e9t\u00e9 arr\u00eat\u00e9e pour la m\u00eame raison [4]. Les \u00e9tudes qui font \u00e9tat d\u2019un certain succ\u00e8s se caract\u00e9risent par un recours tr\u00e8s pr\u00e9coce au plasma convalescent et \u00e0 un produit dot\u00e9 d\u2019une concentration \u00e9lev\u00e9e en anticorps neutralisant le virus [5].   Il ne faut pas s\u2019en \u00e9tonner puisque nous savons que la r\u00e9ponse immune typique \u00e0 un pathog\u00e8ne (ou vaccin) survient en 5 jours \u00e0 peu pr\u00e8s. L\u2019emploi de plasma convalescent pourrait de fait nuire \u00e0 certains patients en cr\u00e9ant une r\u00e9action immunitaire forte susceptible d\u2019aggraver la maladie [3]. L\u2019\u00e9tude am\u00e9ricaine C3PO a aussi montr\u00e9 que le traitement de patients au moyen de plasma convalescent avant leur hospitalisation, mais dans les 7 jours suivant l\u2019apparition des sympt\u00f4mes n\u2019avait que peu d\u2019effet sur l\u2019\u00e9volution de la maladie [6].<\/p>\n\n\n\n

De m\u00eame, les essais cliniques pr\u00e9liminaires portant sur les immunoglobulines hyperimmunes isol\u00e9es de plasma convalescent ont \u00e9t\u00e9 d\u00e9cevants, et la plupart ont \u00e9t\u00e9 interrompus. Encore une fois, c\u2019est probablement li\u00e9 davantage au moment o\u00f9 le patient a re\u00e7u le produit. <\/p>\n\n\n\n

Le plasma convalescent pourrait encore aider une certaine population de patients, \u00e0 savoir ceux qui ne produisent pas de r\u00e9action immunitaire robuste parce qu\u2019ils sont immunod\u00e9prim\u00e9s, soit en raison d\u2019une maladie sous-jacente ou de la prise de m\u00e9dicaments immunosuppresseurs apr\u00e8s une greffe d\u2019organe, par exemple. Nous devrions savoir sous peu s\u2019il s\u2019agit de la population cible d\u2019un traitement par plasma convalescent ou si nous devons \u00e9laborer des strat\u00e9gies d\u2019identification beaucoup plus pr\u00e9coce des patients dans l\u2019\u00e9volution de leur maladie.<\/p>\n\n\n\n

R\u00e9f\u00e9rences :\r\n<\/p>\n\n\n\n

1.  Luke TC, Kilbane EM, Jackson JL et coll. Meta-Analysis: Convalescent Blood Products for Spanish Influenza Pneumonia: A Future H5N1 Treatment?  Ann. Intern. Med. 2006;145:599-609. <\/p>\n\n\n\n

2. B\u00e9gin P, Callum J, Heddle NM et coll. Convalescent plasma for adults with acute COVID-19 respiratory illness (CONCOR-1): study protocol for an international, multicentre, randomized, open-label trial. Trials. 2021 May 4;22(1):323 <\/p>\n\n\n\n

3.  B\u00e9gin P, Callum J, Jamula E et coll.  Convalescent plasma for hospitalized patients with COVID-19: an open-label, randomized controlled trial. Nature Medicine 2021 Sep 9. doi: 10.1038\/s41591-021-01488-2. En ligne avant publication. <\/p>\n\n\n\n

4.   Estcourt LJ, Turgeon AF, McQuilten ZK et coll.  Effect of Convalescent Plasma on Organ Support-Free Days in Critically Ill Patients With COVID-19: A Randomized Clinical Trial. JAMA 2021 Oct 4;e2118178. doi\u202f: 10.1001\/jama.2021.18178. En ligne avant publication.  <\/p>\n\n\n\n

5.  Libster R, Marc GP, Wappner D et coll. Early High-Titer Plasma Therapy to Prevent Severe Covid-19 in Older Adults. N Engl J Med 2021 Feb 18;384(7):610-618 <\/p>\n\n\n\n

6.  Korley FK, Durkalski-Mauldin V, Yeatts SD et coll. Early Convalescent Plasma for High-Risk Outpatients with Covid-19.   N Engl J Med 2021 DOI: 10.1056\/NEJMoa2103784. En ligne avant publication.  <\/p>\n\n\n\n

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Universit\u00e9 de Toronto Transfusion Medicine Rounds<\/h2>\n\n\n\n

16 d\u00e9cembre 2021 \u00e0 12h00 \u2013 13h00<\/p>\n\n\n\n

MLT Session: Challenging Serology Cases, presented by Ms. Minda Agpalo, Dr. Waseem Anani, Dr. Celina Montemayor<\/p>\n\n\n\n

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\"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

1. Qu\u2019en est-il du traitement par plasma convalescent?
\n2. Un essai clinique important conclut que le plasma convalescent n\u2019aide pas les patients atteints de la COVID-19
\n3. Participation des patients \u00e0 l\u2019essai\u00a0CONCOR-1\u00a0: Formation du comit\u00e9 consultatif communautaire et participation<\/p>\n","protected":false},"author":16,"featured_media":7803,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_price":"","_stock":"","_tribe_ticket_header":"","_tribe_default_ticket_provider":"","_ticket_start_date":"","_ticket_end_date":"","_tribe_ticket_show_description":"","_tribe_ticket_show_not_going":false,"_tribe_ticket_use_global_stock":"","_tribe_ticket_global_stock_level":"","_global_stock_mode":"","_global_stock_cap":"","_tribe_rsvp_for_event":"","_tribe_ticket_going_count":"","_tribe_ticket_not_going_count":"","_tribe_tickets_list":"[]","_tribe_ticket_has_attendee_info_fields":false,"_EventAllDay":false,"_EventTimezone":"","_EventStartDate":"","_EventEndDate":"","_EventStartDateUTC":"","_EventEndDateUTC":"","_EventShowMap":false,"_EventShowMapLink":false,"_EventURL":"","_EventCost":"","_EventCostDescription":"","_EventCurrencySymbol":"","_EventCurrencyCode":"","_EventCurrencyPosition":"","_EventDateTimeSeparator":"","_EventTimeRangeSeparator":"","_EventOrganizerID":[],"_EventVenueID":[],"_OrganizerEmail":"","_OrganizerPhone":"","_OrganizerWebsite":"","_VenueAddress":"","_VenueCity":"","_VenueCountry":"","_VenueProvince":"","_VenueState":"","_VenueZip":"","_VenuePhone":"","_VenueURL":"","_VenueStateProvince":"","_VenueLat":"","_VenueLng":"","_VenueShowMap":false,"_VenueShowMapLink":false,"footnotes":""},"categories":[138,138],"tags":[],"class_list":["post-7800","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bulletin"],"acf":[],"_links":{"self":[{"href":"https:\/\/transfusionontario.org\/fr\/wp-json\/wp\/v2\/posts\/7800","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/transfusionontario.org\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/transfusionontario.org\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/transfusionontario.org\/fr\/wp-json\/wp\/v2\/users\/16"}],"replies":[{"embeddable":true,"href":"https:\/\/transfusionontario.org\/fr\/wp-json\/wp\/v2\/comments?post=7800"}],"version-history":[{"count":0,"href":"https:\/\/transfusionontario.org\/fr\/wp-json\/wp\/v2\/posts\/7800\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/transfusionontario.org\/fr\/wp-json\/wp\/v2\/media\/7803"}],"wp:attachment":[{"href":"https:\/\/transfusionontario.org\/fr\/wp-json\/wp\/v2\/media?parent=7800"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/transfusionontario.org\/fr\/wp-json\/wp\/v2\/categories?post=7800"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/transfusionontario.org\/fr\/wp-json\/wp\/v2\/tags?post=7800"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}