{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T05:32:11Z","timestamp":1783488731973,"version":"3.55.0"},"reference-count":51,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2022,6,30]],"date-time":"2022-06-30T00:00:00Z","timestamp":1656547200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003196","name":"Ministero della Salute","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100003196","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Immunol."],"abstract":"<jats:p>IgM memory B cells, are a peculiar subset of memory B cells, which probably originates in the spleen and outside germinal centers and provide a rapid line of defence against mucosal infections. Their role in counteracting COVID-19 is still elusive but, recent evidence, mainly boosted by studies on spleen function\/involvement in COVID-19, seems to support the notion that this subset of memory B cells could exert a protective role against this virus, along with other coronaviruses, particularly in the acute setting of the infection, as outlined by worst clinical outcomes observed in unvaccinated patients with impaired IgM B memory response and spleen function. Herein we critically summarise the current landscape of studies on IgM memory B cells, focusing on the clinical impact of their depletion, by comparing the COVID-19-related splenic dysfunction with other hypo- and asplenic conditions and by adding recent data on follow-up studies and postulate a mechanistic explanation for their reduced numbers. The early detection of an impaired IgM memory B cell response in patients with COVID-19 may contribute to their improved care through different strategies, such as through tailored vaccine strategies, prompt hospital admission and\/or administration of anti-infective treatments, thus resulting in an better prognosis, although at present management algorithms are still unavailable. Moreover, further studies with longer follow-up are needed to assess the evolution of COVID-19-associated\/exacerbated immune deficit.<\/jats:p>","DOI":"10.3389\/fimmu.2022.889876","type":"journal-article","created":{"date-parts":[[2022,6,30]],"date-time":"2022-06-30T10:24:30Z","timestamp":1656584670000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":12,"title":["Role of IgM Memory B Cells and Spleen Function in COVID-19"],"prefix":"10.3389","volume":"13","author":[{"given":"Carlo Maria","family":"Rossi","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marco Vincenzo","family":"Lenti","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stefania","family":"Merli","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Antonio","family":"Di Sabatino","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2022,6,30]]},"reference":[{"key":"B1","unstructured":""},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(20)30920-X","article-title":"SARS-CoV-2 and Viral Sepsis: Observations and Hypotheses","volume":"395","author":"Li","year":"2020","journal-title":"Lancet (London England)"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1002\/EJI.202149470","article-title":"Natural Killer Cell-Mediated ADCC in SARS-CoV-2-Infected Individuals and Vaccine Recipients","volume":"2022","author":"Hagemann","year":"2022","journal-title":"Eur J Immunol"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.3389\/FCVM.2021.745758","article-title":"Long COVID 19 Syndrome: Is It Related to Microcirculation and Endothelial Dysfunction? 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