Histomorphological patterns of regional lymph nodes in COVID-19 lungs.
Pathologe
; 42(Suppl 1): 89-97, 2021 Nov.
Article
in English
| MEDLINE | ID: covidwho-1971686
ABSTRACT
BACKGROUND:
A dysregulated immune response is considered one of the major factors leading to severe COVID-19. Previously described mechanisms include the development of a cytokine storm, missing immunoglobulin class switch, antibody-mediated enhancement, and aberrant antigen presentation.OBJECTIVES:
To understand the heterogeneity of immune response in COVID-19, a thorough investigation of histomorphological patterns in regional lymph nodes was performed. MATERIALS ANDMETHODS:
Lymph nodes from the cervical, mediastinal, and hilar regions were extracted from autopsies of patients with lethal COVID-19 (nâ¯= 20). Histomorphological characteristics, SARS-CoV2 qRT-PCR, and gene expression profiling on common genes involved in immunologic response were analyzed.RESULTS:
Lymph nodes displayed moderate to severe capillary stasis and edema, an increased presence of extrafollicular plasmablasts, mild to moderate plasmacytosis, a dominant population of CD8+ Tcells, and CD11c/CD68+ histiocytosis with hemophagocytic activity. Out of 20 cases, 18 presented with hypoplastic or missing germinal centers with a decrease of follicular dendritic cells and follicular Thelper cells. A positive viral load was detected by qRT-PCR in 14 of 20 cases, yet immunohistochemistry for SARS-CoV-2â¯N-antigen revealed positivity in sinus histiocytes of only one case. Gene expression analysis revealed an increased expression of STAT1, CD163, granzyme B, CD8A, MZB1, and PAK1, as well as CXCL9.CONCLUSIONS:
Taken together, our findings imply a dysregulated immune response in lethal COVID-19. The absence/hypoplasia of germinal centers and increased presence of plasmablasts implies a transient Bcell response, implying an impaired development of long-term immunity against SARS-CoV2 in such occasions.Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
COVID-19
Limits:
Humans
Language:
English
Journal:
Pathologe
Year:
2021
Document Type:
Article
Affiliation country:
S00292-021-00945-6
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