Autoantibodies to protein S may explain rare cases of coagulopathy following COVID-19 vaccination.

Yalcinkaya A, Cavalli M, Aranda-Guillén M, Cederholm A, Güner A, Rietrae I, Mildner H, Behere A, Eriksson O, Gonzalez L, Mugabo CH, Johnsson A, Lakshmikanth T, Brodin P, Wadelius M, Hallberg P, Landegren N

Sci Rep 14 (1) 24512 [2024-10-18; online 2024-10-18]

While Coronavirus disease 2019 (COVID-19) vaccines have proven to be both effective and generally safe, rare but severe adverse events following immunization (AEFIs) are described. Autoantibodies to platelet factor-4 are associated with catastrophic thrombotic AEFIs, but comprehensive investigations of other autoantibodies are lacking. We aimed to detect and describe autoantibodies targeting coagulation-related proteins in a population-wide cohort (SWEDEGENE) including AEFIs attributed to COVID-19 vaccines in Sweden. Subjects were recruited from December 2020 to October 2022 and were stratified based on diagnosis and COVID-19 exposure. Screening was carried out in two phases, with a multiplex bead-based assay in the first subset (until September 2021) and with targeted assays for the second (until October 2022). Positivity was defined based on absolute, relative, and biological/technical thresholds. Patients with coagulation-related AEFIs were older and the Vaxzevria vaccine was overrepresented in this group. Two cases had antiphospholipid antibodies but none had PF4 antibodies. We identified six positives for protein S autoantibodies. Protein S concentrations were negatively correlated with autoantibody response in patients with immunoreactivity and functional analysis revealed low protein S activity in three subjects. Our population-wide analysis reveals cases with autoantibodies against protein S which possibly underlie coagulopathic AEFIs.

PubMed 39424883

DOI 10.1038/s41598-024-75514-x

Crossref 10.1038/s41598-024-75514-x

pmc: PMC11489816
pii: 10.1038/s41598-024-75514-x