IMEX   05356
INSTITUTO DE MEDICINA EXPERIMENTAL
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
RECCURENCE OF ATYPICAL HEMOLYTIC UREMIC SYNDROME AFTER COVID-19 VACCINATION
Autor/es:
ALICIA CHAVARRI; ANALÍA SÁNCHEZ-LUCEROS; CÉLIA DOS SANTOS; CARLOS G FONDEVILA; MARÍA F ALBERTO
Lugar:
Toronto
Reunión:
Conferencia; Toronto Complement Conference; 2021
Resumen:
BACKGROUNDAtypical Hemolytic Uremic Syndrome (aHUS) is a complement-mediated thromboticmicroangiopathy. Pathophysiological mechanism involves uncontrolled complementactivation due to a genetic or acquired anomaly coupled with a triggering event. Wereport a case of aHUS recurrence following COVID-19 vaccination.MATERIAL AND METHODSWhole blood (EDTA) was collected and processed with CD46-PE, CD45-PerCP,isotype control-PE markers. Staining was measured through median fluorescenceintensity and expressed as CD46/isotype ratio. Sanger sequencing was used foridentification of variants in CD46 gene. All the participants provided informed writtenconsent.RESULTSProband (P) is a 39-year-old woman admitted for nausea, vomiting, epigastric pain andhaematuria, three days after first dose of ChAdOx1 nCov-19 vaccine. Laboratory testingshowed MAHA (Hb:8.8g/dL, Ht:26%), thrombocytopenia (80x109/mm3) and acutekidney injury (Cr:2.15mg/dL, Ur:92mg/dL). P and three of her siblings haveexperienced recurrent TMA episodes since childhood. In 2019, genetic study from P?ssister (S) identified two heterozygous variants in CD46, one pathogenic (Glu179Gln)and one of uncertain significance (Cys94Tyr). We demonstrated that P carries the samevariants and observed a 50% decrease of CD46 expression in both P and S (fig.1).Platelet transfusion, corticosteroids and 9 sessions of plasmapheresis contributed torapid recovery of P.DISCUSSIONGlu179Gln was reported to increase CD46 expression on granulocytes in aHUS patientand to reduce C4b cofactor activity1. We observed that combination of Glu179Gln andCys94Tyr was associated with low levels of CD46 on cell surface.CONCLUSIONThis case report supports the evidence of COVID-19 vaccine as a precipitating event foraHUS recurrence.REFERENCES1. Frémeaux-Bacchi et al., J Am Soc Nephrol, 2006; 17: 2017?25.