Severe Parvovirus B19 Infection in Patients with Sickle Cell Disease Hospitalized in Intensive Care Unit.

Parvovirus B19 infection can lead to severe complications in patients with chronic haemolysis. The aim of this study was to describe severe Parvovirus B19 infections in adult patients with sickle cell disease (SCD). In this multicentre, retrospective, observational cohort study, adult patients with SCD admitted to intensive care units (ICUs) between 2011 and 2024 with acute Parvovirus B19 infection were included. Unsupervised analysis was performed including clinical and biological characteristics to identify clusters of patients with different outcomes. Clinical phenotypes were defined based on patient clustering. Parvovirus B19 genomes from ICU (n=15) and non-ICU control patients (n=15) admitted to the hospital during the same period were sequenced and compared. Sixty-one patients (52% female, median age: 29 years [IQR: 24;38]) from eight ICUs in France were included. Three clusters of patients were identified. From these clusters, three groups of patients with distinct clinical phenotype were identified: erythroblastopenia (n=26), bone marrow necrosis (BMN) and fat cerebral embolism syndrome (CFE) (n=17), and other vaso-occlusive manifestations (n=18). Length of stay in the ICU and hospital was longer in patients with BMN/CFE. There was no difference in Parvovirus B19 genotype or NS1 or VP1/2 amino-acid diversity between the groups. Similar results were observed between patients who were admitted to the ICU and those who were not. ICU patients with SCD and acute Parvovirus B19 infection presented three clinical phenotypes associated with different initial severity and outcome, but with similar Parvovirus B19 clades and amino-acid diversity.