Binding and activation of plasminogen at the surface of Fusobacterium necrophorum

Proteomic Characterization of Plasma in Lemierre's Syndrome

BACKGROUND

 The underlying mechanisms of thrombosis in Lemierre's syndrome and other septic thrombophlebitis are incompletely understood. Therefore, in this case control study we aimed to generate hypotheses on its pathogenesis by studying the plasma proteome in patients with these conditions.

METHODS

 All patients with Lemierre's syndrome in the Skåne Region, Sweden, were enrolled prospectively during 2017 to 2021 as cases. Age-matched patients with other severe infections were enrolled as controls. Patient plasma samples were analyzed using label-free data-independent acquisition liquid chromatography tandem mass spectrometry. Differentially expressed proteins in Lemierre's syndrome versus other severe infections were highlighted. Functions of differentially expressed proteins were defined based on a literature search focused on previous associations with thrombosis.

RESULTS

 Eight patients with Lemierre's syndrome and 15 with other severe infections were compared. Here, 20/449 identified proteins were differentially expressed between the groups. Of these, 14/20 had functions previously associated with thrombosis. Twelve of 14 had a suggested prothrombotic effect in Lemierre's syndrome, whereas 2/14 had a suggested antithrombotic effect.

CONCLUSION

 Proteins involved in several thrombogenic pathways were differentially expressed in Lemierre's syndrome compared to other severe infections. Among identified proteins, several were associated with endothelial damage, platelet activation, and degranulation, and warrant further targeted studies.

Lemierre Syndrome Presenting as Acute Mastoiditis in a 2-Year-Old Girl with Congenital Dwarfism

Lemierre syndrome is defined by septic thrombophlebitis of the internal jugular vein caused by Fusobacterium. Historically, these infections originate from the oropharynx and typically are seen in older children, adolescents and young adults. More recently, otogenic sources in younger children have been described with increasing frequency. We present a case of a two-year old, who initially developed an otitis media with perforation of the tympanic membrane and went on to develop mastoiditis and non-occlusive thrombosis of the venous sinus and right internal jugular vein. Fusobacterium necrophorum was grown from operative cultures of the mastoid, ensuing computed tomography scan revealed occlusion of the internal jugular vein and the patient was successfully treated with clindamycin, ciprofloxacin and enoxaparin. This case demonstrates the importance of considering Fusobacterium in otogenic infections and the consideration of Lemierre syndrome when F. necrophorum is identified

Fusobacterium necrophorum, an emerging pathogen of otogenic and paranasal infections?

Fusobacterium necrophorum is a rare causative agent of otitis and sinusitis. Most commonly known is the classic Lemièrre's syndrome of postanginal sepsis with suppurative thrombophlebitis of the jugular vein. We report five patients diagnosed recently with a complicated infection with F. necrophorum originating from otitis or sinusitis. Two patients recovered completely, one patient died due to complications of the infection, one patient retained a slight hemiparesis and one patient had permanent hearing loss. Diagnosis and management are discussed. A possible factor in the emergence of F. necrophorum is proposed.