ABSTRACT
A previously healthy 5-week-old female was admitted for sepsis secondary to methicillin-resistant Staphylococcus aureus (MRSA) bacteremia. After several days of hospitalization, she experienced acute decompensation in mental status despite having received targeted antibiotic therapy. Imaging revealed left peritonsillar/parapharyngeal space abscess, left venous thrombophlebitis of the internal jugular vein, and septic emboli of the lungs and brain consistent with Lemierre syndrome. Bedside needle aspiration of the parapharyngeal abscess confirmed MRSA involvement. Unfortunately, the patient continued to deteriorate over the next several days and life support was withdrawn on hospital day 16. We present the youngest reported case of Lemierre syndrome and review the literature.
Subject(s)
Bacteremia/diagnosis , Fusobacterium Infections/diagnosis , Lemierre Syndrome/diagnosis , Staphylococcal Infections/diagnosis , Superinfection/diagnosis , Thrombophlebitis/physiopathology , Bacteremia/complications , Bacteremia/drug therapy , Disease Progression , Emergency Service, Hospital , Fatal Outcome , Female , Fusobacterium Infections/drug therapy , Fusobacterium Infections/etiology , Humans , Infant, Newborn , Lemierre Syndrome/etiology , Lemierre Syndrome/therapy , Magnetic Resonance Imaging/methods , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Rare Diseases , Risk Assessment , Staphylococcal Infections/complications , Staphylococcal Infections/drug therapy , Superinfection/therapy , Thrombophlebitis/drug therapy , Thrombophlebitis/etiologyABSTRACT
RATIONALE: Autoimmunity has long been associated with pulmonary hypertension. Bronchus-associated lymphoid tissue plays important roles in antigen sampling and self-tolerance during infection and inflammation. OBJECTIVES: We reasoned that activated bronchus-associated lymphoid tissue would be evident in rats with pulmonary hypertension, and that loss of self-tolerance would result in production of pathologic autoantibodies that drive vascular remodeling. METHODS: We used animal models, histology, and gene expression assays to evaluate the role of bronchus-associated lymphoid tissue in pulmonary hypertension. MEASUREMENTS AND MAIN RESULTS: Bronchus-associated lymphoid tissue was more numerous, larger, and more active in pulmonary hypertension compared with control animals. We found dendritic cells in and around lymphoid tissue, which were composed of CD3(+) T cells over a core of CD45RA(+) B cells. Antirat IgG and plasma from rats with pulmonary hypertension decorated B cells in lymphoid tissue, resistance vessels, and adventitia of large vessels. Lymphoid tissue in diseased rats was vascularized by aquaporin-1(+) high endothelial venules and vascular cell adhesion molecule-positive vessels. Autoantibodies are produced in bronchus-associated lymphoid tissue and, when bound to pulmonary adventitial fibroblasts, change their phenotype to one that may promote inflammation. Passive transfer of autoantibodies into rats caused pulmonary vascular remodeling and pulmonary hypertension. Diminution of lymphoid tissue reversed pulmonary hypertension, whereas immunologic blockade of CCR7 worsened pulmonary hypertension and hastened its onset. CONCLUSIONS: Bronchus-associated lymphoid tissue expands in pulmonary hypertension and is autoimmunologically active. Loss of self-tolerance contributes to pulmonary vascular remodeling and pulmonary hypertension. Lymphoid tissue-directed therapies may be beneficial in treating pulmonary hypertension.
