Toll-like receptor 2 expression level on monocytes in patients with viral infections: monitoring infection severity.

For viral infectious diseases, reliable biomarkers capable of monitoring recovery and therapeutic effects and that simultaneously discriminate between viral and bacterial infection are necessary. In this study, by using flow-cytometric quantification system, Toll-like receptor 2 (TLR2) expression levels on monocytes of influenza patients (n=47) were compared with those of healthy volunteers (n=50). Subsequently, throughout their acute, convalescent and healed phases, TLR2, C-reactive protein (CRP), serum amyroid A (SAA), and neopterin levels were followed. Additionally, TLR2 levels in other viral infectious diseases were assayed. The results showed that TLR2 level in influenza patients was remarkably up-regulated in acute phase compared to healthy volunteers (p<0.001). Thereafter, TLR2 levels normalized in good accordance with their recovery processes. CRP and neopterin levels were relatively widely distributed from normal to abnormally high levels in acute phase in spite of similar disease severity among the patients. SAA levels did not necessarily reflect the patients' clinical course during their recovery. Clinical observations of other viral infections also indicated that TLR2 levels were compatible with infection severity. TLR2 expression level on monocytes might serve as a unique biomarker useful in viral infectious diseases.

Pyogenic liver abscess related to dental disease in an immunocompetent host.

A 59-year-old man with poor oral hygiene presented to our hospital because of fever and chills. Abdominal ultrasonography and enhanced computed tomography (CT) revealed a liver abscess. The patient had no history of immunodeficiency and we confirmed the patient had no immunologic abnormalities. Blood culture revealed Fusobacterium nucleatum, a bacterium commonly found in the oral cavity. Even if a patient is immunocompetent, poor oral hygiene might be an independent risk factor for a pyogenic liver abscess. Professional mechanical tooth cleaning (PMTC) and appropriate self-care are recommended as a prophylaxis against not only dental, but also systemic diseases.