title: Toll-like receptor 2 expression level on monocytes in patients with viral infections: monitoring infection severity.
abstract: 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.
authors.affiliation: Department of Cardiovascular, Respiratory and Metabolic Medicine, Graduate School of Medicine, Kagoshima University, Kagoshima, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kajiya
authors.forename: Koji
authors.initials: K
authors.lastname: Orihara
authors.forename: Shuichi
authors.initials: S
authors.lastname: Hamasaki
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Oba
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Hirai
authors.forename: Kinya
authors.initials: K
authors.lastname: Nagata
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Kumagai
authors.forename: Sanemasa
authors.initials: S
authors.lastname: Ishida
authors.forename: Naoya
authors.initials: N
authors.lastname: Oketani
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ichiki
authors.forename: So
authors.initials: S
authors.lastname: Kuwahata
authors.forename: Shoji
authors.initials: S
authors.lastname: Fujita
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Uemura
authors.forename: Chuwa
authors.initials: C
authors.lastname: Tei
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D002097:C-Reactive Protein / Q000032:analysis; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007251:Influenza, Human / Q000175:diagnosis* / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology*; D019798:Neopterin / Q000097:blood; D011379:Prognosis; D000685:Serum Amyloid A Protein / Q000032:analysis; D051195:Toll-Like Receptor 2 / Q000096:biosynthesis*
chemical_list: D015415:Biomarkers; D000685:Serum Amyloid A Protein; D051195:Toll-Like Receptor 2; D019798:Neopterin; D002097:C-Reactive Protein