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.
Kajiya
Takashi
T
Department of Cardiovascular, Respiratory and Metabolic Medicine, Graduate School of Medicine, Kagoshima University, Kagoshima, Japan.
Orihara
Koji
K
Hamasaki
Shuichi
S
Oba
Ryutaro
R
Hirai
Hiroyuki
H
Nagata
Kinya
K
Kumagai
Tomoaki
T
Ishida
Sanemasa
S
Oketani
Naoya
N
Ichiki
Hitoshi
H
Kuwahata
So
S
Fujita
Shoji
S
Uemura
Nobuhiro
N
Tei
Chuwa
C
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*
D015415:Biomarkers; D000685:Serum Amyloid A Protein; D051195:Toll-Like Receptor 2; D019798:Neopterin; D002097:C-Reactive Protein