ABSTRACT
<p><b>OBJECTIVE</b>Rotavirus is the single most common cause of severe dehydrating diarrhea in young children worldwide, but the pathogenesis and immunity against this disease are not completely understood. A prospective study was conducted to assess gene expression of toll-like receptors (TLR) in children with acute rotavirus diarrhea.</p><p><b>METHODS</b>Seventy-five children with acute rotavirus diarrhea and 38 control children were enrolled in this study from Sep. 2004 to Jan. 2005. All the 75 patients had detailed records of clinical characteristics. Rotavirus antigen was detected by ELISA from stools. Peripheral blood mononuclear cells (PBMC) were separated by Ficoll reagent and RNA was extracted by Trizol. The levels of mRNA for five TLRs in PBMC were examined by fluorescent quantitative RT-PCR.</p><p><b>RESULTS</b>Patients with acute rotavirus infection had elevated mean levels of TLR 2, 3, 4, 7, 8 mRNA expressions in PBMC within 3 days since onset of the disease, P less than 0.05. But only TLR 2, 3, 8 mRNA levels remained increased in patients within 7 or 14 days since onset (P less than 0.05). Mean levels of mRNA for TLR 4 in PBMC was higher in patients with more severe diarrhea including longer duration of diarrhea, more episodes of diarrhea per day and higher severity scores (P less than 0.05).</p><p><b>CONCLUSION</b>Manifold TLR may play roles in the start-up and regulation of immune responses in children with acute rotavirus diarrhea. These findings will be helpful to further recognize immune response in Chinese children with rotavirus diarrhea and, consequently, may provide directions and insights that could prove critical to the prevention or treatment of this important disease.</p>