Effects of rhinovirus infection on the expression and function of cystic fibrosis transmembrane conductance regulator and epithelial sodium channel in human nasal mucosa.

BACKGROUND: Changes in expression and function of the cystic fibrosis transmembrane conductance regulator (CFTR) and epithelial sodium channel (ENaC) have been found to cause airway surface liquid (ASL) derangement and to impair mucociliary clearance, both of which have been linked to the pathogenesis of rhinovirus (RV) infection. OBJECTIVES: The effects of RV infection on the expression and function of CFTR and ENaC in nasal epithelial cells were investigated. METHODS: Nasal epithelial cells obtained from 14 turbinoplasty patients were infected with RV serotype 16 (RV-16) for 4 hours. Expression of CFTR, α-ENaC, ß-ENaC, and γ-ENaC was determined by real-time polymerase chain reaction, Western blot analysis, and confocal immunofluorescence microscopy. Functional changes in the CFTR and ENaC proteins were assessed by measuring transepithelial resistance (TER) using a voltmeter combined with ion channel modulators. RESULTS: Rhinovirus infection increased expression of CFTR, α-ENaC, ß-ENaC, and γ-ENaC messenger RNA (mRNA) and protein compared with controls (P < .05 each) and increased the expression of all 4 proteins on confocal immunofluorescence microscopy. Treatment of cells with the ENaC blocker amiloride and the CFTR activator forskolin increased TER in RV-infected cells, whereas forskolin decreased TER in uninfected cells. The CFTR inhibitor NPPB, however, blocked CFTR more in RV-infected than in noninfected cells. CONCLUSIONS: Rhinovirus increased the expression of CFTR and appeared to alter its function. In contrast, ENaC expression and function were increased by RV infection. Therefore, RV infection may impair mucociliary transport of nasal epithelium by these alterations.

Levocetirizine inhibits rhinovirus-induced bacterial adhesion to nasal epithelial cells through down-regulation of cell adhesion molecules.

BACKGROUND: The first critical step for bacterial infection is attachment of bacteria to the cell adhesion molecules of epithelial cells. The rhinovirus (RV)-induced increased expression of cell adhesion molecules including fibronectin (Fn) and carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) is closely related to the activation of nuclear factor-kappa B (NF-κB). Recent studies have demonstrated that Levocetirizine (LCT) has anti-inflammatory properties that are mediated by inhibitory effects on NF-κB in addition to classic antihistaminic effects. OBJECTIVE: To investigate the inhibitory effects of LCT on the RV-induced expression of Fn and CEACAMs in human nasal epithelial cells (HNECs) and identified the effects of LCT on secondary Staphylococcus aureus and Haemophilus influenzae adhesion to RV-infected HNECs. METHODS: Primary HNECs obtained from inferior turbinate mucosa were pretreated with 50 nM LCT 24 hours before RV-16 infection and for 48 hours thereafter. The expression levels of Fn and CEACAMs were assayed by real-time polymerase chain reaction (PCR) and Western blotting. Bacterial adhesion to cells was assessed by confocal microscopy. RESULTS: Fibronectin and CEACAM messenger RNA (mRNA) and protein levels in HNECs were significantly increased by RV-16 infection. Levocetirizine significantly reduced these increases in mRNA levels and protein expression of Fn and CEACAMs. Confocal microscopy showed that treatment with LCT significantly reduced the adhesion levels of S aureus and H influenza in RV-infected HNECs compared with RV-infected, untreated HNECs. CONCLUSION: These findings suggest that LCT inhibits the expression of Fn and CEACAMs and has the potential to prevent secondary bacterial infections in RV-infected HNECs by interfering with bacterial adhesion.

Asian sand dust enhances rhinovirus-induced cytokine secretion and viral replication in human nasal epithelial cells.

CONTEXT: Asian sand dust (ASD) originating in the arid deserts of Mongolia and China causes annual severe air pollution events in the Asia-Pacific area, including Korea, Japan, and China. ASD is thought to impact public health by aggravating or inducing respiratory illness. Among the most common respiratory illnesses is the common cold caused by rhinovirus (RV) infection. To date, however, the impact of ASD on RV infection has not been studied. OBJECTIVE: In this study, we investigated the effect of ASD on RV infection in human nasal epithelial cells. METHODS: Primary human nasal epithelial cells grown at an air-liquid interface were treated with ASD and/or RV. After RV infections were confirmed using semi-nested reverse transcription-polymerase chain reaction (RT-PCR), mRNA expression and protein secretion of the inflammatory cytokines interferon-γ (IFN-γ), interleukin-1ß (IL-1ß),IL-6, and IL-8, indicators of the severity of RV-induced inflammation, were measured by real-time PCR and enzyme-linked immunosorbent assays. Viral titer was also assayed by culturing viruses to compare viral replication between RV-only and ASD-plus-RV groups. RESULTS: ASD significantly increased RV-induced IFN-γ, IL-1ß, IL-6, and IL-8 mRNA levels and protein secretion in primary nasal epithelial cells. In addition, ASD caused a significant increase in RV replication. CONCLUSIONS: Our results suggest that ASD may potentiate common cold symptoms associated with RV infection not only by enhancing IFN-γ, IL-1ß, IL-6, and IL-8 secretion, but also by increasing viral replication.

Detection of parainfluenza virus 3 in turbinate epithelial cells of postviral olfactory dysfunction patients.

OBJECTIVES/HYPOTHESIS: Postviral olfactory dysfunction (PVOD) develops after a common cold, but little is known about the viral pathogen inducing olfactory dysfunction. We hypothesized that human parainfluenza virus 3 (PIV3) may cause PVOD. We therefore assayed the nasal cavity mucosae of PVOD patients for the presence or persistence of PIV3. METHODS: We assessed 25 patients (5 men, 20 women), ranging in age from 31 to 85 (mean, 51) years, diagnosed with PVOD and 22 controls (18 men, 4 women) diagnosed with nasal septal deviation between July 2005 and August 2006. Inferior turbinate epithelial cells were collected using a Rhino-probe mucosal curette, and PIV3 was assayed by seminested reverse-transcription polymerase chain reaction. RESULTS: PVOD occurred most frequently between May and July. Hyposmia was observed in 60% of patients and anosmia in 40%. The most common clinical symptoms were rhinorrhea, sore throat, nasal obstruction, fever, myalgia, cough, and hoarseness. Patients usually visited the outpatient clinic within 3 months after the onset of olfactory dysfunction. Twenty-two of 25 (88.0%) epithelial samples from PVOD patients were positive for PIV3 compared with 2 of 22 (9.1%) epithelial samples from controls. CONCLUSIONS: The high detection rate of PIV3 in the turbinate epithelial cells of PVOD patients suggests that PIV3 may be the causative virus of PVOD.

Chemopreventive efficacy of all-trans-retinoic acid in biodegradable microspheres against epithelial cancers: results in a 4-nitroquinoline 1-oxide-induced oral carcinogenesis model.

Retinoids are known to suppress carcinogenesis in various epithelial tissues. Among them, all-trans-retinoic acid (atRA) is recognized as one such active retinoid. However, despite the known anticarcinogenic activity of atRA, it exhibits its short plasma half-life during repeated oral administration due to the "acute retinoid resistance" in the liver. This has been the major limitation in clinical applications of atRA. Therefore, in order to render atRA more suitable for clinical uses, sustained delivery of atRA using biodegradable microspheres is suggested in this study. When 50 mg atRA/kg of atRA-loaded microspheres were subcutaneously administered to rats once, the atRA concentration in plasma was maintained around 6.5 ng/ml for 7 weeks, with only minor signs of toxicity. When the chemopreventive efficacy of atRA-loaded microspheres was evaluated using a model of 4-nitroquinoline 1-oxide-induced oral carcinogenesis in F344 rats, a single injection of atRA-loaded microspheres significantly suppressed oral carcinogenesis. Additional injections of atRA-loaded microspheres, however, did not indicate further suppression of carcinogenesis.

Retinoic acid 4-hydroxylase-mediated catabolism of all-trans retinoic acid and the cell proliferation in head and neck squamous cell carcinoma.

All-trans retinoic acid (RA) can be catabolized to polar metabolites by microsomal P450s (P450). The aim of this study was to confirm if retinoic acid 4-hydroxylase (CYP26) is a P450 induced by RA and to investigate the role of cellular RA binding proteins (CRABPs), using a slow catabolizer, AMC-HN-4, and a rapid catabolizer, AMC-HN-6. Also, we analyzed the effect of RA catabolism on cell proliferation of head and neck squamous cell carcinoma (HNSCC) in vitro and in vivo. Both cell lines weakly expressed CYP26 and CRABPs, but RA induced CYP26 only in AMC-HN-6. The sensitivity to RA was variable by the amount of CYP26, and the rapid catabolism by CYP26 made AMC-HN-6 resistant to RA in vitro. In addition, The RA had a stronger effect on the inhibition of tumor growth of AMC-HN-4 than that of AMC-HN-6 in vivo. Conclusively, the CYP26 activity might be one essential factor for the RA sensitivity, but in cells showing induction of CYP26, the RA sensitivity is inversely related to the rate of RA catabolism.

The effect of cellular retinoic acid binding protein-I expression on the CYP26-mediated catabolism of all-trans retinoic acid and cell proliferation in head and neck squamous cell carcinoma.

The aim of this study was to confirm if catabolism of all-trans retinoic acid (RA) is enhanced by type I cellular retinoic acid binding protein (CRABP-I) expression and to investigate the effect of this enhanced catabolism on cell proliferation of the head and neck squamous cell carcinoma (HNSCC) cell line, AMC-HN-7. We also analyzed the effects of CRABP-I on RA-induced retinoic acid receptor (RAR) activity. The expression of the CRABP-I in stably transfected AMC-HN-7 cell lines (HN7-BPIa and HN7-BPIb) resulted in a lower sensitivity to administered RA compared with that of controls in a clonogenic assay. HN7-BPIs cells showed an increased amount of polar metabolites of RA in thin-layer chromatography. The transcriptional activity of the reporter plasmid RARE(DR5)-tk-CAT after the treatment of RA was lesser in HN7-BPIs than in controls. These results suggest that the increased CYP26-mediated catabolism of RA by CRABP-I transfection might decrease the amount of RA that is accessible to the nuclear receptors and make HNSCC cells resistant to RA.

Levocetirizine inhibits rhinovirus-induced up-regulation of fibrogenic and angiogenic factors in nasal polyp fibroblasts.

BACKGROUND: Up-regulation of matrix metalloproteinases (MMPs), vascular endothelial growth factor (VEGF), and transforming growth factor (TGF) beta, may contribute to the formation of nasal polyps (NPs). Rhinovirus (RV) infection enhances expression of MMP-2, MMP-9, and VEGF in NP fibroblasts and of TGF-beta in respiratory epithelial cells. We investigated the inhibitory effects of levocetirizine (LCT) on the RV-induced expression of (1) fibrogenic (MMPs and TGF-beta) and (2) angiogenic (VEGF and TGF-beta) factors in NP fibroblasts. METHODS: NP fibroblasts obtained from 11 male patients with chronic rhinosinusitis with NPs (CRSwNPs), were infected with RV serotype 16 (RV-16) for 4 hours. Cells were treated with 50 nM of LCT 24 hours before infection and for 48 hours thereafter. Expression of MMP-2, MMP-9, VEGF, and TGF-ß mRNA and protein were determined by real-time polymerase chain reaction and enzyme-linked immunosorbent assays, respectively. RESULTS: LCT significantly inhibited RV-induced increases in MMP-2, MMP-9, VEGF, and TGF-beta mRNA, and protein expression, in NP fibroblasts (p < 0.05 for each comparison). CONCLUSION: LCT inhibits RV-induced up-regulation of fibrogenic and angiogenic factors in NP fibroblasts, suggesting that LCT may prevent NP formation in patients with CRSwNP caused by RV infection.

The effect of a low concentration of hypochlorous acid on rhinovirus infection of nasal epithelial cells.

BACKGROUND: Low concentrations of hypochlorous acid (HOCl) have been shown to exhibit both antibacterial and anti-influenza virus activity, but HOCl still has not been used to kill human rhinovirus (HRV). To model the antiviral effect of nasal irrigation with low-level HOCl in patients with the common cold, we tested the effects of a low concentration of HOCl on HRV infection of primary human nasal epithelial cells (HNEC). METHODS: Cells were infected with HRV for 24 hours and treated with HOCl three times, for 5 minutes each time, at 12 hour intervals. The effects of HOCl on rhinovirus-induced secretion of IL-6 and IL-8 were assessed by ELISA and HRV replication was determined by viral titration. RESULTS: HOCl treatment significantly inhibited HRV-induced secretion of IL-6 and IL-8 and significantly reduced viral titer. The effects of HOCl peaked at 1 minute after HOCl generation and decreased thereafter. CONCLUSION: These in vitro findings indicate that nasal irrigation with low-level HOCl solution may improve clinical symptoms in patients with the common cold.

Staphylococcus aureus increases cytokine and matrix metalloproteinase expression in nasal mucosae of patients with chronic rhinosinusitis and nasal polyps.

BACKGROUND: Staphylococcus aureus is a common bacterial pathogen associated with chronic rhinosinusitis with/without nasal polyps (CRSw/sNP). We investigated the effect of S. aureus on the secretion of eotaxin, interleukin (IL)-5, IL-8, IL-13, matrix metalloproteinase (MMP) 2, MMP-9, and tissue inhibitor of MMP (TIMP) 1 in nasal mucosae from CRSwNP patients to assess the roles of these materials in NP pathogenesis. METHODS: We infected organ cultures of NP and inferior turbinate (IT) mucosae taken from patients with CRSwNP with S. aureus ATCC 25923 for 24 hours and incubated the cultures for an additional 48 hours at 37°C. S. aureus infection and staphylococcal enterotoxins were confirmed by real-time polymerase chain reaction. Eotaxin, IL-5, IL-8, IL-13, MMP-2, MMP-9, and TIMP-1 protein levels were measured by ELISA. RESULTS: S. aureus infection significantly increased the concentrations of eotaxin, IL-5, IL-8, and IL-13 in the IT and NP groups (p < 0.01 for all comparisons). S. aureus infection also significantly increased the concentrations of MMP-2, MMP-9, and TIMP-1 in both groups (p < 0.001 for all comparisons). After S. aureus infection, the relative increases in eotaxin (6.42 versus 3.56), IL-5 (15.29 versus 8.89), MMP-2 (1.95 versus 1.58), MMP-9 (2.34 versus 1.95), and TIMP-1 (1.45 versus 1.31) were greater in the NP group than in the IT group. CONCLUSION: S. aureus infection enhances the secretion of cytokines, MMP-2, MMP-9, and TIMP-1 by both NPs and IT mucosae from patients with CRSwNP. S. aureus may play an important role in the pathogenesis of NP via tissue remodeling as well as eosinophilic inflammation.

Clarithromycin inhibits rhinovirus-induced bacterial adhesions to nasal epithelial cells.

OBJECTIVES/HYPOTHESIS: We investigated the inhibitory effects of clarithromycin (CM) on the rhinovirus (RV)-induced expression of fibronectin (Fn) and carcinoembryonic antigen-related cell adhesion molecules (CEACAMs), which act as major receptors for Staphylococcus aureus and Haemophilus influenzae, respectively. We further investigated the effects of CM on secondary S. aureus and H. influenzae adhesions to RV-infected primary human nasal epithelial cells (HNECs). METHODS: Cells were pretreated with 10 microM CM 24 hours before RV-16 infection and for 48 hours thereafter. The expression levels of Fn and CEACAMs were assayed by reverse transcriptase-polymerase chain reaction and Western blotting. Bacterial adhesion to cells was assessed by confocal microscopy and the fluorescence intensity of adherent bacteria was analyzed using Image-Pro Plus 5.1 (Media Cybernetics, Bethesda, MD). RESULTS: Clarithromycin significantly inhibited the RV-induced gene and protein expression of Fn and CEACAMs in HNECs. Compared with RV-infected cells, CM treatment significantly reduced the adhesion levels of S. aureus and H. influenzae in RV-infected HNECs to the levels seen in noninfected control cells. CONCLUSIONS: These findings indicate that CM has the potential to prevent secondary bacterial infections in RV-infected HNECs by inhibiting the expression of Fn and CEACAM, thereby interfering with bacterial adhesion.

Rhinovirus enhances various bacterial adhesions to nasal epithelial cells simultaneously.

OBJECTIVES/HYPOTHESIS: Viral upper respiratory tract infections are often followed by secondary bacterial infections in the form of acute rhinosinusitis. We investigate the effect of rhinovirus infection on the expression of cell adhesion molecules and bacterial adherence to primary human nasal epithelial cells. METHODS: Cells were infected with rhinovirus serotype 16 (RV-16), and then Staphylococcus aureus, Streptococcus pneumoniae, or Hemophilus influenzae were added to the culture. Rhinovirus-induced expression of fibronectin, platelet-activating factor receptor, and carcinoembryonic antigen-related cell adhesion molecule, was assayed by confocal microscopy, real-time polymerase chain reaction, and Western blot analysis. Bacterial adhesion to cells was assessed by confocal microscopy and the fluorescence intensity of adherent bacteria was analyzed using Image-Pro Plus 5.1 (Media Cybernetics, Inc., Bethesda, MD). RESULTS: RV-16 infection significantly increased the gene and protein expression of fibronectin, platelet-activating factor receptor, and carcinoembryonic antigen-related cell adhesion molecule in nasal epithelial cells. Compared with rhinovirus-uninfected control cells, the adhesion of S. aureus, S. pneumoniae, and H. influenzae increased significantly to 2.53-fold, 1.51-fold, and 2.74-fold of control levels, respectively, in rhinovirus-infected nasal epithelial cells. CONCLUSIONS: These findings suggest that increased expression of host cell adhesion molecules may be the mechanism accounting for the increase in susceptibility to bacterial rhinosinusitis associated with rhinovirus-induced upper respiratory infections.

Rhinovirus upregulates matrix metalloproteinase-2, matrix metalloproteinase-9, and vascular endothelial growth factor expression in nasal polyp fibroblasts.

OBJECTIVES/HYPOTHESIS: Upregulation of matrix metalloproteinase (MMP) and vascular endothelial growth factor (VEGF) has been suggested to have an important role in the pathogenesis of nasal polyps (NPs). The aim of this study was to investigate the effect of rhinovirus (RV) infection on the expression of MMPs, tissue inhibitor of metalloproteinase (TIMP)-1, and VEGF in NP fibroblasts. METHODS: NP fibroblasts (5 x 10(5) cells/mL) obtained from patients with chronic rhinosinusitis with nasal polyps (CRSwNP) were infected with RV serotype 16 (RV-16) for 4 hours. The RV-16 infection was confirmed by seminested reverse transcriptase-polymerase chain reaction (RT-PCR) and in situ hybridization. After 48 hours, MMP-2, MMP-9, TIMP-1, and VEGF protein levels were measured from culture supernatants by enzyme-linked immunosorbent assay. The changes in the expression of MMP-2, MMP-9, TIMP-1, and VEGF mRNA were assayed by RT-PCR. RESULTS: RV-16 infection significantly enhanced the gene and protein expressions of MMP-2, MMP-9, and VEGF in NP fibroblasts, whereas TIMP-1 expression was not significantly affected by RV-16. MMP-2, MMP-9, and VEGF protein expression increased by 2.39-, 2.99-, and 3.02-fold, respectively, in RV-infected NP fibroblasts compared to noninfected controls. RV-16 infection also significantly upregulated the expression of MMP-2, MMP-9, and VEGF mRNA by 1.27-, 1.70-, and 1.53-fold, respectively, compared to control levels. CONCLUSIONS: These in vitro findings suggest that RV infection may contribute to the pathogenesis of NP formation in patients with CRSwNP.

Levocetirizine inhibits rhinovirus-induced ICAM-1 and cytokine expression and viral replication in airway epithelial cells.

Levocetirizine inhibits the production of intercellular adhesion molecule (ICAM)-1 and secretion of interleukin (IL)-6 and IL-8, which may have beneficial effects on the pathophysiologic changes related to human rhinovirus (HRV) infection. We investigated the effects of levocetirizine on rhinovirus infection in primary human nasal epithelial cells (HNEC) and A549 cells. Cells were treated with different concentrations of levocetirizine, ranging from 0.5, 5 or 50nM, either starting at the time of infection and continuing thereafter, or beginning 24h before infection and continuing thereafter. Levocetirizine treatment inhibited the HRV-induced increase in ICAM-1 mRNA and protein levels, as well as the HRV-induced expression of IL-6 and IL-8 mRNA and protein levels. Viral titer, as measured by culture in MRC-5 cells, was reduced by levocetirizine. Levocetirizine treatment also reduced the increased nuclear factor-kappa B (NF-kappaB) expression seen with HRV infection. Levocetirizine inhibited the expression of Toll-like receptor (TLR)3 mRNA and protein levels. These findings indicate that, in HNEC and A549 cells, levocetirizine inhibits HRV replication and HRV-induced upregulation of ICAM-1, IL-6, and IL-8, TLR3 expression and NF-kappaB activation. The results of this study suggest that levocetirizine may have a possible clinical application in the treatment of airway inflammation caused by HRV infection.

Infection rate and virus-induced cytokine secretion in experimental rhinovirus infection in mucosal organ culture: comparison between specimens from patients with chronic rhinosinusitis with nasal polyps and those from normal subjects.

OBJECTIVE: To investigate the difference in susceptibility to rhinovirus (RV) infection and RV-induced inflammatory response between the nasal mucosae from patients with chronic rhinosinusitis with nasal polyps (CRS/NP) and subjects without CRS/NP (hereinafter, normal subjects). DESIGN: In vitro study. SETTING: Tertiary care rhinology clinic. PATIENTS: We conducted RV infection experiments on the organ cultures of NPs and inferior turbinate mucosae from 16 patients with CRS/NP and sphenoid sinus and inferior turbinate mucosae from 19 patients who underwent transsphenoidal pituitary surgery. MAIN OUTCOME MEASURES: Successful RV-16 infection was determined by positive identification of RV on the surface fluid of organ culture using seminested reverse transcriptase-polymerase chain reaction. Effects of RV on interleukin 6 (IL-6) and IL-8 secretion were measured by enzyme-linked immunosorbent assay. RESULTS: The successful RV infection was achievable in 9 of 16 NP samples (56.3%) and 9 of 16 turbinate samples (56.3%) from patients with CRS/NP compared with 11 of 19 sphenoid sinus samples (57.9%) and 15 of 19 turbinate samples (78.9%) from normal subjects. The RV infection increased IL-6 and IL-8 secretion 236% and 173%, respectively, in NP samples, and 218% and 178%, respectively, in turbinate samples from patients with CRS/NP; compared with 231% and 145%, respectively, in sphenoid mucosa samples, and 181% and 148%, respectively, in turbinate samples from normal subjects. However, there were no statistical differences among the 4 groups. CONCLUSION: These in vitro findings suggest that subjects with CRS/NP mucosa might not be more susceptible to RV infection, and did not secrete more cytokines in response to rhinovirus infection, than those with normal mucosa.

Staphylococcal enterotoxins A and B enhance rhinovirus replication in A549 cells.

BACKGROUND: Staphylococcal enterotoxin A (SEA) and staphylococcal enterotoxin B (SEB) have been reported to be important in the pathogenesis of chronic rhinosinusitis (CRS). To elucidate the pathophysiological responses in the nasal mucosae of CRS patients associated with rhinovirus (RV) infection, we investigated the effects of SEA and SEB on RV infection in A549 cells. METHODS: Changes in expression of intercellular adhesion molecule (ICAM) 1 were assessed by flow cytometry, and effects on cytokine secretion were measured by ELISA. The changes of ICAM-1, IL-1beta, IL-6, and IL-8 mRNA were assayed by real-time polymerase chain reaction. The effect of RV replication in the cells was assessed by viral culture, followed by determination of viral titer. RESULTS: RV infection increased ICAM-1 expression and cytokine secretion, but the SEs did not further increase the RV-induced expression of ICAM-1, IL-1beta, IL-6, and IL-8 mRNA and protein. The SEs, however, induced dose-dependent increases in viral titer. CONCLUSION: SEA and SEB enhanced rhinoviral replication in airway epithelial cells, indicating that airway epithelial cells with CRS are more favorable environments for RV infection.

Detection of rhinovirus in turbinate epithelial cells of chronic sinusitis.

BACKGROUND: In contrast to the well-established association of rhinovirus (RV) with acute sinusitis, little is known about the role of RV infections in the pathogenesis of chronic sinusitis. Therefore, we assayed the nasal cavity mucosae of chronic sinusitis patients lacking signs of acute viral infection for the presence of RV. METHODS: Nasal lavage fluids and turbinate epithelial cells from 39 sinusitis patients and 27 control subjects were tested. Turbinate epithelial cells were collected using a Rhino-probe mucosal curette. Picornavirus was assayed by an initial reverse-transcription polymerase chain reaction (PCR), and picornavirus-positive samples were assayed by nested reverse-transcription PCR to detect RV. RESULTS: All lavage fluids from both groups, as well as control epithelial cells, were negative for picornavirus. In contrast, 8 of 39 (21%) epithelial cell samples from sinusitis patients were positive for picornavirus. RV-specific nested-PCR revealed that all eight of these samples were positive for RV. CONCLUSION: The detection of RV in the turbinate epithelial cells of chronic sinusitis patients suggests that RV may be important in the pathogenesis of chronic sinusitis.