Determination of avidity of IgG against protein antigens from Streptococcus pneumoniae: assay development and preliminary application in clinical settings.

The measurement of antibody levels is a common test for the diagnosis of Streptococcus pneumoniae infection in research. However, the quality of antibody response, reflected by avidity, has not been adequately evaluated. We aimed to evaluate the role of avidity of IgG against eight pneumococcal proteins in etiologic diagnosis. Eight pneumococcal proteins (Ply, CbpA, PspA1 and 2, PcpA, PhtD, StkP-C, and PcsB-N) were used to develop a multiplex bead-based avidity immunoassay. The assay was tested for effects of the chaotropic agent, multiplexing, and repeatability. The developed assay was applied to paired samples from children with or without pneumococcal disease (n = 38 for each group), determined by either serology, polymerase chain reaction (PCR), or blood culture. We found a good correlation between singleplex and multiplex assays, with r ≥ 0.94.The assay was reproducible, with mean inter-assay variation ≤ 9% and intra-assay variation < 6%. Children with pneumococcal disease had lower median avidity indexes in the acute phase of disease for PspA1 and 2 (p = 0.042), PcpA (p = 0.002), PhtD (p = 0.014), and StkP-C (p < 0.001). When the use of IgG avidity as a diagnostic tool for pneumococcal infection was evaluated, the highest discriminative power was found for StkP-C, followed by PcpA (area under the curve [95% confidence interval, CI]: 0.868 [0.759-0.977] and 0.743 [0.607-879], respectively). The developed assay was robust and had no deleterious influence from multiplexing. Children with pneumococcal disease had lower median avidity against five pneumococcal proteins in the acute phase of disease compared to children without disease.

Distinct regulation of tonsillar immune response in virus infection.

BACKGROUND: The relationships between tonsillar immune responses, and viral infection and allergy are incompletely known. OBJECTIVE: To study intratonsillar/nasopharyngeal virus detections and in vivo expressions of T-cell- and innate immune response-specific cytokines, transcription factors, and type I/II/III interferons in human tonsils. METHODS: Palatine tonsil samples were obtained from 143 elective tonsillectomy patients. Adenovirus, bocavirus-1, coronavirus, enteroviruses, influenza virus, metapneumovirus, parainfluenza virus, rhinovirus, and respiratory syncytial virus were detected using PCR. The mRNA expression levels of IFN-α, IFN-ß, IFN-γ, IL-10, IL-13, IL-17, IL-28, IL-29, IL-37, TGF-ß, FOXP3, GATA3, RORC2, and Tbet were directly analyzed by quantitative RT-PCR. RESULTS: Fifty percentage of subjects reported allergy, 59% had ≥1 nasopharyngeal viruses, and 24% had ≥1 intratonsillar viruses. Tonsillar virus detection showed a strong negative association with age; especially rhinovirus or parainfluenza virus detection showed positive association with IFN-γ and Tbet expressions. IL-37 expression was positively associated with atopic dermatitis, whereas IFN-α, IL-13, IL-28, and Tbet expressions were negatively associated with allergic diseases. Network analyses demonstrated strongly polarized clusters of immune regulatory (IL-10, IL-17, TGF-ß, FOXP3, GATA3, RORC2, Tbet) and antiviral (IFN-α, IFN-ß, IL-28, IL-29) genes. These two clusters became more distinctive in the presence of viral infection or allergy. A negative correlation between antiviral cytokines and IL-10, IL-17, IL-37, FOXP3, and RORC2 was observed only in the presence of viruses, and interestingly, IL-13 strongly correlated with antiviral cytokines. CONCLUSIONS: Tonsillar cytokine expression is closely related to existing viral infections, age, and allergic illnesses and shows distinct clusters between antiviral and immune regulatory genes.

Virological and serological analysis of rhinovirus infections during the first two years of life in a cohort of children.

The occurrence of rhinovirus infections in a cohort of 329 children during the first 2 years of life was determined by virus detection and serological methods. Rhinovirus detection on nasopharyngeal aspirates and middle ear fluids comprised a combination of virus isolation in HeLa Ohio cells and a reverse transcription-polymerase chain reaction (RT-PCR)-hybridization assay on the inoculated cell cultures. Nasopharyngeal aspirates were collected when the child was referred to the study clinic because of respiratory symptoms. Nasopharyngeal aspirates and middle ear fluids were collected after clinical diagnosis of an acute otitis media. Complement-fixing antibodies to rhinovirus were determined from scheduled serum specimens collected at 6, 12, 18, and 24 months of age and from paired sera taken in the cases of acute otitis media. Rhinovirus infections were shown to be common in infants, 24% of the children had complement-fixing antibodies at the age of 6 months and 22% had had at least one rhinovirus episode indicated by virus detection. At the age of 2 years, 91.3% of the children had rhinovirus-specific antibodies, while 79% of the children had experienced rhinovirus infection as judged by the virus detection tests. However, the complement-fixation assay was poor as a diagnostic test. Of 458 acute otitis media episodes studied, 41% were shown to be associated with a rhinovirus by RT-PCR-hybridization, while significant fourfold rise in rhinoviral antibodies was detected only in 7% of the cases.

Pulmonary imaging and function in the common cold.

The common cold is generally considered to be an upper respiratory tract infection. We studied the lower respiratory tract in 76 otherwise healthy young adults with the common cold. Viral infection was diagnosed in 56 (74%) of the 76 subjects. Rhinovirus was detected in 42 (55%) subjects. Chest radiography (CR) and high-resolution computerized tomography (HRCT) were carried out in 40 subjects on day 7, and pulmonary function testing with bronchodilator challenge was carried out in 36 patients on days 7 and 21 of the study. Clinical examinations were carried out on days 1, 7 and 21. The subjects recorded their symptoms on a diary card for 20 d. The mean duration of cough was 8.4 (SD 6.5) d and that of sputum production 5.9 (SD 6.4) d. No abnormal findings were detected in the lungs on auscultation. CR and HRCT showed no pulmonary changes associated with the common cold. No clinically remarkable increases were seen in peak expiratory flow, forced expiration volume in 1 s or forced vital capacity after bronchodilator challenge on either days 7 or 21. All patients made a clinical recovery without antimicrobial therapy within 21 d. We conclude that the common cold in young otherwise healthy adults is an upper respiratory tract infection and that clinically important abnormalities in the lower respiratory tract are rare.

Detection by reverse transcription-polymerase chain reaction of influenza C in nasopharyngeal secretions of adults with a common cold.

The lack of practical methods for a laboratory diagnosis of influenza C virus infections and the seemingly benign nature of the virus contribute to the fact that 50 years after its first isolation, relatively little is known about the epidemiology and the clinical impact of this virus. Reverse transcription-polymerase chain reaction (RT-PCR) was used to amplify influenza C RNA fragments from clinical specimens. Two hundred otherwise healthy adults with recent onset of a common cold were studied. Nasopharyngeal aspirates were collected at entry to the study and 1 week later. Serum samples for antibody determinations were obtained at the first visit and after 3 weeks. Influenza C was detected in 7 of the 200 patients by 2 different RT-PCR formats. All 7 patients had a significant increase in antibody titers between serum samples collected during the acute and convalescent phases of the illness. Influenza C appears to be one of the many viruses that cause acute upper respiratory tract infections in adults.

Validity of ultrasonography in diagnosis of acute maxillary sinusitis.

BACKGROUND: Accurate diagnosis of maxillary sinusitis is difficult on the basis of clinical examination only because the signs and symptoms of sinusitis are nonspecific. A simple, rapid, and readily available method for diagnosing maxillary sinusitis in primary care would increase the accuracy of the diagnoses and thus reduce unnecessary antibiotic treatment. OBJECTIVE: To investigate the validity of ultrasonography compared with radiography and magnetic resonance imaging (MRI) in detection of maxillary sinusitis. DESIGN: Ultrasonography and plain-film radiography of the paranasal sinuses were performed on all patients and MRI was performed on 40 randomly selected patients on day 7 of the study. SETTING: Study office at the Department of Pediatrics of Turku University Hospital, Turku, Finland. PATIENTS: One hundred ninety-seven young adults who contacted the study office within 48 hours of the onset of symptoms of the common cold. MAIN OUTCOME MEASURES: Detection rates of maxillary sinusitis by ultrasonography, radiography, and MRI. RESULTS: Acute maxillary sinusitis was diagnosed in 24% of the sinuses by radiography and in 28% by MRI. Compared with MRI findings, the sensitivity of ultrasonography for detection of maxillary sinusitis was 64% (specificity, 95%). Using a 2-step diagnostic approach in which radiological findings were additionally considered in cases of negative ultrasound findings, a sensitivity of 86% (specificity, 95%) was observed. CONCLUSIONS: The high specificity of ultrasonography indicates that a positive ultrasound finding can be regarded as evidence of maxillary sinusitis. The addition of plain-film radiography in cases of negative ultrasound findings increases the diagnostic sensitivity to clinically acceptable levels without loss in specificity. Active use of ultrasonography would substantially decrease the need for radiological imaging of the sinuses and also help reduce unnecessary antibiotic treatment in primary care. Arch Otolaryngol Head Neck Surg. 2000;126:1482-1486

Intranasal fluticasone propionate does not prevent acute otitis media during viral upper respiratory infection in children.

BACKGROUND: Acute otitis media (AOM) is the most common complication of a viral upper respiratory infection (URI) in children. The virus-induced host inflammatory response in the nasopharynx plays a key role in the pathogenesis of AOM. Suppression of this inflammatory process might prevent the development of AOM as a complication. OBJECTIVE: We sought to assess the effect of intranasally administered fluticasone propionate on prevention of AOM during a viral respiratory infection. METHODS: A total of 210 children (mean age, 2.1 years; range, 0.7-3.9 years) with normal middle ear status and URI of 48 hours' duration or less were randomly allocated to receive either fluticasone (100 microg twice daily) or placebo for 7 days. The specific viral cause of the infection was determined from nasopharyngeal aspirates obtained at the first visit. The children were re-examined at the end of the 7-day medication period. RESULTS: In the fluticasone group AOM developed in 40 (38.1%) of 105 children compared with 29 (28.2%) of 103 children receiving placebo (P =.13). The viral cause of the respiratory infection was determined in 167 (86.1%) of 194 children from whom a nasopharyngeal aspirate was obtained. In children with rhinovirus infection, AOM developed significantly more often in the fluticasone group (45.7%) than in the placebo group (14.7%, P =.005). CONCLUSION: Intranasally administered fluticasone does not prevent the development of AOM during URI but may increase the incidence of AOM during rhinovirus infection.

Lack of induction by rhinoviruses of systemic type I interferon production or enhanced MxA protein expression during the common cold.

To study whether MxA protein expression is systemically upregulated during rhinovirus infection, blood specimens were collected from 40 patients with common cold and MxA expression in mononuclear cells analyzed by flow cytometry. None of the patients with a confirmed rhinovirus infection (n = 15) or with an infection of unknown etiology (n = 20) had elevated expression of the MxA protein (median fluorescence intensity, 549 and 582, respectively) when compared to healthy controls (n = 11, median 590). Patients with influenza infections had significantly elevated values (n = 5, median 750), and interferon could be detected only in serum samples from influenza patients. In conclusion, expression of MxA in blood lymphocytes and an apparently systemic type I interferon response is not induced during rhinovirus infection or during most other cases of common cold in young adult patients.

Effects of the common cold and intranasal fluticasone propionate treatment on mucosal host defense assessed by human saliva.

OBJECTIVE: The purpose of this investigation was to study the effect of a potent topical steroid, fluticasone propionate, on patients with early signs and symptoms of the common cold. To characterize the mucosal inflammatory response, salivary defense factors and flow rate in these patients were analyzed. STUDY DESIGN: Forty patients with symptoms of the common cold were randomized into 2 groups to receive either high-dose fluticasone propionate (100 microg per nostril) or placebo 4 times daily for 6 days. Paraffin-stimulated whole saliva was collected on day 1 (before the onset of medication), day 7 (posttreatment), and day 21 (follow-up). RESULTS: Salivary flow rate, innate host defense factors, and total protein content were not affected by the common cold. IgA increased between day 7 and day 21 (P < or = .01; Student 2-tailed t test), and the relative proportions of salivary peroxidase and IgA increased on day 7 (P = .01) and day 21 (P= .05). In patients receiving fluticasone, saliva flow rate was lower on day 21 (P < or = .05) than on days 1 and 7. The innate salivary defense factors were not affected, but IgA increased both on day 7 (P < or = .001) and on day 21 (P < or = .001) in comparison with day 1. CONCLUSIONS: Of the oral mucosal defense factors, only IgA is activated during the common cold. Intranasally administrated fluticasone propionate does not have a suppressive effect on salivary antimicrobial capacity.

Oral prednisolone is an effective adjuvant therapy for acute otitis media with discharge through tympanostomy tubes.

OBJECTIVE: To determine the efficacy of a short course of oral prednisolone as an adjuvant therapy for acute otitis media draining through tympanostomy tubes. STUDY DESIGN: In a randomized, double-blind, placebo-controlled study, children with acute discharge (<48 hours) through tympanostomy tubes received either prednisolone (2 mg/kg/d; n = 23) or placebo (n = 27) for 3 days. All children received amoxicillin/clavulanate (40/10 mg/kg/d) for 7 days. The children were examined daily at the study clinic until the drainage ceased. RESULTS: The median duration of otorrhea in the prednisolone group was 1.0 days (25% to 75% range, 1.0 to 2.0 days), compared with 3.0 days (25% to 75% range, 2.0 to 4.0 days) in the children receiving placebo (P <.001). The duration of otorrhea was

Sinusitis in the common cold.

BACKGROUND: Acute community-acquired sinusitis is considered a bacterial complication of the common cold. Radiologic abnormalities in sinuses occur, however, in most patients with upper respiratory virus infections. OBJECTIVE: Assessment of the occurrence, clinical profile, laboratory findings, and outcome of radiologically confirmed sinusitis was carried out as part of a common cold study in young adults. METHODS: Clinical examinations and radiography of the paranasal sinuses were carried out on days 1, 7, and 21 in 197 patients with the common cold. The symptoms were recorded on diary cards on days 1 to 20. Ten viruses and 5 bacteria were studied as etiologic agents of common cold as reported earlier. Serum C reactive protein concentrations, erythrocyte sedimentation rates, and total white blood cell counts with differentials were determined in 40 randomized subjects on day 7. The effect of 6 days of intranasal fluticasone propionate treatment of the common cold in the prevention of sinusitis was analyzed. RESULTS: On day 7, 39% of patients with the common cold in the placebo group (n = 98) had sinusitis, which we would prefer to call viral sinusitis. The symptoms of patients with sinusitis and those without it were not clinically distinguishable. Viral infection was detected in 81.6% of patients with sinusitis. No significantly increased levels of antibodies to bacteria were detected. Serum C reactive protein concentrations, erythrocyte sedimentation rates, and white blood cell counts were low in patients with sinusitis. All patients made a clinical recovery within 21 days without antibiotic treatment. Fluticasone propionate treatment tended to prevent paranasal sinusitis, especially in rhinovirus-positive subjects. CONCLUSION: Viral sinusitis frequently occurs in the early days of the common cold, but it is a self-limited illness. The sinuses should not be imaged in patients with the common cold if the signs and symptoms of illness gradually become less severe and no specific signs suggestive of bacterial sinusitis occur.

The common cold: effects of intranasal fluticasone propionate treatment.

OBJECTIVE: A double-blind, randomized, placebo-controlled trial was conducted to study the effect of the intranasal corticosteroid, fluticasone propionate (FP), in the naturally occurring common cold. METHODS: One hundred ninety-nine young adults received high-dose FP (200 microg four times daily) or placebo beginning 24 to 48 hours after onset of the common cold for 6 days. All symptoms were recorded on diary cards on days 1 to 20, and clinical examinations were carried out on days 1, 7, and 21. Nasopharyngeal aspirates were collected on days 1 and 7 for detection of rhinoviruses (found in 105 subjects) and Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis (found in 52 subjects) in the nasopharynx. RESULTS: In general, FP treatment had no clinically recognizable effects on the symptoms of the common cold, although it significantly reduced nasal congestion and cough on some study days. After treatment, rhinoviruses were cultured more often in the FP treatment group (37% vs 14%, p < 0.001), but this had no effect on the symptoms of common cold. FP treatment produced no changes in the colonization of pathogenic bacteria in the nasopharynx. Some symptoms of common cold were significantly more severe during days 1 to 10 (p < 0.05) in subjects found to have positive cultures for S. pneumoniae, H. influenzae, or M. catarrhalis in the nasopharynx on day 1 (n = 33). CONCLUSION: FP treatment does not have any marked effects on the symptoms of the common cold. FP treatment induced prolonged shedding of viable rhinoviruses. Some symptoms of the common cold were significantly more severe in subjects with pathogenic bacteria in the nasopharynx.

Molecular diagnosis of human rhinovirus infections: comparison with virus isolation.

To compare the sensitivity and specificity of RT-PCR with that of virus isolation in the detection of human rhinoviruses, we tested nasopharyngeal aspirates from 200 patients on the 1st and 7th days after the onset of the common cold. An assay utilizing a short amplicon in the conserved 5' noncoding region was found highly sensitive. Of 192 positive samples altogether, 65 were found positive by RT-PCR only, 6 were positive by isolation exclusively, and 121 gave positive results in both tests.

Viruses and bacteria in the etiology of the common cold.

Two hundred young adults with common colds were studied during a 10-month period. Virus culture, antigen detection, PCR, and serology with paired samples were used to identify the infection. Viral etiology was established for 138 of the 200 patients (69%). Rhinoviruses were detected in 105 patients, coronavirus OC43 or 229E infection was detected in 17, influenza A or B virus was detected in 12, and single infections with parainfluenza virus, respiratory syncytial virus, adenovirus, and enterovirus were found in 14 patients. Evidence for bacterial infection was found in seven patients. Four patients had a rise in antibodies against Chlamydia pneumoniae, one had a rise in antibodies against Haemophilus influenzae, one had a rise in antibodies against Streptococcus pneumoniae, and one had immunoglobulin M antibodies against Mycoplasma pneumoniae. The results show that although approximately 50% of episodes of the common cold were caused by rhinoviruses, the etiology can vary depending on the epidemiological situation with regard to circulating viruses. Bacterial infections were rare, supporting the concept that the common cold is almost exclusively a viral disease.