Serologic survey for antibodies against three genotypes of bovine parainfluenza 3 virus in unvaccinated ungulates in Alabama.

OBJECTIVE To determine titers of serum antibodies against 3 genotypes of bovine parainfluenza 3 virus (BPI3V) in unvaccinated ungulates in Alabama. ANIMALS 62 cattle, goats, and New World camelids from 5 distinct herds and 21 captured white-tailed deer. PROCEDURES Serum samples were obtained from all animals for determination of anti-BPI3V antibody titers, which were measured by virus neutralization assays that used indicator (reference) viruses from each of the 3 BPI3V genotypes (BPI3V-A, BPI3V-B, and BPI3V-C). The reference strains were recent clinical isolates from US cattle. Each sample was assayed in triplicate for each genotype. Animals with a mean antibody titer ≤ 2 for a particular genotype were considered seronegative for that genotype. RESULTS Animals seropositive for antibodies against BPI3V were identified in 2 of 3 groups of cattle and the group of New World camelids. The geometric mean antibody titer against BPI3V-B was significantly greater than that for BPI3V-A and BPI3V-C in all 3 groups. All goats, captive white-tailed deer, and cattle in the third cattle group were seronegative for all 3 genotypes of the virus. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that BPI3V-A may no longer be the predominant genotype circulating among ungulates in Alabama. This may be clinically relevant because BPI3V is frequently involved in the pathogenesis of bovine respiratory disease complex, current vaccines contain antigens against BPI3V-A only, and the extent of cross-protection among antibodies against the various BPI3V genotypes is unknown.

Respiratory virus is a real pathogen in immunocompetent community-acquired pneumonia: comparing to influenza like illness and volunteer controls.

BACKGROUND: Viral pathogens were more commonly reported than previously estimated in community-acquired pneumonia (CAP) patients. However, the real role of virus was still controversial. METHODS: Consecutive adult patients with CAP between April and December, 2009 were prospectively enrolled. A four-fold or greater increase of IgG-titres against respiratory viruses in pair sera was tested by means of hemagglutination inhibition assay or indirect immunofluorescence. Swab samples were tested by cell culture and/or nucleic amplification tests. Viral etiology was considered definitive if at least one of the above tests was positive. RESULTS: Viral etiology was established in fifty-two (34.9%) of 149 CAP patients, twenty-two (81.5%) of 27 influenza like illness patients, and none of 75 volunteer controls. Forty-seven CAP patients were infected by a single virus (24 influenza A virus, 5 influenza B, 10 parainfluenza virus type 3 [PIV-3], 2 PIV-1, 2 adenovirus, 2 human rhinovirus and 2 coronavirus OC43), five cases by two or three viruses co-infection. Fever ≥ 39 °C (66.7%), fatigue (64.6%), and purulent sputum (52.1%) was the most common symptoms in viral pneumonia patients. On multivariate analysis, myalgia was included in the model for pneumonia associated with influenza infection. In the CURB-65 model only influenza infection was found independently associated with severe disease (CURB-65 score ≥ 3) out of variables, including age(years), sex, current smoking status, sick contact with febrile patients, numbers of comorbidity, presence of influenza infection, presence of PIV infection, with P = 0.021, OR 7.86 (95% CI 1.37-45.04). CONCLUSION: Respiratory virus was not a bystander, but pathogenic in pneumonia and was a common cause of CAP.

Parainfluenza virus type 3 Ab in allogeneic hematopoietic cell transplant recipients: factors influencing post-transplant Ab titers and associated outcomes.

Parainfluenza virus type 3 (PIV-3) can cause severe respiratory illness among hematopoietic cell transplantation (HCT) recipients. Factors associated with PIV-3-specific Ab level, and the association between PIV-3 Ab levels and clinical outcomes in HCT recipients who acquire PIV-3 infection, are unknown. We evaluated PIV-3-specific hemagglutination inhibition Ab levels and clinical outcomes among 172 patients with PIV-3 infection following HCT. In a multivariable linear regression model, high post-transplantation Ab levels were independently associated with higher pre-transplantation recipient titer (mean difference 0.38 (95% confidence interval (CI), 0.26, 0.50), P<0.001). Significant associations between pre-HCT Ab titers in both patients and donors and occurrence of lower respiratory tract disease (LRD) after HCT were not observed. In conclusion, low pre-transplantation titers are associated with low Ab levels after HCT. The relationship between PIV-3 Ab levels and outcomes remain uncertain. Further study is needed to prospectively evaluate the dynamics of PIV-3-specific Ab responses and the relative contribution of PIV-3-specific Ab to protection from infection acquisition and progression to LRD.

Retrospective analysis of weekly intravenous immunoglobulin prophylaxis versus intravenous immunoglobulin by IgG level monitoring in hematopoietic stem cell transplant recipients.

Patients undergoing allogeneic hematopoietic stem cell transplant (allo HCT) have a higher incidence of infections partly due to secondary hypogammaglobulinemia. We evaluated the role of IVIG in allo HCT patients who received prophylactic IVIG 200 mg/kg once weekly regardless of IgG level (Group 1, n = 115) compared with patients who received IVIG based on IgG level <400 mg/dL (Group 2, n = 114). Primary endpoints were the utilization of IVIG, incidence of veno-occlusive disease (VOD), graft-versus-host disease (GVHD), and documented infections within the first 100 days after allo HCT. Patients in both groups were similar except for a higher number of matched unrelated donor (MUD) transplants in Group 2 (62 vs. 41, P = 0.01). There were no significant differences in the incidence all grades of GVHD (55 vs. 50), VOD (2 vs. 0) or infections in the two groups except for a higher incidence of para-influenza infections in group 1 (9 vs. 0, P = 0.003) coinciding with the flu season. We recommend monthly monitoring of IgG level and replacement only if IgG level is <400 mg/dL.

Mapping of an antigenic site on the nucleocapsid protein of human parainfluenza virus type 3.

Human parainfluenza virus type 3 (hPIV3) is a respiratory tract pathogen. The current study aimed to investigate immunodominant regions of hPIV3 nucleocapsid (N) protein by using monoclonal antibodies (mAbs) raised against recombinant N protein and human serum specimens from hPIV3-infected individuals. A panel of murine mAbs was generated following immunization with yeast-expressed hPIV3 N protein self-assembled to nucleocapsid-like particles. All mAbs recognized native viral nucleocapsids in hPIV3-infected cells as confirmed by an indirect immunofluorescence analysis. Antigenic sites recognized by the mAbs were mapped using recombinant overlapping N protein fragments. One major immunodominant site was identified in the carboxy-terminal region (amino acids [aa] 397-486) of hPIV3 N protein. Further analysis with smaller N protein fragments and a synthetic peptide revealed one linear epitope representing aa 437-446 of the N protein located within this antigenic site. This epitope was reactive with 46% of hPIV3 IgG-positive sera. These results suggest that the above antigenic site on the N protein is important in eliciting a humoral immune response against hPIV3.

[Use of polymeric suspensions as a viral sorbent to detect cattle serum antibodies].

The paper shows it possible to use stained polymeric microspheres, 1.7 microm in diameter, that contain viruses onto the surface, in the latex agglutination test to detect antibodies to the bovine serum viruses of infective rhinotracheitis, parainfluenza-3, viral diarrhea, respiratory syncytial infection, and adenoviral infection.

Phase 2 evaluation of parainfluenza type 3 cold passage mutant 45 live attenuated vaccine in healthy children 6-18 months old.

A phase 2 evaluation of live attenuated parainfluenza type 3 (PIV3)-cold passage mutant 45 (cp45) vaccine was conducted in 380 children 6-18 months old; 226 children (59%) were seronegative for PIV3. Of the 226 seronegative children, 114 received PIV3-cp45 vaccine, and 112 received placebo. No significant difference in the occurrence of adverse events (i.e., runny nose, cough, or temperature > or =38 degrees C) was noted during the 14 days after vaccination. There was no difference between groups in the occurrence of acute otitis media or serous otitis media. Paired serum samples were available for 109 of the seronegative vaccine recipients and for 110 of the seronegative placebo recipients; 84% of seronegative vaccine recipients developed a > or =4-fold increase in antibody titers. The geometric mean antibody titer after vaccination was 1 : 25 in the vaccine group and <1 : 4 in the placebo group. PIV3-cp45 vaccine was safe and immunogenic in seronegative children and should be evaluated for efficacy in a phase 3 field trial.

Transmission pattern of parainfluenza 3 virus in guinea pig breeding herds.

In searching for the cause of experimental variations in respiratory research data, serology revealed the prevalence of antibodies against parainfluenza virus type 3 (PIV 3) in guinea pigs. The aim of the present study was to explore the transmission rate, course, and kinetics of enzootic PIV 3 infection in guinea pig breeding units. In the first part of the study, blood samples to be analyzed for PIV 3 antibodies were collected from guinea pigs of a PIV 3-positive breeding colony at different times after birth. In the same breeding unit, 6 of 12 2-week-old guinea pigs were relocated and separately housed. The PIV 3 serum antibody titers of the two groups were compared at various times from birth to 13 weeks after birth. In the second part of the study, the spread of infectious virus and virus persistence were explored by housing seronegative sentinel animals together with 2- to 3-week-old guinea pigs from three different PIV 3-positive breeding units. The guinea pigs remaining in the breeding colony as well as those removed and housed separately showed declining serum antibody titers for about 1 month after birth, thereafter the titers were stable until about 8 weeks after birth. Five weeks later, the mean antibody titer of the guinea pigs remaining in the breeding colony had increased to a markedly higher level than that of the relocated, separately housed guinea pigs. Seroconversion was demonstrated in 7 of the 14 sentinels housed with the 2- to 3-week-old guinea pigs from PIV 3-positive breeding units. Sentinels housed together with PIV 3-positive guinea pigs 24 weeks after the start of the experiment did not seroconvert. We conclude that young guinea pigs born to PIV 3-positive mothers were protected by maternal immunity against infection with PIV 3 during their first 14 days of life. The guinea pig offspring became infected during the period from about 2 weeks until 8 weeks after birth, as demonstrated by seroconversion of sentinel animals and an increasing mean antibody titer seen beyond 8 weeks of age. The study did not reveal any indication of virus persistence or prolonged carrier status.

Giant cell arteritis, polymyalgia rheumatica, and viral hypotheses: a multicenter, prospective case-control study. Groupe de Recherche sur l'Artérite à Cellules Géantes.

OBJECTIVE: Although suspected, a viral etiology has never been proven in giant cell arteritis (GCA). We tested for viruses known to induce multinucleated giant cells in human pathology, which include the parainfluenza viruses (HPIV), respiratory syncytial virus, measles virus, herpesviruses type 1 and 2, and the Epstein-Barr virus. METHODS: A multicenter case-control study on incident cases of temporal arteritis (TA) and polymyalgia rheumatica (PMR). Population based age and sex matched controls were randomly selected. Serological tests for IgG and IgM directed against the viruses listed above were performed, on blood samples taken at the time of clinical diagnosis. RESULTS: Three hundred five new patients were included over a 5 year period, of whom 159 presented with positive biopsy TA, 70 with negative biopsy TA, and 76 with negative biopsy PMR. Thirty-eight percent of cases versus 20.9% of controls were positive for IgM directed against HPIV (p = 0.00005). The association was stronger in the positive TA subgroup [positivity rate 43.31%; odds ratio with controls 2.89 (95% CI 1.82-4.60, p = 0.000006)] than in the PMR or negative biopsy TA subgroups. Only HPIV type 1 was associated with the disease, regardless of the season or the geographical origin of the cases. Positivity rates for HPIV types 2 and 3 and for the other viruses tested were similar in cases and controls. CONCLUSION: Our findings suggest that reinfection with HPIV type 1 is associated with the onset of GCA in a subset of patients, particularly in cases with positive TA biopsy.

The cytotoxic T-lymphocyte response to Sendai virus is unimpaired in the absence of gamma interferon.

Sendai virus is eliminated from the respiratory tract of gamma interferon (IFN-gamma) -/- BALB/c mice with normal kinetics. The level of virus-specific cytotoxic T-lymphocyte (CTL) activity in the cell population recovered by bronchoalveolar lavage is unimpaired, the prevalence of interleukin-4 (IL-4)-producing cells is increased, and the titers of virus-specific immunoglobulins IgG1 and IgG2b are higher in the IFN-gamma -/- mice. The emergence of this T-helper 2 response profile in both lymphoid tissue and the pneumonic lung has no obvious deleterious consequences. Virus clearance is slightly delayed following depletion of the CD4+ subset, with the effect being similar in magnitude for IFN-gamma -/- and +/+ mice. However, the generation of CTL precursors (CTLp) is diminished in the IFN-gamma -/- (but not +/+) mice in the absence of concurrent CD4+ T help. Apparently the clonal expansion of the CTLp population can be promoted either by a cytokine (perhaps IL-2) produced by the IFN-gamma -/- CD4+ T cells or by IFN-gamma made by other cell types in the +/+ mice.

Immunogenicity of purified F glycoprotein of respiratory syncytial virus: clinical and immune responses to subsequent natural infection in children.

Purified F glycoprotein from respiratory syncytial virus (RSV, subgroup A antigenic type) was evaluated in 18- to 36-month-old children as a vaccine. Children had been previously infected with RSV during natural outbreaks of the virus. Single injections of 5, 20, or 50 micrograms of protein resulted in greater than eightfold increases in ELISA and neutralizing antibodies. Second doses of vaccine did not result in further boosts in antibody. Neutralizing antibodies increased not only to the A2 and Long strains (subgroup A strains) but also to strain 18537 (subgroup B). Four of 11 vaccinees became naturally infected during the subsequent RSV outbreak, suggesting that the vaccine was not effective in preventing recurrent RSV infections. Severe illnesses did not occur, indicating that there was not an increase of severity of infection following vaccine in seropositive children. Only 1 of 8 vaccinees tested had fourfold increases in nasal wash IgA to RSV after immunization. Vaccine strategies to stimulate secretory antibodies as well as circulating neutralizing antibodies to RSV need to be developed.

Lack of effect of respiratory syncytial virus infection on theophylline disposition in children.

Conflicting reports raise a question about decreased plasma clearance (Clp) of theophylline in man during viral infections. Thus a dilemma exists concerning requisite dose adjustments. We examined this issue by retrospectively evaluating theophylline Clp in children infected with respiratory syncytial virus (RSV). Two pharmacokinetic approaches were applied to a one-compartment open model to fit theophylline concentrations during 83 hospitalizations of 76 children, 6 to 48 months of age, who received intravenous theophylline therapy and were tested for RSV infection. Iterative linear regression analyses of all theophylline data were used to estimate apparent volume of distribution, elimination rate constant, plasma half-life, and Clp in 39 of the hospitalizations. When insufficient data were available to distinguish apparent volume of distribution and elimination rate constant (n = 44), steady-state estimates of Clp were calculated. An age-matched and percentile body weight-matched cohort design presented RSV as the primary covariate. Theophylline Clp was similar in 29 matched RSV-infected and -uninfected pairs (1.32 +/- 0.14 and 1.25 +/- 0.05 ml/kg per minute, respectively), as were other pharmacokinetic values. Unexpectedly, a significant, inverse linear relationship was found for Clp and percentile body weight. Additionally, children born prematurely and hospitalized in the neonatal intensive care unit had significantly higher theophylline Clp; this did not affect findings regarding RSV infection. Theophylline Clp was not decreased in RSV-infected children. Current theophylline dosing recommendations for young children infected with RSV should not be altered, but careful monitoring of plasma theophylline levels should be continued.

Effects of allergen challenge on plasma concentrations of prostaglandins, thromboxane B2, and histamine in calves infected with bovine respiratory syncytial virus.

To examine the influence of allergen-induced type-1 hypersensitivity on the pathogenesis of bovine respiratory syncytial virus (BRSV) infection, we sensitized calves by aerosol to Micropolyspora faeni (MF) and challenge exposed them during infection with BRSV. The development of MF-specific IgE serum concentrations was confirmed by ELISA. The dynamics of arachidonic acid metabolism and histamine release during a type-1 hypersensitivity reaction in the bovine lung were studied by quantitating the concentrations of prostaglandin (PG)E2, PGF2 alpha, PGI2 as 6-keto-PGF1 alpha, thromboxane (TX) A2 as TXB2, and histamine in plasma of BRSV-infected and/or MF-sensitized/challenge-exposed calves. Four treatment groups were established: (1) BRSV infection only, (2) aerosol sensitization to MF followed by BRSV infection and aerosol challenge exposure to MF, (3) MF aerosol sensitization and challenge exposure without BRSV infection, and (4) aerosol sensitization to MF followed by BRSV infection without MF challenge exposure. Significantly increased concentrations of PGI2 were associated with MF aerosol exposure, particularly when combined with BRSV infection in group 2. After MF challenge exposure, TXB2 concentrations were significantly greater in the virus and MF challenge-exposed group 2. Individual calf data for the change in MF-specific IgE concentration between the first and second MF challenge exposures and the change in PGE2 concentration 30 minutes after the second MF challenge exposure had a highly significant direct correlation. Histamine concentrations were significantly greater in calves infected with BRSV than in uninfected controls regardless of MF exposure. These data further substantiate the thesis that implicates type-1 hypersensitivity as a pathogenic mechanism in BRSV-related disease.

Reinfection of lambs with bovine respiratory syncytial virus.

Eight lambs which were experimentally infected with bovine respiratory syncytial virus (RSV) when they were six to eight weeks old were challenged with the same virus seven months later. After reinfection, lambs developed mild clinical disease and the virus was isolated from nasal swabs from three lambs and peripheral blood from two lambs. Reinfection resulted in changes in peripheral blood cell populations. There was an early increase in the number of CD8+ T lymphocytes and B (LCA p220+) lymphocytes but the proportions of CD4+ and CD4-CD8- T lymphocytes were significantly reduced. Peripheral blood mononuclear cells obtained from lambs reinfected with bovine RSV showed significantly higher responses to bovine RSV antigen in vitro than those obtained from control lambs but their responses to the mitogen phytohaemagglutinin were significantly lower than in control lambs. RSV-specific IgG, IgM and IgA levels of serum samples obtained 10 days after challenge were significantly higher than those of serum samples obtained before challenge.

Eosinophil degranulation in the respiratory tract during naturally acquired respiratory syncytial virus infection.

Eosinophil cationic protein (ECP), a cytotoxic protein contained in the granules of eosinophils, has been suggested as having an important role in the pathogenesis of asthma. To determine whether ECP plays a similar role in bronchiolitis, we tested samples of nasopharyngeal secretions, obtained from a group of 47 children with various forms of illness related to respiratory syncytial virus (RSV) and from 26 children with non-RSV upper respiratory tract illness or bacterial pneumonia, for the presence of ECP by means of a double-antibody radioimmunoassay. Concentrations of ECP in children with RSV bronchiolitis were significantly higher (166.8 ng/ml) than the mean concentration of ECP in both groups of children with RSV upper respiratory tract illness (43.5 ng/ml, p less than 0.002) and RSV lower respiratory tract disease without wheezing (29.1 ng/ml; p less than 0.0002). Children with non-RSV upper respiratory tract illness or bacterial pneumonia had levels of ECP in nasopharyngeal secretions similar to those of children with RSV upper respiratory tract illness or RSV pneumonia. High ECP levels in nasopharyngeal secretions (greater than 50 ng/ml) were predictive of the development of bronchiolitis at the time of RSV infection (p less than 0.001), and the individual ECP levels correlated with severity of the disease as determined by the initial PaO2 concentrations (p less than 0.05). These data suggest that eosinophil degranulation in the respiratory tract occurs during RSV bronchiolitis and may play a significant role in the development of virus-induced airway obstruction.