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Seasonal Asthma Exacerbation and Viral Association in a Pediatric Population Receiving ICS ± LABA Therapy
AB164 Abstracts
Live But Not Heat-Killed Staphylococcus aureus Induce Production Of TSLP And IL-33 In Skin Fibroblasts From Both Healthy Children And Those With Atopic Dermatitis S. Tan, J. L. Pennock, P. D. Arkwright; University of Manchester, Manchester, UNITED KINGDOM. RATIONALE: Staphylococcus aureus (S. aureus) triggers flares in atopic dermatitis (AD). In order to determine the mechanism by which the bacteria induce inflammation we studied the direct effects of S. aureus on TLRinduced cytokine production and survival of skin fibroblast in patients with AD as well as non-atopic controls. METHODS: Skin fibroblasts isolated from ten children with severe AD and ten non-atopic controls were stimulated with heat-killed and live S. aureus, staphylococcal enterotoxin or lipopolysaccharide (LPS). TLR1, 2 and 6 protein expressions was analyzed by FACS and IL-6, TNF-a, IL-33 and TSLP measured by ELISA. Cell viability was also assessed. RESULTS: Live, not heat-killed S. aureus induced TSLP and IL-33 but not IL-6 production in skin fibroblasts derived from both healthy controls and AD patients. LPS induced IL-6 but not TSLP and IL-33. Staphylococcal enterotoxin had no stimulatory effect on these cytokines. Live S. aureus also induced cell death with 80% surviving at 6 hours. There was no specific upregulation of TLR expression by live S. aureus or differences in TLR1/2/6 expression or cytokine production between fibroblasts derived from children with AD and non-atopic controls. CONCLUSIONS: Live, but not heat killed S. aureus or their enterotoxins, are cytotoxic to skin fibroblasts and are potent stimulators of Th2-inducing cytokines. These findings provide an explanation for the prominent role of these bacteria in AD.
619
620
MONDAY
Human Rhinovirus Species Vary By Season And Diagnosis In 21-year Prospective Pediatric Cohort J. E. (Linder) Jackson, D. Kraft, K. M. Edwards, J. V. Williams, E. Miller; Vanderbilt University, Nashville, TN. RATIONALE: Human rhinoviruses (HRV) are common triggers of asthma exacerbation. The role of the newly described HRVC in upper (URI) and lower respiratory illness (LRI) in children over time is poorly understood. Here we examine HRVC in relationship to other HRV species and disease severity over a 21-year period. METHODS: Using Real Time RT-PCR, we tested nasal-wash specimens for HRV, obtained from children enrolled from 1982-2003, presenting with acute respiratory tract illness or otitis media (OM). We sequenced the VP4/ VP2 gene from HRV-positive specimens to determine species. RESULTS: Of 527 samples tested, 190 (36.1%) were positive for HRV: 48% of these were HRVA, 3% HRVB, 36% HRVC, and 13% untypable. Of 407 children with URI, 75% had HRV: 54% were HRVA and 32% HRVC (p50.0002). Of 120 children with LRI, 40% had HRV: 31% HRVA and 50% HRVC (P 5 0.06). Of HRV-positive patients with coryza, 2% had HRVA and 42% HRVC (p50.018). Of HRV-positive patients with acute OM, 57% had HRVA and 27% HRVC (p50.0001). Of HRV-positive patients with wheezing (bronchiolitis or asthma), 29% had HRVA and 48% HRVC (p50.12). HRVA and HRVC often peaked during alternate months; overall HRVA was more likely than HRVC to be present in July and October, and in 1988, 2001, and 2002. CONCLUSION: Our data support that HRVC is not a ‘‘new’’ virus and that HRV species vary over season and time. Because different species are associated with distinct diagnoses, tracking HRV species through time may help us understand patterns in severity of disease and diagnoses.
J ALLERGY CLIN IMMUNOL FEBRUARY 2012
621
Seasonal Asthma Exacerbation and Viral Association in a Pediatric Population Receiving ICS 6 LABA Therapy C. M. Prazma1, B. A. Prillaman1, J. E. Gern2, D. A. Stempel1; 1GlaxoSmithKline, Durham, NC, 2University of Wisconsin-Madison, Madison, WI. RATIONALE: To assess the effect of fluticasone propionate (FP) or FP/ salmeterol (FSC) on the risk reduction of asthma exacerbation and impairment associated with fall respiratory viral infections in a pediatric population. METHODS: This was a 16-week study in pediatric subjects with a recent history of severe asthma exacerbation. Subjects (n5339) treated with FP or FSC were randomized prior to starting the 2010 school year. Subjects collected mucus samples upon self-report of moderate to severe cold symptoms and/or meeting worsening asthma criteria. Mucus amples were analyzed by PCR.Viral-associated severe exacerbations were defined as positive viral sample occurring within the 5 days prior to exacerbation of a or up to 2 days following the start of the exacerbation. RESULTS: Of the 537 mucus samples collected 344 were positive for at least one respiratory virus and 276 were rhinovirus (HRV) positive. Fortyone subjects experienced 49 severe exacerbations (FSC524; FP525) during treatment. Twenty (FSC56; FP514) of the 49 exacerbations were viral-associated and 14 (FSC55; FP59) of those viral-associated exacerbations were associated with HRV. CONCLUSIONS: This prospective study collected mucus samples from subjects receiving FP or FSC during the fall viral period, a period when this age group (4-11 years) is most susceptible to viral-induced exacerbations. While colds and/or episodes of worsening asthma were associated with positive viral samples, the lower than expected number of virus-associated severe exacerbations suggests that FP and FSC therapy may preferentially prevent viral-induced severe exacerbations.
622
LDH/Caspase Ratio in Nasal-Wash Fluid as a Marker of Disease Severity in Bronchiolitis R. Mehta1, K. Patel2, A. Jewell2, K. Jennings3, M. Scheffler4, L. Aideyan2, R. Garofalo1, P. Piedra4,2; 1Department of Pediatrics, University of Texas Medical Branch, Galveston, TX, 2Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, 3 Department of Preventative Medicine and Community Health, University of Texas Medical Branch, Galveston, TX, 4Department of Pediatrics, Baylor College of Medicine, Houston, TX. RATIONALE: Bronchiolitis is the leading cause of hospitalization in infants. The innate immune response, including apoptosis, is important in controlling infection. Apoptosis, or programmed cell death, reduces spread of infection and bystander cellular injury. During severe infection, necrosis is the major cause of cellular injury and organ damage. The balance between apoptosis and necrosis is important in the host response to infection. Lactate dehydrogenase (LDH) is an intracellular enzyme that is released extracellularly during cellular injury. Caspase is a marker of apoptosis. We previously demonstrated in children with bronchiolitis a significant inverse correlation between nasal wash (NW) LDH concentration and disease severity. We extend this observation in a new cohort of children with bronchiolitis. We hypothesize that NW LDH/caspase ratio will be a useful biomarker to predict disease severity in bronchiolitis. METHODS: 112 children, less than 24 months of age, were recruited from the Texas Children’s emergency room with bronchiolitis from October 2010-April 2011. Demographic, clinical information and NW samples were obtained. NW samples were analyzed for respiratory viruses, caspase 3/7, and LDH. RESULTS: Of the 112 enrolled, 55 patients (49%) were admitted to the hospital. RSV was the most common virus isolated. When comparing NW LDH/caspase in hospitalized children to those not hospitalized, the ratio was 36 times higher in hospitalized patients (p50.03020). CONCLUSIONS: Our data supports that hospitalized children with bronchiolitis have a higher NW LDH/caspase ratio because of cellular injury from necrosis, compared to apoptosis in non-hospitalized children. NW LDH/caspase ratio may be a useful predictor of disease severity in bronchiolitis.
Live But Not Heat-Killed Staphylococcus aureus Induce Production Of TSLP And IL-33 In Skin Fibroblasts From Both Healthy Children And Those With Atopic Dermatitis S. Tan, J. L. Pennock, P. D. Arkwright; University of Manchester, Manchester, UNITED KINGDOM. RATIONALE: Staphylococcus aureus (S. aureus) triggers flares in atopic dermatitis (AD). In order to determine the mechanism by which the bacteria induce inflammation we studied the direct effects of S. aureus on TLRinduced cytokine production and survival of skin fibroblast in patients with AD as well as non-atopic controls. METHODS: Skin fibroblasts isolated from ten children with severe AD and ten non-atopic controls were stimulated with heat-killed and live S. aureus, staphylococcal enterotoxin or lipopolysaccharide (LPS). TLR1, 2 and 6 protein expressions was analyzed by FACS and IL-6, TNF-a, IL-33 and TSLP measured by ELISA. Cell viability was also assessed. RESULTS: Live, not heat-killed S. aureus induced TSLP and IL-33 but not IL-6 production in skin fibroblasts derived from both healthy controls and AD patients. LPS induced IL-6 but not TSLP and IL-33. Staphylococcal enterotoxin had no stimulatory effect on these cytokines. Live S. aureus also induced cell death with 80% surviving at 6 hours. There was no specific upregulation of TLR expression by live S. aureus or differences in TLR1/2/6 expression or cytokine production between fibroblasts derived from children with AD and non-atopic controls. CONCLUSIONS: Live, but not heat killed S. aureus or their enterotoxins, are cytotoxic to skin fibroblasts and are potent stimulators of Th2-inducing cytokines. These findings provide an explanation for the prominent role of these bacteria in AD.
619
620
MONDAY
Human Rhinovirus Species Vary By Season And Diagnosis In 21-year Prospective Pediatric Cohort J. E. (Linder) Jackson, D. Kraft, K. M. Edwards, J. V. Williams, E. Miller; Vanderbilt University, Nashville, TN. RATIONALE: Human rhinoviruses (HRV) are common triggers of asthma exacerbation. The role of the newly described HRVC in upper (URI) and lower respiratory illness (LRI) in children over time is poorly understood. Here we examine HRVC in relationship to other HRV species and disease severity over a 21-year period. METHODS: Using Real Time RT-PCR, we tested nasal-wash specimens for HRV, obtained from children enrolled from 1982-2003, presenting with acute respiratory tract illness or otitis media (OM). We sequenced the VP4/ VP2 gene from HRV-positive specimens to determine species. RESULTS: Of 527 samples tested, 190 (36.1%) were positive for HRV: 48% of these were HRVA, 3% HRVB, 36% HRVC, and 13% untypable. Of 407 children with URI, 75% had HRV: 54% were HRVA and 32% HRVC (p50.0002). Of 120 children with LRI, 40% had HRV: 31% HRVA and 50% HRVC (P 5 0.06). Of HRV-positive patients with coryza, 2% had HRVA and 42% HRVC (p50.018). Of HRV-positive patients with acute OM, 57% had HRVA and 27% HRVC (p50.0001). Of HRV-positive patients with wheezing (bronchiolitis or asthma), 29% had HRVA and 48% HRVC (p50.12). HRVA and HRVC often peaked during alternate months; overall HRVA was more likely than HRVC to be present in July and October, and in 1988, 2001, and 2002. CONCLUSION: Our data support that HRVC is not a ‘‘new’’ virus and that HRV species vary over season and time. Because different species are associated with distinct diagnoses, tracking HRV species through time may help us understand patterns in severity of disease and diagnoses.
J ALLERGY CLIN IMMUNOL FEBRUARY 2012
621
Seasonal Asthma Exacerbation and Viral Association in a Pediatric Population Receiving ICS 6 LABA Therapy C. M. Prazma1, B. A. Prillaman1, J. E. Gern2, D. A. Stempel1; 1GlaxoSmithKline, Durham, NC, 2University of Wisconsin-Madison, Madison, WI. RATIONALE: To assess the effect of fluticasone propionate (FP) or FP/ salmeterol (FSC) on the risk reduction of asthma exacerbation and impairment associated with fall respiratory viral infections in a pediatric population. METHODS: This was a 16-week study in pediatric subjects with a recent history of severe asthma exacerbation. Subjects (n5339) treated with FP or FSC were randomized prior to starting the 2010 school year. Subjects collected mucus samples upon self-report of moderate to severe cold symptoms and/or meeting worsening asthma criteria. Mucus amples were analyzed by PCR.Viral-associated severe exacerbations were defined as positive viral sample occurring within the 5 days prior to exacerbation of a or up to 2 days following the start of the exacerbation. RESULTS: Of the 537 mucus samples collected 344 were positive for at least one respiratory virus and 276 were rhinovirus (HRV) positive. Fortyone subjects experienced 49 severe exacerbations (FSC524; FP525) during treatment. Twenty (FSC56; FP514) of the 49 exacerbations were viral-associated and 14 (FSC55; FP59) of those viral-associated exacerbations were associated with HRV. CONCLUSIONS: This prospective study collected mucus samples from subjects receiving FP or FSC during the fall viral period, a period when this age group (4-11 years) is most susceptible to viral-induced exacerbations. While colds and/or episodes of worsening asthma were associated with positive viral samples, the lower than expected number of virus-associated severe exacerbations suggests that FP and FSC therapy may preferentially prevent viral-induced severe exacerbations.
622
LDH/Caspase Ratio in Nasal-Wash Fluid as a Marker of Disease Severity in Bronchiolitis R. Mehta1, K. Patel2, A. Jewell2, K. Jennings3, M. Scheffler4, L. Aideyan2, R. Garofalo1, P. Piedra4,2; 1Department of Pediatrics, University of Texas Medical Branch, Galveston, TX, 2Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, 3 Department of Preventative Medicine and Community Health, University of Texas Medical Branch, Galveston, TX, 4Department of Pediatrics, Baylor College of Medicine, Houston, TX. RATIONALE: Bronchiolitis is the leading cause of hospitalization in infants. The innate immune response, including apoptosis, is important in controlling infection. Apoptosis, or programmed cell death, reduces spread of infection and bystander cellular injury. During severe infection, necrosis is the major cause of cellular injury and organ damage. The balance between apoptosis and necrosis is important in the host response to infection. Lactate dehydrogenase (LDH) is an intracellular enzyme that is released extracellularly during cellular injury. Caspase is a marker of apoptosis. We previously demonstrated in children with bronchiolitis a significant inverse correlation between nasal wash (NW) LDH concentration and disease severity. We extend this observation in a new cohort of children with bronchiolitis. We hypothesize that NW LDH/caspase ratio will be a useful biomarker to predict disease severity in bronchiolitis. METHODS: 112 children, less than 24 months of age, were recruited from the Texas Children’s emergency room with bronchiolitis from October 2010-April 2011. Demographic, clinical information and NW samples were obtained. NW samples were analyzed for respiratory viruses, caspase 3/7, and LDH. RESULTS: Of the 112 enrolled, 55 patients (49%) were admitted to the hospital. RSV was the most common virus isolated. When comparing NW LDH/caspase in hospitalized children to those not hospitalized, the ratio was 36 times higher in hospitalized patients (p50.03020). CONCLUSIONS: Our data supports that hospitalized children with bronchiolitis have a higher NW LDH/caspase ratio because of cellular injury from necrosis, compared to apoptosis in non-hospitalized children. NW LDH/caspase ratio may be a useful predictor of disease severity in bronchiolitis.