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PubMed1992

Bronchiolitis in the history of the asthmatic child.

In a retrospective analysis of the history of 1,700 asthmatic children, 167 (9.8%) were found to have had bronchiolitis during the first 2 years of life. These 167 cases with asthma and bronchiolitis were matched against 215 selected cases of asthma without bronchiolitis. Both groups attended our Ambulatory Care Unit for Asthma. Data were collected from the clinical cards of the children. Asthmatics who had bronchiolitis were found to have an earlier onset of asthma (p less than 0.001), earlier resolution of symptoms (p less than 0.05 total; p less than 0.01 females), and less evidence of atopy (p less than 0.005). It is suggested therefore that the bronchial hyperreactivity in asthma following bronchiolitis may have different underlying mechanisms than in the typical atopic case, without preceding bronchiolitis. Long-term follow-up studies in infants with bronchiolitis are still necessary in order to clarify the process by which bronchiolitis predisposes to bronchial hyperreactivity and asthma. The consequences of the viral infection itself may lead to pathophysiological processes that promote bronchial hyperreactivity. On the contrary, an underlying condition of bronchial hyperreactivity could be the "primum movens" of the bronchiolitis itself.

Asthma↗

PubMedDate not supplied

Early biochemical indicators of the obliterative bronchiolitis syndrome in lung transplantation.

The diagnosis of the obliterative bronchiolitis syndrome in lung transplantation is presently best established by evaluation of postoperative lung function tests. Unfortunately the decline in lung function occurs only when obliteration has progressed significantly and is therefore not an early predictive indicator. To distinguish patients at increased risk for the development of obliterative bronchiolitis, we regularly assessed the chemiluminescence response of polymorphonuclear leukocytes, opsonic capacity, and plasma elastase/beta-N-acetylglucosaminidase in 52 outpatients (25 women and 27 men; mean age 45 +/- 12 years) who underwent transplantation between January 1991 and January 1992. Recent onset bronchiolitis within the described observation period occurred in 16 patients (group obliterative bronchiolitis). A matched cohort of 16 patients was formed according to type of procedure, age and follow-up (control) from the remaining 36 patients. Data obtained from a period 6 months before clinical onset of the syndrome showed a significant drop of the opsonic capacity (group obliterative bronchiolitis = 87% +/- 7%; control = 100% +/- 9%; p < 0.023) and rise of the N-acetyl-D-glucosaminidase (group obliterative bronchiolitis = 7.5 +/- 2 U/L; control = 5.8 +/- 1.8 U/L; p < 0.04). No correlation was found between the number of infectious events or rejection episodes and the incidence of obliterative bronchiolitis. According to these results, it can be concluded that a decrease in the plasma opsonic capacity and a rise in beta-N-acetylglucosaminidase may be early markers before clinical onset of obliterative bronchiolitis. The nonspecific immune system may therefore play an important role in the development of obliterative bronchiolitis.

Acetylglucosaminidase↗

PubMed1977

The epidemiology of bronchiolitis.

From the data presented a composite epidemiologic picture of bronchiolitis can be drawn. If one uses a large brush the picture would be that of a common, mild disease during the first 2 years of life, due primarily to RSV and occurring predominantly in males during the winter and spring months. If the drawing is examined more closely, however, a more complex picture is seen. Our data suggest that this syndrome is very common indeed if children are followed closely and examined carefully, but under these circumstances is quite mild. If more strict criteria, such as hospitalization, are applied for inclusion of patients with bronchiolitis a different age distribution is seen. Most children who become severely ill are under 6 months of age and in this group morbidity and mortality are high. Agents other than RSV cause bronchiolitis but in these instances the age occurrence and seasonal occurrence are different from those seen with RSV disease. The predominance of bronchiolitis in males is striking. Our day care center data suggest that mild bronchiolitis occurs with equal sex frequency. This would suggest that the reason more boys are carried to the pediatrician or hospitalized is because they get sicker. Further studies on this phenomenon are in progress. Finally, our data suggest that many bronchiolitis cases from whom no agents were isolated were due to RSV. There is, however, a segment of bronchiolitis cases that occurs in the young child during all seasons which suggests that the young bronchiole may react to a variety of stimuli. This poses a real problem for the investigator of bronchiolitis; hopefully meaningful answers will be available soon.

Age Factors↗

PubMed1996

Seasonal onset of bronchiolitis obliterans syndrome in lung transplant recipients.

BACKGROUND: Bronchiolitis obliterans syndrome is the major complication in long-term survival of patients with lung transplants. Bronchiolitis obliterans syndrome is thought to represent a form of chronic allograft rejection and is associated with obstructive airways disease. Viral infections or other exogenous factors may trigger this condition. METHODS: Because respiratory viral infections show seasonal clustering we studied seasonal onset of bronchiolitis obliterans syndrome in 157 lung and heart-lung transplant recipients. Individual baseline values of forced expiratory volume in 1 second were evaluated according to the International Society for Heart and Lung Transplantation criteria. For bronchiolitis obliterans syndrome classification, values of forced expiratory volume in 1 second were determined by the average of two measurements made at least 1 month apart. Onset of bronchiolitis obliterans syndrome was defined as the date of the initial pulmonary function test showing a persistent decline of forced expiratory volume in 1 second. Other factors causing obstructive airways disease were excluded. RESULTS: Forty-nine patients (31%) showed development of bronchiolitis obliterans syndrome (n = 10 stage I, n = 13 stage II, n = 26 stage III) with onset of bronchiolitis obliterans syndrome 507 +/- 372 days (mean +/- standard deviation) after transplantation. Baseline value of forced expiratory volume in 1 second was reached at 270 +/- 231 days. Between January and March of each year onset of bronchiolitis obliterans syndrome developed in 23 patients (47%). In the second (April to June) and third (July to September) quarters a persistent decline of pulmonary function test results developed in 13 (27%) and 12 (24%) patients, respectively, whereas only 1 patient (2%) showed deterioration between October and December (p < 0.001). CONCLUSIONS: Seasonal clustering of onset of bronchiolitis obliterans syndrome might thus indicate underlying unknown infectious triggers.

Adult↗

PubMed1989

Structural changes in airways of rats exposed to nitrogen dioxide intermittently for seven days. Comparison between major bronchi and terminal bronchioles.

Structural changes caused by exposure to NO2 were compared between the largest intrapulmonary bronchi (major bronchi) and the terminal bronchioles. Rats were exposed to 50 ppm NO2 for 5 h a day for 7 consecutive days, and microscopic findings were assessed subjectively and quantitatively. Destruction of airway epithelium was present on Day 1, and the reparative phase was observed between Days 3 and 7. Light microscopy showed that on Day 1, loss of cilia and disintegration of epithelium occurred, and that the latter was worse in major bronchi than in terminal bronchioles; apical projections of Clara cells in terminal bronchioles were lost almost totally. Recovery of epithelium began by Day 3 and cilia by Day 5, and ciliogenesis progressed less promptly in terminal bronchioles. Clara cells did not return to normal during the experiment. Furthermore, a decrease in the airway diameter occurred in peripheral airways along with an increase in mural thickness in terminal bronchioles. Mural inflammation was also seen more conspicuously in terminal bronchioles. Electron microscopy revealed that epithelial cells lost secretory granules on Day 1 and began to repair them by Day 5 in major bronchi and by Day 7 in terminal bronchioles. It is likely that epithelium in terminal bronchioles is not particularly sensitive to NO2 compared with that in major bronchi, but that recovery occurs more promptly in major bronchi than in terminal bronchioles. Mechanisms underlying bronchoconstriction occurring preferentially in peripheral airways are also discussed.

Animals↗

PubMed2003

[Measures to be taken in adults with bronchiolitis].

The majority of bronchial and interstitial diseases of the adult are accompanied by bronchiolar inflammation, but over time the use of the term "bronchiolitis" has been limited to a few specific affections. Bronchiolitis with predominantly alveolar involvement Some "bronchiolites" emphasize the problem of an interstitial pneumopathy, since the disease predominantly involves the alveolar spaces. Only a few bronchiolites are severely damaging: bronchiolitis obliterans with organizing pneumonia and interstitial pneumopathy with respiratory bronchiolitis. These predominantly alveolar affections reveal the clinical (crepitant rales), radiographic (multiple or even diffuse opacities), and functional aspects (restrictive ventilation problems). Brochiolitis with obstructive airway problems In this case the disease predominantly involves the bronchioles and spares the alveolar tissue. The term "bronchiolitis" is in this case perfectly justified. The clinical picture is evocative with obstructed airway and a clear pulmonary parenchyma on the thoracic x-ray. These affections belong to the obstructive broncho-pneumopathy group. The prototype is brochiolitis obliterans, the anatomic correlation of which is generally constrictive bronchiolitis obliterans. Occasionally primitive, it frequently complicates the progression of many morbid states (transplants, collagenosis, inhaled or ingested toxic substances.). Diffuse panbronchiolitis Other "bronchiolites" deviate from this framework and are accompanied by marked lesions of other respiratory tracts (membrane bronchioles, cartilage bronchi, mucosa, ear nose and throat). The prototype is panbronchiolitis, described in the Far East. It is exceptional in Europe, where similar but nosologically different clinical aspects are observed during various diseases: cystic fibrosis, Young's syndrome, hypogammaglobulinemia, bone marrow transplant, context of HIV or haemorrhagic recto-colitis.

Adult↗

PubMed2005

Respiratory development of 5- to 6- year-old children experiencing a first bronchiolitis episode before age one.

BACKGROUND: The relationship between early infections due to respiratory syncytial virus (RSV), particularly bronchiolitis in infancy, and the subsequent development of asthma, bronchial hyper-responsiveness, and/or other allergic manifestations, seems increasingly certain, even if the mechanisms involved are not yet quite clear. OBJECTIVES: The objectives of this work were to determine the prevalence of, and risk factors for, asthma and allergy in 5 to 6 year-old children who five years previously, had experienced their first episode of bronchiolitis before the age of twelve months, and to define the possible effect of the age at which the bronchiolitis occurred on the subsequent development of asthma. METHOD: A retrospective cohort survey was conducted, based on the registers of two hospital paediatric emergency units (Unit A: the Ambroise Pare teaching hospital at Boulogne, France and unit B: the General Hospital of Cherbourg, France). The cohort comprised 5-6 years old children who had consulted or been admitted to emergency unit A or B between October 1993 and March 1994 for a first attack of bronchiolitis before the age of 12 months. RESULTS: One hundred and twenty eight children were included in the two centres (centre A: 78; centre B: 50). A familial history of allergy was found in 92 children (71.8%). Fifty-two (40.6%) were exposed to tobacco smoke. One hundred and five children (81.2%) had been hospitalised during the first episode of bronchiolitis, but none had been placed in intensive care. Their mean age at admission was 5.1 months, and 29 children were less than three months old. Ninety seven children (75.8%) had experienced at least one episode of wheezing at some time of their life. In the twelve months before the telephone interview, 40 children (31.3%) had had at least one such episode, 47 (36.7%) an attack of asthma, 32 (25.0%) wheezing after an effort, 43 (39.4%) a dry cough at night, 52 children (40.6%) had exhibited allergic rhinitis signs, and 32 (25.0%) eczema. Among the 47 children who had experienced at least one attack of asthma during the previous twelve months, 27 (57.4%) had a history of familial asthma (p<0.04). This was the only significant relationship observed in this study with regard to risk factors for asthma. No relationship was observed between asthma or recent wheezing on the one hand, and on the others age less than three months during the first bronchiolitis episode (p=0.6), initial hospital admission (p=0.6) tobacco smoke exposure (p=0.27), sex (p=0.10) or day care management until age three (p=0.73). DISCUSSION: This study showed a high prevalence of asthma and other allergic manifestations in children who five years previously, had experienced their first bronchiolitis episode before the age of twelve months. The only risk factor for asthma or chest wheezing identified in this study was a familial history of allergy. These data support the idea that for most children, early acute bronchiolitis, even if severe, is a transient event, with no or very few consequences in the middle or long term. Nevertheless it may be the expression of an interaction between viral infection and atopic familial predisposition leading to lasting bronchial hyper-responsiveness.

Age of Onset↗

PubMed1986

Parental smoking, presence of older siblings, and family history of asthma increase risk of bronchiolitis.

Bronchiolitis is a common lower respiratory tract illness in infants and has substantial acute morbidity and sequelae. To identify risk factors for bronchiolitis, a case-control study was conducted in which 53 subjects who had bronchiolitis were matched with two controls who had no bronchiolitis in infancy. In multivariate analysis, direct effects of passive smoking and older siblings achieved statistical significance. Family history of asthma appeared to interact with older siblings. Among subjects without a family history of asthma, statistically significant predictors proved to be older siblings (odds ratio, 2.31) and passive smoking (odds ratio, 3.87). Among subjects with a family history of asthma, older siblings proved to be an even stronger predictor (odds ratio, 46.81), while the odds ratio for passive smoking did not change much (odds ratio, 4.03). The combined presence of older siblings and passive smoking yielded an odds ratio of 8.94 among subjects without a family history of asthma and 181.67 among subjects with a family history of asthma. Analysis provided risk estimates that were particularly high for certain groups. Among infants with a family history of asthma, 49% who have an older sibling may develop bronchiolitis. If they are also exposed to cigarette smoke, almost 80% may develop bronchiolitis. Among infants without a family history of asthma, bronchiolitis may develop in 46% of infants if there is both an older sibling and exposure to smoke. Exposure of infants to cigarette smoke might diminish more rapidly if clinicians and parents were aware of such high risks. Efforts to reduce morbidity from bronchiolitis in infants might best be directed at the reduction of smoking in families with previous children, particularly if there is a family history of asthma, and at methods that protect infants from respiratory virus carried by siblings.

Asthma↗

PubMed1994

Bronchial asthma and hyperreactivity after early childhood bronchiolitis or pneumonia. An 8-year follow-up study.

OBJECTIVE: To determine the infantile risk factors and long-term outcome up to 8 to 10 years of age for bronchial asthma and hyperreactivity in children with early-childhood bronchiolitis or pneumonia. DESIGN: Prospective follow-up of three groups of children. SETTING: University hospital providing primary hospital care and outpatient consultations for all pediatric patients in a defined area. INTERVENTIONS: None. PATIENTS: The study groups consisted of 62 children with early-childhood bronchiolitis, 29 children with early-childhood pneumonia with no wheezing, and 52 control children. METHODS: Infantile risk factors were prospectively registered until 2 years of age. Clinical examination, performed 7 to 8 years later, included recording of atopic and asthmatic symptoms from the preceding 12 months. The methacholine inhalation challenge test was used to assess bronchial hyperreactivity, and mean midexpiratory flow results were used to assess bronchial obstruction. MAIN RESULTS: Bronchial asthma was present in nine (15%) of the 62 children from the bronchiolitis group, compared with 7% in the pneumonia group and 2% in the control group. Bronchial hyperreactivity indicated by methacholine inhalation challenge was far more common; it was present in 62% of the bronchiolitis group and in 45% of the pneumonia group. Both groups differed significantly from the control group. Decreased mean midexpiratory flow values were observed in 29% and 21% of the bronchiolitis and pneumonia groups, respectively. All 10 asthmatic patients had bronchial hyperreactivity, but only 20% of hyperreactive children had asthma. An analysis of infantile risk factors disclosed only one, an early onset of wheezing, with a significant effect on bronchial hyperreactivity at school age. Elevated IgE values measured during infancy were associated with the development of clinical asthma. CONCLUSIONS: The risk of bronchial asthma was increased after infantile bronchiolitis. Moreover, bronchial hyperreactivity was increased after both infantile bronchiolitis and pneumonia. Methacholine inhalation challenge was a sensitive but nonspecific test for diagnosing bronchial asthma. Both bronchiolitis and pneumonia resulting in hospitalization in early childhood distinguish a group of children with an increased risk for long-term lung function abnormalities and pulmonary illnesses.

Asthma↗

PubMed1997

Risks for bacteremia and urinary tract infections in young febrile children with bronchiolitis.

OBJECTIVE: To compare the risks for bacteremia and urinary tract injections (UTI) in young febrile children with and without bronchiolitis. DESIGN: A prospective cohort study. SETTING: The emergency departments of 3 pediatric referral hospitals. PATIENTS: A convenience sample of 432 previously healthy febrile patients aged 24 months or younger. Patients were divided into groups, based on the presence (n = 163, bronchiolitis group) or absence (n = 269, control group) of wheezing and/or retractions on examination. Blood cultures were obtained from all patients, and urine cultures were obtained from female patients, and male patients aged 6 months or younger. Chest radiographs were obtained on patients with lower respiratory tract signs, and those with lobar pneumonias were excluded (7 wheezing and 8 nonwheezing patients), leaving 156 patients with bronchiolitis and 261 control patients. OUTCOME MEASURES: Growth of any bacterial pathogens from the blood or 10(4) colony-forming units per milliliter or more from the urine. RESULTS: None of the 156 patients with bronchiolitis had bacteremia (95% confidence interval, 0%-1.9%) vs 2.7% of the 261 controls (95% confidence interval, 1.1%-5.4%; P = .049); 1.9% of the patients with bronchiolitis had UTI vs 13.6% of the controls (odds ratio, 0.12; 95% confidence interval, 0.02-0.55; P = .001). None of the subset of patients with bronchiolitis aged 2 months or younger (n = 36) had bacteremia or UTI; however, there were not enough of these younger patients to make statistically conclusive comparisons. CONCLUSIONS: Previously healthy febrile children aged 24 months or younger with bronchiolitis are unlikely to have bacteremia or UTI. Therefore, routine cultures of the blood and urine in these patients are unnecessary. More data are needed regarding the subset of febrile infants aged 2 months or younger with bronchiolitis.

Bacteremia↗

PubMed2002

Immunological mechanisms of severe respiratory syncytial virus bronchiolitis.

Respiratory syncytial virus (RSV) bronchiolitis resulting in respiratory insufficiency is frequently encountered during the winter season in paediatric intensive care units. This review evaluates potential determinants described in severe RSV bronchiolitis with special attention to the role of immaturity of immune responses during infancy. Pre-existent cardiac or pulmonary compromises have been documented as clinical risk factors for severe RSV bronchiolitis. In addition to this group of infants with pre-morbidity, a large proportion of mechanically ventilated RSV bronchiolitis patients are previously healthy full-term infants or premature neonates without predisposing risk factors. In general, infants at this early age have maturation-related deficient cellular immunity. Several studies show an association between decreased cellular immunity and severe RSV bronchiolitis, indeed suggesting that a maturation-related defect of the cellular immune system facilitates severe RSV. In addition, low virus-specific antibody titres prior to RSV bronchiolitis have been shown to be a risk factor for severe RSV bronchiolitis. A low level of cellular and humoral immunity would explain that higher viral titres are found in infants with most severe illness. In conclusion, immaturity of the physiological functions in healthy pre-term infants and neonates, in particular the immune system, appears to be an important factor in the pathogenesis of RSV bronchiolitis resulting in mechanical ventilation.

Bronchiolitis, Viral↗

PubMed2000

Bronchiolitis, an update.

Besides the classical forms of acute and chronic bronchiolitis, different special forms, such as obliterative, respiratory, and follicular bronchiolitis are recognized. In addition, even new entities emerge, such as Sauropus-induced bronchiolitis. Despite this progress in pathology, pulmonologists still prefer the diagnostic term 'small airways disease', instead of the more specific and even etiology-directed diagnoses provided by the morphologic examination. In this overview, an updated classification will be presented, which includes all forms of bronchiolitis described so far. This classification is structured along morphologic features of bronchiolitis. Different forms of acute and chronic bronchiolitis are described, so that a given reaction pattern can be associated with specific causes, such as eosinophilic bronchiolitis in asthma, or necrotizing bronchiolitis in viral infection. However, there exist more than just one morphologic reaction for a given etiologic agent, resulting in an overlap of morphologic appearances for a given disease.

Bronchi↗

PubMed1989

Lung permeability in adult obliterative bronchiolitis.

There is histopathological evidence that, in certain inflammatory disorders involving the smaller airways, extension of the inflammatory process may occur distally into the respiratory bronchioles, alveolar ducts and alveoli (1,2). The objective of this study was to perform a non-invasive evaluation of the possible involvement of gas exchanging regions of the lung in obliterative bronchiolitis presenting with severe airways obstruction. We measured the clearance of technetium 99m-labelled diethylene triamine penta-acetate (99m Tc-DTPA) with time from the lungs to the blood, in 11 normal, non-smoking subjects (mean age 30 years), ten non-smoking patients with cryptogenic fibrosing alveolitis (CFA, mean age 57 years) and ten patients who were non-smokers with obliterative bronchiolitis (mean age 51 years). There was a substantial increase in clearance in patients with CFA, (mean T1/2 19.9 min), compared with either patients with obliterative bronchiolitis (mean T1/2 52.2 min; mean difference 32.3; 95% confidence intervals (CI) 18.40; P less than 0.001) or normal controls (mean T1/2 84.3; mean difference 64.4; 95% CI 55, 74; P less than 0.001). Clearance was also significantly faster in patients with obliterative bronchiolitis than in normal controls (mean difference 32.1; 95% CI 18.48; P less than 0.001). Peripheral deposition of 99m Tc-DTPA was uniform in normal subjects and patients with CFA, but patchy in patients with obliterative bronchiolitis, possibly resulting from altered patterns of ventilation associated with patchy distribution of bronchiolitis within affected lungs. Increased clearance of 99m Tc-DTPA from the lungs in these patients suggests that subtle derangement of the alveolar-capillary membrane occurs in adult obliterative bronchiolitis.

Adult↗

PubMed2006

Increased levels of BAL cysteinyl leukotrienesinacute [corrected] RSV bronchiolitis.

BACKGROUND: Cysteinyl leukotrienes (CysLTs), including LTC4, LTD4 and LTE4, are pivotal mediators in the pathophysiology of asthma. AIM: To determine whether CysLT levels are increased in the lower airways of children with respiratory syncytial virus (RSV) bronchiolitis, as they are in asthmatic children, and to investigate a possible heterogeneity in CysLT levels in children with RSV bronchiolitis. METHODS: Bronchoalveolar lavage (BAL) fluids were obtained from children with acute RSV bronchiolitis (n = 20), from children with acute asthma who had no identifiable virus infection (n = 16) and from control subjects (n = 14). BAL cell counts and differentials were determined, and the concentrations of CysLTs were measured by ELISA. RESULTS: CysLT levels in the asthma (70.6 +/- 52.7 pg/ml, p < 0.001) and bronchiolitis groups (21.9 +/- 23.3 pg/ml, p < 0.05) were significantly higher than in the control group (8.7 +/- 5.2 pg/ml). Among bronchiolitis subjects, the eosinophil-positive subgroup (n = 6) showed significantly higher CysLT levels (49.0 +/- 26.7 pg/ml, p = 0.001) than the control group, but this was not observed in the eosinophil-negative subgroup (n = 14, 10.3 +/- 6.3 pg/ml, p = 0.47). CONCLUSION: CysLT levels are increased in the lower airways during RSV bronchiolitis, although their intensities are lower than those in acute asthma. Among bronchiolitis subjects, high CysLT producers could be distinguished from low CysLT producers by the presence of eosinophilia in BAL fluids, suggesting a pathophysiological heterogeneity in RSV bronchiolitis.

Acute Disease↗

PubMedDate not supplied

Bronchiolitis in adults: pathology and imaging.

The most common high resolution CT (HRCT) findings of bronchiolitis are centrilobular nodules and branching linear structures in the secondary pulmonary lobules or areas of air trapping. These findings can be helpful in suggesting the presence of bronchiolitis. However, they are nonspecific because there are overlapping features among various kinds of bronchiolitis. Bronchiolar or peribronchiolar inflammation appears as centrilobular nodule, while bronchiolectasis filled with secretions manifests with branching linear structure on HRCT. Air trapping is secondary to bronchiolitis. Proliferative bronchiolitis with the findings of patchy areas of consolidation or ground-glass opacity can be distinguished from other bronchiolitis. Mineral dust-induced bronchiolitis and peribronchiolar lesions in sarcoidosis present with perilymphatic (centrilobular plus perilobular) micronodules in the secondary pulmonary lobule. Bronchiolitis in hypersensitivity pneumonia appears with poorly defined centrilobular nodules, associated with ground-glass opacity and air trapping.

Adult↗

PubMed1994

The role of respiratory syncytial virus in acute bronchiolitis in small children in northern Japan.

Respiratory syncytial virus (RSV) plays an important role in acute bronchiolitis, which is life threatening in some infants. We investigated the epidemiology of RSV acute bronchiolitis in children less than 3 years old in northern Japan. From April 1991 to March 1993, 162 infants with acute bronchiolitis were hospitalized in our pediatric wards. The diagnosis of RSV acute bronchiolitis was based on the typical clinical manifestations and the presence of RSV antigen in their nasopharyngeal specimens or the rise of the RSV antibody titer. 124 out of 162 patients (76.5%) were diagnosed as having RSV acute bronchiolitis. 43.5% of patients with RSV acute bronchiolitis were 6 months old or less. The epidemic of RSV acute bronchiolitis commenced in October, peaked in December and ended in summer. RSV is quite prevalent in infants with acute bronchiolitis in northern Japan.

Acute Disease↗

PubMed1999

Plasma surfactant protein-B is elevated in infants with respiratory syncytial virus-induced bronchiolitis.

Respiratory syncytial virus (RSV) is the most frequent cause of bronchiolitis. However the pathophysiology of bronchiolitis is unclear. Leukocytes, especially neutrophils, may play an important role in the pathogenesis of bronchiolitis. Whereas we have previously shown that neutrophils augment epithelial leakage and detachment in RSV infection in vitro, it is unknown whether epithelial damage occurs in vivo in infants with RSV bronchiolitis. We hypothesized that respiratory epithelial damage occurs in infants with RSV bronchiolitis and that surfactant proteins leak into the circulation. The plasma concentrations of surfactant protein-A and surfactant protein-B in infants with RSV bronchiolitis were measured by ELISA. Plasma immunoreactive surfactant protein-B in infants with RSV bronchiolitis was markedly higher than that in matching controls. Our study suggests that alveolocapillary permeability is increased in infants with RSV bronchiolitis in vivo and that surfactant protein-B may be a sensitive marker for lung injury in such infants.

Bronchiolitis, Viral↗

PubMed2004

[Clinical characteristics of bronchiolitis caused by human metapneumovirus in infants].

OBJECTIVE: The fact that the acute lower respiratory infections (ALRI) are associated with a newly discovered virus, human metapneumovirus (hMPV), has been shown in several studies. The authors conducted this study to understand the etiological and clinical characteristics of bronchiolitis, one of the most common ALRI in infants, caused by hMPV. METHODS: Nasopharyngeal aspirate specimens from 54 out of 126 infants with bronchiolitis admitted to the Children's Hospital Affiliated to Capital Institute of Pediatrics, Beijing from November 2002 to February 2003 were examined for hMPV gene fragments by reverse transcription-polymerase chain reaction (RT-PCR). Prior to the detection, the specimens were confirmed as negative for the common respiratory pathogens including RSV, influenza A and B, parainfluenza I, II, III, adenovirus, Mycoplasma pneumoniae by indirect immunofluorescence test, virus isolation and ELISA test. The clinical data of the patients diagnosed etiologically as hMPV infection analyzed included the infants' age, sex, the degree of fever, the severity of wheezing and clinical Lowell score, the findings of chest examination and chest X-ray, the white blood cell count and blood gas analysis, the course of the disease, the major treatments and the outcome of the disease. RESULTS: Twenty-one specimens showed the predicted 213 bp PCR products in agarose gel and the positive rate was 16.7% of all patients (21/126) and 39% of the patients with negative results for common respiratory pathogens detections (21/54). The range of patients' age was 2 - 15 months and the young infants with hMPV bronchiolitis (1 - 6 month of age) accounted for 62% and the male:female ratio was 3.2:1. The patients presented a low-medium grade fever (T < 39 degrees C) accounted for 86%; 81.0% of patients had a white blood cell count lower than 10.0 x 10(9)/L. The radiological findings were patchey opacity in both lungs (68%) and(or) hyperinflation (62%). Assessed by the Lowell score system, 5 out of 21 cases were considered as severe cases. The major clinical findings of hMPV bronchiolitis had no significant difference compared with that of subgroup A hRSV bronchiolitis, and showed longer course of disease than that of subgroup B hRSV bronchiolitis (P < 0.01). CONCLUSIONS: Of the infants with bronchiolitis hospitalized in our hospital from November of 2002 through February of 2003, 16.7% were caused by hMPV infection. These data showed that the major clinical characteristics and the outcome of treatment of hMPV bronchiolitis had no statistically significant difference compared to the cases with either subgroup A or subgroup B hRSV infection.

Bronchiolitis↗