Relationship between respiratory syncytial virus bronchiolitis and future obstructive airway diseases

Abstract

Relationship between respiratory syncytial virus bronchiolitis and future obstructive airway diseases. G. Wennergren, S. Kristjánsson. #ERS Journals Ltd 2001. ABSTRACT: Evidence from a large number of prospective case-control studies shows that respiratory syncytial virus (RSV) bronchiolitis in infancy is often associated with recurrent wheezing and asthma during subsequent years. However, wheezing tends to diminish and most studies show no significant increase in wheezing compared to controls by school age or adolescence. An unresolved question is whether severe RSV infection during infancy causes the respiratory sequelae or inherent abnormalities predispose an infant to develop severe respiratory infection and sequelae, i.e. RSV is associated with the development of pulmonary sequelae.Studies on long-term outcome of RSV bronchiolitis are reviewed from an evidencebased perspective.The majority of prospective placebo-controlled studies do not show any long-term beneficial effects of corticosteroid treatment, i.e. the risk of subsequent wheezing is not diminished by the treatment. The evidence for an increased risk of allergic sensitization after RSV bronchiolitis is not nearly as strong as the evidence for an increased risk of subsequent wheezing. In fact, most studies do not show any significant increase in atopy after RSV bronchiolitis. This suggests that the increased risk of wheezing after RSV is not linked to an increased risk of atopy. There are some indications that infants who develop severe RSV and subsequent wheezing may have aberrations that predate the RSV infection.To decide whether respiratory syncytial virus bronchiolitis causes, or is associated with the respiratory sequelae (or with subsequent allergy), it will be necessary to conduct prospective, randomized studies, where the cytokine profile prior to bronchiolitis onset is known. Such studies should preferably include some form of intervention against respiratory syncytial virus. A more complete understanding of the risk factors for severe respiratory syncytial virus infection and the role of respiratory syncytial virus infection in the initiation of asthma is needed as a basis for large-scale and cost-effective programmes to prevent respiratory syncytial virus-related morbidity. Eur Respir J 2001; 18: 1044-1058. Respiratory syncytial virus (RSV) bronchiolitis is the most common, severe lower respiratory tract infection in infancy. It now seems well established that RSV bronchiolitis in infancy is associated with recurrent wheezing and asthma during the first decade of life. In some children, wheezing after early lower airway infection with RSV is transient, but in many of the children RSV-induced bronchiolitis represents the onset of asthma. In fact, there are results which indicate that severe RSV bronchiolitis in the young infant may shift the T-helper (Th)1/Th2 balance in favour of a Th2 cytokine pattern, leading to development of allergic sensitization and persistent asthma [1,2]. However, the association with risk of development of atopy...

Infantile respiratory syncytial virus and human rhinovirus infections: respective role in inception and persistence of wheezing

“…Multiple epidemiological studies have clearly demonstrated that history of severe RSV bronchiolitis is frequently associated with subsequent persistent wheezing, childhood asthma or both [9][10][11][12][13]. While murine models of RSV revealed pathogenetic mechanisms related to upregulation of neuroimmune mediating genes [14], the pathogenesis of recurrent wheeze after RSV bronchiolitis is still poorly understood, it also remains unclear what factors govern the selection of some individuals and not others to develop obstructive respiratory symptoms in later childhood [15][16][17]. If RSV is the most frequent cause of LRTIs in young infants, HRVs are the most commonly identified virus involved in wheezing exacerbations in older infants, preschool-aged and school-aged children and adolescents [17][18][19][20][21][22].…”

Recurrence of Wheezing Episodes in Children with Respiratory Syncytial Virus and Non-Respiratory Syncytial Virus Bronchiolitis

“…The re are a number of epi de mi o lo gi cal stu di es re gar ding the ro le of res pi ra tory vi ru ses and es pe ci ally RSV in re cur rent whe e zing. 8,10,[16][17][18][19] In one of the stu di es investigating the ro le of RSV in the de ve lop ment of ast hma, 12 studies we re re vi e wed and increased risk of ast hma and re cur rent whe ezing af ter RSV in fec ti on was found in the first 36 months, but the re la ti on showed a tendency to dec re a se with age. 18 Hen der son et al 17 similarly found a re la ti on bet we en RSV bronc hi o li tis be fo re 12 months of age and la ter ast hma, but no re la ti on with atopy.…”

“…[5][6][7] It has be en shown that many chil dren who ex pe ri en ce RSV in fec ti on in in fancy de ve lop subse qu ent whe e zing epi so des la ter and the risk for ast hma is in cre a sed in tho se in fants. [8][9][10][11][12][13] Whe e zing usu ally re-oc curs af ter acu te bronc hi o li tis in 50% of the ca ses. In cre a sed fre qu ency of whe e zing episo des and ast hma among the chil dren with bronc hi o li tis his tory co uld not be exp la i ned with only atopy and fa mily his tory.…”

Çocukluk çağında bronşiyolitler: Etiopatojenez ve immünolojik akciğer hasarındaki yenilikler

“…Respiratuar sinsisyal virüs proteinlerinin sekiz tanesi, enfekte hücrelerde ve viriyonlarda bulunan yap›sal proteinlerdir. Yap›sal olmayan NS1 ve NS2 proteinleri, viriyonlarda de¤il yaln›zca enfekte hücrelerde bulunurlar (6,11,12). Respiratuar sinsisyal virüsünün zarf yüzeyindeki iki önemli antijeni olan füzyon (F) ve ba¤lanma (attachment;G) glikoproteinleri immünojen özellik tafl›r.…”