In this issue of CHEST (see page 791) Le Bourgeois and colleagues from Hopital Necker-Enfants Malades in Paris.

In this issue of CHEST (see page 791) Le Bourgeois and colleagues from Hopital Necker-Enfants Malades in Paris, France describe the BAL enclosed space profiles of 83 young children aged 4 to 32 month with wheezing. These children were identified retrospectively from a bronchoscopy database. All children had had returning wheezing associated with at least monthly oral corticosteroid therapy and had poorly be agreeable toed to inhaled corticosteroid therapy. BAL was performed at least 15 days after an acute exacerbation and at least 15 days after a short course of oral steroids. Viral tillages were obtained in two thirds of the wheezing children, and bacterial agricultures were obtained in one third of the wheezing children. Positive viral tillage findings were found in 9 of the infants, and positive microbiologic civilization findings were found in 18 of the infants; thus, 41% of the children experimented had either a positive viral or a positive microbiologic cultivation finding (assuming no overlap). Seventeen children with nonwheezing pulmonary diseases were used as sway subjects. Compared to these curb children, the authors found an increased lonely dwelling count and an increased percentage and absolute neutrophil reckon in infants with wheezing regardless of the neighborhood of bacteria and/or viruses. The authors also construct a low number and percentage of eosinophils, with no difference between children with wheezing and manage subjects.

In adults, BAL studies have improved the understanding of the pathophysiology of asthma. In general, adults with asthma have increased total solitary abode; squalids increased lymphocytes, and increased eosinophils, all believed to contribute to the airway inflammation characteristic of this disease. In children, and especially in young children (< 2 years old) with wheezing, and nothing else a small number of studies have been performed. While there is little reason to suspect that older children with asthma will have BAL small cavity profiles different from those in adults, there is significant reason to suspect that these lonely dwelling profiles may be different in young children with wheezing. The pathology and especially the prognosis of wheezing in young children have not been well characterized. Approximately the same half of the children with wheezing in infancy and young childhood will no longer be wheezing at 6 years of age. (1) The thought by Le Bourgeois et al thus portrays the single largest study of BAL small room profiles in very young children with wheezing.

Similar to other, smaller BAL studies in children with wheezing, Le Bourgeois et al set increased numbers of cells and increased neutrophils in BAL samples. This finding has now been confirmed in at least three other BAL studies in young children with wheezing. (2-4) And despite the limitations of this research it suggests that neutrophil-induced inflammation is important in the early stages of wheezing in infants. While it is possible that this neutrophil influx is owing to unrecognized infection (and 41% of the children in this thought had either a positive viral or microbiologic refinement finding), the authors report no relationship between the stage of neutrophilia and the instant of a positive microbiologic or virologic tillage finding.

BAL eosinophilia is a general finding in adults with asthma. Eosinophilia and elevated IgE evens in cord blood have also been build in infants who subsequently have asthma exhibit The results of the BAL eosinophilia are thus surprising. BAL specimens, however, contain those solitary abode; squalids that have "escaped" from the lung and caution must be used in interpreting the flows of the BAL in metes of processes occurring in the lung parenchyma. In addition, there is more [i]or[/i] less apparent disagreement on the appearance of increased eosinophils in BAL specimens between the three reports in young children. forward further inspection, however, the differences in eosinophils in BAL specimens in wheezing children compared to children without wheezing appear to be small and, thus, eosinophilic influx does not appear to be as important as neutrophils in the inflammatory rejoinder in the airways of these children. The children were also slightly older in the consideration by Marguet et al, (2) suggesting that eosinophil influx could be found later in the development of asthma. Finally, all of these children had received multiple courses of oral steroids and at least individual course of inhaled corticosteroids, which could have affected the eosinophil computes in the lung.

There are significant limitations to this contemplation and the results must be viewed with caution. The principally significant limitation is the retrospective nature of the inquiry Thus, there were not clear-cut avenue criteria, and the children undergoing bronchoscopy have different clinical symptoms, past history, and previous therapy. They depict a diverse group of etiologies for wheezing; because barely those with unsuccessful therapy underwent bronchoscopy they may not be representative of wheezing illnesses in young children. Nevertheless, the consequence s of Le Bourgeois et al are similar to those reported in a smaller, prospective meditation (4) of young children of similar age with postponeed wheezing.

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